No.: RMC/JnNURM/DRN/01-06/0508
Detail Project Report (DPR) for Drainage Phase-II & Phase-III (Part-1) for Rajkot city
Estimated Cost
Period
Rs. 7688 Lakhs
05-06 TO 07-08
Date of Preparation
Date of Submission
Rajkot Municipal Corporation Dr. Ambedkar Bhawan Dhebarbhai Road, Rajkot – 300 001 ( Gujarat – India) Ph: 2224133, 2239973; Fax:+91-281-2224258 E-mail:
[email protected]; url: www.rmc.gov.in
No.: RMC/JnNURM/DRN/01-06/0508
Detail Project Report (DPR) for Drainage Phase-II & Phase-III (Part-1) for Rajkot city
Contents
C Co on ntteen nttss Forward Executive Summary 1.0 INTRODUCTION…………………………………………………….………….…….. 1.1 Background 1.2 Need of the Project 1.3 Objectives 1.4 Scope & Limitation 1.5 Methodology
1
2.0 BACKGROUND ……………………………………………….…………….. 2.1 Sectoral Policies outlined in CDP 2.2 Linkage of the projects to the CDP
4
3.0 CHARACTERISTICS OF THE AREA………………………………………………….... 6 3.1 Regional Profile with Location Map 3.2 Climate & Rainfall 3.3 Geography 3.4 Environmental Setting 3.5 Growth of City 3.6 Settlement Pattern 3.7 Demographic Profile 3.8 Land Use 3.9 Housing 3.10 Civic Authorities 3.11 Status of Legislation 4.0 EXISTING SYSTEM OVERVIEW……………………………………………………….. 4.1 General 4.2 Rajkot Underground Drainage work –Phase-I & Phase-II 4.3 Rajkot Underground Drainage work Phase-III 4.4 Rajkot Water Supply
22
5.0 EXTENT OF PRIVATISATION………………………………………………………. 5.1 Privatization experience of rmc 5.2 Operation of drainage pumping stations 5.3 Privatization of public grievance cell of drainage department 5.4 Scope for further privatization
28
6.0 DETAILED ENGINEERING DESIGN ………………………………................................33 6.1 Drainage phase-ii (part -1) 6.2 Drainage phase-ii (part-1) sewage treatment plant of 44.50 mld 6.3 Drainage phase-iii (part-1) 6.4 Design of sewage treatment plant at raiya under phase-iii (part-1) 7.0 DETAILED ENGINEERING DESIGN- MECHANICAL & ELECTRICAL ……………. 87 7.1 Necessity of Auxiliary Pumping Stations for Drainage Phase-III 7.2 Criteria proposed for Mechanical works 7.3 Criteria proposed for Electrical Aspects 7.4 Pumping Mains of APS & MPS
Detail Project Report for Drainage Phase-II &II (Part-I) for Rajkot city
i
Contents 8.0 RECOMMANDATIONS..............................................………………………….… 8.1 Issues and Performance Assessment 8.2 SWOT Analysis 8.3 Recommendation
92
9.0 COST ESTIMATES …………………………………….……………………….. 9.1 General 9.2 Based for Cost Estimate 9.3 Cost Estimate for Phase-II (Part-1) 9.4 Cost Estimate for Phase-III (Part-1) 9.5 Total Estimates of Drainage Work Phase-II & Phase-III (Part-1)
97
10.0
Financial Analysis ...........................……..……………………...................... 10.1 General 10.2 RMC Finance 10.3 Present Tariff, Billing and Collection Service Connection 10.4 Drainage Projects & Project Funding
170
11.0
Summing up.. …………………………………. ...……………………………… 11.1 Conclusion
174
Detail Project Report for Drainage Phase-II &II (Part-I) for Rajkot city
ii
Contents
LLiisstt ooff TTaabblleess Table No.
Table Details
Table 1 :
Planning for JnNURM projects.
Table 2 :
Quality of Air
Table 3 :
Population Growth in Rajkot city
Table 4 :
RMC Population projection
Table 5 :
Status of Land Development
Table 6 :
Important Section of BPMC Act.
Table 7 :
GTP & UD Act, 1976 relevancy for MC Infrastructure Development
Table 8 :
Phasing of Sewage
Table 9 :
Phase-I & Phase-II
Table 10 :
Drainage Network (For Old city) –Phase-I & II
Table 11 :
Details of Pumping Station
Table 12 :
Quality of Sewage before & after treatment
Table 13 :
Sources of water
Table 14 :
Zones & Storage Capacity & supply
Table 15 :
Water supply Distribution Net works
Table 16 :
No of Complaints
Table 17 :
Unit sizing: Conventional Activated Sludge Process
Table 18 :
Unit sizing Facultative Lagoons followed by Extended Aeration
Table 19 :
Unit Sizing: Anaerobic Lagoons followed by Aerated Lagoon
Table 20 :
Unit Sizing: Upflow Anaerobic Sludge Blanket Reactor
Table 21 :
Details of T.P.Roads in Town Planning Schemes
Table 22 :
Hydraulic properties of circular sections for Manning's formula
Table 23 :
The Detials Of Designed Capacity Of Pumping Stations For Rajkot Sewerage Project
Phase-
III Table 24 :
The Details Of Designed Pumps And Motors For Pumping Stations For Rajkot Sewerage Project Phase-III
Table 25 :
Abstract Of Cost Estimate For Phase-II
Table 26 :
Summary Of Estimated Project Cost
Table 27 :
Bill Of Quantities For Collective System of T.P. scheme no. 1 part 1, T.P. 1
Table 28 :
Bill Of Quantities For Collective System of T.P. scheme no. 1 part 2, T.P. 4
Table 29 :
Bill Of Quantities For Collective System of T.P. scheme no. 6
Table 30 :
Bill Of Quantities For Collective System of T.P. scheme no. 2
Table 31 :
Bill Of Quantities For Collective System of T.P. scheme no. 3
Table 32 :
Bill Of Quantities For Collective System of T.P. scheme no. 5
Table 33 :
Bill Of Quantities For Collective System of T.P. scheme no. 7
Table 34 :
Bill Of Quantities For Collective System of T.P. scheme no. 8
Table 35 :
Bill Of Quantities For Collective System of T.P. scheme no. 8 slum
Table 36 :
Bill Of Quantities For House Connection of T.P. scheme no. 1
Table 37 :
Bill Of Quantities For House Connection of T.P. scheme no. 1 Part 2 & T.P. 4
Table 38 :
Bill Of Quantities For House Collection of T.P. scheme no. 6
Table 39 :
Bill Of Quantities For House Collection of T.P. scheme no. 2
Detail Project Report for Drainage Phase-II &II (Part-I) for Rajkot city
iii
Contents Table 40 :
Bill Of Quantities For House Collection of T.P. scheme no. 3
Table 41 :
Bill Of Quantities For House Collection of T.P. scheme no. 5
Table 42 :
Bill Of Quantities For House Collection of T.P. scheme no. 7
Table 43 :
Bill Of Quantities For House Collection of T.P. scheme no. 8
Table 44 :
Bill Of Quantities For House Collection of T.P. scheme no. 8 slum
Table 45 :
Bill Of Quantities For House Connection of T.P. scheme no. 1
Table 46 :
Bill Of Quantities For House Connection of T.P. scheme no. 1 Part 2 & T.P. 4
Table 47 :
Municipal Revenue Income
Table 48 :
Level of subsidies
LLiisstt ooff M Maappss No. Map:
1
:
Location Map
Details
Map:
2
:
Development Plan of Rajkot.
Map:
3
:
Drainage Status
Detail Project Report for Drainage Phase-II &II (Part-I) for Rajkot city
iv
Contents
A Abbbbrreevviiaattiioonnss ALV APMC ARV BOD BPMC CA CBO CCP CDS CEPT COD CPHEEO CUR DA FOP GIDC GMFB GOG GOI GPCB GSRTC GUD & HD GWSSB HUDCO IMR JnNURM NGO NIOH OR PF RCC REA RMC RTO RUDA SC SPM ST SWOT TDS UDPFI WPR
Annual Legitable Value Agricultural Produce Market Committee Annual Ratable Value Bio-Oxygen Demand Bombay Provincial Municipal Corporations City Administration Community Base Organization City Corporate Plan City Development Strategy Centre for Environmental Planning and Technology Chemical Oxygen Demand Central Public Health & Environmental Engineering Organization Capital Utilization Ratio Dearness Allowance Financial Operating Plan Gujarat Industrial Development Corporation Gujarat Municipal Finance Board Government of Gujarat Government of India Gujarat Pollution Control Board Gujarat State Road Transport Corporation Gujarat Urban Development & Housing Department Gujarat Water Supply & Sewerage Board Housing & Urban Development Corporation Infant Mortality Rate Jawaharlal Nehru National Urban Renewal Mission Non Governmental Organization National Institute of Health Operating Ratio Provident Fund Reinforced Cement Concrete Rajkot Engineering Association Rajkot Municipal Corporation Regional Transport Office Rajkot Urban Development Authority Schedule Caste Suspended Particulate Matter Schedule Tribe Strength, Weakness, Opportunities and Threats Total Dissolved Solids Urban Development Plan Formulation and Implementation Workers Participation Rate
Detail Project Report for Drainage Phase-II &II (Part-I) for Rajkot city
v
Rajkot Municipal Corporation
Introduction
1
Introduction
1.1 Background Rajkot City with a population of one million (as per census 2001) and with an area of 104.86 Sq. Kms. is situated on the bank of river Aji. This fortified town on the West bank of Aji river was founded by the then ruler of Sardhar in the year 1608. The city is having good road, Rail and Air links with other important centers of the Country. Rajkot city has taken rapid strides in industrial and commercial development and is growing in to an important urban center in the State. Further, very fast industrial development also took place in the vicinity of Rajkot city. Area, like Sapar-Veraval and Lodhika Industrial Estate have also affected in the growth of population of Rajkot city and urban area of Rajkot remarkably. The metropolitan areas, cities and towns have attracted a large numbers of rural migrants for employment, higher education, purchases, medical treatment etc. Due to heavy rush on cities, Government of Gujarat formed independent autonomous urban development authority for six cities in the year 1978. Rajkot Urban Development Authority (RUDA) was formed on 30th January 1978. The authority has to plan, implement and follow up the development of 483 sq.km. This area includes Municipal Corporation and 39 villages in the immediate periphery of the city. Till June 1998 the authority had prepared eight town planning schemes in the immediate periphery of the city boundary towards west side of the city and covered land of three villages namely Raiya, Nanamava and Mavdi. Because of the development took place in the town planning scheme area, basic infrastructure facilities were sought out by the residents and ultimately in the year 1998, city limits of Municipal Corporation on western area (Mavdi, Nanamava and Raiya) was extended for 35.86 Sq.Km and total area of city limits became 69 sq.kms. to 104.86 sq.km. This resulted total population of the city about one million ( as per Census 2001). With the rapid growth of the city, the need arise to augment the existing basic infrastructures services of the city. Since the extended area was without any kind of infrastructure facilities these basic service needs to be implemented on priority basis.
On Implementation of Phase-II (Part-I) project there will be 90% coverage of drainage net work in old city area while in newly merged area as on date no sewerage system exists and presently the sullage water is being disposed of through surface drainage. On Implementation of the Phase-III ( Part-I) project the coverage would be about 42% .
1.2 Need of the Project The city is developing at a rapid pace and the population is expected to reach about 1.5 million by the year 2011. The generation of sewage in the year 2011 would be about 210 MLD, while existing net work and sewerage Treatment Plant is about 44.50 MLD only . This needs spcial attention on augmentation of STP and /or new STP
Detail Project Report for Drainage Phase-II & III (Part-I) for Rajkot City
1
Rajkot Municipal Corporation
Introduction
Govt of India recently launched urban Infrastructure development mission for selected 63 cities of India as Jawaharlal Nehru National Urban Renewal Mission (JnNURM) which also encourages preparing Detail Project Report for under ground drainage project Phase-II ( Part-I) and PhaseIII(Part-I).
1.3 Objectives The broad objectives of the Detail Project Report (DPR) are to determine a technically and economically viable Sewerage & Sewage Treatment project for a phased implementation to meet the requirements of the year 2030. Following are the specific objectives: 1. Assessment of the existing supply situation 2. Population and generation of sewage projections 3. Planning for Projects identified for JnNURM 4. Project scheduling & cost estimates 5. Projects phasing 6. To prepare operational plan 7. Organizational and financial studies 8. To set recommendation with respect to JnNURM reforms & sustainability
1.4 Scope & Limitations of the study 1. The study is limited to Rajkot city admeasuring area app.75 sq.kms. out of 104.86 sq.kms. 2. The study is limited to Drainage DPR for Rajkot city Phase-2 ( Part-I ) and Phase-3 ( Part-1) which are identified and outlined in City Development Plan ( 2005-2012) 3. Projects which are identified in CDP for RUDA area are excluded. 4. The DPR of remaining 30 sq.kms is under way of preparation and same is planned to be processed in the year 2007-08.
Detail Project Report for Drainage Phase-II & III (Part-I) for Rajkot City
2
Rajkot Municipal Corporation
Introduction
1.5 Methodology Aim/Objectives
Situation analysis Waste water characteristics
System analysis
Water supply network • Land use. • Population. • Population density zone wise. • Quantity of domestic waste water generated • Quality of waste water
♦ Institutional and financial analysis Staff structure for the drainage department Total capital investment for the sewerage system O & M expenses for sewerage system Existing Tariff Structure Level of Subsidy Proposed Tariff structure
♦ Total Quantity of water supply in MLD ♦ Quality of water ♦ Seasonal variation in water supply and consumption pattern
Sewerage network and treatment plant ♦ Quantity of waste water collected through sewerage system ♦ Present net work analysis fully covered area partly covered area un covered area present capacity of treatment plant ♦ Quantity of waste water collected through sewerage system ♦ Methods of effluent disposal
Identification of problems and issues
Requirement Assessment • Civil Design • Mech/Elect Design •
♦ Future requirement Population forecast Future Land use Water supply
Selection of best alternatives for cost • Costing
•
Implementation •
Drainage DPR (Phase II & III (part-I)
Detail Project Report for Drainage Phase-II & III (Part-I) for Rajkot City
3
Rajkot Municipal Corporation
2
Background of the study
B Baacckkggrroouunndd ooff tthhee ssttuuddyy
2.1 Sectoral Policies outlined in CDP Rajkot Municipal Corporation with the financial assistance from World Bank, an underground sewerage project was implemented costing Rs.40 crores and the said project was commissioned in the year 1994 with coverage area of 40sq.kms..Rajkot Municipal Corporation has taken up the work to connect the left out area of with underground drainage system and as on implementation of Phase-II work the 90% of old city area will be covered under underground sewerage system. As on date for new area the coverage is nill. The present sewage of old city is being collected through about 350 Km long collective system with 7 nos. of intermediate pumping stations. The whole network will cover approximately 60 sq.kms. of area with coverage of population about 6.5 Lakhs. The sewage is being pumped to the sewage treatment plant, which is located at 5 kms distance from the city. The capacity of the plant is 44.5 MLD, however, it is inadequate to cater the present quantity of sewage about 57 MLD, the process design of the plant is Facultative Lagoon followed by extended Aeration. In accordance with suggestions of citizens, elected representatives, officials & officers of RMC and other stakeholders involved in the entire city development plan process the outcomes and vision for Drainage net work for city the describe the total coverage. Outcomes also assumed that no sewage disposal without treatment to the river. This will require infrastructure development fund as suggested in JnNURM projects expenses. To achieve these out comes following strategies have been formulated in City Development Plan. These are the core value of this Detail Project Report DS1
: New Sewer Program & Sewage Planning_ This program is aimed at improving
the coverage of city waste water and also to cater population of newly merged area. It is proposed to augment existing drainage net work of old city limit by adding more 20 sq.kms. area and to implement an underground drainage system to the present developed area of 15 sq.kms (Out of 35 sq.kms newly merged area)> Similarly newly area the capacity of the plant will be 51 MLD. DS2:
Wastewater Treatment Planning_ the existing sewage treatment having capacity of
45 MLD, which is required to augmented by another 45 MLD. It is proposed as a part of city corporate plan that in the first phase during 2007, the STP is to be augmented for 45 MLD then after successively the capacity can be augmented. DS3
: Coverage of Low Income Settlements_ There is 84 slum notified slum area within
the old city limit of Rajkot. Existing drainage net work passes near to at least 55 slum areas. Therefore it is proposed to cover this locality by using Pay & Use type toilet facility under GOI & GOG scheme of Valmik Swatchhata Abhiyan. The same has been implemented by the Corporation. This will serve as part of slum networking program. It is proposed to use budgetary head of 63\2 as matching fund requirements Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
4
Rajkot Municipal Corporation
Background of the study
: Sewage Operation & maintenance _ Presently RMC privatized the O& M works.
DS4
It is found more effective, & economical. Therefore it is proposed to widen the scope of present contract system.
2.2 Linkage of the projects to the CDP Projects formulated and identified in CDP for drainage focus on_ Phase-II (Part-I) works for Rajkot inner city / old city area which consists of works of collective systems, house connections, pumping station STP etc.,. works of Phase-III i.e. work of newly merged area which consists of house connections, collective system , pumping stations STP etc., for newly merged area. JnNURM projects are identified as under:
No.
Details
20052006200706 07 08 Rajkot Under ground drainage project Phase -II old city area 1 Work of collective system & 300 300 300 house connections for inner city area
Year 200809
Rs. In Lakhs 20092010201110 11 12
Total
300
245
50
50
1545
15 135 0 0 Additional pumping machinery in various pumping station 3 Work of Rising main from 50 455 0 0 poptpara pumping station to sewage treatment plant 4 Extension of existing treatment 0 400 200 200 plant by 44.5 MLD at Madhapar Rajkot Under ground drainage project Phase -III for newly merged area 5 700 700 700 700 Const of main line , collective
50
50
50
300
0
0
0
505
0
0
0
800
500
500
500
4300
2
6
7
8
9
system & house connections in new area & road reinstating work Pumping stations & with electrical mechanical allied works in new area Const of Sewage Treatment Plant of 51 MLD capacity at Raiya Purchase of equipments - Jetting machine-03, cleaning machine 10, power bucket -23 dewatering set-10 sets , safety equipment Development of MIS and Redressal system Total Phase wise percentage
200
200
268
0
200
200
100
1168
0
400
570
0
0
600
500
2070
0
200
500
0
0
0
300
1000
20
0
0
0
0
0
0
20
1285 10.98
2790 23.83
2538 21.68
1200 10.25
995 8.50
1400 11.96
1500 12.81
11708 100
.
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
C Chhaarraacctteerriissttiicc ooff tthhee ssttuuddyy aarreeaa
3
3.1 Regional Profile with Location Map Rajkot is situated in the middle of the peninsular Saurashtra in central plains of Gujarat State of Western India at a height of 138 m above mean sea level. It lies between latitude 22.18 N and longitude 70.51 E. It has an area of 104.86 sq. kms Rajkot is head quarter of Rajkot District and the city is connected with other parts of the country by Rail, Road and Air. There are broad gauge railway line of Western Railway between Viramgam-OkhaPorbandar and meter gauge railway line
between
Jetulsar-Veraval-
Bhavanagar. It is also well connected by broad gauge railway line with Delhi and Bombay the important two Metropolitan cities of India. Also there are major roads and NH-8 a links Kandla, NH-8 B links Porbandar and state capital Gandhinagar. State highways connect Rajkot to other important towns of the region like Surendranagar,Porbandar, Junagadh, Veraval, Bhavnagar, Amreli, Bhuj, Kandla, Ahmedabad,, Baroda etc., The city is also served by an aerodrome and linked by air with Baroda, Bhuj, Bombay, Delhi and Ahmedabad.
3.2 Climate & Rainfall Climate: The climate in the city is hot and dry. The average maximum and minimum temperatures recorded over the last 40 years are 43.5 deg C and 24.2 deg C respectively. Rainfall: The average annual rainfall is 500mm. However, over the last 60 years, it has been below normal during 20 years. In these years, the city along with the Rajkot Urban Development Area (RUDA) faced acute water shortage. The average annual rainfall is observed about 500 mm. in the area.
3.3 Geography Rajkot forms central part of
Saurashtra Peninsula and has a diverse landscape made up of
plateau, hills, linear ridges and alluvial plains. The southern and western parts of the city are primarily covered by Deccan Traps, characterized by undulating topography with the presence of plateaus at some locations. In the northern part, topography is plain with gentle slope towards north and west. The average elevation attained in the district is 130 meters above mean sea level. The general topography of RMC area is almost undulating with level difference from 125 m to 158 m from south east to north west. The city of Rajkot is situated along the Aji River, which is seasonal in nature. The main tributary of Aji in the area is khokhadadi located on southwest side of Rajkot city. Two nos at natural Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
6
Rajkot Municipal Corporation
Characteristics of the area
water reservoirs (lakes) are located near Rajkot city viz. Lalpari and Randerda, at the distance of 4 kms and 6 kms respectively from the city. Across the river Aji , Aji reservoir is built up at a distance of 9 kms from Rajkot city and Aji II at a distance of 15 kms. In the RUDA area Nyari I and Nyari II reservoirs are constructed which are located within of 15 Kms to 30 Kms from the city. In addition to this, for draining storm water, Nos. of Natural courses exist, in RMC and RUDA areas which are ultimately meting to river Aji to drain storm water. Soil Type: Soil of the entire Rajkot area can be broadly classified as medium black to shallow black. The black soil, being rich in minerals and organic matter is more fertile. These soils have been formed even from granite and gneiss parent materials. The depth of the top soil is generally 25 cm to 50 cm deep. The color of soil surface varies from light gray to dark gray and is clayey in texture. The soil reaction is neutral to alkaline with Calcium Carbonate. Beyond 50 cm depth the under ground strata are soft rock & hard rock. The vegetative cover is minimal in the open area due to lack of adequate topsoil. The topsoil is underlain with hard rock formations thereby limiting the growth of vegetation in the region. . Ground Water Table The fluviomarine alluvium of Upper Tertiary to Quaternary age forms poor aquifer because of the predominance of argillaceous nature of formations and poor quality of ground water. The ground water occurs under water table and confined conditions. Depth of tube wells ranges from 30 to 120 meters below ground level, whereas depth to water level ranges from 20 to 100 meter below ground level. The seasonal fluctuations in the water table ranges from 1.8 to 12.0 meters. The yield from the tube wells ranges from 2.50 to 10.00 cubic meters/day. In hard rock areas the availability of ground water in a particular year is the direct response to intensity of monsoon and quick response is seen in such aquifers. In the years of normal and above normal rainfalls the water level decline. The seasonal availability of ground water also varies widely. Rajkot district forms central part of Saurashtra Peninsula and has a diverse landscape made up of plateau, hills, linear ridges and alluvial plains. The southern and western parts of the district are primarily covered by Deccan Traps, characterized by undulating topography with the presence of plateaus at some locations. In the northern part, topography is plain with gentle slope towards north and west. The east west trending linear ridge forming upland south of Rajkot forms water divide for south & southwesterly flowing drainage basin of Bhadar and north & northeasterly flowing drainage basins of Aji, Machhu etc.
3.4 Environmental Setting The presence of industrial and commercial activities on a large scale, in and around Rajkot, tends to have strong impact on the environmental quality of the city. The concentration of polluting industries such as the foundries, electroplating units, Sari –printing, manufacturing of dyes and chemicals within the city and lack of basic infrastructure particularly, inadequate drainage connections and bio-medical waste generation tends to take its toll on the environment. Issues related to air pollution, water pollution and pollution from waste is much of concern about citizens. Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
7
Rajkot Municipal Corporation
Characteristics of the area
Air Pollution : The principal sources of Air pollution in Rajkot are from vehicular emissions, industrial emissions, construction related activities. Uses of Kerosene as fuel by Auto- rickshaw, pollution
from
Chhakada
and
emission relatively
of more
Month
numbers of the two-wheelers are sources
of
vehicular
While
sources
emissions.
of
industrial
emissions are mainly from the foundries, small scale industries and bricks manufacturing kilns. Ambient
air
quality
Aug-2003 Octo-03 Dece-03 Feb-04 Apr-04 July-04 Aug-04 Sep-04
Table : 5.1 Quality of Air SO2 in µg/cu.mt. NOXµ µg/cu.mt. Indu. Area 24 17 18 21 25 7 12 13
Resi. Area NA 17 14 7 15 23 10 11
Indu. Area 18 10 24 21 21 14 12 18
Resi. Area NA 14 19 7 14 8 13 10
SPM in µg/cu.mt. Indu. Resi. Area Area 550 NA 230 120 310 210 190 210 320 130 180 180 230 210 240 160
monitoring is carried out at three locations by Gujarat Pollution Control Board (GPCB) since 2000. The Monthly average of SO2 , NOX, and SPM of last year as collected from two station viz., Aji GIDC Industrial area and GPCB Office- residential area are as shown in the table below: O2 and NOX levels in Rajkot are within the NAAQS (Monthly Average) during both the years. However, the SPM levels in Rajkot are found exceeding NASQS(Monthly Average) during both the years, particularly in Industrial Area and 50% time in a year in residential area. Water Pollution: The city lies within the watershed expansion of Aji river basin and it is network of 19 natural drainage courses, locally known as Voklas. Unfortunately, these voklas are being used for sewage disposals resulted the pollution of water Aji- river in down stream of Aji dam. Nyari-2 dam which collects water from Aji river and Nyari river is fully polluted water dam. An analysis of different water bodies in down stream of Aji dam indicates the most of water bodies within city limit are contaminated. Pollution of under ground water due to electro-plating industries and sari-printing industries is also observed. Pollution due to SW : The main causes for pollution include increasing household and commercial waste, commercial waste as well as bio-medical waste. Though, Rajkot Municipal Corporation is making efforts to ensure minimize the solid waste at source, but the result is not being seen up to the mark.
3.5 Growth of City The city does not have a long history. It was founded by the then ruler of Sardhar 1608 A. D. on the west bank of the river Aji as a small fortified town. by Ruler of Sardhar Gradually, it became a Princely State in the year 1805. The British Government developed the old city area popularly known as Sadar during 1820 to 1870. The old town and Sadar area being part of the city were developing simultaneously.
Both these areas were separated by North-South Railway track then existed but
subsequently railway track was removed. Both these areas merged with each other resulting in coordinated development of the town. Hence the city developed from a village, civic development was Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
8
Rajkot Municipal Corporation
Characteristics of the area
in the process and in the course of time some of the major works came to be permanently visible. To name some of them, we can mention Raj Kumar College, Alfred High School which was subsequently named Mahatma Gandhi High School, Jubilee Garden, Railway line, Railway Junction, Lakhajiraj Railway Station which geared up the development of whole town of Rajkot. By the end of 19th century, Rajkot emerged as a premier town having a population of 36,000. Rajkot was capital of Ex-Saurashtra State and has a central location in the region being a part of Gujarat State. Its importance as a capital is attributed to geographical location, its cultural heritage and the development potential possessed by the city.
The present level of development of the city is
outcome of the process of progressive development going on since decades. It will be useful to recall the historical background of the city enjoying a position of importance in the field of Trade, Industry, Education, Transportation, Communication, Entertainment and urbanization. Rajkot is also affected by the wave of rapid urbanization and industrialization in the country over the last few decades. The development of trade and industry has gradually reshaped the life of the people. In the earlier period, the establishment of cloth mills in the city led to the development of new residential areas like Millpara, Harishchandra Plot, Gundawadi, Kevdawadi etc. The new Railway Station known as Bhaktinagar station also came into being. Further, around the year 1940, new industrial estates, residential areas, schools, colleges, cinema houses came into being. Thereafter, Rajkot eventually became a vibrant trading city with a wide network of transport facilities by air, railway and road. A number of transport companies established their head offices at Rajkot. The Industrial Estates known as Bhaktinagar Industrial Estate and Aji Industrial Estate were established. Trade and Industry fast developing in the city also attracted foreign investment during these periods. This trend of city development generated rising demand for creating new civic amenities in the city.
3.6 Settlement Pattern Rajkot is a town of comparatively recent growth. In about 400 years, it has developed from a small hamlet to a prosperous town today. Up to 1820 the growth was not too rapid, but after the British government established its camp in 1822 the town opened new directions of growth. The industrial development and the urban influence of the city started with the establishment of the first textile mill in the region towards the end of 1910;. About 60 industrial units came into existence between 1900-1920 , which induced development of the city to a great extent. With the have the industries trade and commerce also flourished inviting the immigrant population to a large extent. With increasing industrial, trade and commerce activity, there has been tremendous growth in the population of the town. The city’s population has been experiencing an average growth of around 50 % since 1961. There was a sudden increase in the population in 1941-51 decade ( 99%) which was because of large number of government offices being established in the city of Rajkot after formation of Gujarat
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
9
Rajkot Municipal Corporation
Characteristics of the area
state, creating large number of employment opportunities. However, since then the decadal growth rate is fluctuating between 41% to 54%. The city has grown up in area from 150 hectare in 1901 to 10404 hectare in 1998. i.e. it has growth approximately 70 times of its initial size. The city is growing rapidly in western direction. However, city is also simultaneously growing in all direction. The city can be divided in to three parts due to Aji River and railway tracks, which are passed through the city. The city has greater and prosperous development on the western side, Industrial development on Southern side and low-income housing towards northeastern side. At present, Rajkot Municipal Corporation covers an area of 104. 86 sq.kms. including merged three area viz., Raiya, Nana-Mava and Mavdi area. The city is divided in to 23 administrative wards.
3.7 Demographic Profile Population Growth trends The population of Rajkot city is 10,02,000 as per the 2001 census. The population has grown from 36,151 in 1901 to 10,02,000 by the year 2001. with an average annual growth rate of 3.29%. Table: Population Growth in Rajkot city
During independence period Rajkot city
Year
Population
Growth rate
1901
36151
---
large
1911
34191
-5.42
immigrants’ refugee from Pakistan. Also in the
1921
45845
+34.08
last decade the city registered the growth rate of
1931
59122
+28.96
79.12% , this is attribute to the increasing the
1941
66353
+12.23
Corporation
1951
132069
+99.04
1961
194145
+47.00
1971
300112
+54.58
1981
445076
+48.30
1991
559407
+25.69
2001
1002000
+79.12
experienced highest growth rate 99.04% in between
1941
to
limit
1951
by
because
merging
surrounding village in June-1998.
of
the
three
Chart :1.1.2. Population Growth in Rajkot city
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
Rajkot City Population Trends 1100000 1000000 900000
Population
800000 700000 600000 500000 400000 300000 200000
2001
1991
1981
1971
1961
1951
1941
1931
1921
1911
0
1901
100000
Year Population Projections: The trend of population growth is an important indicator and base for the assessment of future requirements of basic in the area for the future. In 1963, the RMC area was extended from 38 Sq Kms to 69 Kms. Again in June 1998 the RMC area was extended by another 34.865 Sq Kms. This is credited to the immense growth in trade, commerce and industry, in and around Rajkot. Population projections for the RMC area have been carried out on the basis of the past growth trends. It is required to estimate separately for RMC old area and Newly merged area as on June 1998. The population growth rate of RMC area has been given in table. It has been observed that since last 100 years, the population of Rajkot City has increased at different growth rates. The growth rate of Rajkot City from 1901 to 1941 has been calculated as very nominal i.e. 0.15 on average annually. After Independence i.e. after 1951, the rate of population growth of Rajkot City has increased tremendously. Based on the above population figure for the past decades, the RMC population ( excluding newly merged area)has been projected utilizing ratio methods, the geometric growth method as well as incremental increase method and graphical method. The growth rate in higher side found as 3.11% raise per annum, medium as 3.05% and lower growth rate as 2.67%. However, Population growth rate of newly merged area found population growth rate as 11.79%. Therefore, combine population growth rate for RMC old area and the merged area calculated. The combined growth rate found as 4.59% for higher
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
side, 4.05 Medium side and 4.00% for lower side estimation. Table 1.1.3 shows population projections for the years 2011and 2021. Table: RMC Population projection Sr.
Year
Population Projection
No
High
Medium
Adopted Population Projection estimate
Low
1
2011
1,570,000
1,484,500
1,490,000
1,484,500
2
2021
2,215,000
2,207,000
2,232,000
2,207,000
Thus total population of the RMC area in the year 2011 is expected to 14.85 millions while for the year 2021 reach to 22 million persons.
Chart: Rajkot City Population Projection
RMC Population Projection 2500000
Population
2000000 1500000 1000000 500000 0 1971
1981
1991
2001
2011
2021
Year Density : The population of Rajkot city is spread over an area of 104.86 sq.kms., with density of 9556 persons /sq.kms. The density in the older part of the city wards like ward no.1 to ward 8 ranges from 14952 to 35653 persons per sq.kms. the lowest density 3131 person per sq.kms. is registered in ward no.7 having the largest area. Ward no.2 has highest density of 35653 per sq.kms.
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
Table 1.1.5: Ward wise Population, Area and Density of Rajkot city Ward 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Total Newly Merged Area ( 21-23) TOTAL •
Area ( sq.kms.) 0.8227 0.7012 1.0900 1.0822 5.0741 1.7588 3.4360 0.9108 1.4714 1.5277 1.8571 2.875 2.9419 4.0682 1.2919 7.1330 18.8416 4.7052 5.7221 1.3905 69.6836 35.1764 104.86
As per 1991Census Population Density 29766 36181 26738 38132 28104 26289 30411 28101 29505 5815 27097 15406 29677 8637 27547 30245 26943 18311 25669 16802 25322 13635 25499 8869 25222 8573 25602 6293 26761 20663 25316 3549 30999 1645 31146 6619 30848 5391 31235 22463 559407 8028 81971 22330 641378
6116
As per 2001 Census Population Density 25000 30388 25000 35653 29000 28431 30000 27721 61000 12022 52000 29566 52000 15134 27000 29644 22000 14952 42000 27492 28000 15077 34000 11826 41000 13937 37000 9095 26000 20076 26000 3645 59000 3131 46000 9776 58000 10136 35000 25171 755000 10835 247000 7022 1002000
Rise/ Fall -ve -ve +ve -ve +ve +ve +ve -ve -ve +ve +ve +ve +ve +ve -ve +ve +ve +ve +ve +ve
9556
Literacy Rate: Literacy level of Rajkot has always been higher than state literacy levels. With a total literacy rate of 73.86% in the year 2001, the
city has comparatively higher literacy rate than 69.96% of State literacy rate as well as 54.16% of National literacy rate. •
Slum Population: Rajkot city has 84 notified slum area having population of about 202371. It is spread in almost all wards. There are total 106574 males & 95769 female including total children of 88865 (30516 children age below 5 yrs.& 58349 children age 6-17 yrs.). It shows sex ratio as 899:1000. The caste structure is found as 33.29% SC, 2.47 % ST, 45.22 OBC (Other Backward Class) & 10.02% general. The literacy rate is observed 63.70%. Out of 44914 household of slum and urban poor, it is found in total survey of all household that (survey carried out by united research organization survey,2002), 32701 HH are living below Poverty line i.e. about 72%. The total population below Poverty line is about 147342 people. Comparing to total population of Rajkot city, which is 1002000 as per census 2001, the BPL population is about 14.7% of city population.
3.8 Land Use Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
Rajkot city is characterized by a pattern of multiple land uses. The total area developed for urban activities constitute 77% of the Rajkot Municipal Area. Residential use occupies about half of this area, while industries occupy a fifth and commercial zones occupy less than 2%. Although a
Land Use
Residential Commercial Industrial Traffic & Transportation Public & Semipublic Recreational Space Agriculture Water bodies Vacant Land Other TOTAL
Table: Land use Break Up Existing Land Use Proposed Land Use as as per 2001 per DP 2011 Area in Percent Area in Percent Hectare Hectare 4247 40.50 5502 52.47 209 2.00 279 2.66 628 5.99 738 7.04
development
plan
has
been
prepared, poor implementation and enforcement
result
in
quite
different ground realities. Rajkot is plagued by problems of informal sector including slum development,
1400
13.35
1650
15.74
illegal colonies and commercial
149
1.42
249
2.38
encroachments and a lack of
123 995 236 1510 988 10484
1.17 9.49 2.25 14.40 9.42 100 %
523 800 236 -508 10486
4.99 7.63 2.25 -4.84 100 %
industrial zoning and unplanned mixed land use. The developed
for
total urban
area activities
constitute about 77 % of the city
area and balances constitute activities enmarked for vacant land, water bodies and other purposes. •
Residential Uses: The residential development is spread over 54 sq.kms. high density of
residential development is found in older parts of city especially Kotak street, Raghuvir para, Ramnath para, Kumbhar wada, Soni bazaar etc., The densities are low in the newly merged area especially in and around kalwad road, Raiya road, 150 feet ring road, university road and in some parts of junction area, popat para area etc. It is obvious that newly developed area where TP schemes were developed is planned. However, old city areas like Prahlad plot, Jayraj plot area are developed with a regular street pattern, well shaped plots but these area lack open space. Percentage of residential area to total area is found 51.34% while residential area to developed area is 60.23% . •
Commercial Use: Main commercial areas are Soni bazaar, Dharmendra road, Lakhajiraj road,
area around jubilee vegetable market.etc., of old city, which is also described as city area ‘ A’ in GDCR; Yagnik road, Dhebar road, gondal road, Jagnath area etc., which is known as city area ‘B’ etc.; and Kalwad road, amin road, university road, Raiya road, st.kabir road, pedak road etc, called ‘Other area_ as described in GDCR’. Traditionally, dana pith area was for grains & grocery whole sale and retail marketing; lakhaji raj road, kapad market and dharmendra road for clothing sale; soni bazaar for jewellry market; sadar for retail provisions stores etc., are established since long. These commercial activities demand substantial space in prime areas. The percentage of commercial area to total area is found about 1.89%, while same is to develop area seems to about 2.11%. •
Industrial Use: Two Industrial estates were developed by Gujarat Industrial Development
Corporation. They are Bhaktinagar Industrial Estate and Aji Industrial Estate. Above which ,sorathiawadi Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
plot area had been developed by private developers as another industrial area. Besides, National Textile mill, which is closed, occupies very prime land and is spread in huge area. Rajkot city is developed as an industrial city hence, growth of industries and residences of industrial employees developed simultaneously which resulted in mixed land use pattern. The percentage of Industrial area to that of total area and developed area are found 20 % & 22.28% respectively. •
Public Purposed Use:Main components of Pubic purpose use can be described as open space,
parks & play ground, recreational space, hospital space, schools, govt. office buildings etc., The major contribution to the component is by race course complex, which has facility of international cricket stadium, indoor stadium, hockey ground, foot ball ground etc.; garden and fun world & open ground. Other such space is Shastri Maidan. The total public purposed space to total area is 9% while it is 10% against developed area.
3.9 Housing Housing reflects the economy & quality of life of any urban area. Poor planning mechanism leads to slum & illegal growth. Though, there exists an elaborate Regulatory Mechanism to promote, guide & control the building activities, it is often claimed that its procedure are very restrictive and difficult to comply. Such rigidity in regulation mechanism has minimized its scope. Almost 25 to 28 percent addition to the housing stock are estimated to be made informally without obtaining necessary permissions and sanctions. On one side lot of financial agencies and Govt incentives, encourages the development of housing sector where as on other side the regulation mechanism creates complex hurdle to the development. Therefore it is necessary to form housing strategy for better city and reducing slum & illegal development. As described above there are 51.34% land is reserved for Residential purpose. Out of which 80% is being developed. The average house holds size as per census 2001 is 5.64, and the total number of residential property as per RMC tax branch report is 1,65,000 which describes about 40000 yet to be required. It is observed that nearly about 5000 dwelling units are added annually to the housing stock of the city. In contrary to this, the number of applications for development permission received by RMC is as low as sixteen hundred. However, many of these applications are taken for multi-storied building having more than one dwelling unit. On these ground, it is estimated that nearly half of the dwelling unit’s are constructed beyond the framework of regulation framework. The development permission in the Rajkot city is accorded as per the provisions given in General Development Control Regulation (GDCR)- revised May-2000.
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
It is estimated that more than 75% dwelling units out of total
Year
houses constructed for lower income groups, 55% out of total houses
constructed
for
MIG
2001/02 2002/03 2003/04 2004/05
Table: Status of Land Development Developed land Undeveloped and under (hectares) developed land under use (hectare) 7744.843 2740.922 7894.843 2591.157 8052.740 2433.000 8213.795 2272.205
groups and similarly 25% for out of total houses constructed by high-income group housings are constructed without development permission. The incessant process of urbanization and rapid industrialization has increased the population of Rajkot. From 132, 000 in 1951, the population figure rose to 1002000 in 2001 registering a growth rate of about 759 percent in five decades. Though the population has grown by leaps and bounds but the corresponding provision of housing facilities has not kept abreast. Shortage of housing facilities has contributed to the emergence of slums. At present there are 84 (74 recognized + 10 unrecognized) slum localities with an approximately population of 202371 within city Municipal limit. The slums in Rajkot are experiencing a faster growth rate than that of the city in 1972-73. There were only 24 slums, with 4927 nos of households in Rajkot in 1972-73. At present, there are 84 slums with 44914 nos of households. This indicates an increase of 468 per cent in slum population in just thirty years. Since the slum population is 2,02,380 and the present population of Rajkot is about one million, it can be concluded that almost 20 percent of the Rajkot population live in slum areas. Slum Housing: Most of the slum population resides either in pucca or semi-pucca houses. About Table: 4.4 Type of Slum Houses Hutment type Number Percentage Total Temporary( kutcha) 513 1.15 Semi-Permanent 31971 71.18 Permanent 12430 27.67 Total 44914 100
1.15 per cent resides in huts made of kutcha (temporary) materials. Generally a house has one
multi-purpose
room,
kitchen
and
verandah. The roofing material is either local tile or pre-cast slabs. As indicated above,
71.18 per cent of the hutments in the slums in Rajkot are built of semi-permanent or temporary (kutcha) material.
3.10 Civic Authorities The city has 23 election wards and an elected body comprising of 69 members elected at the rate of 3 members per ward having one female member from each ward. The breakup of councilors works out as under: General seats
38
Women councilors
23
Scheduled caste
4*
Backward classes
7*
* Out of 4 schedule caste councilors, one is included in the women's group. Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
** Out of 7 backward class councilors, two are included in the women's group. The ward-wise population and break up of the elected representatives in terms of female councilors, councilors from reserved category as well as from general category is shown in statement kept at Annexure-A. The elected body is responsible for governing the affairs of the municipal corporation. The City Corporation has a mayor whose term is for a period of two and half years and for the first time in the history of Gujarat State by an amendment in law, the mayor has been brought into the main stream of municipal administration. Unlike many other states in india, the Mayor of Rajkot enjoys certain powers to effectively carry forward the activities of city government. The Municipal Corporation's administration is under the control of Municipal Commissioner. His appointment is made by the State Govt. from time to time. He is assisted by Deputy Municipal Commissioners and a large work force of Municipal officers and servants to discharge the functions of the Corporation. The main functions of the corporation are as under: Water supply Sanitation City cleaning and waste disposal Health Roads Streetlights Fire brigades Parks and gardens Library, etc. Separate department of Drainage is under the administrative control of the City Engineer.
3.11 Status of Legislation Law is the basic instrument that defines rights and obligations. The legal framework is governing a particular infrastructure sector development. ‘ Regulatory Frame work’, means the statutes, rules, regulations and administrative orders governing for various components of city development strategy. Legal and regulatory stipulations lay down a framework of planning and management and also emphasise the government’s commitment to improve quality of life of citizens. Though BPMC Act, TP & UD Act and 74th CAA describes duty, functions and powers for Urban Local Bodies in the state, but it is also necessary to set a set of such a regulatory frame works which can develop state of art for running the show as well as total control and command approach for executing infrastructure of the city In the Gujarat, and particularly for Municipal Corporations there are three legal relevancies are essential to explore urban infrastructure development and financial resource generation. These are_ 1. 74th Constitution Amendment Act ( CAA) 2. Bombay Provincial Municipal Corporation Act,1949 3. Gujarat Town Planning & Urban Development Act, 1976. Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
Besides there are number of laws, like Food Adulteration Act, Animal cruelty law, the different legislation enacted in India exclusively for environmental protection and conservation are: a. The Air (Prevention and Control of Pollution) Act 1987 b. The Water (Prevention and Control of Pollution) Act 1974 c. The Environment Protection Act 1980 d. The Forest Conservation Act 1980 e. The Wildlife Protection Act 1972 and f.
The Public Liabilities Insurance Act 1991
It may be interesting to note that there are about two hundred laws dealing with environmental protection both before and after Independence India. The 42nd amendment to the constitution enacted in 1974 has two Articles (Art 48-A) and (Art 5-IA (g) - throwing the responsibility on the State government and on every citizen to protect and improve the environment. A study of these laws reveals that a number of provisions are suggestive and advisory. The Indian Penel Code (IPC Section 270) provides a fine of Rupees 200/- for creating public nuisance and health hazard and Rupees 500/- for making atmosphere noxious. Thus adequate Legislations are there but they require proper review for making it more effective. 74th Constitutional Amendment Act 74th Amendment Bill was passed in December 1992. The Bill was ratified by almost all the states with few exceptions. It received the assent of the President in April 1993, and came into force on June 1,1993. However, the Constitution –74th Amendment – Act 1992, provides for a period of one year by way of transition during which time amendments to the existing State Acts have to be carried out so as to bring provisions of the said Amendments Act. Salient Features of 74th Constitution Amendment Act 1992 a. The provisions of the 74th Constitution Amendment Act 1992, being pad of the constitution are applicable to all the States. They are applicable to the union territories also (243-ZB). b. This Act has conferred powers on the President of India to direct, by a public notification, the application of this Act to a part of a union territory also with such exceptions and modifications as he may specify in such notification (243.78 Proviso). The provisions of this 74th Constitution Amendment Act are not applicable to the scheduled areas specified in Art. 244(1) and the tribal areas specified in Art. 244(7) c. Definition of urban areas (243-q (1)) d. Division of municipal area (urban local body) into wards (243-r (1)) e. Composition of each municipal body (243.r (2) f.
Constitution of ward committees (243-s (1)(2))
g. Levy of taxes and fees (243-x)
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
a. The State Legislature is competent to authorize a Municipal Council to levy, collect and appropriate such taxes, duties, tolls and fees in accordance with such procedure and subject to such limits, (243-X (a)) b. The State Legislature is also empowered to assign to Municipal Council such purposes and subject to such conditions and limits. (243X(b)) c. The State Legislature is competent to make provisions to allotment of such grants-in-aid to the Municipality as it may consider necessary, from the Consolidated Fund of the State (243 X(c)). d. Constitution of funds in the municipal financial administration (243-x(d)) e. Functions & Responsibilities of ULB_ Extract of Twelfth Schedule (Article 243 W) of Constitution of India Schedule –XII gives the list of functions & responsibilities to Urban Local Bodies as describe below: 1. Urban Planning including town planning 2. Regulation of land-use and construction of buildings 3. Planning for economic and social development 4. Roads and bridges 5. Water Supply for domestic, industrial and commercial purposes 6. Public Health, Sanitation conservancy and solid waste management 7. Fire services 8. Urban forestry, protection of the environment and promotion of ecological aspects. 9. Safeguarding the interests of weaker sections of society, including the handicapped and mentally retarded 10. Slum improvement and upgradation 11. Urban poverty alleviation 12. Provision of urban amenities and facilities such as forests, gardens, playgrounds 13. Promotion of cultural educational and aesthetic aspects. 14. Burials and burial grounds; cremations, cremation grounds and electric crematoriums. 15. Cattle ponds: prevention of cruelty to animals. 16. Vital statistics including registration of births and deaths, 17. Public amenities including street lighting, parking lots, bus stops and public conveniences Bombay Provincial Municipal Corporation Act, 1949 In Gujarat, Bombay Provincial Municipal Corporation Act, 1949 was enacted for Municipal Corporation of Gujarat. The act was amended as Gujarat Act No.21 of 1989 on 05.09.1989, thereafter, for Municipal Corporations in Gujarat have to function as per the Bombay Provincial Municipal Corporation Act (Gujarat Amendment) Act, 1989. However, till to day the amendment act is popularly described as BPMC Act.The Act contents 33 main Chapters, Four Appendixes, and Four schedules. Chapter –IV about administrative set-up while Chapter-V to VIII, largely describes the powers & Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
functions including obligatory & discretionary duties of the Corporation as well powers and mode of contractor and Acquisition of property & disposal of properties. Relevant sections of BPMC: Important section of BPMC Act, 1949 in respect to urban infrastructures facilities, taxes etc., are as given below: Sr. No. 1
Relevant Sec. BPMC Act Sewerage Sec.63 (3) Chapter-VI Sec.153-155 & Sect.161 Chapter-XII Sect.161-XII Sect.157-XII Sec.176-177 Chapter-XII Sec.157(2) Chapter-XII
Sec.168 & 169 Chapter-XII The Schedule (A) – Chapter-IX
Main contents of the section
Essential Service: Matters to be provided for by the Corporation as Obligatory duty Drainage works: Drains to be constructed and kept in repair by the commissioner Adoption by corporation of drains and drainage or sewage Powers for making drains Maintenance of Drains including pumping station Sewage Treatment Plant :Appointment of places for emptying of drains and disposal of sewage Purchasing Sewage Cleaning Machinery: For the purpose of flushing, cleaning and emptying the drains, the commissioner may construct or set up such reservoirs, sluices, engines & other works , as he shall from time to time deem necessary Prohibition : Commissioner may close or limit the use of existing private drains & Vesting & Maintenance of drains for sole use of properties Drains & Drainage works: Describes the ways and means of new drainage network as well public & private bath-room & WC
2
Environment & Slum Up-Gradation Sec.280-284G-XVI Declaration of Clearance area besides re-development area Sec.63/2 Clause for fund allocation of 10% budgeted exp. For the development Chapter-VI of backward area. Sec. 307 -XVIII Overcrowded dwelling Sec.308 - XVIII Unsanitary huts and sheds Gujarat Town Planning & Urban Development Act, 1976 Gujarat Town Planning & Urban Development Act 1976 enacted, which came in to force from 21st June 1976.The act extended to whole of Gujarat. The GTP & UD Act consist of eight chapters and 124 sections. TP Schemes Micro Level Planning tools: Section 40 to section 76 describes various provisions in respect to micro level planning viz., TP scheme largely it contains three parts 1. Draft Scheme 2. Preliminary Stage 3. Final stage It follows following path 1. Preparation of the Final Scheme by T .P. 0. (Section52/3). 2. Declaration of decision of T.P.O. to parties (Section 54).
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Characteristics of the area
3. Constitution of the Board of Appeal to hear and decide appeals (Section 55/1) 4. Board of Appeal's decision communicated to TPO (Section 62/2). 5. Sanction of the Final Scheme with or without the modifications (Section 65/lb) 6. Final scheme comes into force (Section 65/2) Relevant Section of GTP & UD Act-1976 for Infrastructure Development Table: GTP & UD Act, 1976 relevancy for MC Infrastructure Development Sr. No 1
Relevant Sec. GTP&UD Act,1976 Main contents of the section Sewerage & Storm Water 12(2)(e) Proposals for water supply, drainage, sewage disposal, other public utility amenities and services including supply of electricity and gas 12(2)(n) 23(1)(vi) 40(3)(f) 40(3)(jj)(a)
2.
Finance 23(1)(vi-a) 23(1)(viii) 24(1) 77(1)(b) 77(1)(g) 92
Provisions for preventing or removing pollution of water or air To execute works in connection with supply of water, disposal of sewerage and provision of other services and amenities; Drainage inclusive of sewerage, surface or sub-soil drainage and sewage disposal The allotment of land from the total area for roads, garden/O.S., infrastructure and plots for sale To levy and collect such fees for the execution of works referred above To enter into contracts, agreements or arrangements Local authority functioning in the urban development area to pay contribution to development authority Sums to be spent for the cost of works Amount of the cost of infrastructure provided in the area adjacent to the area Power of authority to borrow money
********
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Rajkot Municipal Corporation
Existing Situation
E Syysstteem mO Ovveerrvviieew Exxiissttiinngg S w
4 4.1 General
Prior to implementation of underground sewerage project, the city waste was being collected through surface drainage and was being disposed off in the river Aji which ultimately was meeting at Aji-II reservoir constructed in down stream of Rajkot city on river Aji . However, as per the guidelines of Water Pollution Control Board, it is not permissible to dispose off the untreated sewage in natural courses. Under the circumstances, Rajkot Municipal Corporation started under ground drainage work phase wise programmes is as under_
Sr Phase No 1 Phase-I
2
Phase-II (Part-1)
3
Phase-II (Part-2)
4
Phase-III (Part-1)
5
Phase-III (Part-2)
Table:4.1 Phasing of Sewage City area /coverage
Status of work
Old city area which is admeasuring 69 sq.kms. out of Works are already completed between which 40 sq.kms. had been covered in this phase 1981 to 1994 Old city area which is admeasuring 69 sq.kms. out of Works are proposed to which 20 sq.kms., which is planned carry out during 2006 to 2008 period Old city area which is admeasuring 69 sq.kms. out of Works will be carried which remaining 9 sq.kms., which is yet to be planned out during 2008 to 2010 period Newly merged which is admeasuring 35.86 sq.kms., out Works are proposed to of which 15 sq.kms., which is planned be carried out during 2006 to 2008 period Newly merged which is admeasuring 35.86 sq.kms., out Works will be planned of which 20.86 sq.kms., which is yet to be planned and carried out during 2008 to 2010 period
4.2 Rajkot Underground Drainage work - Phase- I & Phase-II Phase-I & Phase-II Drainage Network : Rajkot Municipal Corporation with the financial assistance from World Bank, an underground sewerage project was implemented costing Rs.40 crores and the said project was commissioned in the year 1994. Subsequently, Rajkot Municipal Corporation had taken up the work of to connect the left out area of with underground drainage system and on completion of Phase-II ( Part-I) 90% of old city area will be covered under underground sewerage system and balance area of old city is proposed to be covered during the year 2008-10. The present sewage of old city is being collected through about 350 Km long collective system with 7 nos. of intermediate pumping stations. The sewage being pumped to the sewage treatment plant for the treatment, the capacity of the plant is 44.5 mld, however, it is inadequate to cater the present quantity of sewage about 64 MLD.
Detail Project Report for Drainage Phase-II & III ( Part-I ) for Rajkot city
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Rajkot Municipal Corporation
Existing Situation
In 1980-81, the project was conceived for whole city approximately 60 Sq. Kms. area. However, at that time the development of the city was only in 35 to 40 Sq. kms. & remaining 20 sq. kms. was Greenfield under the circumstances the project was specified in two parts as under : Table : 4.2 Phase-I & Phase-II Zone under Phase-I ( 40 sq. kms. area ) 350 kms 450 kms 7 nos. 22 Sets 44.5 mld capacity
Zone under Phase-II ( 20 sq. kms. area ) 1. Collective System pipe line 55 kms 2. House connecting pipe line 58 kms 3. Civil work for p.s. 4. Pumping Machinery 11 sets 5. Sewerage Treatment 44.5 mld capacity (proposed) 6. Rising mains 900 mm dia ps.pipe 900 mm dia ps.pipe line line 4.16 km 4.16 km 7. Execution cost Rs.40 Cr. 21 Cr (proposed) Thus, Rajkot underground sewerage project costing Rs.40 crores covering area around 40 sq.km of walled city was implemented by Govt. of Gujarat with loan assistance from World Bank during the period 1984 to 1994 in which, following works were executed with the base year 1980-81. 1.
Collective system and house connections 800 kms
2.
Civil work of pumping station.. 7 nos. in city.
3.
Non-clog C.F.pumping sets .. 22 sets
4.
900 mm dia prestressed concrete rising main 3.5 km long.
5.
44.5 mld capacity sewage treatment plant at Madhapar.
The project was conceived with base year 1980-81 with covering area of old city 69 sq.km. but at that time the city was not fully developed and as such in stage-I the only developed area covering 40 sq.km was considered splitting the work of pumping machinery, sewage treatment plant and collective system. The project was prepared by Consultant M/s.Paramount Pollution Control Pvt.Ltd., Baroda. Phase-I & II drainage network is divided into 12 nos. of drainage zones and spread over to 20 wards out of 23 wards. However, in certain wards some pockets will yet remain vacant which will be connected later on.
Sr.No. 1
Table:4.3 Drainage Network (For Old city) –Phase-I & II Description Phase-I Phase-II Collective system pipe line 350 km. 55 km
2
House connection pipe lines
450 km
58 km
3
Main manholes
10,000 Nos
2,500 Nos
4
House connection chambers
1,10,000 Nos
9,518 Nos
5
Drainage connections
1,60,000 Nos
6
Pumping stations
Detail Project Report for Drainage Phase-II & III ( Part-I ) for Rajkot city
15,000
7
23
Rajkot Municipal Corporation
Existing Situation
Rajkot Municipal Corporation drainage collective system consisting of 1800 mm dia RCC NP4 Class to as small as 150 mm diameter stoneware. The pipe materials are RCC / prestressed. For house connections, normally stoneware pipes are used with 100 mm diameter chambers. Some parts of house connections are given by using PVC pipes. However, PVC pipes are largely discouraged. House connections are laid about 45 cms to 90 cm below ground level while collective system are laid up to as much as 2 to 6 mt below ground level. Pumping Stations: There are seven pumping station which pumps sewage water of city area to Madhapur Sewage Treatment Plant. The details of pumping stations are as under_ Table:4.4 Details of Pumping Station Name of pumping station
Pedak road
Capacity in cum/h
Nos. Of motor
Stand by
Power requirement in HP.
35
3
1
30
Bedipara
315
3
1
120
Bedinaka
950
3
1
200
Geet gurjari society
100
3
1
40
Gujarat housing board
215
3
1
60
Popatpara small
20
2
1
15
Popatpara main
1200
5
3
600
Total
22
1065
Phase-I & Phase-II existing Sewage Treatment Plant : Sewage treatment plant of 44.5 mld capacity, is located 6 kms away from Rajkot. As per the ongoing project report for ultimate stage requirement the total capacity of plant requires to be kept 90 mld but at the time of implementation the capacity of plant was kept 44.5 mld for Phase-I requirements. The treatment plant is designed to give full treatment to sewage. Principle process adopted for existing STP is extended aeration process. The disposal of treated sewage is for irrigation purpose and discharge in Aji-II reservoir. The details of raw sewage and treated sewage are as follows: Sr No
1 2 3 4 5
Table:4.5 Quality of Sewage before & after treatment Raw Sewage Treated Sewage Strong sewage Normal Desired as Results of during water sewage per standard present treated scarcity period for irrigation sewage from STP Ph 6.5 to 7.5 6.8 to 7.5 5.5 to 9.0 7.8 BOD in ppm 400 200 100 18.20 COD in ppm 1000 630 -100 Total suspended solid in 750 525 200 10 ppm Total dissolved solids in 2000 1000 2100 800 ppm Parameter
Detail Project Report for Drainage Phase-II & III ( Part-I ) for Rajkot city
24
Rajkot Municipal Corporation
Existing Situation
The Phase-I scheme was conceived with base year population 80-81 and was implemented during 1984 to 1994. Because of severe water crisis during 1985 to 1988 and excavation in hard rock the progress was slow. Subsequently, the city is developed fast and as on 1999-2000 all most all left out area were developed fully and RMC started the work of Phase-II (Part-I) for approximate in area of 20 sq.km. At first instant, work of collective system and house connection are taken up on hand in 2000-01 and since then most of the city area has been covered under underground sewage system. The total quantity of sewage being generated daily is around 57 to 58 MLD. Under the circumstances, at present, the existing plant is being over loaded and because of which during the current year Rajkot Municipal Corporation has decided to augment the capacity of existing plant by 44.5 mld and capacity of pumping machinery and additional rising main i.e to take up works under Phase-II(Part-I).
4.3 Rajkot Underground Drainage work - Phase- III As stated earlier, in 1998 the city limit of Rajkot was increased by the government and approximately 35.86 sq.kms. area of surrounding was merged ( see Annexure 1.3 ). The main areas are of three urban bodies namely; Nana Mava Raiya and Mavdi. At the time of merger the above areas were without any kind of infrastructure facilities and as such Rajkot Municipal Corporation has given the priority to provide all infrastructural facilities to these areas at the estimated cost of Rs.200 crores approx. For immediate relief to the people residing in this area, at the first instance for scientific disposal of the sullage water the most of the area has been covered under surface drainage. At present, most of the area has been covered under the surface drainage temporarily so that hygiene problem may not arise. Simultaneously a detailed underground drainage project of this area have been conceived in the year 2000-01 through the consultant. For this phase- III there is no any Sewage Treatment Plant and hence it is planned to construct 51 MLD sewage treatment plant in said area.
4.4 Rajkot Water Supply The Rajkot Municipal Corporation (RMC) is making great efforts to provide water supply to the citizens. RMC is drawing water from various sources viz. Bhadar, Aji-I, Nyari-I, Nyari-II, Lalpari & Randarda Lake and from Narmada canal based pipeline. The major sources are Aji-I, Nyari-I, Nyari-II and Bhadar which are described as under: Aji-I with Twine lake of Lalpari & Randarda Water Supply Scheme: This is the scheme for the purpose of water supply was constructed by the then Saurashtra State Government. This is the first water supply scheme serving Rajkot city. After the commissioning of this water supply scheme people were supplied filter water through house connection for the necessary requirement of water. This scheme was commenced in 1955 and still it is working. The availability of water from the said reservoir Detail Project Report for Drainage Phase-II & III ( Part-I ) for Rajkot city
25
Rajkot Municipal Corporation
Existing Situation
is for 4.5 mgd i.e. 20.43 MLD. Similarly, Rajkot Municipal Corporation is getting about 1.5 mgd i.e. 6.81 MLD from twin lakes of Lalpari and Randarda. Thus, total quantity available at Aji-I head work in normal year 20.43 + 6.81 = 27.24 MLD. Nyari-I Water supply Scheme: Due to strategy and geographic location, Rajkot has attracted so many people from outside, which resulted in higher demand for water supply. Same demand cannot be Sr. No 1 2
Table: 4.6 Sources of water Particulars Aji-1 Nyari-1 Distance form City Dam Details Live storage Dead storage Total Storage MCFT
5 kms.
8 kms.
1007 Mcft. 21 Mcft 1028
945 Mcft. 20 Mcft. 965
NyariII 22 Km
Bhadar 65 kms.
fulfilled
by
reservoir.
Aji Hence
Corporation had decided to construct a dam near
In
450 45 500
7030 Mcft. 45 Mcft. 7075
Rajkot
city
for
water
supply to fulfill required additional water.
demand
of
This is the first
dam owned by Rajkot Municipal Corporation. This scheme commenced in 1975 and the population of the western part of the city is being served through the said scheme. The present availability of water from the reservoir is 4.7 mgd, about 1.0 mgd from seepage. Total 5.7 mgd i.e. 25.90 MLD, Bhadar Water supply Scheme : To provide better sanitary facilities to the public of Rajkot by means of underground drainage Rajkot Municipal Corporation has implemented water supply scheme based on Bhadar reservoir located at 60 kms. away from Rajkot.. This scheme is major scheme for the supply of water to Rajkot city. The scheme was completed within 135 days during the year 1988. The Bhadar reservoir is for irrigation purpose, however, Government of Gujarat has reserved 10 mgd of supply in reservoir for drinking purpose to Rajkot and accordingly every year water is being made available from the said reservoir depending upon the storage available in the reservoir. After implementation of the said scheme the existing Aji and Nyari system was interconnected with Bhadar so that water from one zone to another zone could be transferred. At present, the total availability is 45 MLD. Nyari-II Water Supply Scheme: In 1998 the city limit was extended by the government and because of which water supply demand of newly merged area had increased by 2.5 mgd. And accordingly, the State Government had given the reservation of 1.5 mgd in Nyari-2 reservoir and 1.0 mgd from seepage of Nyari-2 and accordingly to cater the demand of newly merged area namely; Nana Mava, Raiya, and Mavdi, a water supply scheme costing Rs.15 crores was implemented by Rajkot Municipal Corporation based on Nyari-II reservoir. Drinking Water from the Narmada Canal : The Government of Gujarat has planned to implement a water supply scheme based on Narmada reservoir wherein 0.86 MAF quantity has been reserved for drinking purpose for 12 Districts of State Government. The water supply project based on Narmada costing Rs.7000 Crore is under implementation with the State Government. In the above water
Detail Project Report for Drainage Phase-II & III ( Part-I ) for Rajkot city
26
Rajkot Municipal Corporation
Existing Situation
supply project, the allocation of water for Rajkot city is 160 MLD which is to be obtained from the Table : 4.7 Zones & Storage Capacity & supply Zone ESR/ GSR Capacity Total water Supply (MLD) from each headwork ( MLD) Aji 38 37 Nyari 30 30 Gurukul 20 21 Jubillee 20 19 150’ ring road 35 33 TOTAL 143 140
section-A
i.e.
Dhodhidhaja
Dwarka
pipeline
project.
However, the said segment of the project is yet to be implemented and as such as a temporary measure Government of Gujarat have planned to supply 75 MLD
of quantity to Rajkot from the section- Maliya Jamnagar. Water from Bhadar , after treating water at Ribda is transmitted to the underground sumps at Gurukul and Jubillee water distribution Stations. At Aji head works, water from available Aji dam, Lalpari & Randarda lake and Narmada pipe line is being filtered at Aji and same is being stored and transmitted to Dudhsagar sub head works, 150’ring road., Mavdi headworks and Jubillee water distribution stations . Water from Nyari-1 dam is being supplied, after treatment at Nyari filter plant to Nyari zone which includes sub zones like sojitranagar ESR etc., Water collected from Nyari-2 dam is treated at Ghanteshwar filter plant and supplied through sub-zones Bajrangwadi. Water. Main pipe lines are of Mild Steel, PS , and AC Pressure line ranges from 900 mm to 450 mm as main. Distribution networks is of AC pressure pipe line with diameter 450 mm to 80 mm. Total length of Transmission line is about 250 kms. The total distribution network length excluding the transmission lines is 1375 kms. Table : 4.8 Water supply Distribution Net works Details Unit Number of Zones 5 Number of Sub zones 11 Mains line length 105 kms. Distribution line length 1350 kms.
A total storage capacity of
202
million liters is available in the form of underground sumps and overhead service reservoirs at various water works and other distribution stations. The storage capacity
adequacy of all the water distribution stations to the total water supply is 144 percent.
Mode of supply : Intermittent 20 minute daily by zoning Rate of Supply : 110 LPCD to 125 LPCD proposed to have 150 LPCD Present total city water supply : 150 MLD *******
Detail Project Report for Drainage Phase-II & III ( Part-I ) for Rajkot city
27
Rajkot Municipal Corporation
5
Extent of Privatization
E Exxtteenntt ooff P Prriivvaattiissaattiioonn
5.1 Privatisation experience of RMC The local bodies of our country are facing major problem of lack of financial and human resources to manage the breakneck growth of the cities. Few years back Rajkot was also experiencing the same. It is then that the corporation took some of the timely and bold measures to combat the problems, which have emerged with the wake of urbanisation. The Corporation has now pioneered the art of "Privatisation". NGOs have been involved in the services like Crematorium, Dispensaries, Libraries, Planetarium, Science Centre etc. while the contractors are involved in Parks, Solid Waste Management, Street Lights Maintenance, water supply & under ground drainage treatment plant, Security and Amusement Parks. This has opened new avenues for the corporation to reduce the establishment of expenditure while allowing for better management and quality services. Situation before the initiative
•
Resource constraints obstructed the initiatives of Corporation to solve various problems related to the increasing size and pressures of its growth.
•
The tax structure in Rajkot Municipal Corporation has also remained static over the years coupled with the political problems attached with raising the taxes.
This
resulted in low leverage to augment finances. Strategy adopted
•
Privatisation of high priority services was introduced to supplement the existing service delivery. The experience gained in initiating the private sector involvement and later in managing and supervising the works has helped the Corporation to evolve standard tender documents.
•
Involvement of the private sector demanded larger vigilance and monitoring. It required: 1. Setting the duties of contractor, the rates of work and evaluation procedure. 2. Advertising the tender and hiring the competent contractor. 3. Monitoring activities of contractor. 4. Getting the work done as per contract under the supervision of staff.
Detail Project Report for Drainage Phase- II & III (Part-I) for Rajkot city
28
Rajkot Municipal Corporation
•
Extent of Privatization
The following services have been privatised till now: A. Solid Waste Management B. Street Lights C. Water Supply and Drainage Pumping Station treatment plants and Pipelines D. Collection of Toll Taxes and Serving of Tax bills E. Security Guards F. Maintenance of Gardens & Entertainment Projects G. Mobile Clinic H. Telephone EPABX and Xerox Service J. Maintenance of Public Toilets K. Drainage Complaint Cell Management
5.2 Operation of Drainage Pumping Stations At present, sewage is conveyed to treatment plant through under ground pipe network with the help of pumping. There are seven pumping stations are located in different area to pump the sewage. Out of seven pumping station, operation and maintenance of six pumping station is given to the private contractor, and remaining is operated through RMC employee. The maintenance of six sewerage pumping station is given under service contract by calling for tenders on yearly basis. In the six pumping station where privatization has been induced, RMC’s liability is reduced to mere payment of electric bill and replacement of major parts. At each pumping station the contractor has to provide one electrician and one helper per shift. Monitoring and regulatory supervision of contractor’s work is carried out by the Assistant engineer and Deputy executive engineer.
Total cost incurred in operating and maintaining the six pumping station is fixed on shift basis. It is estimated that Rs 17.75 lacs per year for the running maintenance and operation cost of 7 pumping station, which means per pumping station per year the average cost comes to 2.54 lacs. We assume that pumping station is operated on an average for two shifts per day. So total average cost per shift per pumping station is comes to Rs. 350 only.
5.3 Privatization of Public Grievance Cell of Drainage Department Recently, RMC has taken further step in involvement of private sector in delivery of urban services. The complain sale of drainage department is privatized by RMC. For ward no. two to eight, Responding and redressal to complain is given to private contractor. As per contract, the contractor has to ensure quick reddressal of complains regarding the drainage services in ward no. two to eight. Detail Project Report for Drainage Phase- II & III (Part-I) for Rajkot city
29
Rajkot Municipal Corporation
Extent of Privatization
It is observed that total no. of complaint received in ward no. two to eight was 58441 for eight months. Sr. No.
1. 2. 3. 4. 5. 6. 7. 8. 9. 10 11. 12. 13
Table:5.1 No of Complaints Month No. of Complaints
April 05 5320 May 05 4030 June 05 6549 July 05 5141 August 05 4243 September 05 4746 October 05 4268 November 05 4190 December 05 4871 January 06 5038 February 06 4769 March 06 5276 Total 58441 Note: • 10% of complaint is of Main line • 90% of complaint is of House connection chamber. • The cost for Main line complaint is Rs 250 per complain, while for house connection is Rs 25 per complain.
Total expenditure incurred to redressal of the complains was Rs 27.76 lacs for financial year 2005-06. The contractor’s works remain satisfactory. Previously, response and redressing of complain was took four to five days and some time complain never attended. But after the task is assigned to the private contractor, the response and redressing of complain becomes fast. So by privatizing, RMC achieves efficiency in managing complains as well as cost savings.
5.4 Scope for further Privatization Experience of Rajkot Municipal Corporation shows that by privatizing many services cost effectiveness as well as quality of services improved. Sanitation service has also good potentiality to involve private sector. Recently Rajkot Municipal Corporation has successfully privatized the complaint cell and operation and maintenance of drainage pumping station. To further involve private sector, sanitation service can be un bundled in to following sub sector.
1) Issue and collection of bill on service contract base. 2) Operation and maintenance of collection system on management contract base. 3) Construction of collection network on concession base. 4) Construction, operation and maintenance of waste water treatment plant on concession base.
Detail Project Report for Drainage Phase- II & III (Part-I) for Rajkot city
30
Rajkot Municipal Corporation
Extent of Privatization
A) Issue and collection of bill: Issuing of bills and collection of the billing amount can be privatized on service contract basis. For performing the given task, private contractor will receives the prefix amount. Preference should be given to the reputed well known organization to award contract. Following points should be considered in designing the service contract. •
The contractor has to develop billing and collection system which includes issuing of bills, collection of payments, necessary supervision and development and updating of database.
•
The minimum collection target must be designed based on the past experience.
•
The contractor has to deposit the all collected amount whether cash, cheques or in other form on the same day of receipt.
•
The contractor is liable for any loss of money.
•
Incentive fee should be given to the contractor for the over and above minimum collection target.
•
Penalty clause also designed for the not achieving the minimum target.
•
To evaluate the performance of the contractor, contractor has to submit performance report every month.
•
At the end of contract duration all the updated database must be submitted to RMC.
•
Contract can be terminated at any time if RMC fills that the performance of contractor is not up to the mark.
B) Operation and Maintenance of collection and conveyance system: The operation and maintenance contract should be given on management contract basis. In this form of contract the liability for the capital investment remains with RMC and the repairing and maintenance expense will be born by the contractor. The contract covers all the Operation and Maintenance and necessary repairs including predictive, preventive and corrective maintenance activities for all the assets assigned to the contractor. In this form of contract, the ownership of all the assets remains within the employer. The contract should be awarded under competitive situation. In designing the contract following point should be kept in mind. •
As the operation and maintenance of sanitation service requires skill personnel as well as special equipment, the contractor has to employ qualified personnel and must have required equipment.
•
The contractor shall not make any capital expenditure on the sanitation service.
•
The contractor must submit the monthly maintenance report.
•
The contractor must pay in timely manner to his employees as per minimum labour wages.
•
The contractor has to carry out the necessary repairs within the predefined time as soon as he receives complaints.
•
Failing to repair in stipulated time will be liable for the penalty.
Detail Project Report for Drainage Phase- II & III (Part-I) for Rajkot city
31
Rajkot Municipal Corporation
•
Extent of Privatization
In case of emergency, the contractor has to carry out the necessary repairing work as directed by the RMC.
•
If RMC fills the working of contractor is unsatisfactory, the contract can be terminated.
C) Construction of collection network and treatment plant for newly merged area: The construction of collection network and waste water treatment plant for newly merged area should be given to the private sector either on concession basis or forming joint venture Company with private sector. If the contract is given on concessionary base, then the total capital investment as well as expenditure for operation and maintenance for the service will be born by the private sector. At the end of contractual period (usually 25 to 30 years) the whole system should be handed over to the RMC. During the contract period all necessary charges should be levied by the contractor.
********
Detail Project Report for Drainage Phase- II & III (Part-I) for Rajkot city
32
Rajkot Municipal Corporation
6
Civil Designs
D Deettaaiilleedd E Ennggiinneeeerriinngg D Deessiiggnn-- C Ciivviill
6.1 Drainage Phase-II (Part -1) The underground drainage project of Rajkot city costing Rs.36.00 crores was sanctioned by the government and was implemented by GWSSB with the financial assistance of World Bank in the year 1982-83, the said project was framed considering the part of the city area developed at that time. The majority of the peripheral area of the city were not developed and as such these areas were proposed to be considered in Phase-II work and were not incorporated in the cost estimate, however, the detailed design was carried out by GWSSB for the whole area of the city so that as and when needed the remaining area could be connected with drainage project. The execution Phase-I of the project was carried out by GWSSB in the year 1984-85 and was completed in the year 1992-93. The main causes of delay in the work are acute scarcity of water during 1985 to 1988 and excavation in hard rock. The project was commissioned successfully in the year 1994. In Phase-I the following works were completed and commissioned. •
Collective system with house connections almost in 40 sq.km area
•
Civil work for 7 pumping stations
•
providing and erecting pumping machinery suitable for stage-I requirement Total 22 sets
•
900 mm dia PSC rising main from main pumping station to STP through field.
•
44.5 MLD capacity sewerage treatment plant with disposal arrangement with 50% capacity As on date, the said scheme is in working condition and same is under maintenance with
Rajkot Municipal Corporation. So far, Rajkot Municipal Corporation has given about 1,60,000 house connections sewage is being treated in the existing plant at Madhapar. The part of the work of zone-311 was carried out by Rajkot Municipal Corporation from its own fund with the cost of rs.4 crores. Thus, the total expenditure incurred on Phase-I work is around Rs.40 crores and Rajkot Municipal Corporation is making repayment of the loan regularly. As stated above, the original project was framed with the development of the city up to 1980 but subsequent to 1980, all the peripheral areas have been developed fully and are now required to be connected with the existing drainage system, as the system has been designed to cater the whole area of the city. And accordingly, Rajkot Municipal Corporation has taken up the Phase-II (Part-I) work in a phase manner onward 2000 from support of the budget allocation. So far, approximately, works to the tune of Rs.400 lacs has been completed and commissioned. In Phase-II (Phase-I), the following works are yet to be carried out: 1. The work of collective system with house connection in approximately 20 sq.km area 2. Installation of pumping machinery for additional load – 11 sets 3. Extension of existing sewerage treatment plant by 44.5 mld 4. Power connection 5. Compound wall and area development Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
33
Rajkot Municipal Corporation
Civil Designs
6. Work of Rising Mains The design criteria for collecting system, pumping stations, Treatment Plant in Phase-II (Part-I) and Phase-III ( Part-I) are adopted as per CPHEEO Manual on Sewerage and Sewage Treatment (Second Edition)
6.2 Drainage Phase-II (Part-1) Sewage Treatment Plant of 44.50 MLD First phase sewerage was commissioned in 1994 covering 65 % of old city limits and Second Phase covering remaining 35% of the old city limits is on verge of completion and ready to commission by March 2006. Till 2001 the STP at Madhapar was receiving about 45 mld flows, which was in line with rated capacity of 44.5 mld capacity STP at Madhapar. Now this STP is receiving about 60 mld flow and it is projected that implementation of the network in entire area of old city limits would generate flows of about 89 mld requiring augmentation of existing Sewage Treatment Plant (STP) at Madhapar by 44.5 mls capacity. There exists 6 auxiliary Sewage Pumping Stations (SPSs) and discharging wastewater into gravity sewer leading to Terminal SPS at Madhapar. Hence, construction of STP shall be completed as early as possible. Since RMC has already set up STP at Madhapar, staff is familiar with various aspects of the same and hence salient features of the STP are Madhapar shall be looked into prior to formulating process design of new STP at Raiya. The basic principle followed for the existing Sewage Treatment Plant at Madhapar is facultative lagoons followed by extended aeration system. The areas of concern were ease of operation, maintenance, low energy cost and sustainability of the process with shock loads. Existing Sewage Treatment Plant and Disposal Facilities To cater to the flows from phase I & II sewerage system, a STP of 44.5 mld has been set up at Madhapar. The plant is functional since 1994. It is based on facultative lagoons and total power consumption is of the order of 600 HP. Sewage is admitted to inlet chamber and screened prior to undergoing physical treatment. Grit Chamber removes the heavy grit particles and then sewage is admitted to facultative lagoons. Here, the sewage undergoes biological treatment by facultative and micro-aerophil bacteria for 1.5 days. Then sewage is admitted to extended aeration tank, wherein, it is aerated for suspended growth aerobic treatment. Clarifiers have been constructed to settle biological solids and to achieve desired effluent standards. Sludge is being returned to aeration tank to maintain Mixed Liquor Suspended Solids (MLSS) concentration above 2000 mg/l. Proposed Sewage Treatment Plant It is proposed to construct 44.5MLD capacity STP at Madhapur just near to existing plant. The process design of the plant is adopted conventional activated sludge process.
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
34
Rajkot Municipal Corporation
Civil Designs
Design Criteria for STP The design characteristics for the Madhapur STP arrived at on basis of the statistical analysis of the result of the inlet concentration (samples collected and analysed by RMC) at Madhapar STP over last eight months. The data is annexed as Annexure: It was decided to adopt BOD value of 200 mg/l and SS concentration of 525 mg/l for the design purpose in earlier report, which fairly matches with the data available. Following design parameters are adopted for the design of STP. Raw sewage characteristics Parameter
Value for Design purpose
pH value
Unit
6.8-9.1
SS
525 mg/l
COD
630 mg/l
BOD
200 mg/l
Alkalinity
185 mg/l
Sulphates
110 mg/l
Phosphates
10 mg/l
Total Kjeldah Nitrogen
16.8 mg/l
Ammonical Nitrogen
15 mg/l
Organic Content in grit
4 mg/l
O&G
15 mg/l
Treated sewage characteristics
Parameter
Value for Design purpose
Unit
pH value
6-9
SS
< 100
mg/l
COD
< 100
mg/l
BOD
< 30
mg/l
O&G
< 10
mg/l
* Pre-1995 discharge norms prescribed 30 mg/l SS and 20 mg/l BOD value, which was duly revised as above.
Observation on raw sewage characteristics RMC has awarded O & M contract to private operator and a procedure has been established to collect data on various parameters of raw sewage for last year. Data for the months of February through September are taken in to consideration. Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
35
Rajkot Municipal Corporation
Civil Designs
From the analysis, it is observed that the concentration of Suspended Solids (SS) is very high during morning hours. Data recorded for morning session 0830 to 0930 indicates SS concentration as high as 2000 mg/l. This is peculiar situation in semi-urban area experiencing scarcity of water, wherein major water intensive activities are at halt during evening and late night hours leading to deposition of solids in to sewers. These get re-suspended during peak flow, which takes place in morning session. Volume of solids to be handled would be enormously high and special attention must be given to this aspect, particularly sludge storage/sump and handling equipment like pump sets and/or classifier mechanism. However, this is not accompanied by steep rise in BOD values. Hence, shock load will not have significant effect on aerator (oxygenation equipment). But sludge production would vary on hourly basis and hence retention time of the sludge sump would be decided accordingly. Analysis of various treatment processes Numbers of processes are in vogue for treatment of domestic sewage (municipal wastewater). This ranges from physico-chemical process to direct oxidation process (zimpro process) for treatment of wastewater. However, physico-chemical processes are generally used for small capacity plants, in particular, industrial plants. Physical process followed by biological process and purely biological processes are more popularly used world over. Each system has its’ own cutting edge features for selection of particular process for some region and respective time context. Physical process followed by biological process and purely biological process are predominantly used in India and Gujarat region. Best examples for STPs based on physical process followed by biological process are conventional activated sludge process (suspended growth), trickling filter (attached growth), and anaerobic lagoons followed by facultative lagoons etc.. Best examples for biological processes are facultative lagoons followed by extended aeration lagoons, Upflow Anaerobic Sludge Blanket (UASB) followed by polishing lagoons etc. Selection of best process suitable for sewage generated in Rajkot would be governed by number of factors. However, attributes for selecting suitable treatment process will decide the treatment steps. Major attributes are enlisted hereunder. 1.
Ease of construction
2.
Simplicity of system requiring less equipment
3.
Ease of operation and maintenance
4.
Availability of spare parts for trouble free O & M
5.
Reliability of process: i.
well established design criteria
ii. proven process parameters iii. established kinetics
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
36
Rajkot Municipal Corporation
Civil Designs
iv. amenable to control v. ability to absorb shock loads 6.
Need of skilled/ unskilled staff
7.
Nuisance potential from mosquitoes/ fly/ odour
8.
Ease of access to components of the system for repairs and maintenance
9.
Safety of operating/ maintenance personnel
Apart from above factors, raw sewage characteristics also play an important role. Availability of skilled personnel and spare parts will play major role while selecting the process. Amongst selected processes, its’ Capex and Opex, capitalized cost and financial sensitivity will govern the finally selected process.
In view of above aspects, following processes have been evaluated. 1)
Conventional Activated Sludge Process (with & without power generation)
2)
Facultative Lagoons followed by Extended Aeration (with & without power generation)
3)
Anaerobic Lagoons followed by facultative lagoons
4)
UASB (with & without power generation)
Each alternative is analysed with its’ capital cost (Capex), operation & maintenance cost (Opex), energy charges, resource recovery (power generation), financial sensitivity (capitalized cost with different IRR). Subsequent chapters address the design of each unit of the STP and above factors. Operation of STP depends upon so many factors. But introduction of advanced tools like PLC/ microcontroller/ micro-processor based process control systems would enhance control over process and also achieve the energy saving. Developed countries have fully automated plants and unit operations, which has got very high O & M cost. Hence, emphasis has been made to introduce modern tools suitable for Indian condition. Few of the areas of automation suggested are: Aerator operation: DO levels in the tank shall be maintained at 2 mg/l. during lean flow period, if it exceeds, number of aerators to be stopped on rotation basis could be introduced. Also diminished level of DO would give alarm for attention of the aeration unit. Pumping operation: Level based sensor to start/off the pumps on rotation basis.
Flow measurement: Flow entering into each battery depends upon the sizing of the gates, as built levels etc. Even though, the gate opening is proper, flow distribution is likely to vary. Hence, to measure the flow entering to each unit is crucial information to decide the performance of the same and rectification thereof for process control.
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
37
Rajkot Municipal Corporation
Civil Designs
A) Conventional Activated Sludge Process (Casp) This process is based on suspended growth system. Raw sewage is admitted to the inlet chamber for further processing for removal of large particles. Floating matter are trapped in the screen and removed with help of rack mechanism and put to conveyor belt for disposal through collection vehicle. Grit is removed in grit chamber and then sewage is admitted to Primary Clarifier for physical settling process. After primary settling, sewage undergoes biological process wherein biomass is activated to consume the BOD and biodegradable matter is converted to carbon dioxide and water vapor with help of aerobic bacteria. Level of dissolved oxygen and mixed liquor suspended solids are maintained with help of return sludge from secondary clarifier. Food to microbe ratio, substrate, mean cell resident time, decay rate of bacteria to enhance growth of aerobic biomass is maintained apart from aeration. After aeration, biomass attains saturation level of activity and then admitted to secondary clarifier for settling of biomass and accumulation of sufficient quantity of return sludge to help activation of biomass in aeration tank. Sludge produced is returned and wasted through raw sludge pump house or digester, wherein biomass is digested anaerobic ally and sludge concentration is increased from 1-2 % to 6-8%. Supernatant is returned back to PST for treatment. Sludge from digester is taken to centrifuge or filter press or sludge drying beds prior to final disposal and utilization as manure. Filtrate from drying beds/filter press/centrifuge would be returned to PST for further treatment. Bio-gas generated in digester could be taken to Gas Holder and utilized for power generation or flared. Description of functional requirement of each unit for CASP is discussed in brief.
1)
Inlet Chamber
2)
Screen Chamber
3)
Detritor
4)
Parshall Flume
5)
Primary Clarifier (PC)/Primary Settling Tank (PST)
6)
Aeration Tank
7)
Secondary Clarifier (SC)/Secondary Settling Tank (PST)
8)
Raw sludge pump house
9)
Return sludge pump house
10)
Filtrate pump house
11)
Sludge digester
12)
Gas holder
13)
Sludge drying beds/ filter press/ centrifuge
14)
Dual-Fuel gas engines/ gas flaring system
First three units are considered to be Preliminary Treatment Units. 4th, 5th and 6th are secondary treatment units and remaining are supporting units for MWwTPs. Though all the units are Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
38
Rajkot Municipal Corporation
Civil Designs
designed to handle peak flows and other loadings, sludge digesters need to be designed for sufficient solids loading for effective functioning in the view of the high concentration of SS. 1.
INLET CHAMBER : An Inlet Chamber is provided as receiving unit to STP with special
arrangements. In case of normal operations, the sewage will be diverted to STP and in case of eventuality/ repair/ maintenance, a bypass arrangement is provided for discharge of sewage into receiving body. 2.
SCREEN CHAMBER : Screening is an essential step in treatment of sewage to facilitate
removal of large size floating materials like rags, plastics, tobacco pouches, wooden pieces etc. which otherwise would damage pumps and interfere with the performance of the subsequent units. This consists of bars placed parallel in vertical or inclined system across the flow to trap the floating material. Generally 20 mm spacing is considered to be adequate for STPs. However, considering the problem of pouches of tobacco passing thru’ it parallel to flow, finere screens with spacing of 12 mm followed in mesh pattern are in vogue. 50 mm x 10 mm thick flats are considered to be standard practice in India. Timer based racking mechanism cleans the screen periodically and put the screenings to belt conveyor system. Material is conveyed to collection van provided beneath the end of the belt conveyor for final disposal. CI Gates upstream and downstream to the screen are provided to control flow.
3.
DETRITOR :Detritus Tank popularly known as detritor is provided after screen to remove
heavy inorganic fraction of the sewage prior to physical and biological process. Difference in settling velocities between organic and organic content due to specific gravity is the basic principle followed to design the unit. Grit consists coarse sand particles, ash, clinker, egg shells and silt coated by organic matter (generally marginalized group use silt/ash for washing of utensils) etc. Grit is considered to be non-putrescible possessing higher hydraulic subsidence value than organic matter. Grit removal, if not done, causes abnormal wear and tear to mechanical parts, scrappers/ pumps/ aerators etc. With proper hydraulic design, grit can be effectively removed from the sewage. To prevent loss of useful organic content and to prevent emanation of highly malodorous emissions from the removed grit, grit classifier based on reciprocating mechanism is provided.
4.
PRIMARY CLARIFIER (PC)/PRIMARY SETTLING TANK (PST) :PST removes organic
matter (SS), scum and reduce BOD in quiescent condition. Brownian motion and settling characteristics of solids supported by proper overflow rate and weir loading rate enhances settlement of solids. It also settles BOD (integral part of SS) and hence reduces BOD load on subsequent units. Reduction in BOD load will have great effect on power consumption. Plastics escaped from the screen and grit chamber would float on surface and can be removed by scum arm provided at top. Various functional parts like inlet, baffle, scrapper, outlet weir, sludge removal, telescopic valve, scum box are major components of the PST.
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
39
Rajkot Municipal Corporation
5.
Civil Designs
AERATION TANK : Microbes present in sewage can consume substrate (biodegradable
organic matter) if favorable pH value and oxygen is available for faster consumption of organic matter. This unit is heart of the process. Various parameters are controlled to maximize efficiency. Food to microbe ratio, power level, MLSS, means cell residence time, decay rate, volumetric loading, organic loading etc. Washout of microbes must be avoided. It is desirable to maintain DO level at 2 mg/l, which may diminish to 0.5 mg/l as an alarming level. Growth of filamentous bacteria and Nocardia must be avoided and controlled. Sufficient HRT shall be maintained to prevent washout. Entire biomass gets activated in this system by means of suspended growth. Microbes can move to any place within reactor to get food and balance struck between microbes and substrate facilitates conversion of organic matter into active biomass. 6.
SECONDARY CLARIFIER (SC)/SECONDARY SETTLING TANK (SST) :SST permits activated
biomass to settle in form of sludge and sludge settled is pumped back to aeration tank to maintain MLSS. Due to highly active biomass, lumps of biomass are formed and higher ratio of volume to surface area enhances the settlement. Now, major portion of organic content is converted into biomass, which is settled as sludge. Supernatant comprise very low BOD and SS and other parameters. In case the treated sewage is to be discharged into natural water body, the parameters comply with the norms prescribed by pollution control board. However, in case treated sewage is to be reused for some purpose like gardening, recreational activities, tertiary treatment shall be given. 7.
RAW SLUDGE PUMP HOUSE :Raw sludge accumulated in PST is generally put to SDB or
sludge digester. Considering low volumes, this is very small units and used as control room for PTU. 8.
RETURN SLUDGE PUMP HOUSE :Performance of aeration tank depends upon effective
function of this pump house. Generally return flow varies from 25 % to 50 % depending upon concentration of sludge. Considering its’ functional importance, 100% standby pump sets are provided in this unit. 9.
FILTRATE PUMP HOUSE : Filtrate from sludge drying bed/filter press/centrifuge contains
high BOD and SS and hence prior to disposal into natural water body, it shall be treated. Filtrate pump house pumps back filtrate to the inlet chamber of PST and hence only treated sewage is discharged from the STP. Though quantity of filtrate is very low in terms of percentage, overall quantum is in terms of few thousand liters and hence it must be treated prior to discharge. 10.
SLUDGE DRYING BEDS/ FILTER PRESS/ CENTRIFUGE : Digested or raw sludge is dewatered
and converted to utilizable form of sludge cake for manure. Sludge drying bed is most common form of concentrating the sludge and it is most common practice in India. 11.
SLUDGE DIGESTER : Digestion of sludge is achieved in this unit to break the long chains and
convert it to simple form ready to use as manure for improved absorbance as nutrient and reduce the harmful effects on environment. Initially, design of digester with mechanical mixing of sludge posed serious problems of civil structure and blasting. This has been overcome with help of gas mixing Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
40
Rajkot Municipal Corporation
Civil Designs
system, being used in India for more than 10 years with satisfactory performance. Sludge volume also reduces in this system and area required for sludge reduces to a great extent. 12.
GAS HOLDER :Gas produced in digester is collected here for further utilization like power
generation with uniform feeding to Dual-Fuel Engines or flaring. 13.
DUAL-FUEL GAS ENGINES/ GAS FLARING SYSTEM : Gas produced in the digester is
enriched with methane and high calorific value. Dual fuel engines capable of using gas (80-90%) and diesel (20-10%) can yield power sufficient to run more than half of the operations of the STP. Though it is very attractive, STPs initially set up with an objective to have captive power generation either in CASP or UASB has not been successful on large scale. Above steps briefly describes preliminary aspects of various process units. Sufficient details are discussed about basic principles and area of attention for successful performance of the STP based on CASP. There are many more forms of the CASP like continuous flow (as described above), plug flow, Sequential Batch Reactor etc., but this is most common form easy to maintain and operable and adopted in India. This process is having following advantages 1)
Rajkot is commercial capital Saurashtra region attracting number of skilled personnel and hence availability of skilled labor/ personnel is not a problem for this process
2)
Availability of spare parts is also not a problem since all the equipments like scrapper, aerator are already installed in existing STP and RMC officials are familiar with the equipment and are easily available
3)
Process is having high level of reliability, well established reaction kinetics, amenability to control, can absorb shock loads.
4)
Less potential of nuisance from mosquitoes/ fly/ odour
5)
Easy access to components of the system for repairs and maintenance
6)
More safety of operating/ maintenance personnel
7)
Since the process is proven world wide, construction techniques are known and hence easy to construct (the word conventional itself suggests its’ large scale acceptability)
8)
Easy to maintain the process parameters
9)
Area requirement is very low amongst all 4 processes under consideration. Hence, future expansion is possible, particularly in urban area like Rajkot –where land is scarce.
Disadvantages of the process are: 1)
Sludge digesters pose operational problems due to moving mechanical parts- some of the municipal authorities had overcome this problem by using non-moving mechanical mixers. E.g. Vadodara, Delhi
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
41
Rajkot Municipal Corporation
2)
Civil Designs
Skilled personnel (biologist) are required to maintain process parameters like MLSS, BOD, COD, SS etc. Unit Sizing: Conventional Activated Sludge Process All dimensions are in m unless otherwise specified
Sr.
Name of Process Unit
Size of the unit
Power
rqnt
(W+SB) HP 1
Preliminary Treatment Units Inlet Chamber
1 No., 6.5 x 4.5 x 3.3
-
Screen Chamber
2 Nos., 11 x 1.5 x 1.5
6+6
Grit Chamber
3 Nos., 8 x 8 x 1.1
6+3
Parshall Flume
1200 mm throat As per Int.
2
Primary Clarifier
2 Nos., 32.5 dia 3.85 ht
6+0
3
Aeration Tank
2 Nos., 36 x 72 x 4.15
400+0
4
Secondary Clarifier
2 Nos., 37 dia 3.5 ht
3+3
5
Raw Sludge Pump House
1 No., 4.5 dia, 6 m ht
15+15
6
Return Sludge Pump House
1 No., 17.5 dia, 6 m ht
60+(30+30)
7
Filtrate Pump House
1 No., 3.5 dia, 5 m ht
5+5
8
Sludge Drying Beds
28 Nos., 20 x 20 without digester,
10
Nos.
with
digester 9
Sludge Digester
2 No., 24 dia, 11 ht
50+50
10
Gas Holder
2 Nos., 20 dia, 6 ht.
6+0
11
Power Generator
18 x 12 x 6
-405
B) Facultative Lagoons followed by Extended Aeration (FLEA) : This process is based on suspended growth system. Raw sewage is admitted to the inlet chamber for further processing for removal of large particles. Floating matter are trapped in the screen and removed with help of rack mechanism and put to conveyor belt for disposal through collection vehicle. Grit is removed in grit chamber and then sewage is admitted to facultative lagoon for biological process. Here biomass is supplied with limited quantity of oxygen to support facultative microbes, which can survive at lower DO level. After facultative treatment, sewage undergoes aerobic biological process wherein biomass is activated to consume the BOD and biodegradable matter is converted to carbon dioxide and water vapor with help of aerobic bacteria. Level of dissolved oxygen and mixed liquor suspended solids are maintained with help of return sludge from settling lagoon. Food to microbe ratio, substrate, mean cell resident time, decay rate of bacteria to enhance growth of aerobic biomass
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
42
Rajkot Municipal Corporation
Civil Designs
is maintained apart from aeration. After extended aeration, biomass attains saturation level of activity and then admitted to settling lagoon for settling of biomass and accumulation of sufficient quantity of return sludge to help activation of biomass in extended aeration tank. Sludge produced is returned to extended aeration tank or put through sludge digester and/or directly to sludge drying beds/filter press/centrifuge, wherein biomass is dried and sludge concentration is increased. Filtrate from drying beds/filter press/centrifuge would be returned to facultative lagoon for further treatment. Description of functional requirement of each unit for FLEA is discussed in brief. 1)
Inlet Chamber
2)
Screen Chamber
3)
Detritor
4)
Parshall Flume
5)
Facultative Lagoons (FL)
6)
Aerobic Lagoon (AL)
7)
Secondary Clarifier (SC)/Secondary Settling Tank (PST)/ Settling Lagoon
8)
Return sludge pump house
9)
Filtrate pump house
10)
Sludge digester
11)
Gas holder
12)
Sludge drying beds/ filter press/ centrifuge
13)
Dual-Fuel gas engines/ gas flaring system
First three units are considered to be Preliminary Treatment Units. 4th, 5th and 6th are secondary treatment units and remaining are supporting units for MWwTPs. 1.
INLET CHAMBER : An Inlet Chamber is provided as receiving unit to STP with special
arrangements. In case of normal operations, the sewage will be diverted to STP and in case of eventuality/ repair/ maintenance, a bypass arrangement is provided for discharge of sewage into receiving body. 2.
SCREEN CHAMBER :Screening is an essential step in treatment of sewage to facilitate
removal of large size floating materials like rags, plastics, tobacco pouches, wooden pieces etc. which otherwise would damage pumps and interfere with the performance of the subsequent units. This consists of bars placed parallel in vertical or inclined system across the flow to trap the floating material. Generally 20 mm spacing is considered to be adequate for STPs. However, considering the problem of pouches of tobacco passing thru’ it parallel to flow, finere screens with spacing of 12 mm followed in mesh pattern are in vogue. 50 mm x 10 mm thick flats are considered to be standard practice in India. Timer based racking mechanism cleans the screen periodically and put the screenings to belt conveyor system. Material is conveyed to collection van provided beneath the end of the belt conveyor for final disposal. CI Gates upstream and downstream to the screen are provided to control flow. Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
43
Rajkot Municipal Corporation
3.
Civil Designs
DETRITOR : Detritus Tank popularly known as detritor is provided after screen to remove
heavy inorganic fraction of the sewage prior to physical and biological process. Difference in settling velocities between organic and organic content due to specific gravity is the basic principle followed to design the unit. Grit consists coarse sand particles, ash, clinker, egg shells and silt coated by organic matter (generally marginalized group use silt/ash for washing of utensils) etc. Grit is considered to be non-putrescible possessing higher hydraulic subsidence value than organic matter. Grit removal, if not done, causes abnormal wear and tear to mechanical parts, scrappers/ pumps/ aerators etc. With proper hydraulic design, grit can be effectively removed from the sewage. To prevent loss of useful organic content and to prevent emanation of highly malodorous emissions from the removed grit, grit classifier based on reciprocating mechanism is provided. 4.
FACULTATIVE LAGOON : Sewage traveling long distances generally turns septic while
entering into STP and presence of anaerobic and facultative bacteria dominates the system. Conversion of this condition to aerobic condition is power intensive and hence concept of developing facultative culture for biological process of sewage was conceived. Here low level of DO is maintained and thus odor emanation is eliminated. Generally HRT ranges from 1 to 3 days and STPs in Mumbai are set up on this principle. Then sewage undergoes further treatment in aerobic lagoons. 5.
AEROBIC LAGOON : After facultative process, microbes can survive aerobic condition and
are activated to consume maximum substrate. Aerobic bacteria dominate the system. Power level is almost double as compared to facultative one. Sludge from settling tank is returned to this lagoon to maintain MLSS. Generally mixing requirement governs the design rather than oxygen demand as in case of CASP since HRT is comparatively very high. Here the biomass enters into phase of endogenous respiration minimizing sludge production. Maintaining of MLSS and MLVSS is important for better performance. 6.
SETTLING TANK/ LAGOON : SST/SL permits activated biomass to settle in form of sludge
and sludge settled is pumped back to aeration tank to maintain MLSS. Due to highly active biomass, lumps of biomass are formed and higher ratio of volume to surface area enhances the settlement. Now, major portion of organic content is converted into biomass, which is settled as sludge. Supernatant comprise very low BOD and SS and other parameters. In case the treated sewage is to be discharged into natural water body, the parameters comply with the norms prescribed by pollution control board. However, in case treated sewage is to be reused for some purpose like gardening, recreational activities, tertiary treatment shall be given.
7.
RETURN SLUDGE PUMP HOUSE : Performance of aeration tank depends upon effective
function of this pump house. Generally return flow varies from 25 % to 50 % depending upon
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
44
Rajkot Municipal Corporation
Civil Designs
concentration of sludge. Considering its’ functional importance, 100% standby pump sets are provided in this unit. 8.
SLUDGE DRYING BEDS/ FILTER PRESS/ CENTRIFUGE : Digested or raw sludge is dewatered
and converted to utilizable form of sludge cake for manure. Sludge drying bed is most common form of concentrating the sludge and it is most common practice in India. 9.
FILTRATE PUMP HOUSE : Filtrate from sludge drying bed/filter press/centrifuge contains
high BOD and SS and hence prior to disposal into natural water body, it shall be treated. Filtrate pump house pumps back filtrate to the inlet chamber of PST and hence only treated sewage is discharged from the STP. Though quantity of filtrate is very low in terms of percentage, overall quantum is in terms of few thousand liters and hence it must be treated prior to discharge. 10.
SLUDGE DIGESTER : Digestion of sludge is achieved in this unit to break the long chains and
convert it to simple form ready to use as manure for improved absorbance as nutrient and reduce the harmful effects on environment. Initially, design of digester with mechanical mixing of sludge posed serious problems of civil structure and blasting. This has been overcome with help of gas mixing system, being used in India for more than 10 years with satisfactory performance. Sludge volume also reduces in this system and area required for sludge reduces to a great extent. 11.
GAS HOLDER :Gas produced in digester is collected here for further utilization like power
generation with uniform feeding to Dual-Fuel Engines or flaring. 12.
DUAL-FUEL GAS ENGINES/ GAS FLARING SYSTEM :Gas produced in the digester is
enriched with methane and high calorific value. Dual fuel engines capable of using gas (80-90%) and diesel (20-10%) can yield power sufficient to run more than half of the operations of the STP. Though it is very attractive, STPs initially set up with an objective to have captive power generation either in CASP or UASB has not been successful on large scale. Above steps briefly describes preliminary aspects of various process units. Sufficient details are discussed about basic principles and area of attention for successful performance of the STP based on FLEA. There are many more forms of the FLEA like without return sludge, only facultative lagoons followed by maturation pond etc., but this is most common form easy to maintain and operable and adopted in India. STP at Madhapar, Rajkot is also based on this process. This process is having following advantages 1)
Availability of spare parts is not a problem since all the equipments like scrapper, aerator are already installed in existing STP and RMC officials are familiar with the equipment and are easily available
2)
Process is having high level of reliability, well established reaction kinetics, amenability to control, can absorb shock loads.
3)
Marginal potential of nuisance from mosquitoes/ fly/ odour
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
45
Rajkot Municipal Corporation
4)
Civil Designs
Since the process is proven world wide, construction techniques are known and hence easy to construct (STPs based on this process are established at cities like Ahmedabad, Mumbai etc. indicating its’ large scale acceptability)
5)
Easy to maintain the process parameters
Disadvantages of the process are: 1)
Sludge removal pose operational problems due to lower level and large area to be covered for de-silting. Chances to damage to membrane are more during operation of sludge removal.
2)
Difficult access to components for repair and maintenance
3)
Skilled personnel (biologist) are required to maintain process parameters like MLSS, BOD, COD, SS etc.
4)
Less safety of operating/ maintenance personnel in case defects in aerators are to be rectified
5)
Area requirement is very large as compared to CASP and restricts future expansion
6)
Power consumption is very high and production potential is low. Unit Sizing: Facultative Lagoons followed by Extended Aeration All dimensions are in m unless otherwise specified Sr.
Name of Process Unit
Size of the unit
Power rqnt (W+SB) HP
1
2
3
Preliminary Treatment Units Inlet Chamber
1 No., 6.5 x 4.5 x 3.3
-
Screen Chamber
2 Nos., 11 x 1.5 x 1.5
6+6
Grit Chamber
3 Nos., 8 x 8 x 1.1
6+3
Parshall Flume
1200 mm throat As per Int.
Facultative Lagoons
2 Nos., 78 x 152 at top
240+0,
54 x 140 at both, 6 m
Nos., 15 HP
2 Nos., 78 x 50 at top
300+0, 6 Nos.,
Aerated Lagoon
58 x 50 at bot, 5 m 4
Settling Lagoon
2 Nos., 78 x 31 at top
16
50 HP -
52 x 18 at bot, 6.5 m 5
Return Sludge Pump House
1 No., 17.5 dia, 6 m ht
50+50+(50 SB)
6
Filtrate Pump House
1 No., 3.5 dia, 5 m ht
7.5+7.5
7
Sludge Drying Beds
28 Nos., 20 x 20 without digester,
10
Nos.
with
digester 8
Sludge Digester
2 No., 24 dia, 11 ht
50+50
9
Gas Holder
2 Nos., 20 dia, 6 ht.
6+0
10
Power Generator
18 x 12 x 6
-175
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
46
Rajkot Municipal Corporation
Civil Designs
C) Anaerobic Lagoon followed by Aerated Lagoon (ANAL) : This process is based on suspended growth system. Raw sewage is admitted to the inlet chamber for further processing for removal of large particles. Floating matter are trapped in the screen and removed with help of rack mechanism and put to conveyor belt for disposal through collection vehicle. Grit is removed in grit chamber and then sewage is admitted to anaerobic lagoon for physical settling and anaerobic treatment of sewage (biological process). BOD & SS reduces considerably to reduce oxygen demand in subsequent process train. Hydrogen Sulfide and methane generated at bottom level during the anaerobic process gets dissolved in upper layer reducing odor nuisance. After anaerobic process, sewage undergoes aerobic process wherein biomass is supplied with sufficient quantity of oxygen to support aerobic and facultative microbes, which can survive at medium/ lower DO level. Biodegradable matter is converted to carbon dioxide and water vapor with help of aerobic bacteria. Level of dissolved oxygen is maintained with help of aerators. Food to microbe ratio, substrate, mean cell resident time, decay rate of bacteria to enhance growth of aerobic biomass are maintained apart from aeration. After extended aeration, biomass attains saturation level of activity and then admitted to clarifier for settling of biomass. Sludge produced is in form of biological solids, which would enter into phase of endogenous respiration reducing quantity of sludge to a great extent. Depth of settling lagoon is maintained in such a way that cleaning of lagoon would be required at an interval of 10 years. Description of functional requirement of each unit for ANAL is discussed in brief. 1)
Inlet Chamber
2)
Screen Chamber
3)
Detritor
4)
Parshall Flume
5)
Anaerobic Lagoons (AN)
6)
Aerobic Lagoon (AL)
7)
Settling Lagoon
First three units are considered to be Preliminary Treatment Units. 4th, 5th and 6th are secondary treatment units and remaining are supporting units for MWwTPs. 1.
INLET CHAMBER : An Inlet Chamber is provided as receiving unit to STP with special
arrangements. In case of normal operations, the sewage will be diverted to STP and in case of eventuality/ repair/ maintenance, a bypass arrangement is provided for discharge of sewage into receiving body. 2.
SCREEN CHAMBER : Screening is an essential step in treatment of sewage to facilitate
removal of large size floating materials like rags, plastics, tobacco pouches, wooden pieces etc. which otherwise would damage pumps and interfere with the performance of the subsequent units. This consists of bars placed parallel in vertical or inclined system across the flow to trap the floating material. Generally 20 mm spacing is considered to be adequate for STPs. However, considering the Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
47
Rajkot Municipal Corporation
Civil Designs
problem of pouches of tobacco passing thru’ it parallel to flow, finere screens with spacing of 12 mm followed in mesh pattern are in vogue. 50 mm x 10 mm thick flats are considered to be standard practice in India. Timer based racking mechanism cleans the screen periodically and put the screenings to belt conveyor system. Material is conveyed to collection van provided beneath the end of the belt conveyor for final disposal. CI Gates upstream and downstream to the screen are provided to control flow. 3.
DETRITOR : Detritus Tank popularly known as detritor is provided after screen to remove
heavy inorganic fraction of the sewage prior to physical and biological process. Difference in settling velocities between organic and organic content due to specific gravity is the basic principle followed to design the unit. Grit consists coarse sand particles, ash, clinker, egg shells and silt coated by organic matter (generally marginalized group use silt/ash for washing of utensils) etc. Grit is considered to be non-putrescible possessing higher hydraulic subsidence value than organic matter. Grit removal, if not done, causes abnormal wear and tear to mechanical parts, scrappers/ pumps/ aerators etc. With proper hydraulic design, grit can be effectively removed from the sewage. To prevent loss of useful organic content and to prevent emanation of highly malodorous emissions from the removed grit, grit classifier based on reciprocating mechanism is provided. 4.
ANAEROBIC LAGOON : Sewage traveling long distances generally turns septic while entering
into STP and presence of anaerobic and facultative bacteria dominates the system. Conversion of this condition to aerobic condition is power intensive and hence concept of utilizing anaerobic culture for biological process of sewage was conceived. Here absence of DO is maintained by deep lagoons. Odor emanation could be eliminated since uppermost layer acts as a solvent to gases escaping from the system. Generally HRT ranges from 1 to 1.5 days and STPs in Ahmedabad are set up on this principle. Then sewage undergoes further treatment in aerobic lagoons. 5.
AEROBIC LAGOON : After anaerobic process, microbes can survive facultative and aerobic
condition and are activated to consume maximum substrate. Aerobic bacteria dominates the system. Generally mixing requirement governs the design rather than oxygen demand as in case of CASP since HRT is very high comparatively. 6.
SETTLING TANK/ LAGOON : SST/SL permits activated biomass to settle in form of sludge.
Due to highly active biomass, lumps of biomass are formed and higher ratio of volume to surface area enhances the settlement. Now, major portion of organic content is converted into biomass, which is settled as sludge. Here the biomass enters into phase of endogenous respiration minimizing sludge production. Supernatant comprise very low BOD and SS and other parameters. In case the treated sewage is to be discharged into natural water body, the parameters comply with the norms prescribed by pollution control board. However, in case treated sewage is to be reused for some purpose like gardening, recreational activities, tertiary treatment shall be given.
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
48
Rajkot Municipal Corporation
Civil Designs
Above steps briefly describes preliminary aspects of various process units. Sufficient details are discussed about basic principles and area of attention for successful performance of the STP based on ANAL. There are many more forms of the ANAL like return sludge from settling lagoon, microaerofoil based system etc., but this is most common form easy to maintain and operable and adopted in India. This process is having following advantages 1)
Availability of spare parts is not a problem since all the equipments like scrapper, aerator are already installed in existing STP and RMC officials are familiar with the equipment and are easily available
2)
Process is having high level of reliability, well established reaction kinetics, amenability to control, can absorb shock loads.
3)
Marginal potential of nuisance from mosquitoes/ fly/ odour
4)
Since the process is proven world wide, construction techniques are known and hence easy to construct (STPs based on this process are established at Ahmedabad indicating its’ large scale acceptability)
5)
Easy to maintain the process parameters
6)
Power consumption is low as compared to FLEA.
Disadvantages of the process are: 1)
Sludge removal pose operational problems due to lower level and large area to be covered for de-silting. Chances to damage to membrane are more during operation of sludge removal.
2)
Difficult access to components for repair and maintenance
3)
Less safety of operating/ maintenance personnel in case defects in aerators are to be rectified
4)
Area requirement is very large as compared to CASP and restricts future expansion
5)
Power consumption is moderate and there is no potential for production of power. Unit Sizing: Anaerobic Lagoons followed by Aerated Lagoon
All dimensions are in m unless otherwise specified Sr. 1
Name of Process Unit
2
Preliminary Treatment Units Inlet Chamber Screen Chamber Grit Chamber Parshall Flume Anaerobic Lagoons
3
Aerated Lagoon
4
Settling Lagoon
Size of the unit
1 No., 6.5 x 4.5 x 3.3 2 Nos., 11 x 1.5 x 1.5 3 Nos., 8 x 8 x 1.1 1200 mm throat As per Int. 2 Nos., 92 x 97.5 at top 68 x 89 at bot, 6 m 2 Nos., 92 x 160 at top 72 x 160 at bot, 5 m 2 Nos., 92 x 33 at top 66 x 20 at bot, 6.5 m
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
Power rqnt (W+SB) HP 6+6 6+3 400+0, 16 Nos., 25 HP -
49
Rajkot Municipal Corporation
Civil Designs
D) Up flow Anaerobic Sludge Blanket Reactor followed by Polishing Lagoons (UASB-PL) This process is based on anaerobic suspended growth system unlike earlier processes. Raw sewage is admitted to the inlet chamber for further processing for removal of large particles. Floating matter are trapped in the screen and removed with help of rack mechanism and put to conveyor belt for disposal through collection vehicle. Grit is removed in grit chamber and then sewage is admitted to UASB reactor. Sewage is uniformly distributed over entire tank. Four basic steps of anaerobic process takes place in this reactor and biomass consumes biodegradable matter during it’s’ passage through sludge blanket. All three operations, pre-sedimentation, anaerobic treatment and final sedimentation including sludge stabilization makes it attractive treatment option. Sludge developed in reactor tries to settle under gravity when applying moderate upward velocities in the reactor. Anaerobic microbes developed in reactor are kept in the compartment for sufficient time. Organic compound present in the sewage are absorbed or adsorbed on the sludge particles in the reactor during it’s’ passage through the bed. Organic compound gets converted to methane enriched bio-gas and small part into new bacterial mass after anaerobic biodegradation. Bio gas consists of methane CH4, carbon dioxide CO2, hydrogen gas H2, hydrogen sulfide H2S and traces of ammonia NH3 and nitrogen N2. Biogas generated in reactor is considered to be advantageous to promote this process. However, gas generation is found to be effective with high COD values and particularly useful for industrial waste. Sensitivity of process to absorb shock load and sulphate poisoning is considered to challenge before designers and operators of the plant. After UASB, polishing unit in form of lagoon or physicochemical process or conventional activated sludge process are must to achieve discharge norms. Description of functional requirement of each unit for UASB-PL is discussed in brief. 1)
Inlet Chamber
2)
Screen Chamber
3)
Detritor
4)
Parshall Flume
5)
UASB Reactor (UASBR)
6)
Pre Aeration Tank
7)
Aerobic Lagoon (AL)
8)
Settling Lagoon
9)
Sludge pump house
10)
Filtrate pump house
11)
Gas holder
12)
Sludge drying beds/ filter press/ centrifuge
13)
Dual-Fuel gas engines/ gas flaring system
First three units are considered to be Preliminary Treatment Units. 4th, 5th and 6th are secondary treatment units and remaining are supporting units for MWwTPs.
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INLET CHAMBER : An Inlet Chamber is provided as receiving unit to STP with special
arrangements. In case of normal operations, the sewage will be diverted to STP and in case of eventuality/ repair/ maintenance, a bypass arrangement is provided for discharge of sewage into receiving body. 2.
SCREEN CHAMBER : Screening is an essential step in treatment of sewage to facilitate
removal of large size floating materials like rags, plastics, tobacco pouches, wooden pieces etc. which otherwise would damage pumps and interfere with the performance of the subsequent units. This consists of bars placed parallel in vertical or inclined system across the flow to trap the floating material. Generally 20 mm spacing is considered to be adequate for STPs. However, considering the problem of pouches of tobacco passing thru’ it parallel to flow, finere screens with spacing of 12 mm followed in mesh pattern are in vogue. 50 mm x 10 mm thick flats are considered to be standard practice in India. Timer based racking mechanism cleans the screen periodically and put the screenings to belt conveyor system. Material is conveyed to collection van provided beneath the end of the belt conveyor for final disposal. CI Gates upstream and downstream to the screen are provided to control flow. 3.
DETRITOR : Detritus Tank popularly known as detritor is provided after screen to remove
heavy inorganic fraction of the sewage prior to physical and biological process. Difference in settling velocities between organic and organic content due to specific gravity is the basic principle followed to design the unit. Grit consists coarse sand particles, ash, clinker, egg shells and silt coated by organic matter (generally marginalized group use silt/ash for washing of utensils) etc. Grit is considered to be non-putrescible possessing higher hydraulic subsidence value than organic matter. Grit removal, if not done, causes abnormal wear and tear to mechanical parts, scrappers/ pumps/ aerators etc. With proper hydraulic design, grit can be effectively removed from the sewage. To prevent loss of useful organic content and to prevent emanation of highly malodorous emissions from the removed grit, grit classifier based on reciprocating mechanism is provided. 4.
UPFLOW ANAEROBIC SLUDGE BLANKET (UASB) REACTOR : Upflow Anaerobic Sludge
Blanket (UASB), was developed to treat industrial waste possessing high COD and BOD, posing power intensive treatment-if one opts for aerobic treatment. Hence anaerobic treatment was found to be techno-economical. Deficiencies of Septic Tank/s Imhoff Tanks/ Upflow Anaerobic Filters were attended and researchers have tried to ensure uniform distribution of flow, restricted upward velocities etc. To maintain sludge blanket at mid-level, upward velocity shall be applied to flow at moderate range. Wastewater enters the reactor from bottom at uniform flow rate and travels upward direction. This eliminated necessity of separate sedimentation tank. Anaerobic bacteria are developed in the reactor for sufficient time. In order to ensure sufficient contact between the incoming sewage and the sludge blanket (mass of anaerobic bacteria), the velocity of upward flow is restricted and uniform feeding rate of wastewater is ensured all over the bottom of the reactor. Organic compound present in the sewage are absorbed/ adsorbed on the sludge particles in the reaction zone. Further mixing is Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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achieved by movement of biogas in upward direction, the density currents and settling of solids in downward direction. Organic compound are converted to biogas consisting of methane-enriched gas and new bacterial biomass. The gas is collected in the gas collector and used as energy source. A gas, liquid and solid separator (GLSS) is provided below the gas collector in order to maximize collection of gas (gas bubbles attached to sludge particles could lose contact and can be trapped into gas collector). 5.
PRE AERATION TANK : After UASBR, anaerobic microbes dominates the system since
sewage has undergone anaerobic treatment. Gases like methane and hydrogen sulfide are at saturation level and nature of the bio-culture is anaerobic. To change the anaerobic nature of the sewage and to make it amenable for aerobic treatment, pre-aeration shall be provided. Basic objective of this unit is to remove dissolved gases of anaerobic process and prepare culture suitable for aerobic treatment. 6.
AEROBIC LAGOON : After pre-aeration, sewage would undergo aerobic treatment in lagoons
to facilitate aerobic conversion of organic matter into biomass and gases. 7.
SETTLING TANK/ LAGOON : SST/SL permits activated biomass to settle in form of sludge.
Due to highly active biomass, lumps of biomass are formed and higher ratio of volume to surface area enhances the settlement. Now, major portion of organic content is converted into biomass, which is settled as sludge. Supernatant comprise very low BOD and SS and other parameters. In case the treated sewage is to be discharged into natural water body, the parameters comply with the norms prescribed by pollution control board. 8.
SLUDGE PUMP HOUSE : Sludge produced in the UASB is collected in the sump and pumped
to the sludge drying beds/ centrifuge/ filter press to reduce water content and amenable to use as manure. Concentration of sludge varies from 2% to 6% depending upon the status of biological process within reactor. Generally higher concentration prevails in the reactor, if performance is good. Considering its’ functional importance, 100% standby pumpsets are provided in this unit. 9.
SLUDGE DRYING BEDS/ FILTER PRESS/ CENTRIFUGE : Digested or raw sludge is dewatered
and converted to utilizable form of sludge cake for manure. Sludge drying bed is most common form of concentrating the sludge and it is most common practice in India. 10.
FILTRATE PUMP HOUSE : Filtrate from sludge drying bed/filter press/centrifuge contains
high BOD and SS and hence prior to disposal into natural water body, it shall be treated. Filtrate pump house pumps back filtrate to the inlet chamber of PST and hence only treated sewage is discharged from the STP. Though quantity of filtrate is very low in terms of percentage, overall quantum is in terms of few thousand litres and hence it must be treated prior to discharge. 11.
GAS HOLDER : Gas produced in digester is collected here for further utilization like power
generation with uniform feeding to Dual-Fuel Engines or flaring. 12.
DUAL-FUEL GAS ENGINES/ GAS FLARING SYSTEM : Gas produced in the digester is
enriched with methane and high calorific value. Dual fuel engines capable of using gas (up to 8090%, generally 60%) and diesel (20-10%, generally 40%) can yield power sufficient to run more than Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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half of the operations of the STP. Though it is very attractive, STPs initially set up with an objective to have captive power generation either in CASP or UASB has not been successful on large scale. This process is having following advantages 1)
It is a buzzword and considered to be adaptive if this process is implemented
2)
Power generation is considered to be only attractive aspect and advantage due to emerging power scenario world wide.
Disadvantages of the process are: 1)
Process is having very low level of reliability, reaction kinetics are yet to well-established, not easy amenability to control and absorb shock loads.
2)
Sludge removal pose operational problems due to higher depth and accessibility.
3)
Difficult access to components for repair and maintenance
4)
Highly skilled personnel (biologist) are required to maintain process parameters
5)
Less safety of operating/ maintenance personnel in case defects in hood/ baffle, gutter, GLSS are to be rectified
6)
Area requirement is very large as compared to CASP and restricts future expansion
7)
Power generation is main slogan to promote the process. However, operationalisation of dual fuel engines for purely domestic waste has not become successful.
8)
Process is not proven world-wide, construction techniques are known to limited agencies restricting competition and rectangular reactors with higher depths becomes more costly.
9)
In case of disturbance of sludge blanket, resumption takes long time
10)
Lifecycle of upper hood and dome is not assured leading to uncertainty of the recurring cost. Unit Sizing: Upflow Anaerobic Sludge Blanket Reactor
Sr.
Name of Process Unit
Size of the unit
Power rqnt (W+SB) HP
1
1 No., 6.5 x 4.5 x 3.3 2 Nos., 11 x 1.5 x 1.5 3 Nos., 8 x 8 x 1.1 1200 mm throat As per Int. 4 Nos., 32 x 32 x 6 2 Nos., 10.5 x 10.5 x 3.1
6+6 6+3
2 3
Preliminary Treatment Units Inlet Chamber Screen Chamber Grit Chamber Parshall Flume UASB Reactor Pre-Aeration Tank
4
Aerated Lagoon
5
Settling Lagoon
6 7 8 9 10
Sludge Pump House Filtrate Pump House Sludge Drying Beds Gas Holder Power Generator
2 Nos., 88 x 176 at top 64 x 164 at bot, 5 m 2 Nos., 88 x 48 at top 64 x 36 at bot, 6 m 1 No., 6 dia, 7 m ht 1 No., 4.5 dia, 4 m ht 22 Nos., 20 x 20 1 No., 18 dia, 5 ht. 12 x 8 x 6
Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
15+0, 2 Nos., 7.5 HP 400+0, 16 Nos., 25 HP 7.5+7.5 6+0 -100
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TECHNO-ECONOMICAL ANALYSIS OF VARIOUS PROCESSES FOR SEWAGE TREATMENT Each of the process described in earlier chapters have distinct advantages and limitations. In the present context, while number of MWwTPs/ STPs are constructed under various projects/ grants/ aid for urban renewal/ river cleaning and are operational, challenges before technical feasibility of any/ all processes could be taken up and can successfully overcome various problems. However, practicability of each option, based on which particular process is selected, shall be looked into and yard-stick shall dictate a particular process rather than comparing all processes based on merits and demerits. Applicability of particular process for the expected raw sewage characteristics at Raiya is of the prime importance to select a particular option. Economical aspects and options, sensitivity needs to be analyzed before concluding for a particular process and then finally decide the treatment option. Technical considerations Based on the studies made by our team, data available about various STPs functional in India, supporting literature and merits/ demerits noticed, feed back from field operators, designers, and various ULBs, it is found that CASP/ FLEA and ANAL are betters options and more acceptable as compared to UASB. In our opinion UASB is not attractive option, since sewage is purely domestic in nature leading to low potential of power generation. CASP is having wider acceptability as compared to lagoons owing to sludge removal problems from the lagoons and maintenance of aerators. In case of lagoons, sewage level varies to a considerable extent. This is important aspect while selecting aerators for lagoons. Oxygen transfer depends upon submergence, which is limited in case of fixed aerators and hence efficiency of the MWwTP/STP is affected. Floating aerators are found to be best option, provided boat and other means are available for maintenance and repair. Except for Mumbai, other ULBs find it difficult to maintain and hence one has to compromise on efficiency by selecting fixed aerators. For CASP, Sludge Digesters on other hand have had problems of dome and explosion, maintaining anaerobic condition etc., which could be overcome by adopting gas mixing system instead of mechanical mixers. Hence, all the processes are treated as technically at par despite basic deficiencies related to O & M, even controlling behavior of microbes, less known reaction kinetics as in case of UASB. To conclude about best option, it is necessary to compare capital costs and O & M costs, NPV etc., to arrive at most economical option for sewage treatment. Subsequent paragraphs addresses this aspect prior to recommending the suitable process. Recommendations: Based on various analysis and applicability of the process for the said STP, Conventional Activated Sludge Process is most economical and it is recommended to select the CASP with power generation module for construction of the STP at Madhpar.
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6.3 Drainage Phase-III (Part-1) •
Background: During the period about last 10 years further development occurred in RUDA
area mostly on the west side of the old city and along South North direction also. The specific planning of development in these areas was not sought out during that time, however, on the occupied plots at various pockets in the said area, the construction of buildings were going on without having any permission basic facilities like roads, electricity and water supply network as well as waste water disposal system. This area came under rule of RMC in the year 1998. Therefore now, it is a duty of the authority to provide all the basic facilities as stated above, to the people of those areas. To provide drinking water facilities to the people of those areas a water supply project based on Nyari-II reservoir and its seepage was carried out, but due to scarce of water in the reservoir, the water supply system could not be put in to commission during this year. Similarly, subsequent problem of waste water disposal shall have to be faced immediately after commissioning of drinking water supply. To solve this problem a Sewerage Project Phase-III was thought out by Rajkot Municipal Corporation •
Field Survey : For the proposed project area, where town planning schemes was prepared,
the road alignment survey was carried out. This includes taking of levels at 30 mt. Interval along the roads, all the crossings and turning points etc have been covered with additional levels at 30 mt interval on center line of the road. For areas outside the town planning schemes, i.e. pockets developed like near Mavdi village, layout of such areas have been prepared and incorporated with the levels at 30 mt interval. Total length of roads are shown in the below mentioned table. Details of T.P.Roads in Town Planning Schemes Sr No 01 02
03
04 05 06 07
Name & Nos.of scheme T.P.S. 1 Raiya T.P.S. 2 Nana Mava T.P.S. 3 Nana Mava T.P.S. 4 Raiya T.P.S. 5 T.P.S. 6 Raiya T.P.S. 7&8 Mavdi
Length of Roads (in Meter)
Total
Sub Road
Tot. of Roads
45m
30m
24m
28m
18m
15m
12m
9m
1420
--
1400
1000
80
--
7385
3090
24375
24840
39215
240
2180
1180
1340
--
1340
4380
1240
11900
21140
33040
1260
--
1260
--
--
280
5710
5370
13880
8200
22080
--
--
1120
--
2800
--
4320
6150
14390
8280
22670
-1600
600 --
1060 1460
---
---
-820
4840 5500
2120 3160
8620 12540
8040 17040
16660 29580
--
--
--
--
--
--
--
--
21755
25000
46755
Total
210000
Ground levels have been recorded in the level books and same have been submitted as Survey And Investigation Report( For Population Projection Kindly Refer Annexure). The TBM list with location and RL in meters for TP scheme 1 to 8 and pocket areas have been identified , Sketches of locations also have been shown in the drawing No.01 to 08. Field Book record i.e. level Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Book No.01 to 21 have been also incorporated in the survey report for permanent record for Rajkot Municipal Corporation. For preparation of estimation of sewer lines, trial pits in the project area have been taken. •
Population Projection: The population projection is forecasted based on past available
data of population and sample studies of two TP areas partly developed and / or under developing, considering the number of persons 5 per house / flat for the occupation of 65% of total houses. Thus the projected population in the year 2030 is forecasted to 3,97,000 including the prospective population of three villages also as drainage collective system is generally designed for 30 years of period. •
Water supply: Saurashtra region is the semi arid zone and Rajkot city is falling in this area
where water is scares. Other cities of Gujarat State like Vadodara, Surat and Ahmedabad, total quantity of water per capita is supplied (considering all other sources) 250 liters and these figures are always taken into account by the consultants for calculation of generation of waste water for the design of collective system of sewer lines. Whereas to run the underground drainage, Central Public Health and Environmental Engineering Organization. (Ministry of Urban Development) has fixed criteria per capita bases and it is 140 to 150 liters / capita water requires to run the underground drainage system smoothly. Therefore, Rajkot Municipal Corporation has followed minimum requirement of water supply as per the criteria fixed by the CPHEEO New Delhi 140 to 150 LPCD to function the underground drainage of city area as well as proposed project area. The proposed project area is only of residential zone and hence no other demand like industry etc has been taken into account. The Rajkot Municipal Corporation has also planned to provide sufficient supply the water required for efficient functioning an commissioning of this sewerage project of extended area of the city simultaneously. •
Waste water generation: Normally 80 to 85% of the quantity of water reaching the
consumer's end is considered as waste water for the sewerage disposal system. Per capita waste water flow for the design of sewerage system is considered as 128 liters in this design. The estimation of ground water infiltration shall be practically zero as the ground water table in this region are very much below the designed depth of sewer lines. However, the provision of ground water infiltration has been estimated as per the criteria shown in Manual on sewerage & sewage treatment (Page 40) i.e. minimum 500 liters / km day for approximately 200 kms length is equal to 0.10 MLD which is negligible quantity against the total flow of the project. •
Design of sewers : The system design parameters for sewers are as per CPHEEO manual
which is the requirement of financing institutions. The design criteria for sewers are as follows:
•
Design Year: The design year considered for the sewerage system for this project area is 2030.
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Civil Designs
Design Flow : The design is based on the waste water generated duly considering the water
demand of 150 LPCD as stated above in the year 2030. The design flow is therefore considered as 128 LPCD after considering losses and considering that 85% of water supply is converted to sewage. •
Peak Factor : Peak factors, depend upon the density of population, topography of the project
area and hours of water supply etc for design of sewerage system of project area, peak factor 2.25 is to be considered for the design based on contributory population recommended by CPHEEO in the manual. However, looking to the individual TP scheme population 2.50 peak factor is taken in the sewer design. The peak factor is applied to the projected population for the design year. •
Average Dry weather flow :This would comprise average domestic sewage flow and
infiltration. •
Peak Dry weather flow : This is the design flow. It comprises peak domestic sewage flow
and infiltration. •
Design formula :For design of new sewerage system, Manning's formula is adopted which is;
For Circular conduits V=
0.003968(D)0.67 x (S)0.50 N
•
Q=
(1/N) (3.118x10-6)D0.67 x S0.5
Q=
Discharge in lps
V=
Velocity in mps
N=
Manning's Co-efficient of Roughness
D=
Internal dia. of pipeline in mm
S=
Slope of hydraulic gradient
Coefficient of Roughness : For sewerage system, NP2/NP3/NP4 class RCC pipes for higher
diameter as well as stoneware glazed pipes for smaller diameter sewer line are generally provided. The roughness coefficient, N, is assumed same for all diameters of RCC pipes with collar joints and is considered 0.015. For stoneware pipes for all diameters, N, is assumed 0.013. As pipes deteriorate with age, a roughness co-efficient is considered corresponding to fair condition of the interior surface of sewers. •
Minimum size of Sewer: A minimum diameter of 150 mm has been considered to identify
the proposed sewer under study. Three factors are influencing for deciding the diameter of sewer pipeline. •
Proposed gradient in sewer line : Rajkot city is under semi arid zone and availability of
water quantity here is scarce resource. Hence, minimum criteria of water supply 140 LPCD to 150 LPCD is adopted by the Corporation for smooth functioning of sewer lines. Rajkot city Sewerage project phase-I was started in the year 1979 and completed and commissioned after 23 years of period. The main reason of delay of this project was a severe hard rock excavation and steep slope of initial pipelines in the design. Initial slopes of 150 mm dia pipelines were taken 1 in 80 to get very Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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easy initial self cleansing velocity. Due to such design, depth of pipeline had gone very deep and due to hard rock it was found more difficult in the excavation. Ultimately, a decision was taken to adopt grade of 150 mm dia pipeline 1 in 130 which is found sufficient for 750 population of initial stage to achieve self cleansing velocity during peak hours. Hence based on the past experience of Rajkot city sewerage project phase-I and its present results of well functioning in the water scares period. It is proposed to provide 150 mm diameter as minimum for initial sewer lines. Major lengths of sewers in any project area are always with smaller diameters and these initial pipeline sections are not getting enough flow in the commissioning stage. Hence, as per the recommendations of World Bank in the previous sewerage project Phase-I, Stoneware pipes of minimum diameter 150 mm size is proposed in this project for initial sewer lines and same will be more convenient in cleaning in the initial stage of commissioning. More care is required for frequent cleaning during initial period. Stoneware pipes of ISI quality are now easily available in the market and hence it is recommended to use 150 mm to 250 mm dia pipes in this project as stoneware salt glazed ISI marked quality for initial sections of sewer lines.
•
Minimum Depth of Cover : The minimum depth of cover to be provided over the top of pipe
is 1.0 meter for diameter equal to and above 300 mm.
•
Self Cleansing Velocities :A minimum velocity of 0.75 to 0.80 mps at design peak flow (in
the year 2030) in the sanitary sewer is considered subject to a minimum velocity of 0.6 mps for present peak flows (in the year 2001) as per the recommendations of CPHEEO manual. Limiting velocities for particles varying in specific gravity from 1.01 to 2.65 were studied. The specific gravity of grit is usually in the range of 2.4 to 2.65. For minimum velocity of 0.6 m/sec all particles of specific gravity 2.65 and size less than 1.0 mm will remain in suspension. Hence, the velocity of 0.6 m/s should be adequate to prevent situation in sewers. However, the problem of silting may occur in early years, particularly for smaller sewers with velocities of flow less than 0.6 m/s but the assumption is made that the deposited silt would be flushed out during the peak flows. Where such velocities are not obtained periodical flushing would be required.
•
Design capacity of sewers : Sewers designed to carry estimated peak flows generated in the
year 2030 will run partially full for all variations in the flow. The maximum permissible depth of flow in sewers for established velocity criteria are tabulated in the following table.
•
Depth of Flow : From considerations of ventilation in waste water flow, sewers should not be
designed to run full. All sewers are be designed to flow 0.8 full at ultimate peak flow. However, as per Hydraulic design the depth of flow at Ultimate Peak is between 0.45 to 0.8.
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Following table shows the hydraulic properties of circular sections for Manning's Formula.
Hydraulic properties of circular sections for Manning's formula Depth Ratio
Area Ratio
Hydraulic radius Ratio
Velocity Ratio
Discharge Ratio
d/D
a/A
r/R
v/V
q/Q
0.100
0.052
0.254
0.401
0.021
0.200
0.143
0.482
0.615
0.088
0.300
0.252
0.684
0.776
0.196
0.400
0.373
0.857
0.902
0.337
0.500
0.500
1.000
1.000
0.500
0.600
0.626
1.110
1.072
0.671
0.700
0.748
1.185
1.120
0.838
0.800
0.858
1.217
1.140
0.988
0.900
0.949
1.192
1.124
1.066
1.000
1.000
1.000
1.000
1.000
where d, a, r, v and q denote depth of flow, area, hydraulic radius, velocity of flow and discharge respectively for partial flow condition and D, A, R, V and Q are the corresponding characteristics for full flow condition. •
Topography of the proposed project area : Detailed survey investigations have been
completed and based on the detailed survey the actual topographical conditions, sewerage network have been prepared to have minimum excavation of pipelines. A natural drain (Vonkala) coming from South direction of the project area flows towards North i.e. from near by Mavdi village to passing through out skirt of the extended area of the city to the west of the villages of Munjaka and Raiya meeting to the tributary of river Nyari on up stream of Nyari II reservoir. Therefore in general the natural slopes of the ground have been taken into account for planning the sewerage network.
•
Design methodology and analysis of sewerage network : Population distribution have
been carried out on present and projected density and same have been distributed per manhole in the TP scheme layout. Special consideration is given to the areas where high rise buildings exists and areas where such type of high rise buildings are expected in future. Per manwhole increase of flow has been calculated and for each sewer section, present average flow, present peak flow, projected average flow, projected peak flow and full flow have been calculated and applied as basic data of hydraulic design of sewer sections of entire network. Network have been prepared as per Town Planning Scheme Numbers 01 to 08 considering each Town Planning Scheme as individual drainage zone for convenience of execution, maintenance and supervision. The hydraulic analysis of all sewer sections as collective system have been carried out using Excel Computer Software Programming for all the four conditions of all sewer sections of network. It
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has been cross checked with the computer software recommended by the UNDP Sewer Software Version 3.0. Statements of design of sewer sections and designed Invert Levels have been attached herewith as an annexure. •
Sewer appurtenances: Manholes are to be provided at all junctions, change of sewer size,
gradient and direction. As per the RMC practice the spacing of manhole is kept between 25 to 40 mt for all diameters. •
Spacing of manholes adopted are as follows:
•
Pipe dia of 300 mm - 450 mm - 30 m
•
Pipe dia of 500 mm - 900 mm - 40 m
•
Pipe dia of 1000 mm - 1800 mm - 50 m
However, additional manholes are to be provided on junctions of the street avoiding standard distance. For sewers of 600 mm diameter and above, scraper manholes are proposed to be provided at major junctions and at about 200 m c/c. The typical details of proposed house connection chamber, conical type manhole, A, B, C, D1, D2 and scraper manhole S1, S2, S3 are shown in Annexure.
Bedding for sewers: The type of bedding (First class bedding, concrete cradle, full encasement) shall depend on the depth at which the sewer is laid. Thus the load due to backfill and superimposed load (live load), and the three edge bearing strength of pipe will be the governing criteria for selection of appropriate bedding factors.
6.4 Design of Sewage Treatment Plant at Raiya under Phase-III (Part-1) Existing sewage treatment plant In the phase-I, the waste treatment process has been adopted keeping view the most of the waste will contain a domestic waste i.e. sewage excreta and sullage water rather than any other major industrial waste. Therefore process of treatment is provided considering the characteristics of raw sewage having BOD 200mg/l, which is a facultative aerated lagoon followed by extended aeration for the capacity to treat 44.50 MLD. This treatment unit does not carry any further additional load due to further augmentation or future provision of extended area. However, additional land has been kept reserved in the premises of existing treatment site for the purpose of any additional treatment units for the Sewerage Project Phase-II of old city area. While as per the topographical situation mentioned previously the land located nearby village Raiya is technically as well as economically feasible for adoption of new waste water treatment units and disposal of treated waste for sewerage project phase-III Acquisition of Land : Additional land is already reserved at existing sewage treatment plant site nearby Madhapar under Phase-I and Phase-II sewerage project but it will not suffice to accommodate sewage treatment units proposed under phase-III sewerage project, and which is also not feasible as narrated in the preliminary project report, technically as well as financially. The land near village Raiya has been acquired, to accommodate sewage treatment units including some necessary disposal facilities. The Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
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Gujarat Pollution Control Board (GPCPB) has already approved the site and RMC has already finalized DTPs Process design options The number of approaches and advanced techniques are prevailing at present to treat the domestic waste water as well as industrial waste water. Normally biological treatments are used world wide and they are suitable for sewage treatment plant,. Following are the options of biological treatment for treatment of domestic sewage. Following review is made.
Looking to the techno-economical aspect- Conventional Activated Sludge Process with Sludge digester is recommended to be adopted for Sewage Treatment Plant Location of the Works The Works are to be constructed at Raiya located approximately 3 km west of the city limits of Rajkot in the State of Gujarat, India. The detailed location is shown on the Drawings.
Description of the Works The Works shall comprise the provision of a sewage treatment plant to treat up to 51 Mld of raw sewage generated in new area and to discharge the treated sewage into a natural drain leading to river Nyari of the specified quality. The sewage treatment plant shall comprise the following: (a)
Unit processes and services •
Inlet chamber;
•
Screen Chamber;
•
Grit Chamber;
•
Parshall Flume;
•
Primary Clarifier;
•
Aeration Tank;
•
Secondary Clarifier;
•
Sludge Digester and Sludge Drying Beds;
•
Raw Sludge and Return Sludge Pump Houses
•
Sewage sampling;
•
Service water;
•
MCC Room.
Raw Sewage Raw Sewage Quality Generally, the raw sewage has a low suspended solids, but during morning hours, its concentration rises from less than 200 mg/l to 800-1000 mg/l. At the same time other parameters does not change substantially. Detail Project Report for Drainage Phase-II & Phase-III (Part-I) for Rajkot City
61
Rajkot Municipal Corporation
Civil Designs
The treatment works shall be designed to treat sewage of the following quality:
Raw Sewage Quality Parameter pH
Units of measurement pH units
Value 6.5 - 9.2
Suspended Solids
mg/l
525
Biological Oxygen Demand
mg/l
200
Chemical Oxygen Demand
mg/l
630
Alkalinity
mg/l
185
Sulphates
mg/l
110
Total Kjeldah Nitrogen
mg/l
10
Ammonical Nitrogen
mg/l
16.8
Organic content in grit
%
4
Oil & Grease
mg/l
15
The quality of the raw sewage entering into existing Sewage Treatment Plant at Madhapar over the period January 2005 to December 2005 is summarized in Appendix ___.
Sewage Treatment Plant Performance The sewage treatment plant shall be designed for continuous operation even with reduction of flow by 50%, the performance of the plant should not be affected. The purpose of the treatment plant is to produce treated sewage suitable to discharge it into natural water body as per the guidelines stipulated by Gujarat Pollution Control Board (GPCB) and as per guidelines of Central Public Health and Environmental Engineering Organisation (CPHEEO) as summarised in Table. When the sewage treatment plant is operated in accordance with the Contractor’s operating instructions at an output varying within the normal operating range (50 % to 100 % of rated flow), the quality of the treated sewage, the primarily treated sewage (from the launder of primary settling tank) and the secondarily treated sewage (from the launder of secondary settling tank) shall comply with the requirements stated in Table: Required Treated Sewage Quality Sample
Compliance Requirement
Effluent from PST
BOD
