E852, Vol. 2
RUSSIAN FEDERATION
ROSTOV VODOKANAL AND ROSTOV OBLAST ADMINISTRATION
Public Disclosure Authorized
Grant for Preparation of the Project on Reduction of Nutrient Discharges
and Methane Emissions in Rostov-on-Don
Public Disclosure Authorized
FINAL REPORT
on
ENVIRONMENTAL IMPACT ASSESSMENT,
PUBLIC AWARENESS AND EDUCATION
Public Disclosure Authorized
South-Russia Centre for Preparation and Implementation of
International Projects (CPPI-S)
Public Disclosure Authorized
Rostov on Don
2004
The Environmental Assessment Team
The core team involved in the development of this EIA were:
Prof. A Khovansky, economics of nature management and environment
management, sociology, social economy
Dr. L Kosmenko, hydrochemistry
Mrs. I Mikheeva, health protection
Prof. V Privalenko, environment protection
Mrs. T Tarasenko, water supply and water abstraction
Mr. E Ulshtein, technical planning and design
Mrs. N Tsapkova, waste management
2
Contents
Contents
3
SUMMARY
6
Chapter 1 Background
7
Chapter 2 Explanatory Note
9
Chapter 3 Objective and needs in implementation of the proposed activity
10
3.1. Nutrient reduction in wastewater
10
3.2 Sludge Processing and Methane Utilisation
11
3.3. Dissemination Programme
11
Chapter 4 Description of alternative options to achieve stated objective
12
4.1. Existing system of wastewater treatment
12
4.1.1 Existing equipment and system of waste water treatment of the WWTP
Phase I
12
4.1.2. Existing equipment and system of waste water treatment of the WWTP
Phase II
13
4.1.3. Existing equipment and system of sludge processing
13
4.1.4 Current loading on the plant
14
4.1.5. Existing sludge volumes and quality
16
4.2 Planned activities on the WWTP reconstruction
18
4.2.1. Proposed volume and composition of wastewater
18
4.2.2. Standards of wastewater treatment
19
4.2.3 Planned content of the WWTP wastewater and technological scheme of
wastewater and sludge treatment
21
4.2.4. Wastewater treatment models
25
4.2.5. Planned activities on sludge treatment
31
4.2.6 Upgrade of technical design of 2000 and step-by-step division of
construction
40
4.2.7. Alternative options to achieve stated objective of the proposed activity44
Chapter 5. Description of possible environmental impacts for alternatives options45
5.1. Environmental Impacts at Present
47
5.2 Environmental Impacts during Construction
47
5.3 Environmental Impacts during Operation
49
Chapter 6 Relevant Environmental Legislation for Selected Options
60
Chapter 7. Description of Environmental Conditions
64
7.1 Natural conditions within the WWTP site
64
3
7.1.1. Climate
64
7.1.2. Topography and hydrography
64
7.1.3. Hydrogeology and protection of ground water
66
7.1.4. Vegetation cover
66
7.1.5. Soils
67
7.1.6. Fauna
67
7.1.7. Specially protected areas
69
7.2. Social and economic situation
69
7.2.1. Demography
70
7.2.2. Population economic activity
70
7.3 Assessment of the current environment situation
71
7.3.1 Survey methodology
71
7.3.2. Surface water assessment
72
Chapter 8 Assessment of the proposed activity environmental impact
77
8.1 Air quality
77
8.2. Impact on surface water quality
85
8.2.1. Zero option no reconstruction.
85
8.2.2. Option with biological treatment, wastewater advanced treatment and
phosphorous chemical stripping
93
8.2.3. Option with nutrients reduction only with biological treatment of
wastewater
95
8.3 Impact on ground water
96
8.4 Impact on soil and underlying rocks
96
8.5 Impact on vegetation and fauna
96
8.6 Impact of waste
96
8.7 Environmental conditions for project implementation
98
Chapter 9 Measures on mitigation and/or reduction of adverse environmental impact
of the proposed activity
99
9.1 Proposals on mitigation of risks due to toxic gases emissions
99
9.2 Proposals on mitigation of adverse impact on the Lower Don aquatic
ecosystems as a result of the WWTP reconstruction
99
9.3 Proposals on mitigation of risks associated with ground water pollution
99
9.4. Proposals on mitigation of risks associated with the WWTP sludge storage99
Chapter 10 Environmental consequences of possible emergency situations
101
Chapter 11 Uncertainties
102
4
Chapter 12 Justification of selected option of the planned WWTP reconstruction103
Chapter 13 Public hearings on EIA and activities on environmental education and
public awareness
104
Chapter 14 Environmental Management Plan
105
14.1 Mitigation Plan
105
14.2 Monitoring Plan
109
14.3 Training and Capacity Building Requirements
110
14.4 Social aspects of project implementation
110
Chapter 15 Dissemination Programme
111
Key conclusions
113
Annex 1 Minutes of the meeting of interested agencies and general public on
Environment Management Plan
122
Annex 2 Protocol of the EIA public hearings
123
Annex 3 Project booklet (in Russian)
128
Annex 4 Project leaflet (in Russian)
130
5
SUMMARY
Present Report is prepared by specialists of the CPPI-S in accordance with the Contract
No. 2 for consulting services on Environmental Impact Assessment, public awareness
and education as part of preparation works of the Project on Reduction of Nutrient
Discharges and Methane Emissions in Rostov-on-Don (GEF grant No. TF 027721).
Report was prepared in compliance with the existing legislation and procedural
requirements, juridical acceptable both for the Russian Federation and IBRD (World
Bank). In particular, the Report is a basis for approval of the project by an authorized
Russian authority (Ministry of Natural Resources) in compliance with the Law on State
Expertise, as well as the Report meets the requirements of the World Bank OP/BP/GP
4/01 for category B projects. Report in Environmental Assessment meets the
requirements of "regulations on assessment of environmental impact of the proposed
activity in the Russian Federation" (May 16th, 2000, 377).
As part of the consulting services the following tasks were conducted by the CCPI-S to
prepare the present Report:
Description of the environment status in the pilot area
Analysis of legal documents in the sphere of environment management and
protection
Identification of possible environmental impacts due to implementation of alternative
decisions of Rostov WWTP reconstruction.
Development of Environment Protection Action Plan
Promote co-ordination between agencies and public participation
English version of the Report is a slightly shortened Russian version of the EIA report
with all important information preserved. It consists of 123 pages, 15 main chapters, 9
figures and 4 annexes.
As on June 1st, 2004 based on materials prepared by SWECO International it was
concluded that option of the WWTP reconstruction providing biological treatment,
advanced treatment of waste water and phosphorus chemical removal with sludge
compaction in methane tanks (digestion), collection and utilisation of methane on
designed CHP plant is the most preferable in order to achieve waste water quality
objectives.
6
Chapter 1 Background
The Government of the Russian Federation received proceeds from the Global
Environmental Facility (GEF) in USD324,000 equivalent for implementation of the
Project on Reduction of nutrient discharges and methane emissions in Rostov-on-Don.
Grant beneficiary if the RF Ministry of Natural Resources and FCGC "Ecologiya" acted
as the project Implementation unit (PIU) further referred as a "Customer".
The Project would consist of two sub-projects:
reduction of nutrient discharges, and
reduction of methane emission.
The overall objective of this work is to assess environmental impact of the planned
reconstruction of the Rostov Vodokanal wastewater treatment plant (WWTP) in
compliance with the existing Russian legislation and requirements of the World Bank
OP/BP/GP 4/01 for category B projects. In the Russian Federation the Law on State
Expertise and "Regulations on assessment of the impact posed by the proposed activity
on environment in the Russian Federation" regulate the EIA requirements (2000). It is
expected that trying to gain ToR objectives the following interrelated outputs will be
achieved: (a) to provide Project's approval by the Federal bodies responsible for the
State Environmental Expertise; (b) to provide information to users and key stakeholders
on improved waste water management practice, risks associated with the improper
WWTW; and (c) to involve general public in implementation of project-support waste
water management improvements, including possible replacement of phosphorous
containing detergents by another types of detergents.
According to the World Bank requirements EA Report should describe possible negative
and positive impact and propose measures aimed at mitigation or reduction of the risk
of pollution, compensation of adverse impact and improvement of environmental
activities. Recommendations should be presented in a form of Environment
Management Plan.
Technical state of the works was described in three reports: Project on reconstruction of
the Rostov WWTP is presented in a Feasibility Study: reconstruction of the Rostov
WWTP (Phases I and II) (2000), report prepared by "JACOB-GIBB" (2003) and
"SWECO INTERNATIONAL" (2004). The EIA is based on these reports.
The Rostov WWTP works (Phases I and II) is located on the left bank of the River Don,
within a floodplain, 3 km downstream railway bridge, opposite the Besymyanny Island,
100 m off the coastal line. Construction site of the Rostov port borders the WWTP site
at north together with the Don River; WWTP Phase III construction site - from the south-
east; pond of a fishing farm and Zarechnaya industrial zone - from the northeast; pond
of a fishing farm, bituminous concrete plant and motorway Rostov-Bataysk - from the
west and northwest.
Normative sanitary-protection zone (SPZ) for thw WWTP is 1000 m (according to
SanPiN 2.2.1/21.1.1200-03). Residential area locates on the right bank of the Don river,
about 1200 m.
A present amount of wastewater treated at the existing WWTP of Phases I and II is
313,000m3/day.
The following are part of the WWTP:
7
Mechanical treatment works: inlet camera; screen building; grit traps and primary
settlement tanks.
Biological treatment works: aeration tanks; secondary settlement tanks; contact
reservoirs.
Works for wastewater disinfecting: chlorination room with chlorine store; mechanical
dewatering plant; sludge drying beds.
Supporting facilities: administrative building; boiler-house; blowing house; garage;
mechanical plant; pumping stations for transfer of raw sludge, digested sludge,
etc.; pumping station for transfer of treated wastewater to the don river.
The following scheme is used for wastewater treatment: wastewater from Rostov-on-
Don, Bataysk and industrial enterprises is collected via two main tunnelled interceptors.
Wastewater is transferred across the River Don to the East Bank via a syphon to the
Main Pumping Station which pumps wastewater to the inlet camera. Then crude
wastewater is screened to remove large floating objects. After that wastewater enters
grit traps where mineral particles 0.2-0.25 mm size are settled.
After grit traps wastewater enters primary settlers to settle mineral and organic
suspended solids. After mechanical treatment wastewater enters aeration tanks and
mixes with activated sludge in conditions of mandatory aeration. Here starts biological
treatment of wastewater. Air is pumped into the aeration tanks.
After aeration tanks wastewater enters secondary settlers. Their purpose is to separate
activated sludge and treated water. Major part of organic matter of activated sludge is
settled in secondary settlers.
Liquid chlorine is added to wastewater for disinfecting purposes. It enters head conduits
where treated wastewater contacts chlorine.
Treated wastewater is piped to the outfall into the Don river by means of pumping
station located at the WWTP site.
Boiler-house locates at the WWTP site. It serves for heating purposes. There are gas
three boilers in the boiler-house. Reserve fuel is not envisaged.
There is a supporting space at site used for technical maintenance and current repair of
equipment.
EIA and implementation of recommendations presented in the Report should prove that
studied project options are environmentally appropriate and sustainable; and that any
environmental consequences were defined at an early stage of the project development
and taken into account in the final project structure.
8
Chapter 2 Explanatory Note
Justification documentation for the project are:
Feasibility Study: reconstruction of the Rostov WWTP (Phases I and II) developed
by the Designed Institute North-Caucasus GiprokommunVodokanal in 2000;
In 2001 Halcrow Group Ltd. developed "Strategic Plan and Short Term Investment
Plan for the Municipal Water Services of the City of Rostov-on-Don" and
"Reduction of Nutrient Discharges and Methane Emissions in Rostov-on-Don.
Environmental Impact Assessment";
"JACOB-GIBB" together with Helsinki Consulting Group both responsible for Joint
Environmental Programme JEP-II conducted Project Feasibility Study;
By competitive bidding Rostov Regional Foundation for Social Projects (RRFSP) has
awarded SWECO INTERNATIONAL in cooperation with North-Caucasus
Giprokommunvodokanal to elaborate the Process Design Report and the technical
Project for the task.
9
Chapter 3 Objective and needs in implementation of the proposed activity
Project long-term objective is to reduce euthrophication level of the Azov abd Balck
seas through reduction of nitrogen and phosphorous discharges and greenhouse gases
emissions.
Project goals:
Reduction of nutrient (nitrogen and phosphorous) discharges into the Don River
through rehabilitation and improvement of the wastewater treatment at Rostov
WWTP of Municipal Water and Wastewater Company (Rostov Vodokanal, RVK)
Reduction of wastewater sludge and reduction of organic matter in wastewater
through the Rostov WWTP sludge digestion and dewatering.
Reduction of methane emissions from the Rostov WWTP sludge through methane
gas capture and combustion and usage of collected methane for electric power
generation and heat utilization.
Development of a Programme for dissemination of experience on reduction of
nutrient discharges and methane emissions at municipal enterprises in other
regions of Russia and possibly to the countries of the Azov-Black sea basin.
3.1. Nutrient reduction in wastewater
The objective for nutrient removal is to reduce nutrient levels in the effluent by the
following: total phosphorus - 60% reduction, nitrogen - 50% reduction. In the long-term
the works will eventually need to be improved, to ensure compliance with the following
stringent Russian Discharge Consent:
BOD
3 mg/l
Suspended
solids
3
mg/l
Total
Nitrogen
9
mg/l
Phosphorus
0.3
mg/l
Activities on nutrient removal include reconstruction and reequipping of the existing
technological tanks and constructions of the WWTP Phase II.
Primary settlers of the WWTP Phase II are extremely depreciated; scrapers need
reconstruction and replacement.
At present it is recommended to keep pre-aeration and equipment for activated sludge
pumping.
Activities on reconstruction of the existing aeration tanks will be minor. Dispersants and
air-blowers will be replaced; number of aerators will be increased. Lines will be repaired
in turns to provide constant capacities for wastewater treatment. Wastewater will be
treated in three phases: an anaerobic (preparing bacteria for phosphorus removal in
later stages of the process), an anoxic stage (nitrates are reduced) and an aerobic
(absorption of ammonia and phosphorus by bacteria). Existing secondary settlers will be
provided with lamella separators and bioreactors (filters with brush loading). Bioreactors
will be added to reconstructed WWTP Phase I. Inclusion of filters with brush loading is
necessary for additional treatment to comply to Russian norms for discharges into water
bodies.
10
Required reduction of phosphorous in treated wastewater could be achieved using
biological treatment. However, in anaerobic conditions phosphorous absorbed by
sludge will be then evolved into solution. Thus, chemical treatment will be required for
sludge water generated in conditions of sludge dewatering. Sludge after dewatering will
be disposed to sludge-heaps.
3.2 Sludge Processing and Methane Utilisation
Decreased of sludge volume (and amount of sludge required disposal) will be due to
digestion of compacted sludge in 6 new methane tanks; due to compaction of sludge in
the existing sludge thickeners and sludge dewatering in three new centrifuges. Sludge
water will be transferred to the works head. Before a proper strategy will be developed
sludge will be stored in sludge drying beds or in sludge storage lagoons. Centrifuges
were installed and put into operation. They can produce sludge with content of 30% dry
matter.
Reduction of sludge volume depends on type of methane and operation regime and can
be up to 50% of the existing volume.
Methane generates in conditions of bacteriological sludge digestion. Entering the Earth
atmosphere it contributes into "greenhouse effect" (greenhouse gases). One of the key
objectives is to generate electric and thermal energy as a result of utilization of methane
accumulated in methane tanks. Electric energy generation at site will significantly
reduce amount of gases emitted into the atmosphere (in terms of CO2) and will result in
costs savings for Rostov Vodokanal. Purchase of equipment and construction of
combined heat plant (CHP) is part of activities. CHP will be used for provision of
digestion and dewatering processes with energy (electric and thermal). Both processes
are power consuming. Heat from used gas will be transferred into vapour for sludge
heating and water used for cooling will be abstracted directly to the central heating
system.
3.3. Dissemination Programme
Programme for dissemination the Rostov Vodokanal experience in countries of the
Azov-Black sea basin includes the following:
1. Environmental actions to popularize and disseminate information about Project's
outputs and achievements in towns and cities of the Azov-Black sea basin (preparation
and publication of the brochure with description of key Project outputs, mobile exhibition
or participation in environmental exhibitions in the coastal cities and towns, meetings
with Administrations and Vodokanals of the coastal cities and towns).
2. Training and raising the level of specialist's skills in the sphere of water supply and
water abstraction.
3. Public campaign in mass media.
Towns and cities for results dissemination: in Russia Azov, Taganrog, Novorossiisk,
Sochi; in Ukraine Mariupol, Nikolaev, Sevastopol, Odessa; in Georgia Batumi; in
Bulgaria Varna, Burgas; in Romania Konstansa; in Turkey Samsun.
The ToR for the Programmme of results dissemination developed by the CPPI-S is part
of the present Report.
11
Chapter 4 Description of alternative options to achieve stated objective
4.1. Existing system of wastewater treatment
The wastewater treatment plant (WWTP) is located on the left bank of the River Don in
Zarechnaya industrial area of the city. The majority of wastewater from Rostov-on-Don
is transported across the River Don to the WWTP via the Main pumping station (PS). In
addition, wastewater is pumped directly to the WWTP from the "Gnilovckaya" PS, which
serves western areas of the city. Wastewater from the town of Bataysk, which lies to the
south, is also delivered to the WWTP.
The Rostov WWTP comprises two almost identical treatment streams (Phases I and II).
The site includes areas leaving room for a major extension of the plant, if found
necessary. It will be twice of the existing capacity. Activities on the WWTP extension
started several years ago but then was paused due to lack of funding. There are no
plans for recommencement of the WWTP Phase III.
4.1.1 Existing equipment and system of waste water treatment of the WWTP
Phase I
Existing equipment of the WWTP Phase I includes: screens; grit traps, reservoirs of the
first step (pre-aeration), primary settlement tanks, aeration tanks, secondary settlement
tanks, bioreactors, reservoir for chlorination, compressor house.
Screens. Five hydraulically inclined curved 16 mm screens are installed for large
particles screening. Timers control screens operation. Screenings are fed to the fly
press to remove excess water. Residual particles are placed at sludge heaps.
Grit traps. There are 4 grit traps each 17.7 m long and 1,25 m deep. Screenings are
removed using scrapers towards bunker at the grip traps head. From there sand with
water is raised and then removed and disposed at sand beds.
Reservoirs of the first step. Phase I has 4 identical technological tanks. Preliminary
treated wastewater enters aeration chambers 6.0 m wide and 4.4. m deep. Activated
sludge is returned to a pre-aeration tank but only in conditions of high incoming load.
Primary settlement tanks. Each technological line has four rectangular settlement
tanks (27 m long, 9 m wide and 4.25 m deep). Scraper transporters near basemen feed
settled sludge towards one end of a reservoir. Under hydraulic pressure head sludge
enters pumping station of primary sludge for further transfer to sludge thickeners.
Aeration tanks. Each aeration tank has 4 corridors for sludge mixture aeration. Each
tank has size 9 m wide, 75 m long and 4.7 m deep. Porous aerators locate in each
corridor. Air is supplied along steel distribution pipeline from air-blowing station. Air
volume supplied to aeration tanks is manually controlled. Two sections of aeration tanks
were reconstructed and now third section is under reconstruction.
Secondary settlement tanks. Secondary settlement tanks were reconstructed using
lamella separators. They are 11 m long. Activated sludge is removed by means of
airlifts and then it is returned to aeration tanks. Surplus activated sludge is removed
from system, if necessary, to support its concentration in aeration tanks.
Bioreactors (brush filters). In two reduction conveyers effluents from secondary
settlement tanks are additionally processed in biologically aerated filter in a form of
upstream. In this device "environment" consist of small brushes on which biomass
12
develops. They provide biological treatment and filtration. Filters need backwashing
twice a week. This is air washing under increased flow velocity in four times.
Reservoir for chlorination. After mechanical and biological treatment wastewater is
chlorinated in a reservoir for chlorination in compliance with Russian requirements.
Compressor house. In a compressor house there are six compressors with capacity
750 m3/minute, pressure 0.06 MPa and engines with power 1250 kWt. Compressors are
cooled with water. Usually three compressors are used to serve aeration tanks of
Phases I and II.
4.1.2. Existing equipment and system of waste water treatment of the WWTP
Phase II
Equipment of the WWTP Phase II is similar to equipment of Phase I, except for
bioreactors.
Screens. Five hydraulically inclined curved 16 mm screens are installed for large
particles screening. Screenings are fed to the fly press to remove excess water.
Grit traps. Grit traps of the Phase II are aerated. But process of sand removal is similar
to Phase I.
Reservoirs of the first step. Phase II has 4 identical technological tanks. Preliminary
treated wastewater enters aeration chambers
Primary settlement tanks. Each technological line has four rectangular settlement
tanks (27 m long, 9 m wide and 4.25 m deep). Scraper transporters near basemen feed
settled sludge towards one end of a reservoir. Under hydraulic pressure head sludge
enters pumping station of primary sludge for further transfer to sludge thickeners.
Scrapers for one line were repaired and now only one line operates. Other lines are in a
bad condition or out of service.
Aeration tanks. Each aeration tank has 4 corridors for sludge mixture aeration. Each
tank has size 9 m wide, 75 m long and 4.7 m deep. Nets of porous tubular diffusers
locate on each line. Air from a compressor house is supplied along steel distribution
pipeline. Pipeline and diffusers are in a bad condition with leaking and breaks.
Secondary settlement tanks. Secondary settlement tanks are 30 m long. Width of
each four lines is 9 m. Scrapers locate near baseman. Activated sludge is removed by
means of airlifts and then is returned to aeration tanks. Surplus activated sludge is
removed from system, if necessary, to support its concentration in aeration tanks.
Reservoir for chlorination. After mechanical and biological treatment wastewater of
the Phase II is chlorinated regardless effluents of Phase I. But before discharge into the
Don river they are mixed.
4.1.3. Existing equipment and system of sludge processing
Equipment for sludge processing includes: sludge thickeners, building with centrifuges,
reservoirs for sludge digestion, sludge drying beds.
Sludge thickeners. There are four radial sludge thickeners (18 m diameter and 3.5. m
deep). Sludge from primary settlement tanks and surplus activated sludge is thickened.
Mixture moisture is 94-98%. In summer after addition of flocculating agent thickened
sludge is transported to sludge drying beds for storage. In winter thickened sludge is
13
transported to building with centrifuges.
Building with centrifuges. Three Humbolt centrifuges, buffer storage, polyelectrolyte
systems of mixing and dosing, pumps supplying sludge, conveyers for dewatered
sludge locate in the building. Here moisture of dry solid matter is 28-30%.
Reservoirs for sludge digestion (methane tanks). There are two anaerobic
reservoirs for sludge digestion. Both are out of service. Also two reservoirs are still
under construction.
Sludge drying beds. Sludge drying beds have concrete foundation, asphalted in
inclined sections used for liquid drainage through drainage system backwards to the
inlet of the second line. There are 31 sludge drying beds each 90 x 40 m with nominal
depth of 1 m. Walls are concrete. In summer beds are filled by means of pumps and are
cleared by a loader when sludge reaches moisture content of 70%.
4.1.4 Current loading on the plant
Existing average discharge of wastewater required treatment is about 292,000 m3/day
varying between 280,000 and 310,000 m3/day. Daily peak discharge is more than
360,000 m3/day. This amounts to 10-20% increase in conditions of damp weather.
During reconstruction works at the Phase I inflow to this technological line lies within
100,000-160,000 m3/day; Phase II receives remaining amount of 140,000 180,000
m3/day. Data on flows to the WWTP for the first six months of 2003 are given in Table
4.1.
Characteristics of untreated wastewater inflow to the WWTP for the last 2,5 years are
given in Table 4.2 together with average daily pollution loads. Data is based on data
about average flows in years 2001, 2002 and 2003 (309,000, 291,200 and 292,300
m3/day, respectively).
Average characteristics of treated wastewater from the WWTP Phase I and II for 2001,
2002 and first six months of 2003 are given Table 4.3.
Recent studies of wastewater from the WWTP Phase I (including lines under
reconstruction) and from the WWTP Phase II are given in Table 4.4.
The WWTP Phase I provides higher treatment level. Lower values of BOD5, ammonia
and suspended solids concentrations prove this.
14
Table 4.1 Flows to the WWTP for the first six months of 2003, m3/day
Month
Phase I
Phase II
Combined
Maximum Minimum Average
Maximum Minimum Average
Estimated Estimated Average
Maximum
Minimum
January
143,963
73,446
97,492
206,654
127,584
183,142
317,000
229,000
280,634
February
153,444
85,998
128,795
196,848
150,970
176,156 3 4 8 , 0
348,000
304,951
March
156,560
98,074
129,996
182,138
123,761
158,129
338,698
228,000
288,125
April
207,368
136,352
159,975
201,902
nr
150,000
362,000
290,000
309,975
May
161,886
120,539
143,565
170,590
54,749
141,957
311,000
195,000
285,522
June
139,220
73,371
100,603
208,397
114,163
178,816
344,000
344,000
279,419
Ave. for 6 months
160,407
97,963
126,738
194,422
114,245
164,700
336,783
245164,7
291,438
Notes:
1. Minimum flows can be affected by pumping station break downs.
2. The combined maximum and minimum flows are estimated as the recorded maximums and minimums
for Phases I and II do not necessarily occur on the same day. (Source: Information supplied by RVK)
Positive effect of reconstruction of Phase I is illustrated in Table 4.5 that gives the
effluent results for reconstructed line 3. Wastewater flow has good treatment level with
very low COD value (10 mg/l after bioreactor) and low level of suspended solids. In
reconstructed aeration tanks nitrification is better. However, lack of denitrification
capacities is obvious.
Table 4.2: Wastewater characteristics and loads, 2001 - 2003
Parameter
Concentration, mg/l
Pollution load, kg/day
2001
2002
2003*)
2001
2002
2003*)
BOD5
146.8
181.2
143.7
45,363
52,760 42,004
COD
312.5
91,345
Suspended Solids
175.1
211.3
219.9
54,108
61,524 64,277
Ammonia as N
16.08
15.7
16.8
4,969
4,571
4,911
Nitrite as N
0.04
0.07
0.05
12
20
15
Nitrate as N
0.1
0.12
0.135
31
35
39
Phosphates as P
1.83
1.38
1.77
565
402
517
Notes: data for the first six months of 2003. (Source: Information supplied by RVK)
Table 4.3 Average treated effluent characteristics
Parameter
Annual average concentration,
Annual average load
mg/l
discharged, kg/day
2001
2002
2003
2001
2002
2003
BOD5
28.5
27.4
20.8
8,807
7,978
6,080
COD
n. a.
n. a.
46.3
n. a.
n. a.
13,534
Suspended Solids
35.05
31.4
24.4
10,831
9,143
7,132
Ammonia as N
4.54
2.6
2.7
1,403
757
789
15
Nitrite as N
0.52
0.61
0.48
161
178
140
Nitrate as N
1.55
2.17
2.49
479
632
728
Sum N
6.61
5.38
5.67
2,043
1,566
1,657
Phosphates as P
1.29
0.91
1.15
399
265
336
Table 4.4 Treated wastewater characteristics for Phases I and II, first half year
2003 results
Parameter
Concentration, mg/l
Phase I
Phase II
BOD5 24.0
36.8
COD 38
48
Suspended Solids
30.0
39.5
Ammonia as N
2.39
3.45
Nitrite as N
0.36
0.24
Nitrate as N
4.4
3.02
Phosphates as P
1.35
1.40
7.68
7.68
Temperature, ° 26.6
26.5
Table 4.5 Treated wastewater characteristics for line 3 of Phase I
Parameter
Concentration, mg/l
After secondary
After biorecator
settlement tank
COD 25
10
Suspended Solids
15.6
15.2
Ammonia as N
1.95
1.12
Nitrite as N
0.35
0.41
Nitrate as N
5.03
6.25
Phosphates as P
1.35
1.40
8.16
7.91
4.1.5. Existing sludge volumes and quality
At present total amount of produced sludge consists of 1220 m3/day primary sludge and
1355 m3/day surplus activated sludge. Sludge is pumped to drying beds and
transported to sludge storage lagoons. Sludge from primary settlement tanks has a
moisture content of 95-96%, surplus activated sludge is more than 96%.
There are 31 sludge drying beds each 90 x 40 m with nominal depth of 1 m. Walls are
concrete. Sludge drying beds have concrete foundation, asphalted in inclined sections
used for liquid drainage through drainage system. Walls are made of uncovered
concrete. On average drying bed bottom locates 3.76 m below average level of the Don
16
river. Beds are consecutively filed by means of pumps and are emptied using frontal
loader when content of moister reaches 70%. Sludge retaining time is 1 year. Each year
12-14 beds are emptied. Average moisture content in dried sludge is 77%.
Sludge removed from sludge drying beds is stored at site with total area of 40,000 m2. A
small but unknown quantity of sludge removed from the drying beds is used in City
parks. Neither of this uses result in deceleration of sludge storage, which at present has
reached its maximum. Sludge storage lagoon used from mid-1980-s for sludge removal
is located in foundation pit formed due to sand recovery during the WWTP construction.
In 1984 dam was constructed around pit filled with water. It formed closed lagoon for
sludge storage. Initially dam was 2.5 m higher than bottom level and was constructed
from mixture of clay and sand. Bottom level locates on the Don river average level.
Lagoon design envisaged organization of clay substrate but no data were found about
organisation of the substrate. In 1944 dam height was raised up to 3.5 m above bottom
level and according to project drawings drainage pipes were laid through this extension
to ensure pumping of supernatant liquid back to the outlet. The pipes are not in
operation anymore and at present time water level inside the lagoon is 3 m above the
bottom level. Bottom topography is not described but it was estimated that closed area
is 28 hectares of which 30% have form of islands. Thus, lagoon's capacity was
assessed as 0.7 million m3.
The second slightly larger lagoon adjoins to the first lagoon. Initially the second lagoon
was not envisaged for sludge storage but it contains sludge partly due to leakage
through non-engineering barriers between two lagoons.
Key limitation for use of wastewater sludge for land reclamation is concentration of toxic
substances and helminthes. However, toxic substances concentrations in the Rostov
WWTP sludge gradually decreased due to decrease of industrial effluents.
Wastewater sludge mechanically dewatered or dried at drying beds and kept in natural
conditions for not less than 2 years has moisture content of 54-58%. This is low-hazard
waste (class IV danger) due to increased concentrations of heavy metals (zinc,
chromium, copper, nickel, lead). Pathogens (including salmonella and helminthes ova)
were not found. In 2004 scientific company "BIFAR" (Moscow) assessed quality and
quantity of sludge sampled in January 2004 from the WWTP site. For sludge passports
were drawn. "Environmental certificates" were received for sludge of the municipal
wastewater and their compliance with the following legal documents: "Criteria for
attributing of hazardous waste to classes of danger for environment" (adopted by the RF
Ministry of Natural Resources No. 511 dated 15.06.01); GOST P 17.4.3.07-2001
"Nature protection. Soil. Requirements to wastewater sludge if used as fertilizers";
SanPiN 2.1.7.573-96 "Hygienic requirements to use of wastewater and their sludge for
irrigation and as fertilizer"; SP 2.1.7.1038-01 "Hygienic requirements to organisation and
management of MSW landfills" (Annexes 1-4). Content of organic matter varies in
sludge (in terms of dry matter) in a range of 45-47%, total nitrogen 3.2-2.5%,
phosphorous (in terms of 25) 3.53.4%, lead 45-48 mg/kg, cadmium 5.8-9.4
mg/kg, copper 123-124 mg/kg, nickel 62.6-71.6 mg/kg, zinc 800-832 mg/kg,
chromium - 352-375 mg/kg, manganese 104-109 mg/kg, mercury 0.1-0.5 mg/kg,
arsenic 7.8-9.3 mg/kg.
At the end of March 2004 amount of dewatered sludge disposed at the WWTP site was
25.59 thousand tons (in terms of dry matter) of which 24.46 thousand tons were
17
disposed on sludge drying beds and 1.13 thousand tons at landfill for temporary sludge
storage. As sludge gets dried it is transported from drying beds and is use for
reclamation works at site of the WWTP.
4.2 Planned activities on the WWTP reconstruction
4.2.1. Proposed volume and composition of wastewater
Different estimations on the future flows and pollution loads have been
presented. The Study from 2000, Technical Process Design Report -
Rehabilitation of Wastewater Treatment Plant in Rostov-on-Don (I and II Stages),
suggests an increase of the design flow to 460,000 m3/day, along with increased
pollution loads. The report has been approved and as such the figures will be
used as one target ground for the process analysis and assessment of
technologies for the upgraded Rostov WWTP.
In the JACOB-GIBB report a revised projection of wastewater amounts and pollution
levels are presented, along with an "Expected Short Term Loads" situation. Corrected
parameters for different flows and loads are given in Tables 4.6 4.6a (SWECO
INTERNATIONAL, 2004).
For the following assessment of different process options the following flow and
pollution load situations will be addressed:
A.
Expected Short Term Loads, with Q = 332,000 m3/d, and BOD5 load
= 52,908 kg/day;
B. Revised2025
Loads,
with Q = 360,000 m3/d, and BOD5 load = 70,656
kg/day;
C. Design
Institute
Loads,
with Q = 460,000 m3/d, and BOD5 load = 105,800
kg/day;
Table 4.6 Estimations of current and future loads entering Rostov WWTP
Parameter
Current
Expected
Revised 2025
Design Institute
loads
short term loads
loads
loads
Design flow, m3/d
292,300
332,000
360,000
460,000
Anticipated loads
BOD5, kg/d
42,004
52,908
70,656
103,040
Total suspended solids, g/d
64,277
66,014
79,557
138,000
Ammonia Nitrogen, kg/d
4,911
6,836
9,134
10,120
Total Phosphorus*, kg/d
1,034*
1,781
2,409
4,416
Anticipated concentrations
BOD5, mg/l
144
159
196
230
Total suspended solids, mg/l
220
199
221
200
Ammonia Nitrogen, mg/l
16.8
20.6
25.4
22.0
Total Phosphorus*, mg/l
3.5
5.4
6.7
9.6
Note: *Total phosphorus taken as twice phosphate load.
18
Table 4.6a Designed discharges and load of wastewater on the Rostov WWTP
(SWECO, 2004)
Data on pollution and
Short-term For
2005 Long-term
Unit
discharge
Discharges of wastewater at the works head
Daily average amount
330000
360000
460000 m3/day
Hourly average amount
13750
15000
19167m3/hour
Peak capacity of pumping stations
424246
464000
464000 m3/day
Designed flow per hour, estimates
13833
15000
20500m3/hour
Peak flow, estimates
17677
19333
27605m3/hour
Pollutants loads
BOD5 42,389
70,656
105,800
t/day
COD (allowable value)
84,778
141,312
211,600
t/day
NH4-N 6,836
9,134
10,120
t/day
Nitrogen total
9,092
12,149
13,460
t/day
Phosphrous total
1,781
2,409
4,416
t/day
Suspended solids
66,014
79,557
92,000
t/day
Suspended solids /BOD5 1.56
1.13
0.87
kg/kg
BOD5/Nitrogen 4.66
5.82
7.86
kg/kg
BOD5/Phosphorous 23.8
29.3
24.0
kg/kg
Concentrations
BOD5 128
196
230
mg/l
COD (allowable value)
257
393
460
mg/l
NH4-N 21
25
22
mg/l
Nitrogen total
28
34
29
mg/l
Phosphrous total
5
7
10
mg/l
Suspended solids
200
221
200
mg/l
Minimal and designed temperature
16/20
16/20
16/20
oC
4.2.2. Standards of wastewater treatment
Existing Russian effluent standards for the WWTP formally defined in compliance with
SniP are given in table 4.7.
Table 4.7 Existing effluent standards according to SNiP norms
Determinant
Consent value
BOD5
< 3 mg /l
Suspended Solids
< 3 mg /l
Ammonia nitrogen
< 0.39 mg/l
Nitrite nitrogen
0.02 mg/l
Nitrate nitrogen
9.1 mg/l
Total Nitrogen
< 9.42 mg/l
19
Phosphates (P2O5)
< 0.61 mg/l
Phosphorus (as P2O5-P)
< 0.2 mg/l
As already underlined these standards are in many respects far more stringent than the
ruling consent values for the European Union, defined by the Directive EEC 91/278,
stating the following values (Table 4.7a).
Table 4.7a Existing effluent standards according to Directive EEC 91/278
Determinant
Consent value
BOD5
< 25 mg /l
Suspended Solids
< 35 mg /l
Total Nitrogen
< 10 mg/l
Phosphorus (as total P)
< 1.0 mg/l
The following over all demand for the treatment performance has been defined as the
ruling GEF objectives for nutrient removal at the Rostov WWTP:
Total phosphorus - 60% reduction in the effluent;
Nitrogen - 50% reduction in the effluent.
The given definition on effluent demands is however not undisputable. Two ways of
understanding the statement of the required reduction may be addressed:
1. The JACOB-GIBB report interprets the given definition as follows:
The reduction of P would result in an effluent level of about 2.5 to 3 mg P/l according
to the same philosophy.
The reduction of N would result in an effluent level of about 8 mg N/l, taking into
account that the influent concentration is about 16 mg N/l.
The need for further reduction of P would not be necessary, as the current discharge
levels seem to be < 2.0 mg total P/l.
The need for further reduction of N would not be necessary, as the current discharge
levels seem to be < 8.0 mg total N/l.
2. The other obvious interpretation of the definition is that the demand for further
reduction in the effluent is related to the current levels of P and N discharges. This in
turn would result in the following:
The reduction of P would result in an effluent level of about 0.7 to 1 mg P/l, taking
into account that the current effluent concentration is about 1.5 - 2 mg N/l.
The reduction of N would result in an effluent level of about 3 - 3.5 mg N/l, taking into
account that the current effluent concentration is about 6 - 7 mg N/l.
The need for further reduction of P would call for a chemical P removal, as the
demanded effluent levels would be very hard to achieve by biological P removal
only. The target value for the P level in the effluent will come rather close to the
Snip value of 0.2 mg P (PO4-P)/l
20
The need for further reduction of N would call for an excellent nitrification at all
circumstances and also possibly the addition of external organic carbon, as the
discharge would become very hard to achieve with the available organic carbon
in the wastewater only. It should be observed that the Snip norm calls for a total
N < 9 mg/l.
According to recommendation prepared by SWECO INTERNATIONAL the ultimate
target values for the treated wastewater from the Rostov WWTP will be in accordance
with SNiP norm, but they will be modified by the intermediate effluent level on nitrogen.
For intermediate phase of the WWTP reconstruction the following parameters will be
used for treated wastewater (see Table 4.8):
Table 4.8 Adopted intermediate treated wastewater standards for the Rostov
WWTP
Determinant
Consent value
BOD5
< 15 mg/l
Suspended Solids
< 25 mg /l
Ammonia nitrogen
< 0.39 mg/l
Nitrite nitrogen
0.02 mg/l
Nitrate nitrogen
2.5 mg/l
Total Nitrogen
< 3 mg/l
Phosphates (P2O5)
< 1.95mg/l
Phosphorus (as P2O5-P)
< 0.65 mg/l
A way to analyse the different treatment options with respect to "Environmental
Efficiency" is to apply the "OCP- value". "OCP" means Oxygen Consumption Potential,
and was presented by H. 0degaard, at the Norwegian Technical University, Trondheim,
Norway. This method to analyse a discharge of treated wastewater makes it possible to
calculate oxygen consumption in a receiving body caused by the effluent from a
treatment plant. Oxygen consumption in receiving water is often caused by both primary
oxygen consumption (bacterial degradation of BOD and ammonia) and secondary
oxygen consumption (bacterial degradation of algae caused by phosphorus and
nitrogen). The calculation of OCP is based on the following ratios:
1 kg BOD results in 1 kg in primary oxygen consumption.
1 kg Tot-N results in 4 kg in primary oxygen consumption.
1 kg Tot-P results in 100 kg in secondary oxygen consumption.
1 kg Tot-N results in 14 kg in secondary oxygen consumption.
By using the OCP valued it is possible to express the amounts of BOD, nitrogen and
phosphorus in the effluent from a treatment plant in one common unit. Although OCP is
a simplified measuring tool it is a proper tool to assess the plant efficiency. OCP model
was used to assess the Rostov WWTP efficiency.
4.2.3 Planned content of the WWTP wastewater and technological scheme of
wastewater and sludge treatment
Approved capacity of the WWTP is 460,000 m3/day. However, due to amount of
investments gradual change of the WWTP capacity is required. At the
21
intermediate phase it will be 360,000 m3/day.
According to the required capacity of the WWTP, treatment level and method and
based on SWECO's recommendations and approved Technical Process Design
Report -Rehabilitation of Wastewater Treatment Plant in Rostov-on-Don (I and II
Stages) (1998), WWTP Phases I and II are envisaged in the following
composition:
Phase I works:
.1 Mechanical treatment works:
1. Reception (inlet) chamber
2. Screen building (reconstruction)
3. Horizontal grit traps
4. Pre-aerators primary settlement tanks
B.1 Biological treatment works:
1. Aeration tanks (reconstruction with identification of anoxic zone denitrificator
and aeration zone - nitrificator).
2. Secondary horizontal settlement tanks.
C.1 Works for wastewater advanced treatment (1 stage)
1. Bioreactor with immobilized microflora.
2. Reservoir of dirty washed water.
Phase II works:
.2 Mechanical treatment works:
1. Reception (inlet) chamber
2. Screen building (reconstruction)
3. Aerated grit traps
4. Pre-aerators primary settlement tanks (reconstruction)
B.2 Biological treatment works:
B.2 Biological treatment works:
1. Aeration tanks (reconstruction with identification of anoxic zone denitrificator
and aeration zone - nitrificator).
2. Secondary horizontal settlement tanks (reconstruction).
C.2 Works for wastewater advanced treatment (1 stage)
1. Bioreactor with immobilized microflora (reconstruction of the secondary
settlement tanks)
2. Reservoir of dirty washed water (designed).
C.3 Works for wastewater advanced treatment (2 stage) Phases I and II
1. Reception (inlet) chamber (reconstruction)
22
2. Entrance chamber (designed)
3. Filters of advanced treatment (reconstruction)
4. Pumping station for advanced treatment filters (reconstruction).
5. Reservoir for washing water (reconstruction).
6. Filters media storage facility (reconstruction).
7. Aerator trough (aeration tank) (reconstruction, designed).
D. Facilities for wastewater disinfection, Phases I and II
Chlorination room with chlorine store and later station of UV- disinfection.
E. Outlet of treated wastewater
1. Pumping station No. 4 for treated wastewater.
2. Discharge of treated wastewater from pumping station to dispersing outlet.
3. Dispersing outlet into the Don river.
F. Facilities for sludge processing, Phases I and II
1. Gravel bunkers (extension)
2. Hydrolyzer (existing sludge thickeners D=18 m)
3. Sludge thickeners (reconstruction).
4. Methane tanks (reconstruction, designed).
5. Reservoir for mixture of sludge from primary settlement tanks and compacted
excessive sludge (designed).
6. Heat exchanger building (designed).
7. Gas-holders (designed).
8. Methane tanks pumping station (designed).
9. Sludge dewatering plant (existing).
10. Emergency sludge drying beds (existing).
11. Storage place for dewatered sludge (existing).
12. Sand beds (existing).
13. Site for mixing wastewater with humin-mineral concentrate, and storage facility
(designed).
14. Storage place for humin-mineral concentrate (reconstruction).
J. Supporting buildings and facilities
1. Blowing house (reconstruction).
2. Pumping station No. 1 (reconstruction).
3. Pumping station No. 2 (reconstruction).
4. Pumping station in passes of capacity blocks of Phase II (reconstruction).
5. Pumping station of sludge thickeners (reconstruction).
23
6. Reservoir for compacted excessive sludge (designed at pumping station of
methane tanks).
7. Reservoir of sludge water.
8. Reagent storage building (new construction).
9. Storage facility for dry store of reagents.
10. Administrative building (existing).
11. Garage (existing).
12. Car wash (existing).
13. Repair and engineering workshops (existing).
Site communications
The following technological scheme of wastewater treatment is recommended
(recommendations of JACOBS GIBB and SWECO INTERNATIONAL):
Rostov and Bataysk wastewater are pumped to the inlet cameras of screens
building of Phases I and II.
Tiered 3-5mm Rotoscreen screens (MEVA company) are installed to prevent
large floating solids arriving with wastewater. After separation from floating
solids wastewater enters horizontal and aerated grit traps for precipitation of
mineral suspended matter with hydraulic size of 24.2 mm/sec and 18.7
mm/sec.
After grip traps wastewater enters horizontal settlement tanks to settle organic
and mineral suspended solids.
Phosphorous chemical stripping is envisaged to meet modern requirements to
residual content of phosphorous in treated wastewater. For this it is planned
to enter water solutions of reagents in trough before pre-aerators. Aluminium
sulphate will be used as a key reagent (dose of 80-20 mg/l).
After mechanical treatment wastewater enters biological treatment works with
nitri-denitrification. For this two zones are established in the existing aeration
tanks: anoxic (denitrificator) and aeration (nitrificator). Wastewater and return
activated sludge from secondary settlement tanks (circulating), and sludge
mixture from nitrificator are supplied to anoxic zone. Project envisages
possible supply of sludge from hydrolyzers to the denitrification zone if
amount of organic substrate is insufficient. Propeller mixers with submerged
electric engines mix sludge mixture in anoxic zone. Reduction of nitrogen
occurs in anoxic zone by means of activated sludge microflora. Sludge
mixture spills from anoxic zone to aeration zone. Oxidation of organic matter
and ammonia nitrogen into nitrates occurs in conditions of intensive air
blowing supplied from air-blowing station. After aeration zone sludge mixture
is collected by troughs and further is discharged into secondary horizontal
settlement tanks. Installation of lamella separators is planned to improve
capacity of secondary settlement tanks and sampled water quality.
After secondary settlement tanks wastewater with residual concentration of
suspended solids and organic matter (BOD total) of about 15 mg/l enters
24
advanced treatment works. Two-phase advanced treatment is adopted.
First phase is bioreactor with immobilized microflora consisted of subsequently
operating stages. Each stage of bioreactor includes chamber for water enrichment
with oxygen equipped with air distributor and reactor filled with brush feeding.
Treated water enriched with oxygen in a saturation chamber passes through the
brush feeding which form homogeneous porous space with pore sizes ensuring
formation of bulk structures of activated sludge flake. Treated water saturated with
oxygen is filtered through activated sludge flake.
Biofilm develops due to a developed surface. Biocenose actively participates in
extraction of organic pollutants from wastewater and in oxidation of ammonia
nitrogen.
Second phase (on a basis of reconstructed wire-charging filters) is a filter with
granular loading. There water is treated by means of bottom-up filtration through
sand feeding.
After bioreactor washed water in the form of activated sludge flake enters
reservoirs and then is transferred into anoxic zone (denitrificator). Washed water
after filters rinsing is collected in reservoirs and there it is pumped to the works
head.
After advanced treatment wastewater is piped to an aeration through for saturation
with oxygen by means of mechanical aerators. Adopted way of treatment will
ensure following parameters:
suspended solids 3 mg/l;
organic matter (BODtotal) - 3 mg/l;
ammonia nitrogen -- 0.39 mg/l;
nitrite nitrogen 0.02 mg/l;
nitrate nitrogen 9.1 mg/l
phosphates in terms of phosphorous 0.2 mg/l.
Disinfection is the last phase of wastewater treatment. Liquid chlorine for
disinfection is entered directly into head conduits of wastewater discharge. There
water contacts with chlorine. As chlorine storage facility is dangerous in operation,
Technical project envisages use of modern safe ultraviolet disinfection of
wastewater. Existing chlorination plant will be deactivated and will be in reserve.
Pumping station No. 4 located at the WWTP site discharge treated wastewater
into the Don river.
Outlet for discharge of treated wastewater into the Don river is dispersive and
locates 6.5 km from the WWTP.
Flow of wastewater entering the WWTP is measured for Phase I at siphon
supplying wastewater to pre-aerators; for Phase II in Venturi flume; treated
wastewater by flowmeters installed on head conduits at pumping station No. 4.
4.2.4. Wastewater treatment models
In the following three different process options are analysed. The chosen options
25
are based on the following conditions:
A.
The current biologic reactors have a sufficient volume to include
the demand biologic nitrogen removal;
B.
The composition of the wastewater will not allow for both
advanced biologic nitrogen and phosphorus removal, without an
addition of additional organic carbon;
C.
A chemical precipitation will be needed to achieve the required
P-removal level;
D.
The separated sludge will be digested, either in new reactors, or
in some of the existing ones, after a renovation.
E.
The demand for an advanced reduction of nitrogen
(denitrification) would most possibly call for a very good availability
of organic carbon.
In all options studied below it is foreseen that a part of the separated primary sludge
will undergo anaerobic hydrolysis, in order to "liberate" easily degradable organic
compounds to enhance the denitrification.
First option. The previous studies (elaborated by JACOBS) envisage that the
development of the Rostov plant would be reconfigured in accordance with the "A2O"
process concept. It should be underlined that this biologic nutrient removal model
belongs to a family of similar shaped models, all labelled "single sludge" systems. The
"A2O model" is one of the "earliest" technologies in this field. In other words it is not the
most up to date variant. Later on very similar systems have occurred within the water
industry, such as the BardenNiPho system, the VIP system (sometimes labelled UCT-
process). All these systems are to a larger or lesser based on the same concept, with
separate reactors for anaerobic, anoxic and aerobic conditions.
Second option is based of stage of preliminary sludge formation for fuller phosphorous
removal. Then there will be system of preliminary denitrification of activated sludge later
referred as "Simple recirculation denitrification".
Third option will be based on a "step-feed" configuration, with a number of
anoxic/aerobic reactors in series. In an additional study from JACOBS, presented in
June 2004 it is suggested that the VIP process rather than the A2O process would be
used as the biologic nutrient removing system.
It should be noted that reconstruction of the phase 1 of biological reactors was
completed and their technical state was improved. Further improvement of nutrient
biological removal will be easily organized. Existing configuration of biological reactors
based on traditional configuration of "piston flow" will ensure organization of certain
options of "separate sludge", system of nutrient biological removal. Restructuring of the
existing facilities into interrupted operation will require additional investments and
activities on the WWTP reconstruction without achievement of high parameters of
treatment.
SWECO's analysis shown that pre-precipitation is important even for option with
360,000 m3/day if existing biological aeration tanks will not be enlarged. However, there
is a need in additional reactor capacity for anaerobic reaction.
26
For anaerobic reactors it is proposed that if sludge stays in methane tanks for 1.5 hours
then volume of sludge should be 20,500 m3.
Total additional requirements for anaerobic reaction will be about 10,500 m3 for corrected
designed load of 360,000 m3/day.
For the final design load of 460,000 m3/day the need for additional reactors would be
25,560 m3; for aerobic reactors, the additional volume is assumed to be about 33,760
m3. The total additional need for anaerobic and anoxic reactors would be 59,320 m3 for
the revised design load at 460,000 m3/day.
Based on this estimates prepared by SWECO it is recommended not to enlarge
bioreactor volume but use preliminary sludge formation. Existing volumes can be
divided into anoxic and aerobic zones. Some reactors can be equipped both for mixing
(denitrification) and aeration (nitrification).
Biological removal of phosphorous will be possible in case of anaerobic reactor as
proposed in configuration A2/O. Biological removal of phosphorous reduces only
soluble phosphorous. Decrease of volume of treated effluents extends only on total
amount of phosphorous. Thus, if level of suspended solids in treated effluents will be
high then total amount of phosphorous in treated effluents will be high as well.
For options with preliminary sludge formation the following is true: used volumes of
62,316 m3 for nitrification and 41,544 m3 for denitrification are sufficient to achieve high
level of wastewater treatment from nitrogen compounds. Test on sensitivity to
nitrification shown that reactors' power is sufficient for future loads under normal
conditions.
The Rostov WWTP would be upgraded to meet more stringent N and P removal
standards by use of a pre-precipitation and A/O nitrifying/denitrifying process concept.
At present the Rostov WWTP the Phase 1 has a phase of an advanced treatment. The
"brush filters" are installed on three out of four lines. As described above the efficiency
has a typical "polishing effect. The ability to achieve a major improvement of the effluent
quality is very dubious when only the brush filter stage is in use. Nether the less, as an
intermediate stage it would be possible to install "Brush filters" in the available volume
created in the final settler basins. The available volume would be 10,800 m3, if all
sixteen basins were used.
As already underlined the need for additional advanced treatment capacity would be
needed to improve the discharge quality. By using a final rapid sand filtration stage the
water quality would be improved substantially with respect to suspended solids content,
and as a consequence also the particulate BOD and phosphorus. The sand filtration
stage, once installed into operation would have the following parameters (Table 4.10).
27
Table 4.10 Design data for the rapid sand filtration facility at the Rostov WWTP.
Parameter
Short term
Assumed
"Final"
Units
Design data
design
data
Year
2006
2025
Number of filters in operation
32
32
32
Area per filter unit
93.2
93.2
93.2
m2
Total filter area
2,983
2,983
2,983
m2
Filter type
Vertical upflow
Filter media
Sand
Design flow
13,833
15,000
20,500
m3/hour
Peak flow
17,677
19,333
27,605
m3/hour
Surface load
4.6
5.0
6.9
m3/hour
Maximum surface load
5.9
6.5
9.3
m3/hour
For the stable and successful operation of the sand filtration it is imperative that
the filters are backwashed in a regular manner. The initial design of the backwash
filter system contains the following parts:
Backwash pumps: 3 units each one of 1,004 m3/h at 20 m w.c., and 110 kW
installed power for each one.
Backwash blowers: 2 units each one of 6,000 Nm3/h at 20 m w.c., and 200 kW
installed power for each one.
The backwash water will be pumped from the discharge channel downstream the
filter plant. The backwash water will be collected in two equalisation tanks each
one of 1,200 m3. From these tanks the water would be pumped back into the head
of the plant. For this purpose two units of centrifugal pumps would be installed
each one of 530 m3/h at 35 m w.c. and 160 kW installed power for each one.
The plant is currently operated with a chlorinating stage, in accordance with the SNiP
norm. The actual dosage is 3 g/m3 or about 990 kg Cl2/d. The dosage point is
downstream the "brush filter" stage in Phase I and for Phase II in the outlet pipe to the
main discharge pumping station.
For the longer perspective chlorination should be replaced by an alternative disinfecting
system. As a long-term replacement Giprokommun has designed an UVplant. The UV
lamps will be installed in 9 channels; in each channel there will be 6 sections with 2
modules each, all-together 108 modules sized for 27,600 m3/h of treated wastewater.
The discharge channels are equipped with surface aerators for oxygen supply to the
treated water. The installation contains in all 7 units of slow speed surface aerators, all
with an installed power of 7.5 kW per unit.
By using the OCP model for the different operation modes it is possible to compare
the efficiency. Tables 4.11-4.17 present load options.
28
Table 4.11 Current operation situation, inlet loads, discharge figures and OCP
values
Parameter
Inlet
Discharge
Units
BOD5
42,004
6,080
kg/d
Total-N
6,150
1,657
kg/d
NH4-N
789
kg/d
Total-P
1,034
672
kg/d
OCP
263,268
85,633
kg/d
OCP-efficiency
67.5
%
Table 4.12 Short-term load with Stage 1 upgrade, inlet loads, discharge figures
and OCP values
Parameter
Inlet
Discharge
Units
BOD5
42,389
1,509
kg/d
Total-N
9,092
1,207
kg/d
NH4-N
150
kg/d
Total-P
1,781
121
kg/d
OCP
384,145
30,484
kg/d
OCP-efficiency
%
Table 4.13 Revised 2025 load with Stage 1 upgrade, inlet loads, discharge figures
and OCP values
Parameter
Inlet
Discharge
Units
BOD5
70,656
2,293
kg/d
Total-N
12,149
1,310
kg/d
NH4-N
kg/d
Total-P
2,409
164
kg/d
OCP
530,238
37,016
kg/d
OCP-efficiency
%
Table 4.14 Long-term design load with Stage 1 upgrade, inlet loads, discharge
figures and OCP values
Parameter
Inlet
Discharge
Units
BOD5
70,656
3,680
kg/d
Total-N
13,460
1,840
kg/d
NH4-N
kg/d
29
Total-P
4,416
276
kg/d
OCP
789,673
57,040
kg/d
OCP-efficiency
92.8
%
For the different load situations and with the final technical upgrades installed (including
the sand filtration stage) parameters are given in tables 4.15-4.17.
Table 4.15 Short-term load with final technical upgrade, inlet loads, discharge
figures and OCP values
Parameter
Inlet
Discharge
Units
BOD5
42,389
905
kg/d
Total-N
9,092
905
kg/d
NH4-N
150
kg/d
Total-P
1,781
45
kg/d
OCP
384,145
18,110
kg/d
OCP-efficiency
%
Table 4.16 Revised 2025 load with final technical upgrade, inlet loads, discharge
figures and OCP values
Parameter
Inlet
Discharge
Units
BOD5
70,656
983
kg/d
Total-N
12,149
983
kg/d
NH4-N
kg/d
Total-P
2,409
49
kg/d
OCP
530,238
19,654
kg/d
OCP-efficiency
%
Table 4.17 Long-term design load with final technical upgrade, inlet loads,
discharge figures and OCP values
Parameter
Inlet
Discharge
Units
BOD5
70,656
1,380
kg/d
Total-N
13,460
1,380
kg/d
NH4-N
kg/d
Total-P
4,416
92
kg/d
OCP
789,673
29,900
kg/d
OCP-efficiency
96.2
%
30
The upgrade of the plant with respect to nutrient removal will provide a substantial
improvement of the discharge quality. The OCP- efficiency will increase from about 67
% to almost 93 %. A further investment in an efficient polishing step would only improve
the efficiency by another 3 %. The chosen step-by-step strategy for the upgrade of the
plant may be seen as a very well founded decision, in the light of the OCP-analysis.
4.2.5. Planned activities on sludge treatment
The sludge treatment would be changed in some major parts as compared with the
present operation. The following alterations are foreseen:
The mixing of primary sludge and waste activated sludge may be ended, or used as an
alternative option when found suitable. The primary sludge will be stored for a short
time in 2 of the existing sludge thickeners (diameter = 18 m). There are toe
objectives for this treatment:
A. To provide an efficient thickening of the sludge.
B. To establish an anaerobic hydrolysis of the sludge in order to get more easily
degradable fatty acids available for denitrification in the biological stage.
Excess water from the thickeners, along with a limited amount of thickened
sludge will be pumped into the anoxic chamber.
Activated sludge will be thickened separately. This will be accompanied by use of two
gravity thickeners with addition of polymers for enhancement of the thickening
process. At a later stage it may be needed to upgrade the sludge thickening by
means of mechanical dewatering.
The anaerobic sludge digestion should be changed. The key project objective is to
reduce methane emission. Digestion workshop will be designed taking into account:
A. The amount of sludge from the WWTP will be almost the same despite the
process applied.
B. Primary sludge and activated sludge will be loaded into methane tanks in
series.
C. Methane tanks should be constructed in stages in compliance with stages as
described above.
Digestion will be based on termophilic treatment with a typical operation
temperature of 55°C.
E. Emitted methane will be used for energy production. Typical calculation of the
process will be based on the fact that digestion degree will be about 50% of
removed organic matter. Organic matter will be converted into liquid and
biogas.
Sludge volume was estimated based on implementation of system for nitrogen and
phosphorous removal. The sludge streams at the Rostov WWTP have been calculated
for the Phase I (Table 4.18).
31
Table 4.18 Sludge production and sludge streams at the Rostov WWTP, Phase I
Sludge flow/design situation
Short-term 2025 design
Long term
Units
Primary sludge
33,007
59,668
69,000
kg/day
Chemical sludge
6,640
7,200
9,200
kg/day
Dry solids content in sludge
3
3
3
%
Daily sludge flow to thickening
1,322
2,229
2,607
m3/day
Activated sludge
9,538
10,810
17,140
kg/day
Dry solids content in sludge
1
1
1
%
Daily sludge flow to thickening
954
1,081
1,714
m3/day
Main options for sludge treatment are given below:
1.
The sludge from the primary settlement, a mixture of primary and chemical
sludge will be pumped to the existing small sludge thickeners. This is typical
method during the first years of operation. This will be accomplished by a
recycling of the waste activated sludge to the pre-aeration tanks and finally
removed from the water process along with primary and chemical sludge.
2.
Activated sludge will be thickened separately in large thickeners. This operation
mode will be needed only at a later stage when sludge production will increase.
As in Table 4.18 sludge amount will be substantially lower under present conditions
compared to the designed values. This may allow use of only some of the existing
thickeners during the first years of operation. Needs in thickening capacity are analysed
in Table 4.19.
The existing sludge thickeners, 4 units 18 m diameter ones may be used for thickening
of the total amount of mixed sludge for the sludge amounts for a number of years. These
thickeners need reconstruction. At a later stage, when sludge amount will increase it can
be thickened in two separate sludge streams. All four thickeners will be used for primary
and chemical sludge treatment (Table 4.20).
At a later stage for activated sludge one large sludge thickeners will be required. Even in
conditions of full designed capacity it will be possible to re-circulate part of activated
sludge flow to pre-aeration stage. Due to this recirculating ability recirculating flow will
not exceed 50% of total activated sludge flow. Amount of sludge after thickening is given
in Table 4.21.
Thus, existing volume of thickener will ensure facilities operation using classical gravity
thickening. Mechanical thickening of sludge will be unnecessary within the entire
forecasted period. Even addition of polymer at the phase of gravity thickening will be not
required within first years of operation.
32
Table 4.19 Analysis of needed sludge thickener capacity at the Rostov WWTP,
option 1, designed parameters for all sludge entering gravity thickener
Parameter
Short term Revised
Acceptable values
2025
Units
4
4
n.a.
nos
Type
Circular
Circular
Circular
gravity
gravity
gravity
SS-load on thickeners
65,688
77,678
< 80
kg/day
Specific SS-load on thickeners
65
76
<80
kg/m2/day
Surface per unit
254
254
n.a.
m2
Total surface
1,018
1,018
n.a.
m2
Water depth
3.5
3.5
>3.0
m
Volume per unit
891
891
n.a.
m3
Total volume
3,563
3,563
n.a.
m3
Diameter
18
18
18
m
Dry solids in compacted sludge
5.5
5
> 4.5
%
Daily sludge flow after thickening
1,194
1,554
n.a.
Organic part of the sludge
70
70
n.a.
%
Organic amount of sludge
45,982
54,375
n.a.
kg/day
Table 4.20 Analysis of needed sludge thickener capacity at the Rostov WWTP,
option 1, designed parameters for primary and chemical sludge entering one
gravity thickener (for a long-term period)
Parameter
Long term
Acceptable Units
Thickeners
4
n.a.
nos
Type
Circular gravity
Circular gravity
SS-load on thickeners
78,200
n.a.
kg/day
Specific SS-load on thickeners
77
<80
kg/m2/day
Thickener surface
254
n.a.
m2
Total surface
1,018
n.a.
m2
Water depth
3.5
>3.0
m
Volume per unit
891
n.a.
m3
Total volume
3,563
n.a.
m3
Diameter
18
18
m
Dry solids in compacted sludge
6
>4.5
%
Daily sludge flow after thickening
1,303
n.a.
m3/day
Sludge organic part
70
n.a.
%
Amount of organic in sludge
54,740
n.a.
kg/day
33
Table 4.21 Amount of sludge after thickening for three different levels of load
Parameter
Short-term
Corrected for 2025 Long-term Units
Dry solids, total amount
54,483
77,678
95,340 kg/day
Dry solids in compacted sludge
5.5
5
5.3
%
Daily sludge discharge after thickening
1,194
1,554
1,793 m3/day
Sludge organic part
70
70
70
%
Amount of organic in sludge
45,982
54,375
54,375 kg/day
One of the reconstruction key objectives is to minimize methane emissions from sludge:
sludge anaerobic digestion and use of biogas for power generation. A number of factors
will determine digestion efficiency, such as dry solids retention time in methane tank,
organic load, safety against uncontrolled accumulation of fatty acid and heat control. As
stated above the digestion at the Rostov WWTP will occur at T = 55°C. Sludge retention
time in a methane tank is determined by minimum time under which bacteria form
methane. Theoretically this time is about 5 - 6 days. In addition a safety factor of about
2 - 2.5 is added to theoretical retention time in order to compensate load fluctuations
and composition of organic load. Later it should be kept in mind that ratio between
theoretical and actual hydraulic retention time is 1:2in a separate reactor. Thus,
minimum retention time in each anaerobic methane tank will be 10 -12 days.
For a very large plants such as the Rostov WWTP organization of digestion
should include at least four separate volumes. These can be arranged as two
lines with two methane tanks working in series. It is possible to use all four methane
tanks in parallel.
The second important criterion is to determine maximum organic load on methane tanks
expressed in kg of organic matter per 1 m3 of methane tank per day. Mixed process
with maximum organic load (< 4.5 kg/m3/day) is chosen for a high-rate digestion
typically operated by means of a continuous feeding.
Another practical condition is to define dry solids content in sludge. For energy
balance methane tank should be filled with as little water as possible. As total
sludge flow has to be heated from 20 - 22°C (as an average annual value) to
55°C it is clear that sludge thickening is very much needed for "energy saving".
Maximum "desired" content of dry solids in sludge entering methane tank is
determined by other process parameters, such as possibility to pump sludge
through the pipe system and heat exchangers, and sludge mixing inside methane
tanks.
According to practice content of dry solids in undigested sludge should be less
than 7%. Sludge thickening based on gravity thickening will result in content of
dry solids 5 - 6%. This is positive for good operation of digestion system.
Giprokommunvodokanal studied possibility to use existing methane tanks each 4,000
m3 after necessary reconstruction. The following options were addressed:
A. An upgrade of the existing methane tanks by use of stainless steel sheets
inside the existing structure and by strengthening of concrete structure. In this
34
case the available digestion volume will be 3,500 m3, total 14,000 m3. This
volume will be enough to meet SNiP norms for anaerobic digestion but leaving
no "extra" volume for fluctuations in load or sludge flow. This volume will be
best suitable for "intermediate" design level = 360,000 m3/day.
B. An upgrade of the existing methane tanks in a similar way but with an increase
of each methane tank height in order to get methane tank volume of 5,000 m3.
This option will fit for the final design level = 460,000 m3/day.
C. Construction of four new methane tanks in concrete. Existing methane tanks
will be demolished as available space will be inadequate for construction of
new methane tanks. In this case methane tanks are sized for final target level =
460,000 m3/day.
All other structures and equipment for sludge digestion and gas handling will be
identical regardless shape of methane tanks. Thus, it is possible to compare three
alternative options by marginal construction costs. Based on the existing Russian costs,
investment costs for three possible options of methane tanks can be defined as follows:
Option 1. Total cost of four reconstructed methane tanks each 3,500 m3 is 30 million
roubles.
Option 2. Total cost of four reconstructed methane tanks each 5,000 m3 is 40 million
roubles.
Option 3. Total cost of four new methane tanks each 5,000 m3 is 64 million roubles.
Provided that reconstruction of the existing methane tanks is technically reasonable
further analysis is focused on whether an extension of the methane tank capacity by
40% (from 14,000 m3 to 20,000 m3) will increase operational costs. Comparison of two
options is given with respect to operational costs. Potential for savings is based on
the fact that level of digestion is increasing with increase of sludge retention time in
methane tanks (Table 4.22).
Table 4.22 Relation between dry solids retention time in methane tanks and level
of sludge digestion
Dry solids retention time, days
Level of digestion, %
5
40
7
45
10
50
12
52
16
55
Comparison of three design load options with total digestion volume of 14,000 and
20,000 m3, respectively are given in Table 4.23.
Increase the methane tanks volume from 3,500 to 5,000 m3 will not lead to increase
of operational costs. Annual cost savings will be 2.0 - 3.1 million roubles/year. Costs
for sludge transportation are part of these costs. At present Rostov Vodokanal stores
dewatered sludge at site. However, soon there will be no place for sludge disposal and
new site must be found. This will mean that there will be additional operational costs for
sludge transportation and disposal. If sludge transportation and disposal cost 100
35
roubles/ton then additional annual savings will be 250,000 - 350,000 roubles/year. In its
turn "pay-back period" will be 3-4 years in case of a larger methane tank construction.
Based on this SWECO recommends to construct 4 methane tanks with total volume of
20,000 m3, each 5,000 m3. if this will be adopted the methane tank for the Rostov
WWTP should have sizing given in Table 4.24.
Table 4.23 Comparison of digestion performance under different loads
Parameter
Short-term
Corrected load
Long-term Units
for 2025
Digester size
3,700
5,000
3,700
5,000
3,700
5,000
m3
VSS-reduction 69,279 69,279
80,611
80,611 110099 110099 kg/day
Gas production
5.5
5.5
5.2
5.2
6.0
6.0
%
Energy potential,
total 1,307
1,307
1,550
1550
1830
1830
m3/day
Electric energy
output 70
70
70
70
70
70
%
Gain in electric
production 48,495
48,495
56,427
56,427
78,664
78,664
kg/day
Annual gain (350
days)
3
3
4
4
4
4
number
Gain in operation
m3
cost, electricity
3,700 5,000
3,700
5,000
3,700
5,000
Heat energy output
11,100 15,000
14,000
20,000
14,000
20,000
m3
Gain in heat energy
kg/
output 4.4
3.2
4,0
2,8
5.6
3.9
m3/day
Reduced amount of
sludge 8.54
11.5
9
12.8
7.65
10.9
day
Potential savings in
polymer (4 kg/ton
DS 47
51
48
52.5
46
51
%
Gain in operation
costs, polymer
22,793 24,732
27,085
29,624
36,185
40,119 tons/day
Total gain in
operation cost at
short term
46,486 44,547
53,526
50,987
73,914
69,980 tons/day
Digester size
1,307 1,307
1,550
1,550
1,830
1,830
m3/day
VSS-reduction 3.6
3.4
3.45
3.3
4.0
3.82
%
Thus, if 11 days are taken as a main criterion then organic load will be kept at a
reasonable level in case of "long-term" option. If necessary digestion volume will be
organized distributed into two lines, each reactor will have volume of 5,000 m3. In its
turn this will allow "stage-by-stage" investment by construction of only three out of four
methane tanks. Forth methane tank will be built when it will be necessary. In case of
36
"corrected design loads for 2025" methane tanks capacities will be insufficient if
only three methane tanks will be working. Thereupon construction of the forth
methane tanks will be logical at an early stage.
The need for sludge heating will be dominant for internal process, especially in winter.
Further utilization of heat in digested sludge by "sludge/sludge" heat exchangers will
limit need in sludge heating by hot water in a closed circuit for gas engine cooling.
Stage of sludge heating by classic heat exchanger based on "water/sludge" heat
exchanger will ensure proper temperature for digestion in methane tanks. In summer
need for gas engine cooling will not be arranged only by sludge heating. Excess heat in
the water-cooling circuit will be processed separately.
Table 4.24 Designed size of methane tank for the Rostov WWTP
Parameter
Short term For 2025
Long-term
Units
Total dry solids amounts
69,279
80,611
110,099 kg/day
Dry solids in thickened sludge
5.5
5.2
6.0 %
Daily sludge flow from thickening
1,307
1,550
1,830 m3/day
Organic part of the sludge
70
70
70
%
Organic amount of sludge
48,495
56,427
78,664 kg/day
Units
3
4
4 number
Volume per reactor
5,000
5,000
5,000
m3
Total volume
15,000
20,000
20,000
m3
VSS-load
3.2
2,8
3.9 kg/m3/day
Retention time
11.5
12.8
10.9 day
Digestion degree
51
52.5
51
%
VSS-reduction 24,732
29,624
40,119 kg/day
SS-amounts after digestion
44,547
50,987
69,980 kg/day
Volume at digestion
1,307
1,550
1,830 kg/m3/day
SS-concentration after digestion
3.4
3.3
3.82 %
Digestion temperature
55
55
55 ºC
Design temperature for raw sludge
16
16
16
ºC
Maximum temperature for raw sludge
28
28
28
ºC
Table 4.25 gives a rough indication of the sludge volumes that may be expected
(JACOBS GIBB).
Additional volume of sludge generated as a result of phosphorous chemical stripping is
given in the Table, as well as volume of generated sludge. The UK experience shows
that phosphorous chemical stripping up to 1 mg/l will increase sludge volume by 20%.
37
Table 4.25 Estimated sludge volume
Type of Sludge
With Chemicals for P
Without Chemicals for P
Removal
removal
m3/d %
DS m3/d %
DS
Primary sludge
1,220
3.0
1,220
3.0
Waste Activated
4,550
0.7
3,641
0.7
Totals 5,770
1.3
4,861
1.3
Sludge treatment for further utilisation. Proposals on sludge treatment are based on
mesophilic digestion. Other options may be considered during implementation phase,
including stabilization with lime and composting.
In addition to minimization of methane emissions other obvious benefits from the
digestion of the sludge are:
In conditions of thermal digestion reduction of pathogens (salmonella and
streptococcus) in sludge will be substantial. This will make sludge more
suitable for reuse compared to sludge discharged from the WWTP
now;
Reduction of sludge by 35% will result in direct reduction of operational costs
on polymers (for dewatering) and transportation costs.
As already discussed use of gas energy for electric power support at the
WWTP and sometimes for heating of buildings will contribute to
reduction of operational costs.
Temporary storage of dewatered but not digested sludge causes odour
problems. Complaints from population will likely to increase unless an
efficient anaerobic digestion of sludge will be organised.
Digested sludge will be transferred into a temporary storage reservoir before dewatering
by the existing centrifuges. Centrifuges are in a good technical condition. However,
system of automation does not operate due to absence of supplier instructions.
Centrifuges parameters are given in Table 4.26.
Table 4.26 Summary of technical parameters of centrifuges at the Rostov WWTP
Short-
Corrected for Long-
Parameter
term
2025
term Units
Amount of sludge to dewater
44,547
50,987
69,980
kg/day
Capacity per unit
Flow 100
100
100
m3/hour
Dry solids (DS)-capacity
4,000
4,000
4,000
kg/hour
DS-capacity as utilised at 12 h/d, 2
centrifuges
1,856
2,124
2,916
kg/hour
DS content in dewatered sludge
28
28
28
%
Sludge amounts after dewatering
159
182
250
m3/day
Annual amount of dewatered sludge
58,070
66,465
91,224
m3/year
Requirements in polymers
4
4
4
kg/ton
38
Daily use of polymer
178
204
280
kg/day
Annual use of polymer
65,039
74,441
102,171
kg/year
Higher level of certain pollutants in the reject water from centrifuges must be regarded
as a "negative" effect. Key pollutant will be ammonia nitrogen released from sludge due
to anaerobic hydrolysis. Typical concentration of NH4-N in reject water is about 10 -
15% of incoming amount of ammonia nitrogen.
Final sludge disposal
At present there are no clearly formulated proposals on future sludge utilization.
Developing proposals on sludge use and disposal it is necessary to consider world
experience on their use in reclamation of technogenic excavations (open pits),
authorized and non-authorised damps, and other technogenic objects.
Chemical phosphorous stripping
The cheapest reagent for chemical removal of phosphorous up to 0.6 mg/l is alum - (Al
(SO4)3) with cost of 6,000 roubles/ton. Proposed dose at stage of preliminary
precipitation will be about 50 g/m3 under normal operation conditions. Daily
requirement under different conditions of load is given in Table 4.27.
Introduction of chemical pre-precipitation will increase removal of organic matter
during primary sedimentation from 30% to 55% expressed in BOD5. This will reduce
organic load on biological reactors and will reduce requirements in energy for aeration.
Change as compared with the current load wil result in savings of oxygen and energy
consumption (Table 4.28) 0.918 rouble/kWh.
Table 4.27 Expected consumption levels of alum at the Rostov WWTP under
different wastewater discharge
Load case
Short term
Revised 2025 Long-term Units
Precipitation agent
Alum
Alum
Alum
Daily flow
330,000
360,000
460,000
m3/d
Expected dose
50
50
50
g/m3
Daily use
16,500
18,000
23,000
kg/day
Chemical sludge amount
6,600
7,200
9,200
kg/day
Anticipated cost for chemical
36,135,000
39,420,000 50,370,000
rouble/year
agent
Specific cost for chemical
0.3
0.3
0.3
rouble/ m3
agent
Table 4.28 Changes in oxygen and energy consumption needs in biological
reactors
Load
Short term
Revised 2025 Units
Without
With
Without
With
precipitation precipitation precipitation precipitation
Organic load into
29,672
19,075
49,459
31,795
kg BOD5/day
reactors
39
Oxygen supply, AOR
36,664
29,564
56,229
44,394
kg/day
Oxygen supply, SOTE
83,737
67,521
128,423
101,393
kg/day
Energy needs
1,108
893
1,700
1,341
kWh/hour
Daily use of energy
26,592
21,432
40,800
32,184
KWh/day
Annual energy
9,706,080
7,822,680 14,892,000 11,747,160
KWh/day
consumption
Anticipated cost for
8,910,181
7,181,220 13,670,856 10,783,893
roble/year
aeration energy
Specific cost for aeration
0.07
0.06
0.10
0.08
rouble/ m3
energy
Annual savings by pre-
1,728,961
2,886,963
rouble/year
precipitation
In case of anaerobic digestion amount of sludge will decrease by about 35%. In its turn
this will reduce need in polymers for dewatering. At present there are no expenditures
on sludge transportation as dewatered sludge is stored at site. However, final sludge
disposal place has to be identified, thus, reducing transportation costs.
Immediate benefit for the Rostov WWTP due to introduction of anaerobic digestion will
be longer sludge storage at the WWTP site, as well as decrease of the required volume
for annual storage from 35,000 to 30,000 m3/year.
Another side effect of anaerobic digestion introduction and energy recovery will be
savings in electric energy, as biogas will be used for power generation. Adding up
additional expenditures for pre-precipitation and savings due to digestion introduction
provides information for calculation of net additional operational costs for reconstructed
Rostov WWTP.
In short term conditions additional cost wil be about 10.7 million roubles/year or 0.09
roubles/m3 of treated wastewater.
In conditions of revised load (year 2025) additional cost will be about 8.3 million
roubles/year or 0.06 roubles/m3 of treated wastewater.
Total annual savings are given in Table 4.28a.
Table 4.28a Annual reduction of operational costs at the Rostov WWTP after
reconstruction (roubles/year)
Load case
Short term
Revised 2025
Potential cost savings by polymer reduction
13,393,020
13,522,560
Annual savings by pre-precipitation
1,728,961
2,886,963
Annual savings by digestion gas utilisation
10,322,109
14,726,937
Total cost savings
25,444,090
31,136,460
4.2.6 Upgrade of technical design of 2000 and step-by-step division of
construction
The 2000study presents full reconstruction of the Rostov WWTP. Additional upgrade
actions are considered in this section. Reconstruction of the WWTP is designed step-
by-step due to lack of funding.
40
Water treatment facilities
Total capacity for pre-treatment facilities is envisaged as 460,000 m3/day and is
divided by 50% for two Phases. Anticipated peak flow for each line is 13,300
m3/hour. Facilities for pre-treatment contain following standard elements:
Screening station
At present two parallel screening stations are in operation. These are automatic
screens, including solid waste screening, such as automatic transportation and waste
pressing.
5 inclined curved 16 mm screens are installed at Phases I and II. The spacing of the
screens is 16 mm. These facilities have been recently installed at both phases, and
there is no need in their reconstruction. We think that plan given in technical outline to
install 3 mm fine grade screens (often named as "step-screens") is justified. Use of fine
grade screens has become a "standard procedure" for the modern WWTPs in many
countries. Each Phase will need five screens working in parallel. Each screen will
have hydraulic capacity of about 4,000 m3/hour and total capacity of 40,000 m3/hour.
Intermediate stage will be 360,000 m3/day. Accordingly limited number of new screens
(3 at each Phase) will be installed at the first stage. This will ensure good operation in
most cases in the nearest future and during "project intermediate stage". The screening
capacity will be as given in table 4.29.
Modern presses are equipped with waste washing compartment in order to minimize
odours from waste. System of waste washing will wash out organic matter from waste
returning them on main treatment facilities. The remaining waste will be easier to
dewater and also less smelly. At least two presses for waste will be required at each
Phase. Each waste press with capacity 5 m3/hour will locate in the screens building.
Dewatered waste will be discharged into containers each 10 m3.
Table 4.29 Design data for mechanical screens of the Phase I, Rostov WWTP
Corrected
Unit
Parameter
Short-term
designed data
Average amount of effluents per day
330,000
360,000
m3/day
Average amount of effluents per hour
13,750
15,000
m3/hour
Peak capacity
424,246
464,000
m3/day
Designed flow per hour, tentative
13,833
15,000
m3/hour
Peak capacity, pre-treatment, tentative
17,677
19,333
m3/hour
Number of screens
2*3
2*3
number
Capacity of one unit
4,000
4,000
m3/hour
Total capacity, 5-8 units operating
20,000
32,000
m3/hour
Free intervals (grate gaps)
3
3
mm
Tentative amount of waste
6,000 8,000 8,000 10,000
kg/day
Content of dry matter in some wastes
10
10
%
Amount of waste for pressing
60 - 80
80 100
m3/day
Content of dry matter after pressing
35 - 40
35 - 40
%
Amount of waste after pressing
15 - 24
20 30
m3/day
41
Sand and grit chambers
The WWTP two phases have different sand removing systems. At Phase I system
contains four settlement tanks without supply of compressed air.
Only settlement speed of particles controls removal of sand and other abrasives.
According to data presented by Vodokanal specialists sand separation efficiency is
adequate.
Grit traps of the Phase II have the same size as Phase I grit traps and are equipped
with aeration system.
Pre-precipitation, pre-aeration and primary settling stage
Two new stations for reception, storage and handling of alum will be constructed; one
plant serving each line. Alum will be delivered by tracks; alum will be unloaded into
storage containers; storage time can be up to 30 days storage time. A new building
will be built for the preparation of chemical for precipitation.
Reactors will be installed in the building for preparation of 10% alum solution for
dosing. Four reactors will be built, each 102 m3.
For storage of solution another 4 tanks will be constructed, each 205 m3. Dosage
pumps will be run proportional to the flow entering the plant, and with time based
arrangement as well, to meet the lower need during night-time.
Alum liquid will be added downstream grit traps, thus, using the pre-aeration chambers
for mixing and flocculation
The pre-aeration chambers will be used as at present time, as well as will be able
to receive recirculating activated sludge on water treatment line.
New aeration pumping station will be installed at pre-aeration reservoirs of Phase II.
Existing sludge scrapers at primary sedimentation tanks of Phase II will be
replaced with new one; concrete structures will be repaired; sludge pumps will be
replaced with stainless steel pumps.
Main biologic reactor stage
First main biologic reactors of the Phase II will be upgraded in accordance with the
following statements:
1. All four lines of Phase II will have similar configuration. However, due to limited
funding reconstruction can be divided into two stages. The first stage as intermediate
will cover three out of four lines.
2. First part of each reactor will be used as anoxic reactor. Its volume will be 5,200 m3.
This reactor will be equipped with submerged slow speed mixers to maintain
adequate homogeneous activated sludge liquor in reactor, and also to enhance good
mixing of incoming wastewater with microorganisms. Installed number of mixers per
reactor will be 6 units per line each of about 4.5 kW.
Second half of the existing biological reactors will be used for aerobic reaction. In each
line available volume for aeration is 7,770 m3. New bottom aeration devices will be
installed at three parallel lines. It is preferable to use rubber membrane discs.
Required long-term capacity for the aeration will be 17,730 kg O2/day for each line
equal to about 750 kg O2/hour. Actual water depth is about 4.5 m. Required airflow will
42
be about 3,050 Nm3/hourh.
For recirculation of activated sludge inside biological reactors low pressure high
capacity low-pressure pumps submerged into water will be installed: recirculation
flows from outlet part of the aerobic reactors to the inlet of anoxic reactors wil be 2,000
m3/hour *0.5 m w.c.
For process control of the biologic reactors the following on-line probes would be
installed:
A. At each line a suspended solids meter, range 200 to 8,000 mg SS/l;
B. At each aerobic reactor two oxygen meter probes will be installed. Measurement
range will be 0.0-10.0 mg O2/l.
Final clarifier stage.
Phase II secondary settlement tanks urgently need renovation and technical
improvement. Important repair works has to be carried on concrete constructions, and
discharge channels should be reinstalled. New metal constructions are mainly made of
stainless steel.
Three out of four lines will be needed at the intermediate stage. These will be refitted
with lamella packages, as described above. In total 16 basins will be reconstructed,
thus, providing a capacity compliant to a designed flow of 460,000 m3/day for the entire
plant. However, it is possible that reconstruction will be divided into stages due to
limited investment capacity. Installation of lamella modules in 12 out of 16 basins will
meet intermediate capacity of 360,000 m3/day.
In each of the existing secondary settlement tanks lamella packages will be installed. All
of them will be use half of the reservoir length. Bottom scrapers will be installed and
sludge will be transported to the existing sludge drying beds. For return activated sludge
flow new dry mounted centrifugal pumps will be installed.
Advanced treatment, "brush filters"
The existing "brush filter" at Phase I provides better effluents treatment. Both Vodokanal
and Giprokommunvodokanal have anticipated that Phase II should have the same
phase of advanced treatment. As soon as lamella settlers will be installed at Phase II
there will be available space to install "brush filters".
Advanced treatment, quick sand filtration
Although parts of the construction for sand filters already exist, this stage unlikely to be
included in the first stage of reconstruction. Sand filtration stage will be important for
meeting SNiP norms.
Disinfections stage
Existing chlorination station will not change significantly during first stage of
reconstruction works.
An installation of the UV-radiation plant will become efficient only if sand filtration will be
installed.
Sludge thickening
Sludge thickeners will be renovated and equipped with new sludge scrapers and new
43
overflow weirs from stainless steel. For the first stage four thickeners (18 m in diameter)
will be renovated. At least one thickener will be operating also as anaerobic hydrolysis
reactor. Adequate pumping and piping system will be organized as well.
Later the two larger thickeners each 35 m in diameter will be upgraded or replaced with
new mechanical thickening devices.
Sludge digestion
Existing methane tanks will serve only as structural support for new methane
tanks from stainless steel sheets installed inside the existing methane tanks.
Building containing sludge pumps, heat exchangers, gas collection system, gas
engines for power generation and safety devices will be reconstructed, too. Power
distribution devices will be properly organised inside the building. Two gas storage
tanks will be built each 3,000 m3. A new storage tank for digested sludge will be
built with volume of about 2,000 m3.
Sludge dewatering
Sludge dewatering was installed few years ago. Centrifuges (altogether three units) are
operated manually. It will be necessary to ensure operation of automatic system for
sludge dewatering. Only with well operating automated mechanisms it will be possible
to operate sludge dewatering system in a most cost-effective way 24 hours a day. This
will reduce polymer use and will ensure intervals for centrifuges cleaning.
4.2.7. Alternative options to achieve stated objective of the proposed activity
The following three were selected for environmental impact assessment:
Zero option: the existing situation will remain at the WWTP, no reconstruction
works.
Option with biological treatment, advanced wastewater treatment and chemical
removal of phosphorous.
Option with reduction of nutrients using only biological treatment of
wastewater.
44
Chapter 5. Description of possible environmental impacts for alternatives
options
Description and assessment of possible environmental impacts for alternative options is
done step-by step as options for wastewater treatment and sludge processing are
studied.
The following are considered as possible sources of environmental impacts:
New constructions to be located at the WWTP site;
Elements of the main and supporting technologies (reduction of nutrient
discharges, sludge utilisation, methane utilisation, etc.) which operation is a
reason for environmental changes;
Units with life cycle linked with future facilities construction or operation;
Units operated earlier but not in use now (drying beds, sludge storage lagoons,
etc.).
Types of environmental impact are defined based on two classification features: input in
environment and abstraction from environment. Impact parameters are defined based
on the following indexes:
type of impact (direct, indirect, cumulative, synergetic, including manifestation
in due course);
impact intensity (value in unit time);
level of impact (value on unit of volume or are);
impact duration;
time dynamics of impact;
spatial coverage of impact (spread area).
The concept for improving of wastewater treatment with removal of nitrogen and
phosphorous is based on renovation and expansion of existing assets, consistent with
the stated aim of minimising capital and operating costs.
New construction or reconstruction of the following facilities is envisaged at the
WWWTP:
Phase I works:
1.
screen building (reconstruction with installation of "thin" screenings);
2.
grit traps will be site for addition of liquid alum (reagent for phosphate compounds
settling), thus, pre-aeration chambers will be used for preliminary sedimentation;
3.
aeration tanks (reconstruction with identification of anoxic zone denitrificator
and aeration zone - nitrificator).
Phase II works:
1.
screen building (reconstruction);
2.
pre-aeration tanks - primary settlement tanks (reconstruction: existing sludge
scrapers will be replaced by new scrapers; concrete constructions will be
repaired; sludge pumps will be replaced by stainless steel pumps);
45
3.
aeration tanks (reconstruction with identification of anoxic zone denitrification and
aeration zone - nitrificator);
4.
secondary horizontal settlement tanks (three lines out of four will be completed
with lamella modules and brush filters - bioreactors with immobilized microflora
well proven on Phase 1);
Facilities for wastewater advanced treatment (II stage) of Phases I and II
1. Reception (inlet) chamber (reconstruction).
2. Entry chamber (designed).
3. Filters for advanced treatment (reconstruction).
4. Pumping station for advanced treatment filters (reconstruction).
5. Reservoir for washing water (reconstruction).
6. Filters media storage facility (reconstruction).
7. Aerator trough (aeration tank) (reconstruction, designed).
Facilities for sludge processing, Phases I and II
1. Gravel bunkers (extension);
2. Sludge thickeners D=18 m (reconstruction);
3. Methane tanks (re-equipping up to 5,000 m3);
4. Two reservoirs will be constructed for gas storage 3,000 m3 each and new
reservoir for digested sludge storage (capacity 2,000 m3); power generation
plant; building for heat exchangers; gas-holders; methane tanks pumping
station;
5. Site for mixing wastewater with humin-mineral concentrate, and storage
facility;
Supporting buildings and facilities
1.
Blowing house and pumping stations No. 1 and 2, pumping station in passes of
capacity blocks of Phase II, pumping station of sludge thickeners
(reconstruction), in-site communications will be reconstructed;
2.
Reagent storage building with storage facility (two new plants will be constructed
for alum reception, storage and processing, one plant will serve line 1 or 2
phases).
Various environmental impacts will be registered both during reconstruction or
construction phases due to emission of pollutants, effluent discharges into water bodies,
formation and disposal of production and consumption wastes, and other impacts.
The following three alternative options were selected for environmental impact
assessment:
Zero option: the existing situation will remain at the WWTP, no reconstruction
works.
Option with biological treatment, advanced wastewater treatment and chemical
removal of phosphorous.
46
Option with reduction of nutrients using only biological treatment of
wastewater.
5.1. Environmental Impacts at Present
The WWTP operation poses certain environmental impacts, in particular:
air emissions;
discharge of insufficiently treated wastewater into the Don River;
ground water pollution due to infiltration of sludge water from sludge storage
lagoons;
waste disposal.
Key technological processes with air emissions are: effluents treatment, preparation of
chloric water, burning of gaseous fuel in a boiler-house, gas-welding and electrical
welding operations, sharpening works, transport.
At present level of wastewater treatment is insufficient and does not meet existing
requirements. River water is polluted by nutrients and organic matter due to discharge
of large volumes of insufficiently treated wastewater into the Don River. Sediments have
significant impact on aquatic ecology. Reconstruction of the WWTP is planned to
improve level of wastewater treatment.
Sludge disposed in sludge storage lagoons is enriched with organic matter, nutrients,
and heavy metals. In case of sludge drying and storage these substances infiltrate in
ground water and pollute them. Activities on sludge processing and methane utilisation
are planned to dewater and reduce sludge amount.
WWTP have no significant impact on topography and geology; hydrology; terrestrial
ecology; land use, industry and agriculture; energy consumption; transport
infrastructure; cultural heritage.
Key environmental impacts existing at present time are presented in Table 5.1.
5.2 Environmental Impacts during Construction
There will be no significant impact during construction on climate; hydrology; terrestrial
or aquatic ecology; water resources, supply and sanitation; public health (apart from
occupational health, discussed below); land use, industry and agriculture; fisheries;
energy consumption; transport infrastructure; tourism and recreation; cultural heritage;
groundwater quality; or sediment quality.
The construction of new buildings and tanks will have a slight impact on topography, but
this is not considered to be significant in the context of an industrial complex.
All construction work will have a slight positive impact on `population, employment and
income' through employment generation.
The majority of the potential construction impacts can be minimised through adherence
to proper site practice and health and safety procedures. There are a number of
Russian norms (standards) for construction practices, including SNiPs and the Manual
on Labour and Construction Safety.
Potentially dangerous excavations should be fenced off and warning signs erected. The
site is not accessible to the general public.
47
Construction works may have minor negative impacts on surface water and air quality
through operation of cars, machinery (atmospheric emissions, spillage of petroleum
products, etc.). Impacts can be mitigated by correct choice of fuel and proper machinery
operation, use of spill control procedures, enhanced control on polluted soil collection
and utilisation.
The construction of buildings, tanks and underground pipelines may have an impact on
the groundwater regime. This impact may be assumed to be negative (in disruption of
existing groundwater flows) but the level of impact is likely to be marginal and no
mitigation measures would be required. However borehole monitoring should be
instituted where there is likely to be groundwater diversion or rising water tables
There may be a slight decrease in effluent quality during works which require direct
interruption of process lines, but this is likely to be insignificant because retention time
would not decrease significantly as the works currently has excess capacity.
All works generate construction waste. It is understood that soils excavated during
building and tank construction will be used on site. Apart from soils, it is envisaged that
the waste generated will be relatively small and therefore have only a slight impact on
waste disposal. This impact should be mitigated by compliance with existing
requirements (RF and Rostov Oblast ordinances) for collection, temporary storage and
final disposal of construction waste. Special activities for waste recycling should be
developed and implemented where possible.
Components 1 and 2
The construction works comprise removal of existing screens and grit removers
equipment and installation of new equipment. This will have a minor negative impact on
waste disposal. It is recommended that ferrous equipment should be recycled wherever
possible.
,
.
.
Component 3
The improvements concern redesign of the secondary aeration tanks and the provision
of additional aeration capacity. The construction works include minor changes to the
layout of partition walls and the installation of several mixers at different depths.
Separate works are required for the excavation and construction of an additional
aeration tank, together with feed and return sludge lines and the installation of aeration
devices on the tank floor.
The excavation works are significant involving the removal of up to 20,000 m3 of soil.
The spoil will be used for construction of the tank support walls, site feeder roads and
other embankments such that offsite disposal is avoided. Soil will not be disposed
outside the WWTP.
Component 4
The provision of lamella separators requires only minor construction works to attach the
separators which are provided as packaged units. There will therefore be no significant
environmental impacts during construction.
48
Component 5 Chemical Phosphorus removal
No specific environmental impacts during construction are envisaged as the reagent
storage building already exists and is likely to require only minor refurbishment,
depending on the choice of chemical and equipment required for its preparation.
Component 6 Sludge digestion
This component involves extensive construction works which are likely to generate large
quantities of waste construction materials. This will be mitigated by compliance with city
ordinances on solid waste disposal.
Component 7 Sludge dewatering
Construction of the centrifuges and associated works is almost complete and was
funded by the CSIP, so the impacts are not considered here.
Component 8 CHP Methane use
This component will involve the construction of a new building to house the CHP plant.
No specific negative impacts other than those discussed earlier are envisaged.
5.3 Environmental Impacts during Operation
There will be no impacts during operation on topography, geology and soils; hydrology;
water resources, supply and sanitation; and cultural heritage. At this stage, it is
envisaged that there will be no significant impact on `population, employment and
income' as there will be no major changes in staff needs. Given that this project is grant-
funded, it is considered unlikely that it will have a negative impact on the population in
terms of ability to pay for services.
In a long-term period there are no impacts on land use, industry, agriculture, but some
positive impacts can originate due to disposal of less amount of biologically less
activated sludge.
The new buildings, pipelines and tank are likely to have a minor impact on hydrogeology
due to flow diversion.
Components 1 - 4
As each of these components form part of an integrated process, they have been
assessed as a single process unit. The quantity of grit disposed will not change as a
result of the project, but the quantity of screenings will increase with more regular raking
and the use of finer screens. There will therefore be a slight negative impact related to
increased solid waste disposal and its transportation from WWTW to landfill site. Such
impacts probably do not warrant mitigation measures but if desired, these could include
installation of a screening press, installation of a macerator and return of screenings to
works or installation of a screenings incinerator.
Given that the majority of nitrogen in the river appears to be present as ammonium
which is detrimental to fish, there may be a minor positive impact on fisheries. Given the
complexity of the factors affecting both nitrogen levels and fisheries, however, it is
difficult to estimate this impact with any certainty. The reduction of nitrogen levels with
the reduction in phosphorus levels is likely to decrease the eutrophication of the river,
thus having a minor positive impact on aquatic ecology; and tourism and recreation.
These impacts, and the impact of phosphorus reduction are discussed in more detail in
49
the following section.
Whilst the amount of sludge produced after the WWTP reconstruction will increase this
does not have a corresponding impact on solid waste disposal as all sludge produced
from components 1-4 will pass through a closed cycle to the sludge digesters. There is
therefore no direct connection between the process improvements and solid waste
disposal.
Sludge from primary sedimentation is expected to contain some disease pathogens as
well as parasitic eggs and cysts. Reducing the quantity of sludge carried over into the
final effluent through replacing the scraper mechanism in the primary tanks...With less
carryover of sludge into the final effluent there is also expected to be a small positive
impact on public health.
Whilst the new screening process will require less manpower to operate dosing of ferric
sulphate or lime, reagent monitoring and control will require increased manpower. The
new system could therefore be operated with no net change in manpower. There is also
unlikely to be any significant change in pumping duties once the new system is
operating hence no change in energy requirements. It is envisaged that there will be no
significant operational impacts on climate; energy consumption; transport infrastructure;
terrestrial ecology; groundwater quality; sediment quality or air quality.
Component 5 Chemical P removal
Total phosphorus has the potential to greatly affect the growth rate of individual algae at
concentrations up to 200-300 g/l and probably beyond. Under normal circumstances,
increases in riverine concentrations from likely background concentrations to such
levels are therefore potentially extremely important to the ecology of the river.
Phosphorus is present in wastewater in three forms: orthophosphate, polyphosphates
and organic phosphorus compounds. During biological treatment three main changes
occur:
Organic materials are decomposed and their phosphorus content is converted
to orthophosphate;
Inorganic phosphates are utilized in forming biological flocs; and
Most polyphosphates are converted to orthophosphates.
After biological treatment, phosphorus is largely present as bioavailable
orthophosphate, an ionic compound that reacts and precipitates out of solution in the
presence of metal salts.
Given the presence of phosphates in the sediments and the equilibrium balance of
phosphorus, the following impacts are predicted.
During the first year a steady decline in the levels of concentration of dissolved nitrogen
and phosphorus will be recorded in water of the Don river directly downstream of
Rostov-on-Don. An obvious decline in the Don river nutrient status downstream would
be seen no sooner than 3 years after the reconstruction.
Reduced levels of eutrophication and hence reduced algal blooms will have a positive
impact on river water quality by reducing the frequency of low oxygen and toxin release
events. This will have a beneficial impact on aquatic ecology; public health, fisheries;
tourism and recreation. Given the large phosphorus reservoir in the riverine sediments,
50
positive impacts on sediment quality will accrue over time. In the short term, therefore,
there will be no positive impact on sediment quality.
The use of chemical reagents for phosphorus stripping has both advantages and
disadvantages as shown in Table 5.4.
Chemical dosing will cause an increase in sludge volume. The actual increase depends
both on reagent chosen and the level of phosphorus in the wastewater (i.e. the dosing
level). This represents a minor impact on groundwater quality due to the possible
disposal of larger quantities of sludge to the lagoon.
The chemical stripping process should be monitored carefully to ensure optimum
reagent dosing.
Given the present state of options, it is envisaged that this component will have no
significant impact on climate; terrestrial ecology; energy consumption; groundwater
quality and air quality.
51
Table 5.1.
Environmental impacts of the WWTP at present time
Technological process and
Environmental impact
WWTP functional zones
Natural environment
Human environment
Environmental Quality
hy
lo
l
th
ap
ity
g
y &
ogy
geo
&
ption
on
water
al
ent
lity
ual
ic Hea
g
e
osal
opogr
d use,
lity
lity
lity
d waste
T
, geolo
Climate
Hydrol
Hydro
quatic
i
sheries
r
ansport
ourism &
Terrestrial
Ecology
A
Ecology
Publ
Lan
industry
F
Energy
consum
T
infrastructure
T
recreati
Cultur
herita
Surface water
qua
Ground
qua
Sedim
qua
Air qua
Soils q
Soli
disp
0
0
0
0
0
- -
- -
0
-
0
0
-
0
- -
0
-
-
0
-
Wastewater treatment
(grates, grit traps, first stage
reservoirs, primary
settlement tanks, aeration
tanks, secondary settlement
tanks, bioreactors)
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -
Sludge processing (sludge
thickeners, centrifuges,
reservoirs for sludge
digestion)
- 0 0
-
- 0 0 - 0 0 0 - 0 - - 0 - -
-
Sludge disposal (drying
beds)
Key:
++ Major positive impact; + Minor positive impact; 0 No significant impact;
- Minor negative impact; -- Major negative impact
52
Table 5.2.
Environmental Impacts during Construction
Component
Environmental impact
Natural environment
Human environment
Environmental Quality
n
l
lity
y
ption
e
g
stry &
m
s
tructure
qua
uality
t
y
posa
l
o
du
ali
l
th
itag
nsu
ity
water q
al her
ent qu
lity
ual
ic Hea
d use, in
ulture
d waste dis
Topography,
geology & soils
Climate
Hydrology
Hydrogeology
i
sheries
r
ansport infra
ourism & recreatio
Terrestrial Ecology
Aquatic Eco
Publ
Lan
agric
F
Energy co
T
T
Cultur
Surface water
Ground
Sedim
Air qua
Soils q
Soli
1. Screening, grit removal
2. Primary settlement tanks
3. Secondary aeration tanks
-
4. Lamella settlers
0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
5. Chemical P stripping
0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
6. Sludge digestion
0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -
-
7. Sludge dewatering
0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
8. CHP methane use
0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Key:
++ Major positive impact; + Minor positive impact; 0 No significant impact; - Minor negative impact; -- Major negative impact
53
Table 5.3. Environmental Impacts during Operation (during the next 5 years)
Technological process and WWTP
Environmental impact
functional zones
Natural environment
Human environment
Environmental Quality
gy &
n
l
lity
y
y
ption
e
posa
y, geolo
stry &
s
tructure
qua
uality
t
y
og
g
m
du
ali
ph
y
l
o
l
th
itag
nsu
ra
og
ity
geol
water q
lity
ual
s
al her
ent qu
ic Hea
d use, in
ulture
d waste dis
Topog
soil
Climate
Hydrol
Hydro
i
sheries
r
ansport infra
ourism & recreatio
Terrestrial Ecology
Aquatic Eco
Publ
Lan
agric
F
Energy co
T
T
Cultur
Surface water
Ground
Sedim
Air qua
Soils q
Soli
0 0 0 0 0 ++ + + + 0 0 + 0 + + + + 0 +
Effluent treatment (grates, grit traps,
settlement tanks, aeration tanks,
bioreactors)
0 0 0 0 0 + + + 0 0 0 + 0 + + + 0 0 -
Chemical P stripping
0 + 0 0 0 0 + + 0 0 0 0 0 0 + 0 + 0 +
Sludge processing (sludge
thickeners, centrifuges, methane
tanks)
+ 0 0 + + 0 0 + 0 0 0 0 0 + ++ 0 + + ++
Sludge disposal (drying beds)
0 + 0 0 0 0 0 0 0 0 0 0 0 0 0 0 + 0 0
CHP methane use
Key:
++ Major positive impact; + Minor positive impact; 0 No significant impact; - Minor negative impact; -- Major negative impact
54
Table 5.4. Advantages and disadvantages of chemical P stripping
Advantages Disadvantages
Reliable, well-documented technique
Chemical costs higher than for
Chemical costs can be reduced
biological systems.
substantially if waste pickle liquors
Significantly more sludge produced
(ferrous chloride or ferrous sulphate
than wastewater treatment process
are available and can be used
without metal addition; may
Controls are simple and
overload existing sludge handling
straightforward - easy to maintain high equipment; higher sludge treatment
P removal efficiency by controlling
and disposal costs.
metal salt dosing rate.
Sludge does not dewater as well or
Relatively easy and inexpensive to
as easily as conventional STW
install at existing facilities
sludges where metal salts are not
added.
Sludge can be processed in the same
manner as in non-P-removal systems
Requires tertiary filtration to remove
P in suspended solids.
Primary clarifier metal addition can
reduce organic load to secondary unit Coloured effluents if iron salts are
by 25-35%.
used.
Component 6 Sludge digestion
Sludge digestion will eventually ensure major environmental improvements as the
process leads to a significant reduction in sludge volume, and allows for the capture of
methane for beneficial use. Digestion converts the volatile organic fraction of the sludge
into a mixture of methane and carbon dioxide. The organic load could be reduced by as
much as 50%, depending on the efficiency of the digesters. In the absence of specific
designs, it is therefore only possible to assess the likely impacts in general terms.
Reduction of sludge volume is likely to have a positive impact on groundwater quality
and air quality as it will decrease the volume of sludge disposed to the lagoon in the
short term. This is discussed further in the sludge dewatering section. The lower volume
will also have a positive impact on energy consumption by reducing energy required at
the sludge dewatering stage.
During the digestion process the elevated temperature and long residence time in
anaerobic conditions results in the destruction of pathogens thus reducing the potential
health risks from the sludge. This represents a minor improvement to public health.
The capture of methane in the digesters therefore represents a significant climatic
improvement due to reduce of methane emissions.
The digesters will require an additional heating circuit based on natural gas, as the CHP
system will supply on average only 2/3 of the heat required to raise and maintain
digester temperatures. This represents a potentially negative impact on energy
consumption and climate (due to release of CO2) which may be mitigated by making use
of the CHP cooling water to preheat digester feed when heat in excess of that needed
for building heating is available.
The operation of digesters represents a potential risk due to the presence of areas
55
where explosive gas/air mixtures can be present. It will therefore be vital to introduce the
concept of "zoning". Areas where explosive mixtures may be present should be
identified, and special precautions taken within these areas. This will include locating
equipment which may cause sparks outside the danger zone, and careful choice of
mechanical and electrical plant, pipelines etc. within the zone.
Operation of digesters is a complex process, and staff will need to be given full training
and `hands on' experience. This is vital to the efficient operation of the digestion
process.
It is therefore envisaged that this component will have no significant impacts on aquatic
ecology; terrestrial ecology; transport infrastructure; tourism and recreation surface
water quality; or sediment quality.
Component 7 Sludge dewatering
The centrifuges are designed to produce a handleable sludge cake of approximately
35% dry matter. In the near future sludge from the WWTW will primarily be disposed of
in the existing lagoon and drying beds at the site. The lagoon currently represents an
unknown pollution risk. Risk from leaching to groundwater is not identified. The reduction
in sludge arisings as a result of digestion will therefore lower the risk of pollution of the
Don. This risk will reduce further if and when use of the lagoon ceases and the existing
sludge are removed.
The lagoon is an uncontrolled biological system and emits gases and volatile organic
compounds which although not toxic in the concentrations produced may be a source of
odour nuisance at some distance outside the site boundary. The reduction in volume
and BOD content of the sludge passed to the lagoon will therefore have a minor positive
impact on air quality and human use of the area.
The drying and subsequent aerobic storage of the sludge leads to a further reduction in
infectious organisms particularly of helminths. The sludge drying process may therefore
has a small positive impact on public health.
With continuing sludge disposal to the lagoon, it is envisaged that there will be no
significant impact on terrestrial ecology; land use, industry and agriculture; transport
infrastructure; solid waste disposal; tourism and recreation; or sediment quality.
Component 8 CHP methane use
The net result of the CHP is the conversion of methane to carbon dioxide. Carbon
dioxide has a lower negative impact on climate through global warming than methane.
Calculations suggest that a reduction in methane emissions by 70% and in CO2
equivalent emissions by 60% can be expected. Electricity and heat generated will be
used on site, thus significantly reducing use of electricity generated by the coal fired
power plant at Novocherkassk.
Renovated WWTP will need a significantly higher energy input than the existing situation
mainly due to the high energy demand of the digesters and dewatering facilities. This
energy would be obtained from the Novocherkassk power station but the construction of
the CHP system is therefore considered to be likely to reduce fossil fuel consumption at
the Novocherkassk power station. This will further reduce CO2 emissions, as well as
reducing emissions of sulphates and particulates and production of coal ash.
General environmental impact assessment for the activity on the WWTP reconstruction
is given in Table 5.5 in compliance with the WB requirements.
56
impact
Direct Impacts
Disturbance of stream
0 No
impact
channels, aquatic plant and
animal habitat, and
spawning and nursery areas
during construction
Alterations in watershed
0
No significant change to volume of water discharged to river
hydrologic balance when
wastewater is exported by
collection in large upstream
areas and discharged
downstream
Degradation of
0
No significant change to sensitivity of biological treatment process.
neighbourhoods or receiving
Duplication of digesters and treatment lines should preclude minor
water quality from sewer
process failures.
overflows, treatment works
bypasses, or treatment
process failure
Degradation of receiving
High probability
In the short term (<5 years) upgrading of the WWTW will result in a
water quality despite normal
of permanent
localised reduction of nutrient and organic loading to the Don.
system operation
improvement
Phosphorus levels however may not significantly decrease in the
short term due to re-equilibration of bound P in the sediment.
Low probability
Minor risk from pollution of receiving water by overdosing of
of temporary
phosphorus stripping reagent. Recommendations made for
minor adverse
installation and operation of monitoring system to minimise risk of
impact
overdosing
Public health hazards in the
High probability
No deterioration of water quality near the outfall is expected.
vicinity of discharges or
of minor
Pathogen and odour levels in sludge disposed to lagoon will
reuse sites during normal
permanent
progressively diminish as the improvements to treatment lines,
operation of system
improvement
digester operation and centrifuges are implemented.
Contamination of land
0
No plans in the short term to apply sludge to land
application sites: soils and
crops by toxic substances
and pathogens;
groundwater by toxic
substances and nitrogen
Failure to achieve desired
High probability
Will play a major role (along with other pollution reduction
beneficial uses of receiving
of major
initiatives) in the longer term towards achieving MACs for fisheries
waters despite normal
permanent
downstream of Rostov and drinking water within the Azov region
system operation
improvement
(see Section 5.5.1)
Odours and noise from
0
Works is sited in an established industrial area. Sludge will be less
treatment process or sludge
malodorous as a result of the improved process
disposal operations
Potential negative
Impact
Comments and recommendations
impact
Emissions of volatile organic High probability
Digestion of sludge will result in lower emissions of volatile organic
compounds from treatment
of permanent
compounds
process
minor
improvement
Soil, crop or groundwater
High probability
Sludge disposed to lagoon will contain lower concentrations of N,
contamination and disease
of minor
P and organic matter, thus polluting groundwater less than current
vector breeding or feeding
improvement in
sludge.
at sludge storage
the short-term
and major
improvement in
Heavy metal concentration in the sludge will also be increased
the long-term
during the digestion process thereby reducing the potential to
leach into the groundwater after disposal.
Improvement of sludge quality as progressive implementation of
WWTW investment programme and subsequent removal of sludge
from current storage lagoon (for co-disposal with daily sludge
arisings at landfill) would lead in time to remediation of the lagoon
site
Worker accidents during
Low probability
Impact mitigated by complying with established norms and
construction and operation,
of temporary
procedures.
especially in deep trenching
and avoidable
operations
and adverse
impact
Serious public and worker
0
This project does not involve works on chlorination facilities
health hazard from chlorine
accidents
Nuisances and public health 0
Duplication of digesters and treatment lines together with excess
hazard from sewer
capacity should preclude minor process failures.
overflows and backups
Failure to achieve public
0
No public health improvement within Rostov city. In the long term,
health improvement in
may improve public health aspects of downstream recreation.
serviced area
Dislocation of residents by
0 No
impact
plant siting
Perceived or actual
0
No impact as works located in an established industrial zone
nuisances and adverse
aesthetic impacts in
neighbourhood of treatment
works
Accidental destruction of
0
All works on existing footprint, with no archaeological sites
archaeological sites during
excavation
Potential negative
Impact
Comments and recommendations
impact
Indirect Impacts
Unplanned development
0
No impact
induced or facilitated by
infrastructure
Regional solid waste
No change in
Sludge is currently stored on site. A long term sludge disposal
management problems
impact in near
strategy will be developed as part of the RVK Strategy Plan. Minor
exacerbated by sludge
term. Long term
amounts of construction waste (mostly inert) for disposal to
major
existing landfill.
permanent
improvement
Loss of fisheries productivity High probability
Likely improvements to fishery productivity only in the longer term
of medium
since effective propagation depends not only on surface water
improvement in
quality but on longer term improvements to sediment quality and
the long term
ecological restoration
Decrease of tourist and
High probability
Expected minor improvement at Azov Sea resorts and Rostov city
recreation activities
of minor
with respect to bacteriological/viral quality as a result of upgrading
permanent
of WWTW.
improvement
Chapter 6 Relevant Environmental Legislation for Selected Options
According to the existing Russian Federation legislation any activity with environmental
impact has to be regulated by legal-regulatory documents of federal, regional and local
level.
Main Federal Laws regulating environment protection, natural resource conservation
and recovery are listed below.
· On Environmental Protection; 7, January 10th, 2002.
· On Environmental Expertise, 174, November 23rd, 1995.
· On
Fauna,
24, April 24th, 1995.
· On
Wastes
89-FL, June 26th, 1998.
· On Atmospheric Air Protection, 96, May 4th, 1999.
· On Specially Protected Natural territories, 33, March 14th, 1995.
· On Hydraulic Structures Safety, 117, July 21st, 1997.
· On Safe Use of Pesticides and Agrochemicals, 109, July 19th, 1997.
The following laws containing environmental requirements were adopted in the Rostov
Oblast:
· Oblast law "On payment for water bodies use", No. 230, March 28th, 2002.
· Oblast law "On administrative offence", No. 273, October 25th, 2002.
· Oblast law "On municipal administrative commissions in the Rostov Oblast", No.
274, October 25th, 2002.
· Oblast law "On use of The Earth's interior in the Rostov Oblast", No. 275, October
25th, 2002.
· Oblast law "On forests in the Rostov Oblast", No. 3, September 23rd, 1994.
The following documents regulate methodological basis of environmental design in the
RF:
· "Adoption of the "Instruction on environmental justification of economy or other
activity". RF Ministry for Natural Resources, 539, December 29th, 1995
· Regulations on assessment of planned activity impact on environment in the
Russian Federation (approved by RF Goskomecologiya No. 377, May 16th, 2000;
registered in the RF Ministry of Justice on June 4th, 2000, No. 2307).
· Section 8 "Engineering and technical surveys" in SNiP 11-02-96 developed by the
RF Ministry of Construction (Russia Minstroy), 1997;
· Section "Engineering and technical surveys for construction" in a "Register of
rules of engineering surveys for construction" (SP-11-102-97) developed by the
RF State Committee on housing and building policy (Gosstroy of Russia);
· Sanitary norms and rules for design of industrial Enterprises (SP 245-71);
· Sanitary norms and rules for design, construction and operation of MSW landfill;
· Sanitary rules of keeping of populated territories (SanPiN 42-128-4960-88);
60
· Sanitary rules and norms on protection of surface water from pollution (SanPiN
4630-88);
· Sanitary rules on protection of air quality in the populated places (the USSR
Ministry of Health, 1989);
List of key legal documents used in engineering and technical surveys includes:
SNiP 10-01-94. System of legal documents in construction. General terms.
SNiP 11-02-96. "Engineering survey for construction. General terms.
GOST 17.0.0.01-76. System of standards in the sphere of environmental protection and
improvement of natural recourse use.
GOST 17.0.0.02-79. Measurement assurance of air, surface water and soil pollution
control.
GOST 17.1.1.03-86. Nature protection. Hydrosphere. Classification of water use.
GOST 17.1.1.04-80. Nature protection. Hydrosphere. Classification of ground water in
terms of water use purposes.
GOST 17.1.2.04-77. Nature protection. Hydrosphere. Parameters of state and rules for
taxation of fisheries water bodies.
GOST 17.1.3.04-82. Nature protection. Hydrosphere. General requirements to
protection of surface and ground water from pollution by pesticides.
GOST 17.1.3.05-82. Nature protection. Hydrosphere. General requirements to
protection of surface and ground water from pollution by oil and oil products.
GOST 17.1.3.06-82. Nature protection. Hydrosphere. General requirements to ground
water protection.
GOST 17.1.3.07-82. Nature protection. Hydrosphere. Rules for control of water bodies
and watercourses quality.
GOST 17.1.3.11-84. Nature protection. Hydrosphere. General requirements to
protection of surface and ground water from pollution by mineral fertilizers.
GOST 17.1.3.13-86. Nature protection. Hydrosphere. General requirements to
protection of surface water from pollution.
GOST 17.1.4.01-80. General requirements to methods of oil products identification in
ambient and wastewater.
GOST 17.1.5.02-80. Nature protection. Hydrosphere. Hygienic requirements to
recreation zones of water bodies.
GOST 17.1.5.03-81. Nature protection. Hydrosphere. Analyzers of total organic carbon
in ambient water.
GOST 17.1.5.04-81. Nature protection. Hydrosphere. Instruments and devices for
sampling, primary handling and storage of ambient water samples. General technical
requirements.
GOST 17.1.5.05-85. Nature protection. Hydrosphere. General requirements to sampling
of surface and marine water, ice and precipitation.
GOST 17.2.1.03-84. Nature protection. Atmosphere. Definitions of pollution control.
61
GOST 17.2.3.01-86. Nature protection. Atmosphere. Rules for control of air quality in
settlements.
GOST 17.2.4.02-81. Nature protection. Atmosphere. General requirements to pollutants
identification methods.
GOST 17.4.1.02-83. Nature protection. Soils. Classification of chemical substances for
the purpose of pollution control.
GOST 17.4,1.03-84. Nature protection. Soils. Definitions of chemical pollution.
GOST 17.4.2.01-81. Nature protection. Soils. Nomenclature of sanitary state
parameters.
GOST 17.4.2.03-86. Soils passport.
GOST 17.4.3.01-83. Nature protection. Soils. General requirements to soils sampling.
GOST 17.4.3.03-85. Nature protection. Soils. General requirements to methods of
pollutants identification.
GOST 17.4.3.04-85. Nature protection. Soils. General requirements to control and
protection from pollution.
GOST 17.4.3.06-86. Nature protection. Soils. General requirements to soil classification
in terms of chemical pollutants impact.
GOST 17.4.4.02-84. Nature protection. Soils. Sampling methods and methods of
samples preparation for chemical, bacteriological, helminthologic analysis.
GOST 17.4.4.03-86. Nature protection. Soils. Identification method of potential erosion
danger due to rainfalls.
GOST 2761-84. Sources of a centralised household and drinking water supply.
Hygienic, technical requirements and selection rules.
GOST 2874-82. Drinking water. Hygienic requirements, quality control.
GOST 4979-49. Water for household, drinking and industrial water supply. Methods of
chemical analysis. Sampling, samples storage and transportation.
GOST 20444-85. Noise. Transport flows. Methods for measurement of noise
characteristic.
GOST 23337-78. Noise. Methods for noise measurements on residential area and in
living and public buildings.
GOST 24481-80. Drinking water. Sampling.
GOST 28168-89. Soil. Soil sampling.
GOST 12.1.003-83. SSBT. Noise. General safety requirements.
SanPiN 2.1.4.027-95. Zones of sanitary protection and water supply sources, as well as
drinking water distribution systems.
SanPiN 2.1.4.544-96. Water quality requirements for a decentralised water supply.
Sanitary protection of sources.
SanPiN 4630-88. Sanitary rules and norms for protection of surface water from pollution.
SanPiN 4631-88. Sanitary rules and norms for protection of coastal zones water from
pollution at water use sites.
62
SanPiN 42-128-4433-87. Sanitary norms of permissible concentrations of chemical
substances in soil.
3077-84. Sanitary norms for permissible noise in living and public buildings
All of the above-mentioned federal and oblast laws, legal-regulatory documents will be
applied both during design stage and reconstruction/operation stages.
63
Chapter 7. Description of Environmental Conditions
7.1 Natural conditions within the WWTP site
The Rostov WWTP works (Phases I and II) is located on the left bank of the River Don,
within a floodplain, 3 km downstream railway bridge, opposite the Besymyanny Island,
100 m off the coastal line (see Figure 7.1). Construction site of the Rostov port borders
the WWTP site at north together with the Don River; WWTP Phase III construction site -
from the south-east; pond of a fishing farm and Zarechnaya industrial zone - from the
northeast; pond of a fishing farm, bituminous concrete plant and motorway Rostov-
Bataysk - from the west and northwest.
7.1.1. Climate
Area has a moderate continental climate with dry, unsteady moistening.
Steppe plains are lowlands with soft rolling relief sloping towards the Azov Sea. This part
of the Rostov Oblast is accessible for the Black sea air masses. In the Rostov Oblast
annual amount of total radiation is 111-113 kcal/cm2, annual radiation balance is positive
(47-48 kcal/cm2) and increases from December and January to June July. Largest
increase is from February to March (almost 5 times) and decrease from October to
November (5-17 times). Specifics of geographic location determine absolute domination
of continental moderate air. Territory receives 11% of Arctic air masses, 68% of
moderate air masses and 21% - tropical.
In Rostov dominating are winds with eastern component (53%), of which eastern winds
are 31%; winds with western component amount to 35%, of which western winds are
17% (Figure 7.2).
Strong winds (more than 15 m/sec) have special practical interest. Their average
recurrence in Rostov-on-Don is 28 days/year, maximum 54 days. Largest number of
days with strong wind (up to 44) is recorded in winter and lowest (up to 22) in summer.
The prevailing winds are easterly. Load on the works increases under strong winds. In
Rostov within a year it changes from 20 kg/m2 in August, September to 58 kg/m2.
In Rostov average annual air temperature is 8.9oC. The coldest period lasts for 42 days
from 5th January to 15th February, warmest period lasts 76 days (June August). In
winter daily temperature variation is poor due to high recurrence of cloudy weather. In
Rostov average temperature amplitude does not increase 2.2-3.4°C and in summer it
increases up to 10.3°C due to large number of clear days.
The average annual precipitation is 604 mm (GMO Rostov). The majority of precipitation
occurs in a form of rains (70% for Rostov). Snow (16%) dominates among other forms of
solid precipitation (30%). Total duration of rains is 793 hours/year. On average snow
cover appears at the beginning of December (data of the GMO Rostov). There are 25
days with snow cover. Thickness of the snow cover is 5-8 cm; but steady snow cover
forms not very winter.
7.1.2. Topography and hydrography
In terms of geomorphological zoning scheme of the Volgo-Don region this area belongs
to the Don River valley (Figure 7.3).
The Don River modern valley developed on buried alluvial and marine formations of
64
mainly regressive cycles starting from Baku time, and located on the Lower Sarmat
loams with residues of the Upper Eopleistocene (Margarotovo) and Baku (Semibalka)
terraces.
The Upper Eopleistocene lacustrine and eluvial Scythian loams form foundation of the
modern left bank of the Don River. Width of the Don modern alluvial floodplain terrace
varies from 8 to 18 km. Height is 2-5 m. Surface is cut by flood water into shallow gullies
(eriks and former river-beds). Some places are waterlogged. Terraces substrate is
marine loams, sands, loamy sands and loamy soils.
Dams of fishing farms locate along the entire Don floodplain. Their length is 60-80 m,
width 3-5 m at top and 10-15 m at the bottom. Their height in the upper reach is 1-2 m
and in the lower 5-7 m. they are composed by loamy soils.
Railway and motorways embankments locate in the Don river floodplain between Rostov
and Bataysk. They are 6-7 km long, 40-50 m wide and 8-10 m high. They are composed
by sand and crushed stone.
Despite larger precipitation in summer its impact on surface flow is minor due to soils
aridity in summer and high evaporation. Melting snow water is the main source for
surface water. Spring high water period starts at the second half of February and
maximum levels are recorded at the end of March beginning of April. Water level rises
by 4-6 m. Recession of flood starts mid-May. High water period lasts 1.5-2 months. The
highest recorded level was in 1917 with level rise up to 597 cm above regular water
level.
In summer low water period starts with rare floods. Minimum water level is August-
September. Duration of low water period is 200-250 days. In October its slowly starts to
rise by 0.3-0.5 m. Winter low water period starts the first decade of December. It lasts for
60-70 or 120-130 days. At the end of December beginning of January, after freezing of
the river water level decreases up to minimum. But winter low levels are higher than
summer low levels. Stable freezing occurs only in severe winters and persists for 70-80
days. Ice thickness is 0.2-0.3 m, ice drift lasts 16 days.
The Don River is a typical plain river and navigable through the whole length. River
width is 190-712 m, depth 5.7 11.0 m, flow velocity is 0.1 m/s. Bottom is loamy and
sludgy, sandy here and there. Right bank is high (50-80 m), steep (up to 15°); left bank
is low and gentle. Average riverbed slope is 2.2%. In the lower reaches the Don River
divides into branches and canals. Snowmelt is the main source for the Don River
(amount up to 68%), ground water is 28% and rainfalls only 4%.
Construction of the Tsimlyansk reservoir changed water regime. Now it is mainly defined
by releases from by-wash. High water period is low and extended. Flow volume higher
than 3 km3 is observed only in coincidence of releases from reservoir and flood wave
from the Seversky Donets River. After regulation value of annual flow decreased by 28%
and its further reduction is expected. Flow seasonal distribution has changed. Spring
flow reduced by two times from 21.8 to 9.6 km3. In other seasons flow increased by
almost twice, e.g. in summer-autumn from 3.9 to 7.9 km3 and in winter from 2.2 to 3.3
km3. Compared to natural regime water temperature reduced in spring and increased in
autumn.
Tides arising due to winds pose a significant impact at the river mouth. Easterly wind
drives water away and lows water level (by 2.5 m in 1910). South-easter wind flows from
a sea, surge marine water and rises water level. Average annual water discharge for
65
1952-1982 was 694 m3/s and it was changing from 406 to 1140 m3/s. In winter low water
period water mineralization near Rostov is 0.43 g/l, in summer-autumn 0.71 g/l. in
terms of chemical composition the Don river water is hydrocarbonate-sulphate-chloride,
hydrocarbonate- chloride sulphate and calcium-sodium-magnesium.
Ponds are part of the hydrographic network. Ponds are fed mainly by atmospheric
precipitation and partly due to ground water in a form of springs. Water mineralization
depends on precipitation and seasonal air temperature fluctuations. Fishing ponds
locate in the relief lowering (eriks, marshes). As a rule they are bordered to prevent
flooding. Fishing ponds are filled with water for fish growing period (April-October).
These are typical technogenic landscapes. At present they are rarely used for fish
growing and mainly populated by meadow-marsh communities.
7.1.3. Hydrogeology and protection of ground water
Water-bearing Mid-pleistocene, i.e. modern sub-horizon presents Quaternary aquifer in
the Don river valley. On the left bank of the Don river deposits are presented by sands,
loamy clays, rarely by loamy sand. Thickness of water-bearing deposits is 12 m. depth
of ground water changes from 0.2 14 m increasing towards floodplain terraces. Water
class is sulphate magnesium-calcium, calcium-sodium-magnesium, rarely chloride-
sulphate-sodium.
Aquifer is fed by inflow of ground water from undercover loamy sands and by infiltration
of surface water and precipitation. Aquifers discharge into the Don River and partly into
fractured limestone.
In terms of geomorphology the Rostov WWTP site locates on the left bank of the Don
river. Here during construction of the WWTP a layer of sand was filled on a surface up to
absolute heights of 5.0-6.0 m (fine-grained sands, rarely mean particle size). The
following are lying below: the upper quaternary and modern alluvial deposits presented
by loamy sands (with humus in the upper part 0.6-0.8 m) underlay by black and dark
grey clay, with peat, silt and rare layers of dust-borne sand. Below clay is greenish-grey
or dark-grey with sands and layers of dust-borne sand. Sands (fine-grained and rarely
mean particle size, water saturated) are uncovered under clays at depth of 10.0-12.0 m.
Total thickness of sands remained uncovered.
In terms of hydrogeology this area is a mixture of modern technogenic and upper
quaternary alluvial deposits with ground water. Depth of the studied area is 20 m.
Water-bearing rocks are presented by inwash sands, alluvial loamy and sandy deposits
hydraulically interconnected in a single water-bearing thickness formed due to natural
feed and infiltration of technogenic water at the WWTP site. The Don river water drains
ground water.
7.1.4. Vegetation cover
Vegetation cover is mosaic and presented by several types of vegetation (Figure 7.4).
Marsh vegetation is class of European-Siberian grass and grass-Hypnum marshes.
Large-grass, large-sedge and halophilous scirpus marshes are found in this area. Large-
grass marsh-fluxes locate in wide lowering, low coasts of eriks. They are formed by
Phragmites australis, Scirpus lacustris, S. tabernaemontanii, Typha angustifolia, T.
laxmannii, T. australis. Reed and reed mace associations are less popular than reed-
beds. Marsh motley grass is not abundant and consists of the mentioned above species.
Meadow vegetation includes four types of most typical meadows: excess moistening,
66
medium moistening non-salt and salt, insufficient moistening salt.
Near-water and aquatic vegetation locates in floodplain canals and eriks, as well as in
artificial water bodies (ponds, canals). Vegetation of near-water coenosis belongs to the
same formations as marsh vegetation (reed, reed mace and mainly reed-beds
formations). Flood-plain forests locate in the mouth floodplain and on islands. Fragments
of flood-plain ribbon pussy-willow forests and black poplar forests are very rare and
often exist as separate standing trees. Small areas of shrubby osiers present forest
vegetation. Poplar forests locate between the WWTP and harbor walls.
Anthropogenic modifications of vegetation are due to pastures, mowing, destruction of
vegetation cover under construction works and building activities, and ploughing up.
Modern state of vegetation cover can be assessed as stable.
7.1.5. Soils
Soil map is given on Figure 7.5. Alluvium, mainly clay is a soil forming rock of meadow
soils in the Don river floodplain. Ground water locates 1.0-2.5 m from surface but
sometimes even higher.
Alluvium-meadow soils locate on river mouth and eriks lowering. Soils have well-
developed stratification due to heterogeneous granulometric composition and presence
of submerged humus horizons. Average thickness of humus layer is 30 cm. Humus
content in a layer A is 3-5%. These soils have good water and physical qualities and can
be used for growth of vegetables and horticultural crops.
Meadow sombric soils form in conditions of periodic excessive moistening. Thickness of
humous-accumulative horizon varies from 20 to 40 cm. Transitional humus layer B has
thickness 20-60 cm depending on specific conditions. Humus content in a layer A is 4.5
7.5%. Environment reaction is close to neutral (6.3 7.5).
Meadow-black earth soils locate in higher plain sites. They are close to black earths of
plain-steppe zones. Genetic horizons are clear; transitions are gradual. On average
thickness of humus horizon is about 95 cm, varying from 60 to 110 cm. Ground water
lies deeper than 3 m. Humus content in upper horizons is 6.5. Environment reaction is
close to neutral or alkalescent: ph varies from 6.7 to 7.8.
Ooze-marsh and deltaic soils develop on flooded sites under pileup due to the westerly
winds. Ground water level is close to a surface. In summer evaporating geochemical
barrier is active. Thus, salts content is high in soils upper horizons. Salination and
desalination processes influence on soils physical-chemical features. Humus content is
high (up to 6-8%). However, in this soils gleying processes are well developed, oxygen
regime is unfavourable for meadow vegetation. Thus, grass marshes communities
dominate on ooze-marsh soils.
7.1.6. Fauna
Four classes of terrestrial vertebrates inhabit the Don floodplain:
I. Amphibia - Amphibia;
II. Reptilia Reptile;
III. Aves - Birds;
IV. Mammalia Mammals.
Amphibia
67
The following inhabit described area: smooth newt (Caudata order); red-spotted fire-
bellied toad, toad frogs, green toad, frogs (Ecaudata order). Smooth newt and frog are
listed in the Red Book of the Rostov Oblast with status "category I". They require
rehabilitation and protection of environmental niche.
Reptile
Two orders represent Reptiles. These are:
Chelonia order - pond tortoises;
Squamate order (9 species)
Suborder Lizards sand lizard, Eremias.
Suborder Serpent grass snake, water snake, smooth snake, Renard's viper,
Columber jugularis, C. ravergieri and C. najadum.
Snakes population drastically reduced due to heavy anthropogenic pressure (decrease
of non-arable lands, pollution with different chemicals, high recreational load) and killing
of snakes.
Columbers are listed in the Red Book of the Rostov Oblast: C. jugularis (status
"catergory II"), C. ravergieri and C. najadum (status "catergory I"). Renard's viper is
included into the Red Book of the Rostov Oblast with status "category II".
Birds
Birds are widely presented in the Don river valley up to 90 species (without Passerine).
Rare and endangered bird species
Accipiter badius and short-toed eagle (status category I); black stork, harmel, white-
tailed eagle, golden eagle (status category II); osprey (status category III) were listed in
the Red Book of Russia.
Pale harrier and stock-dove (status category I); white stork, common crane, honey
buzzard, oystercatcher and black-tailed godwit (status category II); ruddy sheldrake,
booted eagle, corncrake and eagle owl (status category III) were listed in the Red Book
of the Rostov Oblast. All these species are recommended for the Red Book of Russia.
Seven of 19 nesting species (harmel, Accipiter badius, white-tailed eagle, corncrake,
black-tailed godwit and pratincole) are elements of the Rostov Oblast gene pool. White-
tailed eagle is a monument of wild nature with an esthetic interest.
Mammals
The followings species are found in the area:
European hedgehog.
Cheiroptera 4 species of Nyctalus family.
Duplicidentata sub-order European hare.
Muridae (about 10 species in the studied area) spotted souslik, great jerboa,
southern birch mouse, harvest mouse, house mouse, Norway rat, musk-rat,
common vole, Russian mole rat.
Carnivora corsac, fox, raccoon-dog, polecat, weasel, stone marten.
Perissodactyle - wild boar.
68
7.1.7. Specially protected areas
Specially protected areas are areas of land, water surface and air with ecosystems and
object having special environmental, scientific, cultural, aesthetic, recreation and
sanitary importance and fully or partly withdrawn from use by special; decrees. They
have a special regime of protection.
The following categories of the above-mentioned areas are defined:
State natural reserves, including biosphere;
National parks;
Natural parks;
State natural game-reserves;
Natural heritage;
Dendrology parks and botanic gardens;
Medical-sanitary districts and resorts.
In the Don area there are 2 wetlands and 3 major ornithological territories with
international rank, 1 reserve, Don federal reserve fishing area, 7 federal hunting game-
reserves, 26 Oblast game-reserves and more than 130 local monuments of nature.
State game-reserves are effective form of environment protection. They exist for many
years and their network is gradually expanding. In the Rostov Oblast by 1982 there were
1 Republican and 21 Oblast game-reserves. Manych-Gudilo republican game-reserve
mainly covers Kalmykiya territory and protects unique bird colonies. Its area within the
Orlovsky and Remontnensky districts (Rostov Oblast) was 150,000 hectares. After
Rostovsky reserve was established (total area 9,464.8 hectares) part of the game-
reserve area became part of the reserve. Large area of lands lost their status of
specially protected areas.
At present in the Rostov Obalst there are 26 state hunting game-reserves of Oblast
importance with the total area of 458,500 hectares (4.5% of Oblast area) and 14 majory
ornithological territories.
Different cultural and historic values are found in the area as it has been populated for a
long time.
Stone tools, household goods were excavated downstream Rostov during archeological
digs at ancient sites.
Scythians appeared in the Don area in the 8th century, the Iron Age. Burial mounds are
most typical for the Scythian period. At the end of the 4th century Sarmat tribes (kindred
to Scythians) penetrated to the Don area from the east. Numerous monuments of the
Sarmat culture can be found in Rostov, Khapry, settlement Gnilovsky, etc.
First Greek settlements originated in the Don area in the 6th century. The largest was
Tanais fortress, main trading center of Bosphorous kingdom.
Monuments of the Upper palaeolith are found in the Don river delta (sites Kamennaya
Balka 1, 2, 3, Mokry Chaltyr).
There are no specially protected areas, natural monuments, architecture and historically
important building in the construction zone.
7.2. Social and economic situation
69
7.2.1. Demography
The area locates in the southwest of the Rostov Oblast and was populated for ages.
Before the 20th century the majority of population was involved in agriculture, but closer
to the beginning of the 20th century metallurgy, metal-working, trade and transport
started to develop. Decrease of population (gradual in after-war time and drastic in the
1990-s) resulted in migration increase. Having reached maximum in 1995 population
gradually decreases. Decrease of population in cities started in 1991 and in the rural
areas since 1998. Rostov Oblast is currently following the national trend of decreasing
population.
According to the All-Russia population census (2002): Rostov population is 1070.2
thousand inhabitants, Azov 82.2 thousand inhabitants, Taganrog 282.5 thousand
inhabitants.
Parameters of population reproduction significantly changed in post-war period.
Compared to pre-war period birth rate decreased by 4 times and death-rate being
minimal in 1960-s has increased almost up to the pre-war level.
Since 2000 birth rate is increasing. In 1999 number of new-born children was 6,783
persons and by 2002 it was 8,401. This is typical for other towns of the studied area.
In 2002 the mortality in Rostov was 15,023 persons, in Azov 1236 and in Taganrog
4847. However, mortality dominates birthrate.
Major towns locate in the area adjacent to the project site. Industry and agriculture,
including irrigated are developed in this area. The area has the highest population
density both rural (more than 20/km2) and average population density (more than
100/km2).
7.2.2. Population economic activity
The area belongs to Rostov industrial node including Rostov-on-Don, Taganrog,
Novocherkassk, Azov, Aksai and Bataysk. All enterprises are closely linked with each
other.
Machine-building is the priority branch in this largest industrial node. Plants produce
grain combines, steam-boilers, aircrafts and helicopters, instruments and apparatuses,
cars, press-forging equipment, vessels, etc. The major joint-stock companies are
Rostselmash, Beriev's TANTK, Rosvertol, Tagaz, Krasny Kotelschik, Santarm, GPZ-10,
Azovsky KPA Plant, Donpressmach, NPP KP Kvant, Priboi, etc.
Food industry holds the second place in terms of production volume. The key branches
are: meat production (meat-packing plant Rostovsky, Bekon, Tavr); dairy industry (dairy
Rostovsky, Taganrogsky, Azovsky); butter-making industry (Yug-Rusi, Rabochii, etc.);
tobacco industry (Donskoy tabak); wine industry (Rostov factory of champagne);
alcoholic beverage industry (Rostov vodka, etc.); brewing trade (Baltika-Don, etc.), flour-
and-cereals industry, macaroni industry, baking, fish industry, etc.
The following large enterprises form chemical complex of the Rostov industrial node:
Empils, Emkras. Plants of Azov, Rostov-on-Don and Taganrog produce plastics,
polymeric materials, and medical products. Woodworking and pulp and paper industries
produce furniture, paper, wallpaper, wood chipboards (plants Rostovbumaga, Tamek,
Rostovmebel, Rostovtara, Azov packaging plant, etc.).
Light industry consists of leather-shoe industry (Donobuva, Rostovobuv, Taganrog
tannery, Donskaya leather, shoe factories of Azov, Bataysk and tagnrog), clothing
70
industry (Elegant, Clothing factories 1, 3, 5, Azov clothing factory), knitting and
hosiery industry, etc.
Metallurgical and construction complex is important in production. Taganrog
metallurgical plant "Tagmet" produces 80% of branch production in the region (steel,
steel pipes). Construction plants produce construction bricks, fabricated reinforced
concrete structures, etc.
Thousands of people are working in industry. All enterprises locate close to reliably
operating sewage and water supply systems.
7.3 Assessment of the current environment situation
Environmental and geochemical surveys in the WWTP area helped to assess modern
state of environment and to forecast possible environment changes under
anthropogenic impact. Survey objective was to find environmental parameters for the
period before the proposed project start.
7.3.1 Survey methodology
Analysis of the modern state of environment included: collection and analysis of
published and summarized materials, field surveys, office studies of data collected.
The following data and materials were used to assess environment state in the area of
the WWTP:
· Actual data on environment protection and map material provided by Rostov
Vodokanal.
· Data of specially authorized state agencies in the sphere of environmental
protection and natural resources use:
Committee on Environment Protection and Natural Resources under Rostov
Oblast Administration;
Central Administrative Board on Natural Resources for the Rostov Oblast, RF
Ministry for Natural Resources;
Rostov Oblast Center for hydrometeorology and environment monitoring;
Rostov Oblast Centre for State Sanitary and Epidemiological Supervision.
· Published
data.
Field survey included:
· clarification of gepmorphological, engineering and geological, hydrogeological
and landscape conditions defining environmental impact of the object;
· identification of possible sources of soils, bottoms, surface and ground water
pollution based on modern situation analysis and area use in the past;
· identification of possible migration routes and possible sites of pollutants
concentration.
During surveys schemes with location of potential pollution sources were prepared.
Specialists of the scientific enterprise "Environmental laboratory" cross-examined local
population about retrospective use of the area, about emergencies happened in the
past, about cases of mass death of plants, animals and birds. They searched for visual
signs of landscapes pollution.
71
Vegetation map, soils and landscape maps were prepared based in survey results.
Relative background for soil cover was defined during engineering and environmental
surveys in the studied area. Geochemical materials received during geochemical studies
at the area of list L-37-X ("Greater Rostov") in 1995-2000 and environmental-
geochemical observations in 2001-2002 formed a reference point for further monitoring
observations.
The upper soil horizon (0.0-0.2 m) with maximum intensity of geochemical processes
was tested during lithochemical studies. Soils were sampled on geochemical profiles
located in a way to test main landscapes in the studied area. The Don River and
floodplain lakes, as well as ground water were sampled during hydrochemical studies.
Samples were preserved using standard methodologies and were sent to the regional
laboratory centre of Uzgeologiya.
Geo-ecological maps of pollutants distribution in different landscape components were
developed using GIS ArcView GIS 3.2 and Spatial Analist 1.0 module.
7.3.2. Surface water assessment
Main impact of the existing and proposed activity is on the Don River. Detailed
assessment of surface water quality is given below in terms of hydrochemical,
hydrobiological and sanitary-toxicological parameters.
The Lower Don hydrochemical, hydrobiological and sanitary-toxicological regime forms
as a result of many factors. The Tsimlyansk reservoir forms main features of river
chemical composition. The Lower Don water is a water with inherited chemical
composition. Initial chemical composition of the Don river water significantly transforms
moving downstream. This is mainly due to inflow of substance of natural and
anthropogenic origin. Part of substances enters channel as a result of lateral erosion.
Other substances enters water column from bottom sediments and ground water.
Follow-up evolution of water chemical composition is due to redistribution of components
in the rivers.
Discharge of insufficiently treated and polluted water of industrial enterprises, housing
and communal services, washing of fertilizers, residues of pesticides, organic matter,
heavy metals from farming lands and farms, storm water, mining and drainage water
pose impact on the Don river water quality.
7.3.2.1 Hydrochemical assessment of surface water
This section is based on results of generalized hydrochemical and hydrobiological
information presented in the "Year-books of surface water quality" on hydrochemical and
hydrobiological parameters within the area of the North-Caucasus Hydromet for a long-
term period.
In terms of chemical composition the Don river water in all phases of hydrological cycle
belongs to a hydrocarbonate class, sodium group. Water mineralization varies from 0.3
to 1.4 mg/l. It slightly reduces during high water period and increases during summer-
autumn and winter low water period (near Aksai it is 460-890 mg/l). values of
mineralization and main ions are given in Table 7.1.
72
Table 7.1 Main ions and the Don river water mineralization, mg/l (average annual)
Site
2+
g2+
-
SO -2
4
Cl-
ions
settlement Razdorskaya
76
26.5
208
171
143
755
Rostov-on-Don 84.0
37.0
194
197
141
759
Azov 79.8
38.6
190
195
160
774
Oxygen regime of the river main channel is satisfactory. Decreased content of oxygen
(below 6 mg/l) were often recorded in delta watercourses, especially in the ranch Mertvy
Donets, Prevoloka and Peschany. This is due to weak water mixing in conditions of
temperature increase.
The Lower Don is polluted by oil products, copper ions, and phenols in the course from
the Tsimlyansk reservoir dam to the river mouth. Most polluted areas locate near
Volgodonsk, Semikarakorsk, Aksai, Rostov. Near Rostov concentration of oil products is
up to 2 mg/dm3, phenols - 0.012 mg/dm3, copper 6 mg/dm3. Sometimes in the Lower
Don concentration of phenols and oil products was up to 30 and more MAC, nitrates and
nitrites up to 15-34 MAC, copper ions 15 MAC, zinc 4 MAC. Water pollution level in
the Lower Don increases towards the river mouth.
Untreated and insufficiently treated residential, industrial, mining and drainage water, as
well as water discharged by irrigation systems are the main sources of the Lower Don
water pollution. Intensive navigation and diffuse run-off from arable lands contributes
into water quality.
The Lower Don tributaries (Seversky Donets, Aksai, Temernik, Manych) contribute to its
pollution.
For the last decades concentration of nitrogen and phosphorous increased in water
bodies of the Lower Don together with increase of primary production and fluctuation of
dissolved oxygen concentration. As a result, intensity of self-purification processes
decreased. Average annual mineralization of the Don river water increased from 464 to
717 mg/dm3. Thus, in some areas technogenic component of ionic flow achieved or
increased natural value. Flow of suspended solids is 3 times less. Now silts dominate at
places of sand deposits. At some places concentration of pollutants in water, silts and
vegetation increased by 3-25 times.
Data on average annual concentrations of pollutants for the last decade were used for
assessment of the Don river water quality. Tables 7.2 7.3 present results for the Don
reach between "input" (upstream Aksai) and "output" (near settlement Koluzaevo).
Change in average annual concentrations is given in figures 7.6-7.7.
In the 1990-s the Don river water quality improved in terms of oil products, copper, iron
and nitrates (I the lower reaches). This is likely due to decline in industrial and
agricultural production recorded in the Don basin in 1990-s. relative improvement of
water quality in the lower reaches appeared later than in the upper reaches. In winter
water quality deteriorates both in the Don River and its tributaries.
73
Table 7.2 Average annual concentrations of pollutants in the Don River upstream
Aksai (mg/dm3)
Parameters
Years
1990 1991 1992 1993 1994 1995 1996 1997 1998
1999
Suspended solids
47 32 36 72 75 154 96 82 - -
Dissolved oxygen
9.78 11.5 10.58 11.07 11.21 10.45 10.92 9.90
-
-
Magnesium
47 38 45 39 31 53 45 32 - -
Chlorides
194 116 222 167 114 155 1.51 156 - -
Sulphates
243 178 242 180 120 209 245 275 - -
Mineralization
948 646 971 765 552 792 875
1011
976
878
COD
83 62 61 64 52 19 60 34 - -
BOD5
3.91 3.41 3.56 3.66 3.48 3.18 2.36 3.25
2.96
3.65
Ammonia
0.033 0.005 0.010 0.24 0.21 0.30 0.16 0.29 0.31 0.47
nitrogen
Nitrite nitrogen
0.063 0.114 0.014 0.026 0.025 0.042 0.023 0.026 0.018 0.026
Nitrate nitrogen
0.055 0.098 0.199 0.33 0.40 0.18 0.14 0.19 0.23 0.50
Phosphates ()
0.099 0.129 0.109 0.078 0.12 0.113 0.170 0.151 0.121 0.105
Total iron
0.49 0.24 0.13 0.11 0.10 0.04 0.05 0.11
0.12
0.03
Copper
0.002 0.0004 0.0011 0.0011
0 0.003
0.0006
0
0.001
0.004
Zinc
0.003 0.0005 0.0008 0.0031 0.0007 0.0018 0.001 0.0004 0.003 0.011
Oil products
0.39 0.10 0.30 0.09 0.07 0.06 0.33 0.21
0.10
0.09
Surfactants
0.006 0.055 0.035 0.019 0.052 0.046 0.055 0.015 0.022 0.017
According to summarized data for 1985-1999 higher pollution of surface horizon is
recorded for oil products and easy oxidable organic matter (in terms of BOD5) and
higher pollution of bottom horizon for nitrites, iron and copper. This is possibly due to
impact of bottom sediments on water quality downstream city pollution sources and
inflow of polluted ground water.
74
Table 7.3 Average annual concentrations of pollutants in the Don River
downstream Koluzaevo (mg/dm3)
Parameters
Years
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
Dissolved
8.89 10.67 10.53
9.74 10.76 10.04 10.22 10.04 9.42 9.90
oxygen
Magnesium
48.3 39.5 44.1
42 30.3 44.8 35.2 32.7 35.7
-
Chlorides
179
121 210 157
108 151
140 145
120 -
Sulphates
234
170 241 159
111 222
242 274
323 -
Mineralization
905 640 941 725 522 813 855 1005 976
-
COD
89
54 59 78
48 17
101 52
84 -
BOD5
3.15
2.59 3.80 3.37
3.79 2.86 2.37 3.52 3.13 3.28
Ammonia
0.038 0.063 0.241
0.76 0.213 0.375 0.161 0.285 0.24 0.41
nitrogen
Nitrite nitrogen
0.078
0.063 0.023 0.033 0.042 0.040 0.028 0.038 0.030 0.019
Nitrate
0.064
0.12 0.27 0.35
0.47 0.157 0.173 0.190 0.22 0.37
nitrogen
Phosphates
0.099
0.128 0.127 0.059 0.108 0.099 0.197 0.134 0.129 0.102
()
Total iron
0.119
0.153 0.175 0.116 0.146 0.122 0.115 0.195 0.127 0.109
Copper
0.22 0.91 0.145 0.121 0.168 0.047 0.077 0.052 0.112 0.026
Zinc
0.004
0.000
0.001 0.002
0.000
0.0004
0.000
0.0002
0.000
0.003
9
3
2
6
Oil products
0.004
0.001 0.001 0.005 0.001 0.002 0.001 0.002 0.003 0.009
Surfactants
0.179
0.094 0.153 0.071 0.08 0.146 0.37 0.395 0.112 0.13
Nitrite nitrogen
0.028
0.031 0.032 0.020 0.013 0.028 0.048 0.016 0.24 0.021
Notes: "-" no data available
Conclusions based on assessment of environment state:
1. Rostov-on-Don emissions define air pollution within the WWTP. Air pollution level
is poor. Only nitric oxide and carbon oxide concentrations are recorded at MAC
levels. Concentrations of some heavy metals are increased in solid-phase
precipitation.
2. Content of copper, iron (in summer), phenols (in summer), organic matter (BOD5),
sulphates and nitrites (in winter) exceeds MAC values in the Don river water at
the reach between the Tsimlyansk reservoir and river mouth. In the Don river
mouth pollution increases in all seasons for sulphates (and water mineralization)
and oil products; in winter - for nitrites, BOD5, iron. River reaches near towns of
Aksai, Rostov, Azov are the most polluted parts (in terms of BOD5, oil products
for all seasons, nitrites - in winter, phenols - in summer).
3. Increase of anthropogenic euthrophication is periodically recorded at the mouth
reach of the Don River. Maximum values of phytoplankton population are
recorded in summer and autumn. At this time significant changes of community
structure are registered due to modification of specific composition of dominant
complex and tendency of certain species for a leading place.
4. Hygienic standards for BOD5 (1.5 2 MAC), COD (1.5 3.5 MAC), total
75
hardness (1.2 1.5 MAC), total iron (1.3 5.1 MAC) and oil products (1.2-32
MAC) (data provided by Centres of Gossanepidnadzor for Rostov-on-Don, Azov,
Taganrog, Azov district) are recorded in the Don river water at water intakes and
in recreation zones of populated areas.
5. In terms of bacteriological pollution the Don river is regarded as a source with an
increased level of epidemiologic danger. Coli-fags, spores of sulphitreducing
clostridias, choleroid microflora were identified in river water. High level of river
water bacteriological pollution is recorded in the Don river mouth area, especially
downstream of Rostov sewage discharges and at the confluence of the Temernik
and Don. Azov city water intake has the most critical situation with water quality in
terms of microbiological pollution. This is due to discharge of insufficiently treated
and crude wastewater of Rostov city in the Don river. Use of drinking water with
bacteriological and viral pollution leads to acute enteric infections and viral
hepatitis type A.
6. Chemical composition of ground water forms due to atmospheric precipitation,
infiltration of technogenic water at the WWTP site, as well as pollutants washing
from unauthorised dump of household and industrial wastes located in the
northern part of the WWTP. Organic substances (high value of BOD5), oil
products (8-58 MAC), iron (even in background zone 34.5 mg/l, 69 time shigher
than MAC; in a pollution point - 112,7 mg/l or 225 MAC), and cadmium (0.035
0.077 mg/l) are the most typical elements of ground water pollution.
7. Level of soil pollution with heavy metals is minor. Contrast and vast lithochemical
anomalies were not discovered at WWTP site.
8. Progressing drying and salination of floodplain landscapes happen due to water
flow regulation and reduction of frequency and duration of floods. Chemical
elements accumulate in the soils upper horizon.
9. In the zone of the Rostov industrial centre natural oxygen and oxy-gley
landscapes in the Don River were transformed into oxy-hydrosulfuric under
technogenesis. Increase of pollutants concentration in all landscape components,
increased accumulation of organic matter at the bottom, intensification of
reduction processes, their shift from sediments to near-bottom waters, flow of
dissolved elements (compounds of nitrogen, phosphorous, microelements) from
silts to water column will accompany this transformation.
76
Chapter 8 Assessment of the proposed activity environmental impact
Existing economic activity pose certain technogenic impact on environments, namely:
Air pollution;
Discharge of treated wastewater into the Don River;
Ground water pollution;
Waste generation.
8.1 Air quality
Bituminous concrete plant, trade port being under construction, terminals of Rostov port
and Yug Rusi, Ltd. are key pollutants in the area of the WWTP (Table 8.1).
Table 8.1 List and amount of pollutants allowed to be emitted into the air (MAE*),
tons/year
Parameter
Enterprise
WWTP Bituminous Rostov port
Close
Korvet, Ltd.
concrete plant
corporation
"Yug Rusi"
Nitrogen dioxide
0.2828
1.6548
0.1753
33.1676
0.0804
Nitric oxide
0.0291
0.238
0.0074
8.0087
0.0051
Ammonia
0.4588
Sulfur
dioxide 0.0657 5.8620
0.0953
0.4936
0.0004
Carbon monoxide
3.0757
7.5420
0.4421
8.0177
0.2170
Methane 5.6771
Ferric oxide
0.0035
0.2618
0.0818
0.2272
Soot
0.508
0.0034
0.0286
0.0006
Dust
10.191
0.3208
0.1862
Grain dust
55.637
Carbohydrates
1.947
0.0012
1.378
Kerosene and
0.027
0.051
0.5811
0.0056
petrol
Note: *Data presented by the Central Administrative Board on Natural Resources for the
Rostov Oblast, RF Ministry for Natural Resources.
According to the inventory there are 148 sources of air emissions on all Vodokanal
industrial sites; 31 source of harmful substances emissions at the WWTP site 9the Don
river left bank). There are 43 pollutants in emissions composition. They form 10 groups
of accumulated impact. Iron and manganese oxides, nitrogen dioxide, hydrogen
sulphide, chlorine, grit, wood dust, carbon oxide, methyl methacrylate, ethyl mercaptan,
etc. are listed among pollutants (Figure 8.1).
Air quality is affected by the following key technological processes:
Wastewater treatment;
Preparation of chloric water;
burning of gaseous fuel in a boiler-house;
gas-welding and electrical welding operations;
sharpening works;
77
transport.
Total amount of air emissions at the WWTP is 124,082 tons/year.
In terms of meteorological conditions the WWTP area belongs to the III zone "increased
potential of air pollution". According to the Rostov Oblast Hydrometeorological Center
background pollution in the area of the WWTP for suspended solids is 0.3 mg/m3, sulfur
dioxide 0.019-0.063 mg/m3, nitrogen dioxide 0.08-0.1 mg/m3, carbon oxide 3.0
mg/m3.
Estimates of air pollution are given in Table 8.2.
Table 8.2 List of parameters and sources with the largest input into pollution in
the area of the WWTP
Parameter
Estimated maximum ground
% of input
Sources with
concentration: MAC part / mg/m3
the largest
input
Residential area
At the border SPZ RA
SPZ
(RA)
Nitrogen dioxide
0.0459/ 0.0039
0.05606/ 0.00477
45.0 50.8 Boiler-house
Ammonia
0.05148/ 0.0103
0.05847/ 0.01169
42.1 39.9 Drying beds
Hydrogen sulphide
0.25166/ 0.00201
0.2858/ 0.00229
74.7 83.9 -«-
Carbon monoxide
0.0127/0.06366
0.01448/ 0.07239
46.0 46.9 -«-
Methanethiol
*/0.02082
*/0.02366
40.1 38.0 -«-
Ethanethiol (ethyl
*/0.03198
*/0.03632
38.5 36.6
-«-
mercaptan)
Ammonia
*/0.30137
*/0.34059
73.5 82.9 -«-
Sulfur
dioxide
*/0.25166
*/0.2858
74.7 83.9 -«-
Note: * - no data.
Level of maximum ground concentrations of pollutants in the WWTP emissions is not
exceeded (0.03-0.34 MAC). Taking into account this results emissions from enterprise
emission sources are proposed as a standard of limiting emission.
Key pollutants are emitted from a surface of wastewater treatment facilities.
Chlorine storage facility locates on the left bank of the Don river, in the Zarechnaya
industrial zone. At the water treatment facilities chlorine is used to support facilities in a
proper sanitary state (primary chlorination), to disinfect drinking water (secondary
chlorination) and to disinfect wastewater. Chlorine is stored in waterproof containers
(800 l capacity and 1 ton weight) under a shed. At present 100 tons of chlorine are
stored at storage facility. Chlorine is transported in containers. Sources of emissions
were not found at chlorine storage facility. At chlorine storage facility there is no
production activity and boiler-house, thus, no pollutant emissions.
78
In terms of sanitary classification, according to SanPiN 2.2.1/2.1.1.1200-03 this storage
facility belongs to enterprises of class III with a standard width of SPZ 300 m. There is
no residential area near chlorine storage facility. The following is envisaged to prevent
emergency emissions from chlorine storage facility: decontamination system, system of
control and alarm about chlorine concentration, blocking systems providing emergency
engaging of ventilation system and disconnection of technological equipment.
Special activities on regulation of emissions in meteorologically unfavourable seasons
are not envisaged, as pollution level is insignificant.
At WWTP site recorded air emissions are 5.68 tons of methane /year (sludge drying
beds and sludge storage lagoons) and 3.076 tons of carbon oxide /year (boiler-room)
(see Figure 8.1). For other pollutants input of the WWTP into atmospheric pollution in
the area of Zarechnaya industrial zone is very low compared to other industrial
enterprises located here (Figure 8.2).
If a plant for methane collection and utilisation will be installed during WWTP
reconstruction, methane emissions will reduce from 14 kg/day to 4 kg/day, i.e. by 11
kg/day or by 4.04 tons/year (by 3.5 times). If collected methane will be burnt then about
68 t/day of carbon dioxide will be emitted into the atmosphere. Carbon dioxide is less
toxic.
"JACOB-GIBB" assessed present emissions of the WWTP gases causing green house
effect taking into account gases from used electric power and coal burning at local heat
station. This data was compared with estimates of emissions after the WWTP
reconstruction (taking into account use of mesophilic methane tanks and heat station
operating on produced biogas) (Table 8.3).
Short-term forecast for 5 years (company "Jacobs GIBB")
Basic (zero) option
Total volume of gases formed in a sludge 39,179 kg/day.
Gas decomposition in conditions of sludge long-term storage 55%
Coefficient of methane generation 0,90 m3/kg of gases
Methane generation from stored sludge - 19,394 m3/day
Methane density - 0,72 kg/m3
Mass of generating methane 13,964 kg/day = 5,097 tons/year
Required electric energy, total - 4273 kWatt,
Including:
Aeration 2827 kWatt
Mixing 661 kWatt
Pumping 384 kWatt
Centrifuge 200 kWatt
Other 200 kWatt
Needs in purchased energy, total 4523 kWatt,
Including:
79
Electric energy from energy system 4373 kWatt
Thermal energy produced by gas boiler 250 kWatt
Green house gases emissions (without 2 from methane tanks):
Methane emissions from sludge storage facility 13,964 kg/day
Global warming potential (GWP) for methane 21
Methane emissions in hydrocarbon equivalent 293,234 kg/day
2 emissions from sludge storage facility 20,086 kg/day
Purchased energy in 2 equivalent 205,082 kg/day
Heating by natural gas in 2 equivalent 1,512 kg/day
Total emissions in CO2 equivalent 519,914 kg/day = 189,769 tons/year
Option with anaerobic digestion of sludge and CHP construction
Total volume of volatile matter in sludge 39,179 kg/day
Gas decomposition in conditions of anaerobic digestion 50%
Gas decomposition in conditions of sludge long-term storage 10%
Coefficient of methane generation 0,90 m3/kg degradable volatile matter
Methane generation in conditions of anaerobic digestion - 17,631 m3/day
Methane generation from stored sludge - 3,526 m3/day
Methane density - 0,72 kg/m3
Mass of methane generating in conditions of anaerobic digestion 12,694 kg/day = 4,633
tons/year
Mass of methane generating from stored sludge 2,539 kg/day = 927 tons/year
Required electric energy, total - 4273 kWatt,
Including:
Aeration 2827 kWatt
Mixing 661 kWatt
Pumping 384 kWatt
Centrifuge 200 kWatt
Other 200 kWatt
Required thermal energy, total - 2840 kWatt,
Including:
Absorbent heating 2590 kWatt
Other necessities (generated by gas boiler) 250 kWatt
Energy generated by the heat power plant, total - 3320 kWatt,
Including:
Thermal 1990 kWatt
80
Electric 1330 kWatt
Purchased energy, total - 3793 kWatt,
Including:
Electric energy from energy system 2943 kWatt
Thermal energy produced by gas boiler 850 kWatt
Green house gases emissions (without 2 from technological tanks)
Methane emissions from sludge storage facility 3,526 kg/day
GWP for methane 21
Methane emissions in hydrocarbon equivalent 74,049 kg/day
2 emissions from sludge storage facility 5,072 kg/day
Purchased energy in 2 equivalent 141,242 kg/day
Heating by natural gas in 2 equivalent 5,141 kg/day
2 emissions of the heat power station 53,169 kg/day
Total emissions in CO2 equivalent 278,673 kg/day. = 101,715 tons/year
Long-term forecast (company "Jacobs GIBB")
Basic (zero) option
Total volume of gases formed in a sludge 50,324 kg/day
Gas decomposition in conditions of sludge long-term storage 55%
Coefficient of methane generation 0,90 m3/kg degradable volatile matter
Methane generation from stored sludge - 24,910 m3/day
Methane density - 0,72 kg/m3
Mass of generating methane 17,935 kg/day. = 6,546 tons/year
Required electric energy, total - 5936 kWatt,
Including:
Aeration 3849 kWatt
Mixing 855 kWatt
Pumping 832 kWatt
Centrifuge 200 kWatt
Other 200 kWatt
Required thermal energy generated by gas boiler 250 kWatt
Total: 5936 + 250 = 6186 kWatt
Green house gases emissions (without 2 from methane tanks)
Methane emissions from sludge storage facility 17,935 kg/day
GWP for methane 21
Methane emissions in hydrocarbon equivalent 376,643 kg/day
81
2 emissions from sludge storage facility 25,799 kg/day
Purchased energy in 2 equivalent 284,939 kg/day
Heating by natural gas in 2 equivalent 1,512 kg/day
Total emissions in CO2 equivalent 688,893 kg/day = 251,446 tons/year
Option with anaerobic digestion of sludge and CHP construction
Total volume of gases formed in a sludge 50,324 kg/day
Gas decomposition in conditions of anaerobic digestion 50%
Gas decomposition in conditions of sludge long-term storage 10%
Coefficient of methane generation 0,90 m3/kg degradable volatile matter
Methane generation in conditions of anaerobic digestion - 22,646 m3/day
Methane generation from stored sludge - 4,529 m3/day
Methane density - 0,72 kg/m3
Mass of methane generating in conditions of anaerobic digestion 16,305 kg/day = 5,951
tons/year
Mass of methane generating from stored sludge 3,261 kg/day = 1,190 tons/year
Required electric energy, total - 5936 kWatt,
Including:
Aeration 3849 kWatt
Mixing 855 kWatt
Pumping 832 kWatt
Centrifuge 200 kWatt
Other 200 kWatt
Required thermal energy, total - 3310 kWatt,
Including:
Absorbent heating 3060 kWatt
Other necessities (generated by gas boiler) 250 kWatt
Energy generated by the heat power plant, total - 4280 kWatt,
Including:
Thermal 2560 kWatt
Electric 1710 kWatt
Purchased energy, total - 4976 kWatt,
Including:
Electric energy from energy system 4226 kWatt
Thermal energy produced by gas boiler 750 kWatt
Green house gases emissions (without 2 from methane tanks)
82
Methane emissions from sludge storage facility 4,529 kg/day
GWP for methane 21
Methane emissions in hydrocarbon equivalent 85,112 kg/day
2 emissions from sludge storage facility 6,515 kg/day
Purchased energy in 2 equivalent 202,859 kg/day
Heating by natural gas in 2 equivalent 4,536 kg/day
2 emissions of the heat power station 68,292 kg/day
Total emissions in CO2 equivalent 377,314 kg/day = 137,720 tons/year
Option with phosphorous chemical stripping and anaerobic digestion of sludge
In case of phosphorous chemical stripping sludge volume can reduce by about 20%.
Thus, total emission of "green house" gases in CO2 equivalent can increase up to
452.777 kg/day = 165.264 tons/year under a long-term forecast.
Table 8.3 Estimates of air emissions under different options of the WWTP
reconstruction
Basic
option
Anaerobic
Basic option
Anaerobic
(without
digestion of
(without
digestion of
sludge
sludge and
sludge
sludge and
compaction)
CHP short-
compaction)
CHP long-
short-term
term forecast
long-term
term forecast
forecast
forecast
Total volume of gases
39,179
39,179
50,324 50,324
emitted from a sludge,
kg/day
Share of decomposed
55
10
55 10
gases in conditions of
sludge storage, %
Gas decomposition in
50
50
conditions of anaerobic
digestion, %
Coefficient of methane
0,90
0,90
0,90 0,90
generation from gases,
m3/kg of gases
Volume of methane
19,394
3,526
24,910 4,529
generated from sludge,
m3/day
Volume of methane
17,631
22,646
generated in conditions
of sludge digestion,
m3/day
Methane density, kg/m3 0,72
0,72
0,72 0,72
Mass of methane
13,964
2,539
17,935 3,261
generating from stored
sludge, kg/day.
Mass of methane
5,097
927
6,546 1,190
generating from stored
sludge, tons/year
Mass of methane
12,694
16,305
83
generating in conditions
of anaerobic digestion,
kg/day
Mass of methane
4,633
5,951
generating in conditions
of anaerobic digestion,
tons/year
Total of generated
5,097
5,560
6,546 7,041
methane, tons/year
Required electric energy,
4273
4273
5936 5936
total (kWatt)
Required thermal energy,
2840
250 3310
total (kWatt)
Purchased energy, total
4523
3793
6186 4976
(kWatt):
Electric energy, kWatt
4373
2943
5936
4226
Thermal energy, kWatt
250
850
250
750
Energy generated by the
3320
4270
heat power plant, total
(kWatt)
Electric energy, kWatt
1330
1710
Thermal energy, kWatt
1990
2560
Table 8.3 to be continued
Basic
option
Anaerobic
Basic option
Anaerobic
(without
digestion of
(without
digestion of
sludge
sludge and
sludge
sludge and
compaction)
CHP short-
compaction)
CHP long-
short-term
term forecast
long-term
term forecast
forecast
forecast
Methane emission from
13,964
3,526
17,935 4,529
sludge storage facility,
kg/day
GWP for methane
21
21
21
21
Methane emissions in
293,234
74,049
376,643 85,112
hydrocarbon equivalent,
kg/day
2 emissions from
20,086
5,072
25,799 6,515
sludge storage facility,
kg/day
Purchased energy in 2
205,082
141,242
284,939 202,859
equivalent, kg/day
2 emissions of the
53,169
68,292
heat power station,
kg/day
Heating by natural gas in
1,512
5,141
1,512 4,536
2 equivalent, kg/day
Total emissions in CO2
519,914
278,673
688,893 377,314
equivalent, kg/day
Total emissions in CO2
189,769
101,715
251,446 137,720
equivalent, tons/day
Total emissions in CO2
251,446 165,264
equivalent under option
84
of phosphorous chemical
stripping, tons/day
Carbonic gas has a minor adverse impact on climate (due to global warming) than
methane. According to estimates, after the WWTP reconstruction methane emissions
will reduce by 70% and emissions equivalent to CO2 by 60% (34-45%). Thermal and
electric energy generated by the proposed CHP will be used at site. This will significantly
reduce use of electric energy purchased from the Novocherkask power plant operating
on coal. Reconstructed WWTP will require more energy than existing mainly due high-
energy consumption of digesters and dewatering plants. If methane generated in
methane tanks will be unused then all electric energy will have to be purchased in the
market. It is difficult to make accurate quantitative estimates but it is clear that
construction of the CHP will allow to reduce consumption of coal required for energy
production. This will decrease emissions of CO2, solid particles and accumulation of coal
ash.
Air quality will significantly improve both at the WWTP site and in the Greater Rostov
area.
8.2. Impact on surface water quality
8.2.1. Zero option no reconstruction.
Existing anthropogenic load on the Don river between Rostov-on-Don and the Taganrog
Bay.
The following contributes to water quality formation and environmental situation in the
Don River at the reach between 65th km and river mouth:
chemical substances received with water from site located upstream Rostov;
chemical substances received with waters of tributaries (rivers Aksai, Temernik,
gullies Bezymyannaya and Kiziterinovka);
surface run-off from adjacent arable lands;
surface run-off from populated settlements, including Rostov;
wastewater of different industrial enterprises;
municipal wastewater.
As mentioned above, higher concentrations of ammonia nitrogen, nitrite nitrogen,
sulphates, total iron, oil products and phosphates are recorded upstream Rostov-on-
Don.
The Temerink river is the most polluted tributary of the I order. Key pollutants are easily
oxidable organic matter (in terms of BOD5), ammonia nitrogen, oil products, anion active
surfactants, total iron and aluminium. Discharges of untreated wastewater (6,570
thounsand m3/year) by Rostov Vodokanal have a major impact on the Temernik river
pollution. Thus, pollution of riverine water increases.
Existing situation with the Temernik river indicates that river rehabilitation is possible
only if discharges of untreated wastewater by Rostov Vodokanal will be eliminated and
river will be isolated from unauthorized rainwater and other municipal and industrial
wastewater. Also riverbed dredging from bottom sediments being source of secondary
pollution will contribute greatly to reduction of the Don river pollution level.
Uzgeologiya data for 1989 1992 gives general idea about surface run-off pollution
85
(Table 8.4). High pollution of surface water streaming down into the Don river along
gullies located in Rostov should be expected for all substances listed in Table 8.4,
except for phenols.
Table 8.4 Content of pollutants in surface water in the Leninsky district, Rostov-
on-Don
Parameter
Concentration in water of the surface flow, mg/l
melting rainfall
6,8-9,6
-
Phenols
n/d -0,007
n/d -0,007
Oil products
0,3-14,3
0,3-8,0
Surfactants 0,03-0,76
0,15-0,57
Zinc 0,2-5,2
0,1-1,5
Copper 0,01-0,07
0,02-0,25
Manganese 0,2-5,8
0,03-0,74
Aluminium 0,3-19,0
0,5-5,9
Lead -
0,03-0,74
Chromium -
n/d
-1,6
Total iron
n/d -2,8
n/d -3,10
Ammonia nitrogen
0,39-69,8
0,93-9,3
Nitrate nitrogen
n/d -2,8
n/d -5,2
Chlorides
98-2472
7,1-213
Mineralization 398-6552
244-920
Note: "-" no observations; n/d substance not identified.
Wastewater of different enterprises is one of the strongest pollution sources of the Don
river. Considerable portion of industrial wastewater arrives to Vodokanals' WWTP where
it is subject to different treatment methods. However, operation of treatment facilities is
not always efficient and insufficiently treated water containing pollutants with an adverse
environmental impact are discharged into the river.
General data on wastewater discharges for the reach between 65-18 km and river
mouth is given in Table 8.5 in terms of enterprise, category of wastewater, volume of
discharged water. Total amount of discharged wastewater is 170 million cubic meters.
Table 8.5 Data on wastewater discharges into the Don River at the reach 0 65
km, million cub. m
Enterprise
TOTAL
Without
including
treatment
Pollution
Standard-
including
Insuffic.
Without
Normativel
Biologic
Physically-
Mechanica
treated
treatmen
y clean
ally
chemically
lly treated
t
Treated
treated
treated
TOTAL
AZOVRYBA /Fish plant/
0.76700
-
-
0.76700
-
-
-
-
Azov
AZOVVODOKANAL, Azov 11.4330
-
0.80700
3.50300
7.12300
6.46400 -
0.65900
Rostoselmash, Rostov
0.07500
-
0.07500
-
-
-
-
-
86
EMPILS, Rostov
0.01400
0.00200
-
0.01200
-
-
-
-
ROSTOVTEPLOSET
0.06500
0.06500
-
-
-
-
-
-
(branch of Rostovenrgo),
Rostov
RABOCHII, Rostov
0.19900
-
-
0.19900
-
-
-
-
BALTIKA-DON ("Don
0.00500
0.00500
-
-
-
-
-
-
Pivo"), Rostov
Rostov VODOKANAL
119.563
12.8550
106.708
-
-
-
-
-
Semikarakorskoye UOS
1.79400
1.79400
-
-
-
-
-
-
Azovsky MUOS
2.48000
2.48000
-
-
-
-
-
-
Fish Plant "VZMORIE",
0.70000
-
-
0.70000
-
-
-
-
Kagalnik Azovsky
"Kuleshevka Fish farm "
4.90000
-
-
4.90000
-
-
-
-
Azov district, Ust
settlement
KAZACHKA, Aksai district
15.7140
-
-
15.7140
-
-
-
-
(Fish farm)
Fish farm named after
2.61900
-
-
2.61900
-
-
-
-
Kirov, Aksai, Aksai district
Fish farm named after
1.57900
-
-
1.57900
-
-
-
-
Miroshnichenko, Rostov
Fish farm named after
1.46000
-
-
1.46000
-
-
-
-
Lenin, Azov district,
settlement Kurgany
Fish farm named after
3.05500
-
-
3.05500
-
-
-
-
CHKALOV, Azov district,
settlement Dugino
AKSAISKY MRUOS,
1.23400
-
-
1.23400
-
-
-
-
Aksai
Fish Famr, Kuleshovka
1.12300
-
-
1.12300
-
-
-
-
settlement, Azov district
AKSAI-INTER, Aksai
0.00100
-
0.00100
-
-
-
-
-
GEDON-SPORT
4.20000
-
-
4.20000
-
-
-
-
Branch OKTYABRSKY of
1.25700
-
1.25700
-
-
-
-
-
ROSTOVUGOL (coal
mining)
Of the total volume of wastewater about 10% is water "polluted without treatment", 62% -
"polluted insufficiently treated", 23% - "normatively clean without treatment", 4% -
normatively treated" (Table 8.5).
Rostov Vodokanal has the largest input both in total wastewater discharges (68%) and
in discharges of "polluted insufficiently treated" water (98%) (Table 8.5). Water discharge
at Rostov Vodokanal amounts to 68% of total water discharge at this river reach.
Vodokanal discharges municipal and industrial wastewater from two water outlets: No. 1
from the WWTP into the Don river, No. 2 untreated wastewater into the Temernik
river.
Rostov Vodokanal WWTP discharges wastewater into the Don river from water outlet
No. 1 located 38 km from the river mouth and along dispersive outlet located 80 m from
the navigation canal centreline and 150 m from the left bank in high water period.
WWTP (Phases I and II) is located on the left bank of the River Don, 100 m from the
coastal line. From the works wastewater is transferred under the pressure via three
concrete conduits (1400) to the discharge works (6.5 km). Discharge works consists of
two runs of steel pipes (1200×14). Dispersive device with 8 heads (3500) locates at
the end of each pipe.
87
In terms of specific character 77% of wastewater is municipal and 23% is industrial.
Wastewater category is insufficiently treated. The following enterprises use the
Vodokanal WWTP: 32 food industry enterprises; 43 machine-building and metal
processing; 22 chemical industry; 24 construction industry; 19 electronics industry;
20 light industry; 59 transport industry; 3 wood industry and 5 fuel-energy
industry.
The WWTP (Phases I and II) were set into operation in 1976 and 1986, respectively;
total designed capacity is 440,000 m3/day. However, due to a change in wastewater
treatment norms the present peak daily flow to treatment was calculated at
313,000m3/day.
Amount of pollutants and composition of wastewater discharged by the Rostov WWTP is
given in Table 8.6.
Table 8.6 Amount of pollutants and chemical composition of Rostov Vodokanal
wastewater discharged into the Don River (RVK data)
Pollutants Actual
Maximum
Required
Maximum
backgroun pollutants Actual
permissible
change of
permissible
d
concentrati discharge of concentratio
actual
discharge of
Wastewater
concentrat ons at site pollutants
n of
pollutants
pollutants
parameters
ions in
of
into a water pollutants at
concentratio
into a water
water
wastewater body,
site of
n at
body,
body,
discharge, gr/hour
wastewater
discharge
gr/hour
mg/dm3
mg/dm3
discharge,
site, mg/dm3
mg/dm3
Suspended solids
13.2 55
1042030
15.0
284190 40
Dry residue
821
1400
26524400
1000
18946000
400
Chlorides 121
281
5323826
281
5323826
0
Sulphates 255
360
6820560
255
4831230
105
Magnesium
36
53
1004138
53
1004138
0
BOD5
3.04
47
890462
3.04
57595.8
43.96
COD 24.1
80
1515680
24.1
456599
55.9
Ammonia nitrogen
0.21
6.13
116139
1.35
25577
4.78
Nitrite nitrogen
0.05
0.85
16104.1
0.05
947.3
0.80
Table 8.6 to be continued
Pollutants Actual
Maximum
Required
Maximum
backgroun pollutants Actual
permissible
change of
permissible
d
concentrati discharge of concentratio
actual
discharge of
Wastewater
concentrat ons at site pollutants
n of
pollutants
pollutants
parameters
ions in
of
into a water pollutants at
concentratio
into a water
water
wastewater body,
site of
n at
body,
body,
discharge, gr/hour
wastewater
discharge
gr/hour
mg/dm3
mg/dm3
discharge,
site, mg/dm3
mg/dm3
Nitrate nitrogen
1.42
5.50
104203
5.50
104203
0
Phosphorous
33723.9
0.2
0.18 1.78
3789.2 1.58
phosphates
Total iron
0.29
0.81
15346.3
0.29
5494.34
0.52
Copper 0.004
0.039
738.894
0.004
75.784
0.035
Zinc 0.004
0.041
776.786
0.035
663.11
0.006
88
Total chromium
0.011
0.07
1326.22
0.07
1326.22
0
Manganese 0.053
0.05
947.3
0.05
947.3
0
Aluminium 0.31
0.035
663.11
0.035
663.11
0
Nickel
0
0.11
2084.06
0.020
757.84
0.07
Lead 0.005
0.029
549.434
0.006
113.676
0.023
Cadmium
0
0.008
151568
0.001
18.946
0.007
Surfactants anion
0.40
1.10
20840.6
0.1
1894.6
1.0
Surfactants non-ion
0
0.46
8715.16
0.46
8715.16
0
Oil products
0.41
0.78
14777.88
0.05
947.3
0.73
Phenols 0
0.0007
13.2622
0.001
18.946
0
Sulphides 0
0
0
0
0
0
Fluorides
0.30
0.44
8336.24
0.44
8336.24
0
Analysis of pollutants in wastewater of enterprise discharging into the Don river at the
studied reach (Table 8.7) shows that Rostov Vodokanal input in pollution is the largest
among point sources.
Table 8.7 Volume of pollutants in wastewater discharged by Rostov Vodokanal
Pollutants
Mass of discharged
Share in total amount of
substances, tons
substance input, %
BOD5 4506
97.8
Ammonia nitrogen
412.6
95.4
Nitrates
10.2
10.6
Nitrites
56.6
90.7
Phosphates 88.5
85.9
Suspended solids
4308
87.6
Surfactants 16.6
99.4
Oil products
24.4
84.7
Total iron
33.8
89.7
Sulphates 4135
35
Chlorides 9600
65.9
Aluminium 1.18
91.4
Copper 1.69
86.1
Zinc 1.61
93.5
Total chromium
1.24
94.5
Thus, the Temernik river water and Rostov Vodokanal effluents pose the major pollution
impact on the Don river in its lower reaches.
Impact on the Don river hydrochemical regime
Long anthropogenic impact led to transformation of water chemical composition due to
increase of pollutants concentration (ammonia nitrogen, nitrites, easily oxidable
substances, oil hydrocarbon, copper and zinc compounds. The tensest river reach is
between Rostov-on-Don, downstream Vodocanal discharges and Koluzaevo settlement.
Repetition factor of MAC exceedence for ammonia nitrogen is 5.1-7.2; nitrite nitrogen -
5.4-9.2; oil hydrocarbon - 7.2-14; copper - 7-8. These are of the major importance for
any activity resulting in change of nutrient and organic matter.
89
Dynamics of nitrogen and phosphorous, BOD5 was studied based on analysis of long-
term observations (1990-2002) of their spatial variation in the Don river water (up to the
river mouth).
Content of nitrogen and phosphorous compounds and organic matter in the Don river
water is given in Table 8.8.
Table 8.8 Variation of nitrogen and phosphorous compounds and organic matter
(in terms of BOD5) (numerator) and their average values (denominator)
Observation site
BOD5,
Nitrogen, mg/l
Phosphorous
mg/l
Ammonia
Nitrite
Nitrate
phosphate,
mg/l
Rostov, upstream
1.08-7.05
0.06-0.88 n/d-0.124
0.01-1.18
0.024-0.440
4.01
0.30
0.026
0.28
0.14
Rostov, downstream
1.00-7.97
0.06-0.87 n/d -0.138 0.01-0.96
0.010-0.656
the WWTP discharge
4.32
0.29
0.032
0.28
0.14
site
settlement Koluzaevo
1.00-7.02
0.06-0.76 n/d -0.200 0.06-0.69
0.010-0.656
3.19
0.27
0.039
0.26
0.124
Azov 1.25-8.57
0.13-0.98 n/d -0.138 0.08-1.52
0.011-0.736
3.58
0.37
0.040
0.25
0.140
B. Kalancha
1.03-5.71
0.04-0.96 n/d -0.218
n/d -0.92
n/d -0.316
settlement Dugino
3.13
0.14
0.040
0.30
0.118
For 1990 2002 concentrations of easily oxidable organic matter changed from 1.25-
8.57 mg/l near Azov to 1.03-5.71 mg/l near B. Kalancha branch. In terms of average
values they increase near Rostov, downstream wastewater outlet and increase towards
the river mouth. In terms of spatial variation ammonia nitrogen and nitrite nitrogen
slightly increase towards the river mouth.
Average values of mineral phosphorous concentration vary insignificantly from 0.118
mg/l near B. Kalancha branch to 0.145 mg/l upstream Rostov. However, variation range
increases from Rostov, upstream Azov and decreases in B. Kalancha branch.
Accumulation of nutrient elements in water was considered as initial parameter of
potential eutrophication of water ecosystems. Thus, conditions favourable for
anthropogenic eutrophication intensification form at river reaches.
Estimated assessment of the WWTP input in increase of nutrient and organic matter in
the Don river water is given in Table 8.9.
In water flow of the Don river near Aksai town is 52.6 million m3/day, then volume of the
WWTP wastewater will be 292.3 thousand m3/day.
At present due to inflow of the WWTP wastewater content of nitrite nitrogen in the Don
river water increases by 23%, nitrate nitrogen by 14%, phosphorous by 7%, organic
matter by 1.7%.
Impact on the Don river hydrobiology regime
Statistical processing of information on qualitative parameters of phytoplankton
development in the Don river water between Rostov and river mouth shown that process
90
of anthropogenic eutrophication is restrained by toxic effect of water environment on
phytoplankton development.
Table 8.9 WWTP input in increase of nutrient and organic matter in the Don river
water
Parameter
BOD5
Nitrogen
Phosphorous
Ammonia
Nitrite
Nitrate
phosphate
Average content, mg/l:
20.8
3.5
1.58
11.03 2.64
In treated WWTP
effluents
In the Don River
4.01
0.30
0.026
0.28 0.14
upstream Rostov-on-
Don
Discharge with the
6080
1023
301
2391 773
WWTP wastewater,
kg/day
Flow into the Don River
210000
15800
1370
14730 7630
upstream Rostov-on-
Don, kg/day
Flow into the Don River
216080
16823
1671
17121 8403
downstream the site of
WWTP effluent
discharge, kg/day
Estimated content in
4.08
0.32
0.032
0.32 0.16
the Don River water
downstream the site of
WWTP effluent
discharge, mg/l
WWTP input in
1.7
6
23
14 14
increase of content in
the Don River water, %
Growth of plankton population and reorganisation of group/specific structure in
compliance with each species's tolerance level and, mainly, due to fall out of oligo- and
mesosanprobes, are recorded if anthropogenic eutrophication will intensify due to water
enrichment with nutrient without any restrictive conditions. Reorganisation of
group/specific structure is. Reduction of development level and diversity of water
species is a result of anthropogenic toxic impact on ecosystems. Increase of such a load
could result in ecosystem death through ecological and metabolic regression.
Phytoperiphiton is the most informative parameter of microsystem response on
anthropogenic impact at different the Lower Don reaches. Due to location on substratum
it allows to assess pollution of aquatic system for certain period of time and deterioration
of aqueous medium quality.
Dominating role of -sanprobe species Navicula cryptocephala and Navicula menisculas
indicates long anthropogenic pollution with municipal and industrial effluents with high
content of mineral forms of nitrogen and phosphorous.
Parameters of macrobenthos development are the most prospective for indication of
91
consequences of the river ecosystems pollution. This is due to the fact that
macrobenthos locates at certain substratum and is relatively slow-moving compared to
quickly diffusive pollutants.
The Don river bottom downstream Rostov is assessed as dirty and very dirty (in
compliance with water quality classification in terms of hydrobiological parameters
adopted in a state observation system and in terms of macrobenthos development).
Results of biotests with use of different test-objects shown that:
water in the Don river lower reaches, except for the river mouth, is toxic for all test-
objects (Daphnia, algae, infusorium, Rotifera) used;
toxicity was recorded in respect to all test-objects used, thus, different links of trophic
chain of aquatic ecosystem experienced anthropogenic toxic pressing;
sometimes water at a reach upstream Rostov Koluzaevo settlement was posing an
acute toxic impact on Daphnia.
Thus, water was polluted by toxic chemical substances before discharged from the
Temernik river and Rostov Vodokanal. Impact of these pollution sources created
additional load on river aquatic ecosystem.
Taking into account complexity of factors defining levels of nitrogen and phosphorous in
ambient water it is difficult to assess effect from reduction of concentrations on
development of biota and aquatic ecosystems under different reconstruction options.
Based on the data received it should be stated that if the present situation will remain
(zero option) then adverse tendency in evolution of population and species composition
of hydrobionts will remain with further degradation of the Lower Don ecosystem.
However, even minor decrease of nutrient and organic matter concentrations has to
ensure restoration or preservation of the existing system equilibrium within permissible
fluctuations of its state, i.e. within its self-regulation.
This method of hydrobiological analysis will assist to trace trends in change of
hydrochemical situation and to assess project goals achievement, as well as will help to
prove or disprove accuracy of objectives definition.
Impact on the Don river aquatic ecosystems
Studied reach of the Don river is pre-mouth and mouth area with slow current velocity
and accumulation of undersize suspended particles. Natural conditions contribute to
substances accumulation and precipitation. Major part of pollutants carried out from the
upstream parts of the watershed concentrates at this river reach. Pollutants from
anthropogenic sources located between Azov and river mouth, including large industrial
center - Rostov accumulate here as well.
Thus, at this river reach influence vector of natural and anthropogenic factors coincides.
Effect of matter accumulation summation both from sources located upstream and
sources located in the studied area is recorded.
Reducing hydrosulphuric conditions formed in sludgy bottom sediments as a result of
anthropogenic impact (mainly due to inflow of large amount of organic matter). Oxy-gley
landscapes were replaced by oxy-hydrosulfuric. Reduction processes often shift from
sediments to near-bottom waters and sediments transform into a source of secondary
pollution. At this reach aquatic landscapes have minimal stability to anthropogenic
impact.
92
Insufficiently treated water of Rostov Vodokanal poses significant impact on
transformation and pollution of aquatic landscapes. Most intense rehabilitation
conditions are in landscapes located downstream the Temernik river confluence and
downstream the WWTP wastewater discharge.
Assessment of anthropogenic impact on the Don river indicates that in order to improve
environmental situation it is necessary to mitigate anthropogenic impact both at the river
reach between Aksai and river mouth, and in the areas located upstream.
8.2.2. Option with biological treatment, wastewater advanced treatment and
phosphorous chemical stripping
During reconstruction of the Rostov WWTP their capacity should be increased up to
460,000 m3/days with wastewater treatment in compliance with requirements and
conditions of their discharge into the Don river being water body of category 1 of
fisheries and drinking water supply purpose.
Meeting requirements of the "Rules of surface water protection from pollution" for a
water body of category 1 of fisheries importance is a condition of the WWTP wastewater
discharges into the Don River. Requirements to treated wastewater satisfy requirements
to a water body.
With account of maximum allowable concentrations of pollutants in control section, as
well as background concentrations in river water content of pollutants in wastewater
should not exceed values given in Table 8.10.
Table 8.10 Assumed and required concentration of pollutants in the WWTP
wastewater
Pollutants
Content in
Content in
Level of
MPD, mg/l MAC in water for
wastewater
wastewater after
wastewater
water bodies,
received by
treatment with
treatment, %
mg/l
the WWTP,
deep nitrification
drinki
fisheries
mg/l
denitrification, mg/l
ng
BODtotal 230 3
98.7
3
3
3
Ammonia
22 0.39
98.23
0.39
2
0.39
nitrogen
Nitrate nitrogen
9.1
9.1
10.24
9.1
Nitrite nitrogen
0.2
0.02
90
0.02
0.825
0.02
Phosphates ()
9.6 (4.22)
0.46 (0.2)
95.21 0.46 (0.2)
0.46 (0.2)
Biological treatment of wastewater with advanced treatment is required to achieve
concentration of organic matter (in terms of BODtotal) - 3 mg/l and of suspended solids -
3 mg/l. Reduction of total nitrogen from 22 mg/l to 9.51 mg/l will require denitrification
process; reduction of phosphates (P2O5) from 9.6 mg/l (in terms of phosphorous - 4,22
mg/l) to 0.2 mg/l in terms of phosphorous will require reagent removal. Reagent will be
introduced to the trough before pre-aerators.
Technological treatment scheme has to include the following processes:
mechanical treatment: grates - grit traps - primary settlement tanks;
biological treatment: anoxic zone (denitrificator) aeration zone (nitrificator)
settlement tank for sludge suspension with installation of lamella modules;
advanced treatment and effluents disinfection: bioreactor for advanced treatment
93
with immobilised microflora - (Phase I) - sand filters (Phase II) - aerator trough as
bubbling facility - chlorination plant, later will be UV-disinfection plant.
Proposed level of the WWTP wastewater treatment is defined by requirements of the
"Rules of surface water protection from pollution" for a water body of category 1 of
fisheries importance and meets them.
Reconstructed Rostov WWTP envisages major reduction of pollutants discharged into
the Don river with wastewater. This allows to achieve reduction of pollutants
concentration in a control section (section of full mixture of natural and waste water) up
to the level in a background section (500 m upstream a discharge place). This will be:
ammonia nitrogen 0.21 mg/dm3;
nitrite nitrogen - 0.05 mg/dm3;
nitrate nitrogen - 1.42 mg/dm3;
phosphates 0.18 mg/dm3;
BOD5 3.04 mg/dm3.
Background concentrations of pollutants were estimated based on statistically
processed data presented by Vodokanal.
Tentative estimates of nutrient and organic matter run-off into the Don river upstream
and downstream the WWTP with use of average annual values in the Don river water
and designed content in the WWTP wastewater after their reconstruction are presented
in Table 8.11.
Table 8.11 Assessment of the WWTP input after their reconstruction in increase of
nutrient and organic matter in the Don river water (option with P stripping)
Parameter
BOD5
Nitrogen
P
Ammonia
Nitrite
Nitrate
phosphate
Average content, mg/l:
In treated effluents of the WWTP
3.0
0.39
0.02
9.1
0.46
after reconstruction
In the Don river water upstream
4.01
0.30
0.026
0.28 0.14
Rostov
Discharge with the WWTP
1380
179
9.2
4186 212
wastewater after their
reconstruction, kg/day
Flow into the Don river upstream
210,000
15,800
1370
14,730 7,630
Rostov, kg/day
Flow into the Don river downstream
211,380
15,979
1379
18,916 7,842
of the WWTP discharge site, kg/day
Estimated concentration in the Don
3.99
0.30
0.026
0.35 0.15
river water downstream of the
WWTP discharge site, mg/l
Input of the WWTP in increase of
0
0
0
25 7
content in the Don river water, %
Thus, after the WWTP reconstruction under this option the WWTP input in the Don river
water pollution in terms of nitrite nitrogen, ammonia nitrogen and organic matter can be
reduced from 23%, 6% and 1.7%, respectively, up to a zero. Content of these
substances in treated wastewater will be equal or less than content in riverine water.
94
Input in terms of phosphorous will reduce twice, i.e. from 14% to 7%. Input in terms of
nitrate nitrogen will increase from 14% to 24% due to transformation of recovered forms
into oxidated. After treatment estimated concentrations of nutrients and organic matter in
ambient water downstream effluent discharge after deep treatment will reduce
insignificantly: for nitrite nitrogen - from 0.32 to 0.26 mg/l, and for phosphorous - from
0.16 to 0.15 mg/l.
The proposed option will provide high level of wastewater treatment. In this case content
of pollutants will comply with stated maximum permissible discharges and existing
regulatory documents. Disadvantages of this method are high cost of the WWTP
reconstruction, more complicated technology of wastewater treatment and additional
costs required for phosphorous chemical stripping.
The Temernik river flows into the Don river at 44 km from the river mouth (upstream the
WWTP wastewater discharge place 38 km). Key parameters determining pollution
level of the Temernik river are easily oxidable organic matter (in terms of BOD5),
ammonia nitrogen, oil products, anion active surfactants, total iron and aluminium.
Significant decrease of the Don river pollution could be expected both as a result of
Vodokanal wastewater treatment and rehabilitation of the Temernik river (exclusion of
discharges of untreated wastewater by Rostov Vodokanal, isolation of unauthorized
rainwater, municipal and industrial wastewater, dredging of bottom sediments being
sources of the secondary river pollution).
In future river water quality may change after the WWTP reconstruction due to activities
implemented between Rostov and river mouth.
Improvement of water organisms habitat, including fish populations could be expected
as a result of partial removal of nitrogen-containing compounds and transfer of nitrogen
from ammonium into oxidated forms (NO3) which are less toxic for biocenosises.
Decrease of organic substances and nutrients discharges will result in decrease of
reduction processes intensity. Oxidised layer preventing entry of pollutants from bottom
into water column will remain longer on bottom sediments surface.
Effective disinfection of treated wastewater will reduce the Don river bacteriological
pollution. However, in order to improve water quality downstream Rostov in terms of
microbiological parameters it is necessary to discontinue discharges of crude (untreated)
wastewater into the Temernik and Don rivers, and to construct storm water sewer.
Indicated activities will significantly reduce microbiological water pollution at water
intakes located downstream Rostov; discontinue use of drinking water hyperchlorination
in Azov and Azov district; reduce sickness rate of enteric infection of bacteriological/viral
nature, and allow wider use of the Lower Don as a recreational zone.
Taking into account complexity of factors defining levels of nitrogen and phosphorous in
ambient water it is difficult to assess effect resulted from concentrations reduction on
development of biota and aquatic ecosystems.
However, even minor decrease of nutrient and organic matter concentrations has to
ensure restoration or preservation of the existing system equilibrium within permissible
fluctuations of its state, i.e. within its self-regulation.
8.2.3. Option with nutrients reduction only with biological treatment of wastewater
This option is intermediate between two options described in sections above. If this
option to be implemented the WWTP input in the Don River water pollution in terms of
95
organic matter, nitrite and ammonia nitrogen, and phosphorous will reduce by 1.5-2
times compared to the existing situation. This will reduce estimated concentrations in
ambient water downstream effluent discharge place for organic matter by 0.04-0.05
mg/l, for ammonia nitrogen by 0.01 mg/l, for nitrite nitrogen by 0.003 mg/l, and for
phosphorous - by 0.005 mg/l.
Disadvantage of this option is a low level of wastewater treatment preventing
achievement of maximum permissible discharges values and meeting existing
requirements to effluents discharged into category 1 water bodies used for fishery and
household/drinking purposes.
This option advantages are less costs for the WWTP reconstruction and operation, more
simple technology of wastewater treatment.
8.3 Impact on ground water
During the WWTP reconstruction it is planned to reduce volume of sludge stored at
sludge drying beds and sludge storage lagoons. Less sludge and storm water enriched
with organic and other pollutants will be filtered into ground water. This will contribute to
reduction of ground water pollution.
System's efficiency is impeded by lack of capacities of final settlement tanks. Risks
associated with use of lamella modules cause significant anxiety. Estimates shown that
studied approach with installation of lamella modules is over optimistic and does not
consider different risks associated with system operation. It is necessary to envisage
increase of sludge processing capacity by 20-30% as it is expected that amount of
sludge produced will increase due to phosphorous chemical stripping.
8.4 Impact on soil and underlying rocks
Planned reconstruction of the WWTP will not contribute to increase of soil and
underlying surface pollution, as well as technogenic flows contacting with soils will have
less pollutants. All reconstruction and construction activities will be held within the
WWTP limits. Thus, use of new lands for construction is not planned.
Foundation pit will be dug during the CHP construction. Grounds filled for industrial site
will be extracted for organisation of ground pit. Natural soil layer is yet not formed here.
Soil protection will be organised through land improvement: access roads, footpaths,
inside spaces will be covered with waterproof asphalt carpet. Transport will be moving
along specially organised roads providing safe traffic without disturbance of vegetation
and soil cover. All places of waste storage are protected from precipitation impact.
8.5 Impact on vegetation and fauna
Involvement of new sites into operation is not planned, so, during construction works
adjacent natural landscapes will not degrade. After the WWTP reconstruction reduction
of agrochemical and hydrochemical load on neighbouring landscapes with decrease of
atmospheric emissions and reduction of filtering sludge water will be beneficial for
growth of floodplain ecosystems' vegetation cover and fauna.
8.6 Impact of waste
The WWTP sludge is the largest in terms of volume. It is the most problematic and
priority waste of the WWTP. This sludge consists of primary sludge and surplus
activated sludge.
Safe handling exists for other types of dangerous and safe waste generated at the
96
WWTP site. This includes collection, temporary storage and transfer of waste to
specialised enterprises regulated by Permissions on waste production and by limits on
waste disposal.
At present total amount of produced sludge consists of 1220 m3/day primary sludge and
1355 m3/day surplus activated sludge. Sludge (mechanically dewatered or dried at
drying beds and kept in natural conditions for not less than 2 years) has a moisture
content of 54-58% respectively and is regarded as waste of class IV danger.
Content of organic matter in sludge varies (in terms of dry matter) over the range of 45-
47%, total nitrogen 3.2-2.5%, phosphorous in terms of 25 3.53.4%.
Environmental impact of the WWTP waste is due to the aggregate exposure of the
following factors:
volume of generation;
qualitative composition;
ways of processing;
ways of disposal;
ways of further use.
Proposed volume of sludge is given in Table 8.12. Additional volume of sludge
generated as a result of phosphorous chemical stripping is given in the Table, as well as
volume of generated sludge. UK experience shows that phosphorous chemical stripping
up to 1 mg/l will increase sludge volume by 20%.
Table 8.12 Estimated volume of sludge, m3/day
Sludge type
Without removal of P with
With chemical reagents for
chemical reagents
removal of P
Primary sludge
1 220
1 220
Activated sludge
3 641
4 550
Total
4 861
5 770
Three alternative options were selected for environmental impact assessment.
Implementation of alternative options will not result in qualitative and quantitative change
in type of waste generated outside main technological process of wastewater treatment.
Thus, only those types of waste, which composition and quantity will change within
construction and reconstruction, i.e., the WWTP sludge and construction waste will be
considered in this section.
1. Zero option no reconstruction
If existing situation remains then environmental impact of production and consumer
waste on the WWTP will gradually increase due to:
a limited space for temporary and constant disposal of the most large-tonnage of less
dangerous enterprise waste the WWTP sludge, and, as a consequence, their
accumulation at the WWTP site and growing environmental impact;
a larger content of nutrient in sludge leading to increased emissions of greenhouse
97
gases.
2. Option with nutrients reduction only with biological treatment of wastewater
Option providing reduction of nutrients only with biological treatment includes various
construction activities: reconstruction of secondary settlement tanks, installation of
lamella settlers, construction of sludge digesters and construction of CHP plant. This will
result in a short-term local impact of large masses of soil on soil cover at the WWTP site
and in a possible minor impact on ground water. Impact will stop after completion of
building and assembly works, after construction of tank support walls from extracted soil,
and covering area.
Quantity of screenings will increase with operation of reconstructed WWTP. Their impact
will not increase due to potential disposal to the Rostov landfill site. Sludge volume will
increase after full biological treatment of wastewater. Then all produced sludge will pass
through a closed cycle to the sludge digesters which will minimise the amount of sludge
produced. This in combination with reduction of nitrogen, phosphorous, BOD determines
potential decrease of sludge negative impact on air, soil, surface and ground water
compared to the "zero" option, mainly due to a decrease of greenhouse gases
emissions.
3. Option with phosphorous chemical stripping
Volume of the WWTP sludge will increase in case of phosphorous chemical stripping.
Sludge increase will depend on selected reagent and its dosing. At present due to later
sludge digestion and dewatering total volume of sludge compared to the existing
situation either will remain the same or will increase insignificantly without growth of
anthropogenic load on environment but limiting possibilities of sludge use. It will be
possible to reduce load on air and ground water due to qualitatively new parameters of
produced sludge and gradual processing of earlier accumulated sludge from the existing
sludge storage lagoons.
8.7 Environmental conditions for project implementation
For the studied area environmental limitations are compliant to norms of maximum
permissible emissions taking into account inputs in background pollution; maximum
permissible discharges in compliance with conditions of their diversion into the Don
River as water body of the 1 category in terms of fisheries and household-drinking
purposes, as well as limited disposal of waste in compliance with existing permissions.
There are no special limitations: the WWTP is located outside the Don river water
protection zone; nearest accommodation locates outside sanitary-protection zone (1000
m).
As there are no special environmental limitations for the WWTP reconstruction,
development of draft document by the RF MNR on agreement of the List on
environmental conditions for completion of preparation and implementation of the
project results will be not required.
98
Chapter 9 Measures on mitigation and/or reduction of adverse environmental
impact of the proposed activity
The majority of the potential adverse environmental impacts during reconstruction of the
WWTP can be minimised through adherence to proper site practice and health and
safety procedures and through proper requirements on dangerous waste collection,
temporary storage and transportation.
9.1 Proposals on mitigation of risks due to toxic gases emissions
Construction works may increase level of air pollution due to emissions from operation of
car engines and mechanisms. But this impact will be local and its impact will be limited
with borders of the WWTP sanitary protection zone.
As a result of the WWTP reconstruction methane emissions will be significantly reduced;
risk of air pollution up to a dangerous level will be reduced as well. Special additional
measures on reduction of air pollution are not required.
9.2 Proposals on mitigation of adverse impact on the Lower Don aquatic
ecosystems as a result of the WWTP reconstruction
Construction works may have a minor deterioration in level of wastewater treatment due
to interruption of processing lines. But possible this will be a minor impact because the
works used at present have excessive capacity.
Construction works may have minor negative impacts on surface water and air quality
through operation of cars and machinery (air emissions, spillage of petroleum products,
etc.). Impacts can be mitigated through correct choice of fuel and plant maintenance, by
spill control procedures and by control of polluted grounds collection and utilization.
9.3 Proposals on mitigation of risks associated with ground water pollution
The construction of buildings, tanks and underground pipelines may have an impact on
the groundwater regime. This impact may be assumed to be negative (in disruption of
existing groundwater flows) but the level of impact is likely to be marginal and no
mitigation measures would be required. However borehole monitoring should be
instituted where there is likely to be groundwater diversion or rising water tables.
Measures on optimization of environmental situation have to be developed.
9.4. Proposals on mitigation of risks associated with the WWTP sludge storage
Risks associated with waste disposal could be significantly mitigated if a proper system
of waste use is implemented at an enterprise.
According to the existing Russian system generated and accumulated dewatered or
dried WWTP sludge is considered as waste of low danger class. According to GOST P
17.4.3.07-2001 "Nature protection. Soil. Requirements to wastewater sludge if used as
fertilizers" and SanPiN 2.1.7.573-96 "Hygienic requirements to use of wastewater and
their sludge for irrigation and as fertilizer" sludge can be used as organic fertilizer in
agriculture, industrial flower-growing, laying out of parks and foresting.
In accordance with item 6.8 SanPiN waste water sludge and compost could be used as
fertilizers for lands used for planting of shrubs and trees, for parks, perennial cultural
grasslands and pastures, for growing industrial crops, silage, and for land reclamation.
It is prohibited to apply sludge in soils in water protection zones and reserves; on soils in
forests, forest parks, pastures and hayfields.
99
Norms for sludge application are set depending on their fertilizing value and content of
heavy metals in soils and sludge. It is prohibited to apply sludge if heavy metals
concentration exceeds norms fixed in SanPiN. If prescribed figures are exceeded then it
is allowed to prepare composts based on sludge mixture with other components (peat,
manure, vegetative waste) with reduction of heavy metals concentration up to levels
prescribed. SP 1.2.1170-02 "Hygienic requirements to safety of agrochemicals" defines
procedure of sludge preparation and application as fertilizers.
According to SP 2.1.7.1038-01 "Hygienic requirements to organisation and management
of MSW landfills" sludge can be disposed at the MSW landfills in the amount of 30% of
MSW mass.
System for the WWTP sludge management has to be developed at the works. It has to
ensure meeting of the existing environmental requirements and norms, as well as to
mitigate total adverse environmental impact.
The following principles should form basis of such a strategy:
Health protection, support and rehabilitation of environment;
Scientifically justified combination of environmental and economic interests of an
enterprise;
Minimization of waste generation and minimization of their final disposal at the
WWTP site;
Maximum involvement of waste into activity.
Implementation of all the priorities is possible under development of infrastructure for
waste management, formation of databank of potential waste users and creation of the
WWTP sludge market, and under creation of information system in the sphere of the
WWTP sludge management.
100
Chapter 10 Environmental consequences of possible emergency situations
Situation
Problem
Solution
Explosion of biogas in
1. Destruction of methane
Introducing the concept of
methane tanks with
tanks.
"zoning" *
sludge
2. Sludge is not compacted;
Repair of methane tanks
occupies a lot of space.
Sludge to be utilized both at the
3. CHP does not operate.
WWTP site and subsidiary
4. Methane is emitted in the
facilities (compost)
atmosphere.
At the CHP to lay in a fuel stock.
Methane surplus to be burnt as
a "fire".
Accident at the CHP
How to use methane generated To repair CHP.
in methane tanks?
To burn biogas as a "fire" or to
Where to get heat for sludge
purchase equipment for
heating during digestion?
methane burning.
Breakage of wastewater Pollution of the Don river
To transfer flow of wastewater to
treatment facility
aquatic ecosystems
another treatment line.
Disastrous flood with
Pollution of the Lower Don river Diking the WWTP territory in
water flooding high
aquatic and terrestrial
case of disastrous flood forecast
floodplain terrace
ecosystems
Act of terrorism (effluents Ecocatastrophe in the Lower
To prevent terrorists penetration
poisoning, androlepsy of Don basin
at the WWTP site; to strengthen
the WWTP workers)
protection of a waste ditch.
* According to the concept of "zoning" in areas where explosive mixtures may be
present special precautions should be taken within these areas. This will include locating
equipment which may cause sparks outside the danger zone, and careful choice of
mechanical and electrical plant, pipelines etc. within the zone.
101
Chapter 11 Uncertainties
1. No direct measurements of air pollution at the WWTP site and within sanitary-
protection zone. This precludes assessment of reliability of estimates on emissions
methane and toxic substances.
2. Due to complex intrareservoir hydrochemical and hydrobiology processes it is
impossible to assess impact of nutrient reduction on hydrobionts growth, on intensity of
reduction processes and inflow of pollutants from the bottom sediments, on
development of pathogenic organisms in the Din river downstream the WWTP
discharges.
3. Surveys of ground water regime are occasional. Thus, materials on their pollution are
non-systematic. Their volume is insufficient for proper conclusions.
Chemical composition of sludge (primary, secondary, active) is insufficiently studied.
There is no data on seasonal dynamics of sludge generation and chemical composition.
Proposals on sludge processing and utilisation are not finally formulated.
It is necessary to determine content of aluminium (gross, in water and acetate-
ammonium extract) in sludge under different methods of wastewater treatment (without
phosphorous chemical stripping and with use of alums) and to verify compliance of
sludge with normative documents:
GOST P 17.4.3.07.-2001 "Nature protection. Soil. Requirements to sludge if used as
fertilisers";
SanPiN 2.1.7.573-96 "Hygienic requirements to use of wastewater and sludge for
irrigation and as fertilisers";
SP 2.1.7.1038-01 "Hygienic requirements to organisation and maintenance of the
MSW landfills".
Content of organic matter in sludge varies: in terms of dry matter 45-47%; total
nitrogen 3.22.5%; phosphorous in terms of 25 3.53.4%; lead 45-48 g/kg,
cadmium 5.8-9.4 g/kg; copper 123-124 g/kg; nickel 62.6-71.6 g/kg; zinc 800-
832 g/kg; chromium - 352-375 g/kg; manganese 104-109 g/kg; mercury 0.1-0.5
g/kg; arsenic 7.8-9.3 g/kg.
Concentration of heavy metals will nor exceed MAC for soil if compost is produced from
this sludge with addition of glauconitic sand, bentonite and other fillers.
102
Chapter 12 Justification of selected option of the planned WWTP
reconstruction
Thus, analysis of environmental conditions and technical feasibility of the WWTP
reconstruction in order to achieve waste water quality objectives shown that option of the
WWTP reconstruction providing biological treatment, advanced treatment of waste water
and phosphorus chemical removal with sludge compaction in methane tanks (digestion),
collection and utilisation of methane on designed CHP plant is the most preferable in
terms of key environmental parameters:
Sludge volume will be reduced by sludge digestion and compaction. This will ease
problem of sludge temporary storage at site.
Reduction of moisture of sludge that will be stored at drying beds will significantly
reduce danger of ground water pollution in case of sludge water filtering.
Burning of biogas at own CHP plant will not only reduce methane emissions but
will also reduce total amount of greenhouse gases both at the WWTP site
and generating power at power plants.
Higher level of treatment of wastewater discharged into the Don river will be
achieved after the WWTP reconstruction. Content of pollutants will comply
with stated requirements of maximum permissible discharges and existing
regulatory documents. This will improve the Don river water quality and
reduce the eutrophication of both the lower river reaches and the
Taganrog Bay.
Phosphorus compounds are extremely dangerous for water ecosystems. They are
limiting factor for development of many organisms (including green-blue
algae contributing in water blossoming). Risk of eutrophication will be
significantly reduced by additional treatment of wastewater from
phosphorus compounds with chemical reagents.
Reliable and well-documented process technology is advantage of the present
option. Management means are simple, i.e. it is easy to support high
efficiency of phosphate removal through control of reagents' doses.
More complicated technology of wastewater treatment and additional costs on chemical
phosphorus stripping are method disadvantages. Wastewater will be coloured if iron
salts will be used as reagents. It will be difficult tidewater this sludge (traditional MSW
without metal salts are easy to dewater). Tertiary filtration will be required to remove
phosphorous in suspended solids.
103
Chapter 13 Public hearings on EIA and activities on environmental education
and public awareness
Environmental education and public awareness, discussion of the EIA materials were
part of the activities through the whole period of work under the present Contract. The
following activities were part of this task:
Publication of materials in mass media
The following articles were published based on materials prepared as part of the
environmental impact assessment:
· Methane power plant for Vodokanal. Newspaper "Gorod N", 28 February
2004. Author E. Petrova.
· On the way to pure water. Bulletin of the Ministry of Construction, Architecture,
and Housing and Communal Services of the Rostov Oblast, No. 2 (6), 2004.
Author Ya. Volgar.
Public hearings were organised in Rostov (Annexes 1-2).
Brochure and leaflets with results of the EIA of the Rostov Vodokanal WWTP
reconstruction, as well as possibility to replace phosphorous-containing detergents
with other types of detergents free of phosphorous were prepared and disseminated
in cities Rostov, Azov, settlement Koluzaevo.
Draft ToR on Project results dissemination was developed (see Chapter 15).
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Chapter 14 Environmental Management Plan
The preliminary review of the Project components conducted within preparation of the
Concept in 2001 2002 shown that the Project would have minor adverse
environmental impact. Based on that Project was given Category B.
However, in order to reduce negative environmental impact at local level the
Environmental Management Plan was prepared. This Plan will be subsequently
improved, added and approved within PDF-B documents development according to
procedures applicable for the Russian Federation and the World Bank.
The objective of the Environmental Management Plan (EMP) is to ensure that the
adverse impacts are mitigated as far as possible, taking into account complementary
institutional strengthening and social aspects. It also recommends ways of mitigation
and monitoring. The EMP therefore contains:
Environmental Mitigation Plan to address the adverse environmental impacts;
Environmental Monitoring plan to record environmental impacts of the Project
and to take corrective action when necessary;
Recommendations for training and capacity building; and
Social aspects of project implementation.
14.1 Mitigation Plan
Mitigation Plan objective is to minimise negative environmental impacts of the Project.
Recommended mitigation measures are presented in a form of a plan (Table 14.1).
Plan's objective is to present the list of potential mitigation tasks and suggest delegation
of responsibilities for their implementation. Agencies which may have responsibilities for
control and monitoring include the Oblast Environmental Committee, Ministry of Natural
Resources (local agencies), City Department of Construction, Rostov Oblast Centre for
Sanitary Supervision, Gosgortechnadzor, Ministry of Emergency Situations. Their
responsibilities are specified by the current legislation of the Russian Federation.
Training requirements are summarised in the last part of the present Plan.
It is not envisaged that the mitigation measures (apart from the required training) will
incur significant extra costs.
The proposed Plan includes the following components for construction and
rehabilitation:
Component 1: Upgrading of screening and grit removal
Component 2: Renovation of the primary settlement tanks
Component 3: Modification and extension of the secondary aeration tanks
Component 4: Incorporation of lamella settlers
Component 5: Chemical Phosphorus stripping
Component 6: Sludge digestion
Component 7, 8: Combined Heat and Power (CHP) Plant Methane use
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Table 14.1 Mitigation Plan
Construction
No. Compon Parameter Impact
Mitigation
Measure
Responsibility
ent*
1 All
Air
quality;
Minor negative impact due to Careful site supervision and working Contractor**, with site supervision
Surface
spillage, (oil, diesel etc), practices as specified in construction from RVK and other bodies as
water quality
careless waste disposal or norms (SNiPs), spill control procedures, necessary
operation of machinery
correct choice of fuel and plant
maintenance.
2
1-4, 7
Air quality on Existing negative impact on air Registration of the existing pollution level RVK, Centre for Sanitary and
technological composition, odour nuisance
before completion of construction and Epidemiologic Supervision
lines and at
reconstruction works.
sites of
sludge
storage
lagoons and
sludge drying
beds
3 All
Solid
waste
Minor negative impact from the Compliance with standard procedures Contractor**, City Department of
disposal
works due to large quantities (city ordinances) for construction waste Construction, with site supervision
of waste construction materials disposal. The construction supervisor from RVK and other bodies as
produced
should ensure best practice, through re- necessary
use of construction materials and the
removal of hazardous wastes for
separate disposal.
4 All
Solid
waste
Minor negative impact from the Compliance with standard procedures Contractor**, City Department of
disposal
works due to large quantities (city ordinances) for soil disposal
Construction, with site supervision
of the yield and conveyed soil
from RVK and other bodies as
necessary
Note: * Description of components see above; **- All contracts within the project have to include an item with requirement that all activities to be
implemented in compliance with the existing regulating documents (SNiPs) and rules on mitigation of adverse impact of noise, dust and transport (including
emergency signs, etc.). In their Contracts should comment on ways to reduce this adverse impact.
106
Table 14.2 Mitigation Plan
Operation
No. Compon Parameter
Impact
Mitigation Measure
Requirements to
Responsibility
ent*
monitoring: measured
parameters and methods
1 5
Surface Pollution of surface
Ensure that chemical dosing is
Standard parameters of
RVK/ Ministry of
water quality water due to
carefully controlled through
water quality. Standard
Natural
overdosing of
development of a sampling regime
laboratory methods
Resources
chemicals for
and regular sampling of effluent and
wastewater delivered for
(local bodies)
phosphate stripping
sludge after lamella separators and
treatment and treated
of sludge in Phosphorus settling tank wastewater plus selected
to ensure correct dosing level
positions within the process
(see Chapter 3, Table 1).
2
6, 7, 8
Air quality
Use of natural gas to
Use excess heat from CHP plant
Periodic control of gas
RVK /
fire boiler to supply
cooling waters whenever possible
equipment.
Gosgortechnadz
energy to sludge
or
digesters and
centrifuges. Magnitude
of impact depends on
design of digesters
chosen
3
6, 7, 8
Energy
Significantly increased
This impact is difficult to mitigate, as Monitoring of gas
RVK
consumption
energy requirements
it is an unavoidable result of process consumption and gas
for sludge digestion
changes designed at improving other composition.
and sludge dewatering
environmental receptors (especially
Periodic control of energy
processes
air quality). The impact can be
efficiency.
mitigated to some extent through
monitoring to ensure that the
processes are operating at optimum
efficiency, thus minimising energy
consumption
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No. Compon Parameter Impact
Mitigation
Measure
Requirements
to
Responsibility
ent*
monitoring: measured
parameters and methods
4
6, 7, 8
Sludge
Ground pollution at
Storage in a special sites, use and
Analysis of dried sludge.
RVK, Centre for
quality
storage sites
disposal taking into account
Levels of moisture content, Sanitary and
requirements for hazardous waste
density, chemical
Epidemiologic
handling stated in the RF
composition, pathogens
Supervision
Government Decree No. 340, 2002
(it is required to develop special
programme for the WWTP sludge
use and disposal).
5 6
Health
and Potential health and
Areas where explosive mixtures may Periodic agencies and state RVK/
safety
safety risk associated
be present should be identified, and
monitoring of compliance Gosgortechnadz
with the presence of an special precautions taken within
with standards of fire and or / Ministry of
explosive air/gas
these areas. This will include
flame safety.
Emergency
mixture in the vicinity of locating equipment which may cause
Situations
the sludge digesters
sparks outside the danger zone, and
careful choice of mechanical and
electrical plant, pipelines etc. within
the zone.
Note: * Description of components see above; **- All contracts within the project have to include an item with requirement that all
activities to be implemented in compliance with the existing regulating documents (SNiPs) and rules on mitigation of adverse impact
of noise, dust and transport (including emergency signs, etc.). In the proposals Contractors should comment on ways to reduce this
adverse impact.
108
14.2 Monitoring Plan
Plan's objective is to ensure that monitoring is conducted in order to:
Provide sufficient information so that the success of the project can be measured in
terms of meeting nutrient and methane reduction objectives;
Identify inefficiencies and failure to meet the targets, allowing process changes to
be made to improve problems;
Enable any negative impacts of the process changes to be identified so that
process changes may be made where possible;
Demonstrate the successes/failures of the project to allow replication, with changes
as required, in other WWTW around Russia; and
Provide improved data on the environmental impact of the Rostov WWTP.
It is important to collect and analyse data on a regular basis in order to detect necessity
for process changes or improvements, or when failures have occurred. There are
training requirements related to the recommended monitoring requirements. Both
monitoring and training will incur additional project costs.
Monitoring during Construction
If recommended site practice and supervision is followed, reasonable monitoring will be
required during construction. It may be appropriate to nominate a Construction
Supervisor to ensure that required environmental and health and safety procedures are
met during construction. Groundwater monitoring would only be required if problem was
identified during construction of a new building, tank or underground pipeline.
Background measurements of air quality will be organised at the WWTP site and within
sludge drying beds and sludge storage lagoons. They will form a "reference point" for
future operation.
Monitoring during Operation
To facilitate operation of a new, more complicated process the WWTP laboratory's
monitoring programme has to be expanded. An expansion to the existing regime is
given in details in Table 14.3 below. Sampling of phosphorus at the reagent dosing
phase is important to ensure correct dosing. It is recommended to sample at least three
times a day.
Table 14.3 Proposed Expansion to Sampling Regime within the works
New monitoring parameters
Location
Frequency
Total phosphorus
Inlet/Outlet
1/day
Total phosphorus
Phosphate stripping
At least 3/day
reagent dosing point
Soluble orthophosphate
Inlet/Outlet
1/day
Volatile Fatty Acids
Inlet to aeration tanks
1/week
Alkalinity
Inlet to aeration tanks
1/day
Suspended solids concentration
Aeration tanks
1/day
Total iron
Outlet
1/day
pH Aeration
tanks
1/day
Dissolved oxygen
Aeration tanks (each zone)
1/day
Nitrate Outlet
1/day
Ammonia nitrogen
Outlet
1/day
It is proposed to develop and implement special monitoring and control programme for
gas equipment and protocol on sampling and air quality monitoring programme.
14.3 Training and Capacity Building Requirements
After completion success of the new process will depend on staff operational skills,
including:
Understanding of new process and all components;
Training in operational requirements;
Planned maintenance;
Safe working conditions, e.g. zoning, chemical usage;
Process monitoring;
Laboratory upgrading;
Computer (IT) equipment; and
Training and permission to work with hazardous substances.
Existing sampling equipment and laboratory facilities are insufficient to achieve
recommended objectives. Laboratory services should be expanded to provide
information required for optimum operation of a new system. This would include:
Routine chemical tests;
Laboratory scale digesters;
Routine efficiency calculations;
Gas volume and composition measurements; and
Instrumental monitoring.
Overall project budget allocates funds for operation and maintenance of the WWTP. It is
recommended that costs for the above-mentioned activities should be included in project
budget to ensure successful operation of new equipment and processes. Projects aimed
at upgrade of the RVK's laboratories are also considered in the RVK Strategic Plan.
14.4 Social aspects of project implementation
Detailed description of social impacts as part of the project implementation will be
available after special social study planned as part of the PDF-B grant activities.
However, it is possible to say that component 1-8 will have minor social impact; it is
expected that impacts will be positive as water quality will improve, and emissions of
greenhouse gases will decrease due to rational use of electric and thermal energy.
Thus, the project has no special activities dealing with social impacts.
All construction and reconstruction activities should be done in compliance with the
existing local and Russian standards in the sphere of construction and environmental
protection. In the proposals Contractors should comment on ways to reduce adverse
impact or compensate temporary inconveniences due to construction works.
110
Chapter 15 Dissemination Programme
For dissemination of experience gained as part of the Project on Reduction of Nutrient
Discharges and Methane Emissions in Rostov-on-Don implementation in Russia and
abroad the following activities were proposed:
To popularise and disseminate information about Project's outputs
Preparation and publication of the brochure with description of key Project
outputs.
Preparation and dissemination of a multimedia film on a CD.
Mobile exhibition or participation in environmental exhibitions in the coastal cities
and towns.
Environmental actions on information and results dissemination in the cities and
towns of the Azov-Black sea basin (for example, the Black Sea Day).
Meetings with representatives of Administrations and Vodokanals in coastal cities
and towns.
Training and raising the level of specialist's skills
Training workshops for decision makers.
Preparation of a training course and raising the level of specialist's skills.
Public campaign in mass media
International workshop for journalists.
Publications of materials on Project results and achievements in local mass
media.
To develop draft Terms of Reference on technical assistance in experience
dissemination.
Key objectives of the ToR:
To promote dissemination of project decisions on reconstruction of the Rostov
WWTP aimed at improvement of the Don River and Azov sea water quality and
rehabilitation of region environment by means of eutrophication reduction and
decrease of pollution from municipal sources.
To learn lessons from the Rostov project and to identify most successful innovations
for their further dissemination in other regions of the Azov-Black sea basin and
the Danube river basin.
To promote dissemination of the Action Plan on Environment protection within the
Azov-Black sea basin.
Objectives of the current task will be achieved through implementation of the following
interrelated tasks:
Task 1. To improve infrastructure
To develop, test and publish training modules on integrated wastewater treatment.
To support training workshops on environmental policy for staff involved in waste
water treatment: municipalities, municipal and Oblast inspections, environmental
agencies and private sector.
111
At the final stage to organize and co-ordinate in Rostov International conference on
waste water treatment issues in order to disseminate information in other regions
of the Azov-Black sea basin.
Task 2. To transfer technology (skills).
To promote dissemination of the most appropriate technology of wastewater
secondary treatment and advanced treatment at the WWTP.
To promote dissemination of the most suitable technology for the WWTP sludge
utilization.
To promote organization of constantly working classes on training and technology
transfer.
To promote communication and partnerships between towns and cities of the region
in respect to integrated wastewater treatment.
Task 3. To inform general public, to improve public awareness and environmental
education.
To promote campaigns in mass media in order to organize public debates and
dialogues on wastewater treatment (regional press and electronic mass media).
International workshop for journalists is proposed in addition to traditional means
of communication with mass media.
To promote assistance in development of a training course on environment
protection (official, unofficial, popular), including water quality, health protection,
sanitary and environmental protection.
In co-operation with the PIU to develop guidelines on best available practice to
reduce nutrient discharges and methane emissions, including publications of
brochures, booklets, multimedia films on CDs.
In co-operation with the PIU to promote organization of training workshops, working
meetings and consultations for staff of the WWTP, environmental agencies and
decision makers.
To provide technical expertise to initiatives of the Oblast authorities in rehabilitation
of the Don river natural ecosystems.
Towns and cities for results dissemination:
in Russia Azov, Taganrog, Novorossiisk, Sochi;
in Ukraine Mariupol, Nikolaev, Sevastopol, Odessa;
in Georgia Batumi, Sukhumi;
in Bulgaria Varna, Burgas;
in Romania Konstansa;
in Turkey Samsun.
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Key conclusions
Project on reconstruction of the Rostov WWTP is presented in a Feasibility Study:
reconstruction of the Rostov WWTP (Phases I and II) (2000), in reports prepared by
"JACOB-GIBB" (2003) and "SWECO INTERNATIONAL" (2004). The EIA is based on
these reports.
Biological treatment and advanced treatment of waste water, removal of phosphate
compounds with chemical reagents, digestion of waste water sludge in methane tanks to
reduce greenhouse gases emissions, and use of the produced methane as fuel for a
combined heat and power (CHP) plant was proposed by the "SWECO
INTERNATIONAL" as a principal option for waste water treatment. The WWTP
reconstruction is designed stage-by-stage due to lack of funding.
At the preliminary phase WWTP capacity will be 360,000 m3/day. For a long-term period
total WWTP capacity is designed as 460,000 m3/day of wastewater. This flow divides in
50% per two phases. Prospective peak flow for each phase is about 13,300 m3/hour.
New construction or reconstruction of the following elements is envisaged in accordance
with the required treatment plant capacity, treatment level and method based on
SWECO's recommendations and according to the approved feasibility study.
Phase I works:
1.
Screen building (reconstruction with installation of "thin" screenings).
2.
Grit traps will be site for addition of liquid alum (reagent for phosphate
compounds settling); thus, pre-aeration chambers will be used for preliminary
sedimentation;
3.
Aeration tanks (reconstruction with identification of anoxic zone denitrificator
and aeration zone - nitrificator).
Phase II works:
1.
Screen building (reconstruction).
2.
Pre-aeration tanks - primary settlement tanks (reconstruction: existing sludge
scrapers will be replaced by new scrapers; concrete constructions will be
repaired; sludge pumps will be replaced by stainless steel pumps);
3.
Aeration tanks (reconstruction with identification of anoxic zone denitrification and
aeration zone - nitrificator).
4.
Secondary horizontal settlement tanks (three lines out of four will be completed
with lamella modules and brush filters - bioreactors with immobilized micro flora
well proven on Phase 1);
Facilities for wastewater advanced treatment (II stage) of Phases I and II
1. Reception (inlet) chamber (reconstruction).
2. Entry chamber (designed).
3. Filters for advanced treatment (reconstruction).
4. Pumping station for advanced treatment filters (reconstruction).
5. Reservoir for washing water (reconstruction).
6. Filters media storage facility (reconstruction).
113
7. Aerator trough (aeration tank) (reconstruction, designed).
114
Facilities for sludge processing, Phases I and II
1. Gravel bunkers (extension).
2. Sludge compactors D=18 m (reconstruction);
3. Methane tanks (re-equipping up to 5,000 m3).
4. Two reservoirs will be constructed for gas storage 3,000 m3 each and new
reservoir for digested sludge storage (capacity 2,000 m3); power generation
plant; building for heat exchangers; gasholders; methane tanks pumping
station;
5. Site for mixing wastewater with humin-mineral concentrate, and storage facility;
Supporting buildings and facilities
1.
Blowing house and pumping stations No. 1 and 2, pumping station in passes of
capacity blocks of Phase II, pumping station of sludge compactors
(reconstruction), in-site communications will be reconstructed;
2.
Reagent storage building with storage facility (two new plants will be constructed
for alum reception, storage and processing, one plant will serve line 1 or 2
phases).
The WWTP improvement in terms of nutrients removal will provide significant
improvement of effluents quality and will allow necessary reduction of phosphorous
concentration by 60% and total nitrogen concentration by 50%.
"SWECO INTERNATIONAL" recommended that final objectives for treated wastewater
of the Rostov WWTP should comply with SNiP norms. The following parameters will be
used for treated effluents at the intermediate phase of the Rostov WWTP reconstruction
(Table 1).
Table. Approved standards for treated wastewater of the Rostov WWTP
Pollutants
Pollutants in treated wastewater
Intermediate Full
reconstruction
Organic matter (in terms of BOD5)
< 15 mg / l
< 3 mg / l
Suspended solids
< 25 mg / l
< 3 mg / l
Ammonia nitrogen
< 0.39 mg / l
< 0.39 mg / l
Nitrite nitrogen
0.02 mg / l
0.02 mg / l
Nitrate nitrogen
2.5 mg / l
2.5 mg / l
Total nitrogen
< 3 mg / l
< 3 mg / l
Phosphates (P2O5)
< 1.95 mg / l
< 0.61 mg / l
Phosphorous (estimated in P2O5-P)
< 0.65 mg / l
< 0.2 mg / l
According to "SWECO INTERNATIONAL" estimates after reconstruction effectiveness
of the POC (potential of oxygen consumption) will increase from about 67% to 93%.
Further investments in effective operation of an additional treatment phase will increase
effectiveness by 3%. Selected strategy of stage-by-stage reconstruction can be
regarded as a highly successful solution.
Various environmental impacts will be registered both during reconstruction and
operation phases due to emission of pollutants, effluent discharges into the Don river,
formation and location of production and consumption wastes and other impacts. The
115
following three alternative options were selected for environmental impact assessment:
Zero option: the existing situation will remain at the WWTP, no reconstruction
works.
Option with biological treatment, advanced wastewater treatment and chemical
removal of phosphorous.
Option with reduction of nutrients using only biological treatment of wastewater.
Undertaken assessment and environment state forecast provided evaluation of the
WWTP reconstruction options:
1. Rostov-on-Don emissions define atmospheric pollution in the Don river left bank
floodplain. Level of atmospheric pollution in the area of WWTP is minor. Only nitric oxide
and carbon concentrations are recorded at MAC levels. Concentrations of other gases
are all lower than MAC values. Concentrations of some heavy metals are increased in
solid-phase atmospheric fall-outs.
At WWTP site recorded emissions are 5.68 tons of methane per year (sludge drying
beds and sludge storage lagoons) and 3.076 tons of carbon oxide per year (boiler-room)
(according to data provided by the Central Board on Natural Resources and
Environment Protection of the Rostov Oblast, RF Ministry for Natural Resources). For
other pollutants input of the WWTP into atmospheric pollution in the area of Zarechnaya
industrial zone is very low compared to other industrial enterprises located here. If
project on the WWTP reconstruction with installation of a plant for methane collection
and utilisation to be implemented then emissions of this gas will reduce from 14 to 4
kg/day (by 3.5 times).
"JACOB-GIBB" assessed present emissions of WWTP gases causing green house
effect taking into account gases from used electric power and coal burning at local heat
station. Data was compared with estimates of emissions after the WWTP reconstruction
(taking into account use of mesophilic methane tanks and heat station operating on
biogas produced). According to the estimates total mass of emissions in terms of CO2
under "zero" option will be 519.914 kg/day = 189.769 tons/year for the year 2006 and
688.893 kg/day = 251.446 tons/year for a long-term period.
In case of sludge anaerobic digestion and construction of CHP plant (without preliminary
sedimentation) total mass of emissions in terms of CO2 will be 377.314 kg/day =
137.720 tons/year.
In case of chemical removal of phosphorous and anaerobic digestion total mass of
green house emissions in terms of CO2 can increase up to 452.777 kg/day = 165.264
tons/year in a long-term forecast.
2. Content of copper, iron (in summer), phenols (in summer), organic matter (BOD5),
sulphates and nitrites (in winter) exceeds MAC values in the Don river water at the reach
between the Tsimlyansk reservoir and river mouth. In the Don river mouth pollution
increases in all seasons for sulphates (and water mineralization) and oil products; in
winter - for nitrites, BOD5, iron. River reaches near towns of Aksai, Rostov, and Azov are
the most polluted parts (in terms of BOD5, oil products for all seasons, nitrites - in
winter, phenols - in summer).
Increase of anthropogenic euthrophication is periodically recorded at the mouth reach of
the Don River. Maximum values of phytoplankton population are recorded in summer
and autumn. At this time significant changes of community structure are registered due
116
to modification of specific composition of dominant complex and tendency of certain
species for a leading place.
Hygienic standards for BOD5 (1.5 2 MAC), COD (1.5 3.5 MAC), total hardness (1.2
1.5 MAC), total iron (1.3 5.1 MAC) and oil products (1.2-32 MAC) (data provided by
Centres of GosSanepidnadzor for Rostov-on-Don, Azov, Taganrog, Azov district) are
recorded in the Don river water at water intakes and in recreation zones of populated
areas. In terms of bacteriological pollution the Don river is regarded as a source with an
increased level of epidemiological danger. Coli-fags, spores of sulphitreducing clostridia,
choleroid micro flora were identified in river water. High level of river water
bacteriological pollution is recorded in the Don river mouth area, especially downstream
of Rostov sewage discharges and at the confluence of the Temernik and Don. Azov city
water intake has the most critical situation with water quality in terms of microbiological
pollution. This is due to discharge of insufficiently treated and crude wastewater of
Rostov city in the Don river. Use of drinking water with bacteriological and viral pollution
leads to acute enteric infections and viral hepatitis type A.
Conditions of the WWTP wastewater discharges into the Don River are stated by
requirements of the "Rules of surface water protection from pollution" for a water body of
category 1 of fisheries importance. Reconstruction of the Rostov WWTP by option with
biological treatment, advanced wastewater treatment and chemical removal of
phosphorous will provide high level of wastewater treatment. In this case content of
pollutants will comply with stated maximum permissible discharges and existing
regulatory documents.
After reconstruction using this option the WWTP input in water pollution in terms of nitrite
nitrogen, ammonia nitrogen and organic matter will reduce from 23%, 6% and 7%,
respectively, up to a zero. Content of these substances in treated wastewater will be
equal or less than content in riverine water. Input in terms of nitrate nitrogen and
phosphorous will reduce by a factor of two, i.e. from 14% to 7%. However, after a deep
treatment estimated concentrations of nutrients in ambient water downstream effluent
discharge place will reduce insignificantly: for nitrite nitrogen - from 0.32 to 0.26 mg/l and
for phosphorous - from 0.16 to 0.15 mg/l.
In case of the WWTP partial reconstruction (intermediate option with waste water
volume of 360,000 m3/day) the WWTP input in the Don River water pollution in terms of
nitrite nitrogen and ammonia nitrogen can be reduced from 23% and 6%, respectively,
up to a zero. Content of these substances in treated wastewater will be equal or less
than content in riverine water. Input in terms of organic matter will reduce from 1.7% to
1.5%; in terms of nitrate nitrogen will reduce by 3.5 times (from 14% to 4%), and for
phosphorous will remain invariable. After treatment estimated concentrations of nutrients
and organic matter in ambient water downstream effluent discharge place will reduce
insignificantly: for nitrite nitrogen - from 0.032 to 0.026 mg/l, for nitrate nitrogen from
0.32 to 0.29 mg/l, and for organic matter - from 4.08 to 4.06 mg/l.
Disadvantage of biological treatment without preliminary chemical sedimentation of
phosphate compounds is low level of wastewater treatment preventing achievement of
maximum permissible discharges values and meeting existing requirements to effluents
discharged into category 1 water bodies used for fishery and household/drinking
purposes.
Effective disinfection of treated wastewater will reduce the Don river bacteriological
pollution. However, in order to improve water quality downstream Rostov in terms of
microbiological parameters it is necessary to discontinue discharges of crude (untreated)
117
wastewater into the Temernik and Don rivers, and to construct storm water sewer.
Indicated activities will significantly reduce microbiological water pollution at water
intakes located downstream Rostov; discontinue use of drinking water hyperchlorination
in Azov and Azov district; reduce sickness rate of enteric infection of bacteriological/viral
nature, and allow wider use of the Lower Don as a recreational zone.
3. Chemical composition of ground water forms due to atmospheric precipitation,
infiltration of technogenic water at the WWTP site, as well as pollutants washing from
unauthorised dump of household and industrial wastes located in the northern part of
the WWTP. Organic substances (high value of BOD5), oil products (8-58 MAC), iron and
cadmium (0.035 0.077 mg/l) are the most typical elements of ground water pollution.
During the WWTP reconstruction it is planned to reduce volume of sludge stored at
sludge drying beds and sludge storage lagoons. Less sludge and storm water enriched
with organic and other pollutants will be filtered into ground water. This will contribute to
reduction of ground water pollution.
4. According to lithochemical survey in the area of the WWTP level of soil pollution with
heavy metals is minor. Contrast and vast lithochemical anomalies were not discovered.
Planned reconstruction of the WWTP will not contribute to increase of soil and
underlying surface pollution, as well as technogenic flows contacting with soils will have
less pollutants. All reconstruction and construction activities will be held within the
WWTP limits. Thus, use of new lands for construction is not planned.
5. Involvement of new sites into operation is not planned, so, during construction works
adjacent natural landscapes will not degrade. After the WWTP reconstruction reduction
of agrochemical and hydrochemical load on neighbouring landscapes with decrease of
atmospheric emissions and reduction of filtering sludge water will be beneficial for
growth of floodplain ecosystems' vegetation cover and fauna.
6. In the zone of the Rostov industrial centre natural oxygen and oxy-gley landscapes in
the Don River were transformed into oxy-hydrosulfuric under technogenesis. Increase of
pollutants concentration in all landscape components, increased accumulation of
organic matter at the bottom, intensification of reduction processes, their shift from
sediments to near-bottom waters, flow of dissolved elements (compounds of nitrogen,
phosphorous, microelements) from silts to water column will accompany this
transformation. Weakening of technogenic pressure on the Don river will be recorded
after WWTP reconstruction. Decrease in discharge of organic substances and nutrients
will result in reduction of river eutrophication and decrease of reduction processes
intensity. Oxidised layer preventing entry of pollutants from bottom into water column will
remain longer on bottom sediments surface.
7. At present total amount of produced sludge consists of 1220 m3/day primary sludge
and 1355 m3/day surplus activated sludge. Sludge (mechanically dewatered or dried at
drying beds and kept in natural conditions for not less than 2 years) has a moisture
content of 54-58% respectively and is regarded as waste of class IV danger.
If existing situation remains then impact of production and consumer waste on
environment will be gradually increasing due to limited place for the WWTP waste
disposal and their accumulation at site.
Option providing reduction of nutrients only with biological treatment includes various
construction activities: reconstruction of secondary settlement tanks, installation of
lamella settlers, construction of sludge digesters and construction of CHP plant. This will
result in a short-term local impact of large masses of soil on soil cover at the WWTP site
118
and in a possible minor impact on ground water. Impact will stop after completion of
building and assembly works, after construction of tank support walls from extracted soil,
and covering area.
Quantity of screenings will increase with operation of reconstructed WWTP. Their impact
will not increase due to potential disposal to the Rostov landfill site. Sludge volume will
increase after full biological treatment of wastewater. Then all produced sludge will pass
through a closed cycle to the sludge digesters, which will minimise the amount of sludge
produced. This in combination with reduction of nitrogen, phosphorous, BOD determines
potential decrease of sludge negative impact on air, soil, surface and ground water
compared to the "zero" option, mainly due to a decrease of greenhouse gases
emissions.
Volume of primary sludge increases in case of chemical removal of phosphorous. But
due to later sludge digestion and dewatering total volume of sludge compared to the
existing situation either will remain the same or will increase insignificantly without
growth of anthropogenic load on environment but limiting possibilities of sludge use. It
will be possible to reduce load on air and ground water due to qualitatively new
parameters of produced sludge and gradual processing of earlier accumulated sludge
from the existing sludge storage lagoons.
8. There will be no significant impact during construction on climate; hydrology;
terrestrial or aquatic ecology; water resources, supply and sanitation; public health
(apart from occupational health, discussed below); land use, industry and agriculture;
fisheries; energy consumption; transport infrastructure; tourism and recreation; cultural
heritage; groundwater quality; or sediment quality.
The construction of new buildings and tanks will have a slight impact on topography, but
this is not considered to be significant in the context of an industrial complex.
All construction work will have a slight positive impact on `population, employment and
income' through employment generation.
Construction works may have minor negative impacts on surface water and air quality
through operation of cars, machinery (atmospheric emissions, spillage of petroleum
products, etc.). Impacts can be mitigated by correct choice of fuel and proper machinery
operation, use of spill control procedures, enhanced control on polluted soil collection
and utilisation.
The construction of buildings, tanks and underground pipelines may have an impact on
the groundwater regime. This impact may be assumed to be negative (in disruption of
existing groundwater flows) but the level of impact is likely to be marginal and no
mitigation measures would be required. However borehole monitoring should be
instituted where there is likely to be groundwater diversion or rising water tables
There may be a slight decrease in effluent quality during works which require direct
interruption of process lines, but this is likely to be insignificant because retention time
would not decrease significantly as the works currently has excess capacity.
All works generate construction waste. It is understood that soils excavated during
building and tank construction will be used on site. Apart from soils, it is envisaged that
the waste generated will be relatively small and therefore have only a slight impact on
waste disposal. This impact should be mitigated by compliance with existing
requirements (RF and Rostov Oblast ordinances) for collection, temporary storage and
final disposal of construction waste. Special activities for waste recycling should be
119
developed and implemented where possible.
9. There will be no impacts during operation on topography, geology and soils;
hydrology; water resources, supply and sanitation; and cultural heritage. At this stage, it
is envisaged that there will be no significant impact on `population, employment and
income' as there will be no major changes in staff needs. Given that this project is grant-
funded, it is considered unlikely that it will have a negative impact on the population in
terms of ability to pay for services.
In a long-term period there are no impacts on land use, industry, agriculture, but some
positive impacts can originate due to disposal of less amount of biologically less
activated sludge.
The new buildings, pipelines and tank are likely to have a minor impact on hydrogeology
due to flow diversion.
The reduction of nitrogen levels with the reduction in phosphorus levels in effluents is
likely to decrease the eutrophication of the river, thus having a positive impact on
aquatic ecology and fisheries. Reduced levels of eutrophication will have a positive
impact on river water quality, decrease of oxygen deficit and toxin release events. This
will have a beneficial impact on aquatic ecology; public health, fisheries; tourism and
recreation. Given the large phosphorus reservoir in the riverine sediments, positive
impacts on sediment quality will accrue over time. In the short term, therefore, there will
be no positive impact on sediment quality.
Sludge digestion will ensure major environmental improvements as the process leads to
a significant reduction in sludge volume, and allows for the capture of methane for
beneficial use. Digestion converts the volatile organic fraction of the sludge into a
mixture of methane and carbon dioxide.
There will be other benefits in addition to reduction of methane emissions form the
WWTP site, such as:
During thermal digestion there will be a significant decrease of pathogens
(salmonella and streptococcus) in sludge. This will make sludge more suitable for
recycling.
Anaerobic digestion will provide longer storage of dewatered sludge at site, as
sludge volume will reduce from 35,000 to 30,000 m3 per year. Decrease in sludge
amount will result in cost savings on polymers (for dewatering) and transportation
of sludge to a disposal site.
Use of energy from methane burning for energy supply to the WWTP, as well as for
buildings heating and digested sludge warming will provide energy savings and
reduction of operational costs.
Reduction of sludge volume in sludge storage lagoons is likely to have a positive impact
on groundwater quality (less filtration of polluted sludge water) and air quality (less
emission of methane, mercaptan, other pollutants).
The operation of digesters represents a potential risk due to the presence of areas
where explosive gas/air mixtures can be present. It will therefore be vital to introduce the
concept of "zoning". Areas where explosive mixtures may be present should be
identified, and special precautions taken within these areas. This will include locating
equipment which may cause sparks outside the danger zone, and careful choice of
mechanical and electrical plant, pipelines etc. within the zone.
120
10. For the studied area environmental limitations are compliance to norms of maximum
permissible emissions taking into account inputs in background pollution; maximum
permissible discharges in compliance with conditions of their diversion into the Don
River as water body of the 1 category in terms of fisheries and household-drinking
purposes, as well as limited disposal of waste in compliance with existing permissions.
Special restrictions are absent: the WWTP locates outside water protection zone of the
Don River, nearest populated settlement is situated outside sanitary protection zone
(100 m).
Thus, analysis of environmental conditions and technical feasibility of the WWTP
reconstruction in order to achieve waste water quality objectives shown that option of
the WWTP reconstruction providing biological treatment, advanced treatment of waste
water and phosphorus chemical removal with sludge compaction in methane tanks
(digestion), collection and utilisation of methane on designed CHP plant is the most
preferable in terms of key environmental parameters:
Higher level in treatment of wastewater discharged into the Don river will be achieved
after the WWTP reconstruction. Content of pollutants will comply with stated
requirements of maximum permissible discharges and existing regulatory
documents. This will improve the Don river water quality and reduce the
eutrophication of both the lower river reaches and the Taganrog Bay.
Phosphorus compounds are extremely dangerous for water ecosystems. They are
limited factor for development of many organisms (including green-blue algae
contributing in river water blossoming). Risk of eutrophication will be significantly
reduced by additional treatment of wastewater from phosphorus compounds with
chemical reagents.
Sludge volume will be reduced by sludge digestion and compaction. This will ease
problem of sludge temporary storage at site. Reduction of moisture of sludge that
will be stored at drying beds will significantly reduce danger of ground water
pollution in case of sludge water filtering.
Burning of biogas at own CHP plant will not only reduce methane emissions but also
will decrease total amount of greenhouse gases both at the WWTP site and
generating power at the Novocherkassk power plant.
Reliable and well-documented process technology is advantage of the present
option. Management means are simple, i.e. it is easy to support high efficiency of
phosphate removal through control of reagents' doses.
More complicated technology of wastewater treatment and additional costs on
phosphate chemical removal are considered as method's disadvantages.
121
Annex 1 Minutes of the meeting of interested agencies and general public on
Environment Management Plan
Grant for Preparation of the Project on Reduction of Nutrient Discharges and
Methane Emissions in Rostov-on-Don
GEF Grant No. TF 027721
Minutes of the meeting of interested agencies and general public on Environment
Management Plan
Rostov-on-Don, RRFSP office
November 16, 2003
List of participants:
1. V Ostroukhova, Head of the Committee on Environment Protection and Natural
Resources under Rostov Oblast Administration
2. V Garin, Head of the Rostov Regional Public Environmental Centre
3. N Bezuglov, Deputy Head of Construction Department, Rostov Municipality
4. V Aleshnikov, Deputy General Director of Rostov Vodokanal
5. V Lavrenov Lead Specialist on Water Supply and Water Abstraction, RRFSP
6. V Khlobystov Lead Specialist on Environment Protection, RRFSP
7. O Pankova, Press-secretary, Committee on Environment Protection and Natural
Resources under Rostov Oblast Administration
Mr. V Lavrenov and Mr. V Khlobystov presented information on preparation of pre-
feasibility study for Grant No. TF 027721.
Environment Management Plan (EMP) was reviewed. Participants commented and
made certain additions to the Plan.
After exchange of views it has been decided:
1. To approve the Plan after making proposed changes and additions.
2. To recommend to Committee on Environment Protection and Natural Resources,
Vodokanal and Rostov Regional Public Environmental Centre to inform general
public about the above mentioned Grant and developed EMP.
3. To submit to the World bank corrected and reviewed EMP.
Minutes prepared by Mr. V. Khlobystov
122
Annex 2 Protocol of the EIA public hearings
Rostov-on-Don, RRFSP office
July 28, 2004
PRESENTED:
A Kosogov
Head of production and technical department, Municipal enterprise
"Construction Department", Rostov-on-Don
E Pochikaeva
Chief medical officer, Rostov-on-Don Centre for State Sanitary and
Epidemiological Supervision
T Rodionova
Deputy chief medical officer, Rostov-on-Don Centre for State
Sanitary and Epidemiological Supervision
O Khoroshev
Deputy General Director, Rostov Regional Public Environmental
Fund
A Orlinsky
Lead Specialist, Rostov Regional Public Environmental Fund
E Shustov
General Director, CPPI-S
A Ignatiev
Deputy Head, Central Administrative Board on Natural Resources
for the Rostov Oblast, RF Ministry for Natural Resources
V Nikanorov
Head of department, Rostov Oblast Committee on Environment
Protection and Natural Resources
N Tsapkova
Director of Information centre, NPP "Don-INK", CPPI-S consultant
V Privalenko
Doctor of Biology, Director of NPP "Environmental laboratory",
CPPI-S consultant
A Khovansky
Head of the chair "Economic and Social Geography", Professor,
geology-geographic department, Rostov State University, CPPI-S
consultant
Yu. Bessmertny
Manager of Habitat Division, Rostov Oblast Centre for State
Sanitary and Epidemiological Supervision
S Karakulev
Chief project engineer, FGUP North Caucasus
Giprocommunvodokanal
S Panova
Lead Specialist on Business Development, DV.kom
A Kazaryants
Deputy General Director, RRFSP
V Khlobystov
Lead Specialist on Environment Protection, RRFSP
V Lavrenov
Lead Specialist on Water Supply and Water Abstraction, RRFSP
AGENDA
To present and discuss results of the Environmental Impact Assessment undertaken by
the South Russian Centre for Preparation and Implementation of Technical Projects.
Kazaryants:
Mr. Kazaryants introduced himself and greeted participants.
He expressed regrets that not many members of general public and funds came to
public hearings, although a note was published in the local media in a proper time.
He briefly described GEF project background. Funds were allocated for project
preparation and work consisted of three parts: feasibility study of WWTP reconstruction,
social assessment and environmental impact assessment (EIA). Feasibility study was
conducted together with "SWECO INTERNATIONAL" (Sweden). Prepared social
assessment was presented to Rostov Vodokanal for comments. South Russian Centre
123
for Preparation and Implementation of Technical Projects (CPPI-S) won the EIA tender.
Participants were informed about meeting's objective: to conduct public hearings of the
EIA, discussions and conclusion on undertaken work.
He presented the EIA developers.
Shustov:
Mr. Shustov introduced himself and greeted participants.
Briefly described CPPI-S, its key activities and working experience.
Presented consultants involved in the EIA, namely: Prof. Khovansky, head of the chair,
Rostov State University; Prof. Privalenko, Rostov State University; Mrs. Kosmenko,
head of hydrobiological laboratory, Hydrochemical Institute; Mrs. Tsapkova, Director of
Information centre, NPP "Don-INK". Mr. Ulshtein and Mrs. Tarasenko (NPP "Don-INK"
employees) were also involved in the EIA. They worked in co-operation and with
assistance of Vodokanal specialists. The ToR has been agreed with the Committee on
Environment Protection and Natural Resources under the Rostov Oblast Administration.
Khlobystov. Clarified tasks and goals stated in the project ToR. He explained that three
options were considered in the EIA: "zero", intermediate and deep treatment. These
were methods available by the time of the EIA presentation.
Khovansky: Prof. Privalenko will present key outputs of the EIA.
Privalenko mentioned that options were changing along with change of local objectives.
There were some problems with understanding which option will be adopted as the final
one. Number of options was clarified after 20 July 2004.
In his presentation Prof. Privalenko covered the following issues:
1. Project objectives (long-term and short-term).
2. Main objective of the present work: the EIA of planned WWTP reconstruction for
three alternative options: "zero" (no reconstruction works); biological treatment,
advanced treatment and chemical removal of phosphorous; reduction of nutrient
concentration using only biological treatment of effluents.
3. Key parts of the EIA.
4. Assessment of environmental conditions (air pollution, surface and ground water
pollution, soil pollution, state of vegetation and fauna, terrestrial and aquatic
landscapes, waste disposal).
5. Technical state of the WWTP, system of the WWTP wastewater treatment.
6. Recommended options of the WWTP reconstruction.
7. Activities on works of Phases I and II, including advanced treatment works,
sludge processing works, supporting buildings and facilities.
8. Analysis of the WWTP impacts on environment, soil cover, vegetation, and fauna,
terrestrial and aquatic landscapes after reconstruction.
9. Justification of the selected option with description of advantages and
disadvantages.
10. Dissemination programme.
Public hearings are part of the EIA. It is important to note that for this area serious
environmental limitations are absent.
Privalenko: Would like to make a few comments. Project envisages scheme of
preliminary denitrification providing nitrogen removal. Phosphorous will be removed in
pre-aerators. Sludge from primary and secondary settlement tanks will be transported to
124
methane tanks for digestion. Then digested and compacted sludge will be suitable for
utilization. It is better to use biological treatment with chemical settlement of
phosphorous because in this case treated WWTP effluents will comply both with drinking
water quality norms and norms for water bodies used for fisheries purposes.
Khovansky: I would like to say some words about our work. Impact assessment was
given for each option in compliance with the WB requirements. Final objective of project
activities is to reduce euthrophication level both in the Lower Don basin and in the Azov
and Black seas. Thus, both point and diffuse pollution sources located downstream and
upstream Rostov should be considered. Agricultural flow is very important as well.
Data on decline of water body pollution as a result of the Rostov WWTP reconstruction
is given in the report. Water body was studied as a sole complex (biota, water, bottom
sediments). Only biological treatment and biological treatment with chemical removal of
phosphorous will decrease pollution load on water bodies. Final objective is to achieve
conformity with stated water quality standards. We support option with chemical
settlement proposed by SWECO because it will enable to achieve stated goals.
Nikanorov: How much the project cost will increase if deep treatment method is used?
Khovansky: We don't have this information. Now planners are carrying out necessary
calculations.
Nikanorov: But do you know the difference?
Khovansky: Unfortunately, I don't have information. Our task was to complete the
environmental impact assessment.
Shustov: This is technical side of the project and responsibility of experts involved in
project design and estimates. I would like to emphasize that water body will benefit from
all proposed options as environmental load on water bodies will reduce.
Rodionova: Past projects envisaged construction of methane tanks. Thus, I have two
questions:
Will be methane tanks operating this time? Have you considered or abolished
reasons for which they were unable to operate earlier?
Does mechanical dewatering plant provide full treatment? Isn't it enough to achieve
necessary level of treatment?
Privalenko: Planners will address these issues. We assessed technogenic impact on
environment during reconstruction and after construction under condition that all
designed facilities will operate.
Shustov: We studied only environmental impact of the proposed options.
Lavrenov: Planners are not here yet, although they were invited. By the middle of
August Feasibility Study will be ready. Estimates will be part of the Feasibility Study.
At present there is no sludge drying in centrifuges installed at mechanical dewatering
plant. Thus, helminthes ova present in sludge preventing its further use. Proposed
mesophilic digestion will enable to use sludge.
Shustov. Mrs. Rodionova's questions will be considered in the Feasibility Study.
Kazaryants: Different foreign companies assisted in Feasibility Studies, including
Jacobs (UK). According to estimates about USD10 million will be required for
implementation of a deep treatment project. This more than twice of what is available at
present time. Again, final option is not selected yet and it is extremely difficult to assess
environmental impact due to absence of this final decision.
Ignatiev: Reduction of phosphorous concentration at the dispersion site from 0.16 mg/l
to 0.15 mg/l is insignificant. It is unclear where did you get this figures. Will it be effective
125
for the river? Data given in the report is unjustified.
Shustov: Water in the Don River is a result of all discharges. System approach is very
important. Funds are allocated to Russian Federation and there is no need to reject
them.
Nikanorov: Basically two options are considered: with chemical removal of phosphorous
and without chemical removal of phosphorous. Is it really worth it, if decline in
concentration is only 0.01 mg/l?
Khovansky: This question is rightful and in due time. Point sources are scattered along
the Don River. Rostov WWTP is one of the largest pollutants in terms of organic
pollution. Figures presented in this work are examples of positive impact on water quality
due to the WWTP reconstruction. Vodokanal poses a significant impact on the Lower
Don water quality and river basin will benefit anyway. In percentage phosphorous
concentration will reduce insignificantly. But decrease in mass of phosphate compounds
discharged by the WWTP into the Don River will be considerable.
At present it is difficult to assess its impact on water quality.
Ignatiev: Such estimates will be interesting because it is necessary to know change of
river water quality after the WWTP reconstruction. Justification should be convincing. In
the EIA everything should be carefully studied for each option with a proper justification.
Khovansky: Difficulties with correct estimates are due to lack of reliable information
about concentration of pollutants in the Lower Don water.
It should be mentioned that even such insignificant decline in nutrient concentration
could be important for a change of aquatic landscapes environment; it could promote
conversion of reduction situation into oxidizing favourable for aquatic ecosystem. This
will prevent secondary pollution of water and entail other favourable consequences,
including restoration of ambient water and bottom sediments quality.
Cumulative positive effect should be expected if this small percents of nutrient load
reduction to be reproduced in other basin parts.
Ignatiev: Did you consider problem with alums to be used at the WWTP?
Karakulev: Alums (although a definition but not a correct one) is the most widespread
coagulant used in Russia at the WWTP. Rostov Vodokanal also uses alums. So far
there were no problems with their use.
Back to methane tanks issue. In the USSR only 7-8 methane tanks were in a real
operation (Riga, Moscow, Minsk, etc.). In Rostov methane tanks were constructed on
the WWTP Phase I but special equipment and instrumentation was not installed. Of two
methane tanks only one was working but only for 9-11 months. Then methane tank was
closed after emergency emission of digested sludge and remained unused for many
years. Instead of methane tanks aerobic mineralizers were used.
Rodionova: Why did methane tanks were not part of Feasibility Study developed in
1999?
Karakulev: This is not really true. That Feasibility Study considered options with use of
methane tanks, landfill for sludge disposal and sludge use/processing. The last one was
adopted as a working one.
Bessmertny: How are you going to accumulate and utilize sludge after application of
aluminium sulphate?
Karakulev: Sludge will be disposed to a landfill without further use for any purposes.
Tsapkova: This is not the best option. At present sludge can be used for decorative
purposes. Wide use of sludge for land-reclamation will be limited in case of chemical
126
settlement of phosphorous. Nothing is said about sludge management and its future
use. Thus, working on Feasibility Study it is important to make estimates for activities on
sludge use and its disposal to a special landfill.
Karakulev: Proposals to set up a special landfill for sludge disposal were presented
several times. But no answer received so far. Five years ago funds for such a landfill
were allocated in the framework of the WB project. But Vodokanal decided to
redistribute funds for other activities, e.g. to replace two water mains.
We are actively using German experience of waste management. There WWTP sludge
of large cities is disposed on landfills without further use.
Tsapkova: Sludge management is not covered in the project.
Karakulev: Feasibility Study is not ready yet. Also, sludge management is not task of
the present project.
Bessmertny: Still, you need to make decision on final waste disposal.
Karakulev: If we are going to use sludge in agriculture then we can't use chemicals.
Processing will result in sludge accumulation; will increase tanks capacity and capital
costs.
Kazaryants: We are discussing work undertaken by ecologists. We are not making final
decisions on the proposed technical scheme. Ecologists can propose recommendations
to solve possible problems. They can be included into the Feasibility Study. Today's
meeting objective is to select option that will be most suitable in terms of environmental
impact. This was covered by the presentation.
Ignatiev: According to the presentation we can recommend biological treatment with
detailed review of this option and with preparation of final proposals.
Bessmertny: Further increase of effluents volume is likely, and aluminium sulphate will
not help if capacity will be insufficient.
Water disinfection and extraction of chlorine residue is a vital issue. This wasn't covered
in technology description. In Azov water samples contain 15% - 100% viruses. It is
necessary to remove chlorine residue and thus, the issue should be mentioned in
project materials and technological scheme.
Kazaryants: We have a unique opportunity to solve part of our problems using GEF
grant. Before final decision we will consider all your comments and proposals. They will
all be included in meeting minutes and will be incorporated into an updated EIA report.
Mr. Kazaryants promised to consider all the comments and to include them into
Feasibility Study document and the EIA report.
Opened public hearings were finished.
The following decisions were adopted in accordance with the agreed agenda:
To include stated comments and proposals into an updated version of the EIA report.
To present completed document within 1 week for review and approval by the project
implementation group.
127
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