Ministry of Provincial Councils & Local Government
Greater Colombo Wastewater Management Project
ADB Loan No: 2557:2558- SRI
Funded by the Government of Sri Lanka through a loan obtained from the Asian
Development Bank
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Greater Colombo Wastewater Management Project
“Joseph Bazalgette saved thousands of lives in London by sorting the sewers. So
why’s the ‘Sewer King’ who risked his own health to help others, whose system’s
still used by millions today. As a result life expectancy being just 30 when he
was born, on 15 March 1891, Bazalgette dies in his Wimbledon home, aged 72”
http://www.history.co.uk/biographies/joseph-bazalgette
4.1 Background and Rational of the Project
Colombo sewerage system has a long history. Richerd Eustace Tickell wrote in
February 1923 in his paper on “Colombo Drainage Works” in the Minute of
Proceedings Vol.216, of the Institution of Civil Engineers, London that the planning
of the sewerage system in Colombo Municipal Council area was commenced in 1896
and the construction work was commenced in 1906. The sewerage system has been
funded by the then government through a loan to the Colombo Municipal Council.
The sewerage systems in Dehiwala, Mt Lavinia Municipal Council and Kolllonnnawa
Urban Council areas were built during 1983-1987 based on the Sewerage Master Plan
by Howard Humphrey done in 1972. Parallel to this the sewerage system in Colombo
Municipal Council area has partly been rehabilitated and expanded. The sewage from
Dehiwala Mt.Lavinia Municipal Council and Kolllonnawa Urban Council areas has
connected to Colombo system for sea disposal. Additionally 11 numbers of
institutions located outside Colombo Municipal limits discharge their sewage through
Colombo system.
Today the Colombo sewer system has experienced many failures requiring urgent
attention. There are several instances that public life was threatened and country’s
economy was affected due to sudden failures in the system. Several studies have been
carried out on the condition of the system and with the understanding of the criticality
of this service the Government has obtained a loan from the Asian Development Bank
to upgrade the most critical component of the system under the Greater Colombo
Wastewater management Project.
The Greater Colombo Wastewater Management Project is designed to improve the
urban environment and public health for the urban and suburban residents in Colombo
through improvements of wastewater management services. The project involves in
upgrading the sewerage infrastructures, strengthening institutional and operational
capacity and project management and implementation.
1.1 Implementation Period
The project has originally planned to be completed within a period of 5 years and was
expected to be completed by 31st December 2014 with a loan closing date of 30th June
2015. The project completion date was extended till 30th June 2017 by taking into account
the time required for completion of agreed activities.
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1.
Project Cost
The project cost is estimated at USD 116.6 million, including taxes and duties
amounting to USD16.6 million. A summary of the cost estimates in $ million is given
in Table below.
Item Description
A
Base Cost
1. Upgrading Sewerage infrastructure
2.
Strengthening Institutional and Operational
Capacity
Amoun
t
81.0
4.2
11.7
3.
Project Management and Institutional Support
96.9
Sub
Total (A+B+C)
116.6
B
Total (A)
14.00
C
Continge
Note: Out of USD116.6 million, the project cost for CMC is USD110 million. The
5.7
balance USD6.6ncies
million is the project cost for rehabilitation works under Dehiwala
Charges
Implementation
Mt. Lavinia MC Financing
and Kollonnawa
UCDuring
areas operated
by the NWSDB.
2. Expected benefits of the project
The expected benefits of the project are:
 Improved wastewater management services, better urban environment, better
public health including living conditions for residents in the Colombo City
and suburbs
 Improved marine and inland water quality
3.
Outputs of the Project
The project comprises three major interrelated areas of interventions.
Component 1: Upgrading Sewerage infrastructure

Rehabilitation of main sewerage system covering pumping station and
pumping mains in Colombo, Kollonnawa and Dehiwala Mt Lavinia
Municipalities

Rehabilitation of Critical Gravity Sewers with under capacity
Rehabilitation of 10km length of sewer lines and Conducting Condition
Assessment of 125km l e n g t h o f sewer lines
Upgrading of Wanathmulla gravity sewer network



Rehabilitation of sea outfalls

Supply of non-fixed operational equipment
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Component 2: Strengthening Institutional and Operational Capacity

Providing institutional development consultancy support to CMC


Develop, Procure, install Business support system for CMC
Develop and install Management Information system and train CMC personnel

Cary out Community Participation and Public Education Programme
Component 3: Project Management and implementation support

Providing Design, Supervision and Management Consultancy support

Support Project management and implementation

Implementation of Capacity Development Programs
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4.
Project Implementing Area - Within Colombo Municipal Council Limits
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5.
Prevailing status of existing sewer lines and pumping stations
The sewer line delivering sewage from the Pumping Station at
Peterson Lane to Wellawatta junction chamber, collapsed at
Galle Road, Wellawatta few years before Project commences.
Colombo Municipal Council repaired the sewer. Such collapses
are noticed only when the road surface starts to sink. Systematic
way to identify such sewer failures prior to notice through a
sinkhole on the road surface is essentially required to minimize
economic loss and social disturbance.
Existing pumping station at Vystwyke in the North
catchment of Colombo sewer system. Pumping
station has been built before 1920. It needs to
urgent replacement.
Behavioral changes are required among the
sewerage users to provide efficient and effective
service to them. Sewers are frequently clogged
due to dumping of garbage, siltation from
rainwater drains etc. Removal of garbage/debris
from sewers requires expensive sophisticated
equipment. Accumulation of silt deteriorates
pumps in pumping stations apart from clogging
of sewers. Sewer and pump house cleaning
operations to remove these and replacement
cost of pumping equipment require large portion
of rate payers’ money.
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6.
Status of Component 1 - Upgrading Sewerage Infrastructure
The component 1 of the project constitutes 80% of the project funds for
rehabilitation of main sewerage system, Rehabilitation of Gravity sewer,
Rehabilitation of Sea outfalls, Rehabilitation of Pumping Stations and supply of
non-fixed operational equipment and resettlement activities.
6.1 Supply of Non-fixed Operational Equipment
The project has procured 4 numbers Jetting and Vacuum Trucks, Spare parts and
accessories worth over Rs.223 Million to Colombo Municipal Council. These 04
jetting machines were given to District Engineer’s offices in the CMC and are
currently used for cleaning of accumulated grit, sand, hard deposits, encrustations
tree roots etc. from nearly 260Km of sewers and 7000 numbers of manholes.
Training of sewer cleaning equipment provided under
the Project. Training on Occupational Safety and
Health was provided at NIOSH, under the Project to
Drainage Engineers, Supervisors and workers. The
need of wearing of safety equipment was dealt at the
training. However it has been difficult to inculcate the
use of safety gears as workers are reluctant due to
practical issues.
6.2 Procurement of Sewer Operation and Maintenance Equipment
Sewer operational and maintenance equipment was also procured and provided to
assist CMC to carry out operational and maintenance tasks of the sewer system. 13
different types of equipment were provided and training on operation and
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maintenance of equipment was also conducted to the CMC staff by the particular
suppliers.
Part of equipment provided under the
Project to Drainage Division of
Colombo Municipal Council to
increase the operational capacity
6.3 Rehabilitation of Sea Outfalls
The Contractor for sea outfalls (including the removal of accumulated grit worth over
Rs. 2127 million) was awarded in March 2013. Work completed in May 2015.
The scope included;
At Mutwal Outfall
 Design and repair to Mutuwal sea outfall by replacing 564 meter length of
damaged pipe section including diffuser section and end plate
 Design and rehabilitation of land based junction chamber
 Design and construction of sea based access chamber
 Cleaning and removal of accumulated grit and debris from outfall pipe line
At Weellawatta Outfall
 Design and construction of sea based access chamber
 Unblocking of diffuser ports and fixing of end plate
 Repair land based damage of out fall pipe line
 Cleaning and removal of accumulated grit and debris from outfall pipe line
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Offshore junction chamber was casted at land
and brought to the sea for launching.
HDPE pipes assembled at land were
towed to sea for launching by floating on
sea surface using air bags. The location of
launching was monitored using real time
GPS equipment
Repair work of Wellawatta outfall pipe
corroded due to H2S attack. Around
10meter length of pipe line from the
junction chamber was repaired due to
crown corrosion.
Construction of access road to Mutwal
junction chamber has improved the living
environment of the community as well.
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6.4 Rehabilitation of Gravity Sewers
Rehabilitation of 10km of sewer lines and Conducting Condition
assessment of 125km of sewer lines
The Contract was awarded in May 2014 and is in progress. The completion date of the
contract is 31st December 2016.
Major outcomes of the activity are enhanced carrying capacity of sewers, reduced
clogging/blockages in sewers, database of condition assessment sewers.
Under this contract, 10 kilometer length of under capacity/defective sewers is
rehabilitated using various technologies. No dig technologies such as micro
tunneling, lining are used for sewer pipe replacement/repair. Where possible, open
excavation pipe laying method is also used for pipe repair. Condition assessment
database is planned to develop of 125 kilometer length of sewer network. Sewers are
being cleaned and surveyed using the CCTV technology and defects are ranked in
accordance with the WRc guidelines.
The defective sewer at Marine Drive is being replaced using micro tunneling
technology. Sewer rehabilitation works at Queen’s Road, Alfred Place, Deanstan
Place and Pedris Road are planned to commence as the next site under the contract.
Cleaning and CCTV survey of sewers in Drainage District 1, 2A and 2B areas is in
progress. During the CCTV survey large numbers of defects in the network have been
identified. The defects found were due to deterioration of pipes due to age, collapses
from improper connections, collapses due to tampering by other utilities have been
surveyed. The defects are being scored using WRc ranking system. The scoring
provides the list of sewers which needs urgent attention for replacement. Most
critically damaged priority sewers are selected for repairing under the contract.
Investigation work at Marine Drive
for sewer construction is being
carried out. Due to traffic
problems the work is carried out
during night. Safety of workers
has been a paramount aspect.
Workers are wearing luminous
jackets for identification by
vehicular traffic. Adequate lighting
has been provided to facilitate the
work.
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Pipe jacking work at Marine Drive. The jacking machine is positioned on the guide rails in the
driving shaft. The alignment is monitored using laser technology. The jacking process is
powered using hydraulic forces.
Cleaning of sewers using high pressure jetting.
Silt enters into sewers through rainwater
connections/diversions unlawfully. Removal of silt
and garbage from sewers needs high tech and is a tedious work. Silt removed from sewer
during cleaning operation is collected in bags for disposing. A worker is collecting silt from a
deep manhole which is a risky operation in terms of health and safety.
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Identification of damages in a sewer cannot be detected often until it surfaces through
sinkholes in roads or properties where the sewer pipe runs. The CCTV carried out has found
large number of defective sewers due to natural cracks due to the age of the system or misuse
of the systems.
Upgrading of Wanathmulla gravity sewer network
The Contract was awarded in January 2014.
The purpose of this Contract is to replace existing sewer pipes running under and
through the substandard houses/settlements in the area by constructing new sewers
along public roads to gain access for operation and maintenance.
The scope includes;
 Construction of new sewer line along Seevali Mawatha
 Construction of new sewer line along Saranapalahimi Mawatha
 Condition assessment of sewer along Pelangastuduwa Road and based on the
assessment carry out necessary repair work
Laying of sewer along roads to improve access
for operation and maintenance.
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Shoring work to support deep
excavation work for construction of
manhole at Wanathamulla sewer
upgrading site
6.5 Rehabilitation of Pumping Stations
The Contract was awarded in June 2015. The work will be completed in 3 ½ years
period.
The scope includes;
 Design, supply, installation and construction of 05 numbers of pumping
stations
 Design, supply, installation and rehabilitation of 06 numbers of pumping
stations
 Design, supply and installation of SCADA system for monitoring of pumping
station operations
 Training of operational staff
Planning and design work of 3 numbers of pumping stations is in progress. This
includes investigation work, hydraulic designs, layout planning of pumping stations
and determining equipment requirements.
The investigation work in progress
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6.6 Planning of new sewer systems for increasing sewerage coverage
Planning and Detail Designs of sewerage scheme for Kirullapona
catchment
Kirullapona catchment is one of none served areas in Colombo city. Currently
population depends on septic tanks or cesspits for disposing sewage. Environmental
Impact Assessment for development of sewerage system was carried out.
Accordingly planning and designing of sewer expansion system was completed.
Selection of Contractor for implementing the construction work has commenced.
The scope comprises of construction of new sewer reticulation system, construction of
pumping stations and connecting the catchment to Colombo sewer network through a
pumping main. This development will enhance the sewage disposal facility of a
population of 50000 by year 2014 in the catchment.
Kirullapona catchment and proposed sewer network, pumping station locations
Planning and Detailed designs of sewerage improvement for Central
Business District
Investigation, planning and designs for sewerage improvement required to facilitate
large scale development in Central Business District is under way. As a part of this,
to facilitate for Shangri-La development work, sewer expansion proposal is planned
to assist Colombo Municipal Council.
The work includes the study of capacity analysis of existing sewers in the area.
Required capacity enhancements, re-routing to provide the coverage and also to
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improve the access for operation and maintenance are taken into account when
planning and designing of the system improvement
7. Status of Component 2 : Strengthening Institutional and Operational
Capacity
The main outcome of this component is strengthening institutional and operational
capacity of the Drainage Division of the Colombo Municipal Council by introducing
Assets Management, Financial Management, Operational Performance Monitoring,
Environmental Regulatory Compliance Monitoring, and Customer Services by
enhancing Community Participation and Public Education.
The services of the Institutional Development Consultant (IDC) are provided in order
to support Colombo Municipal Council in implementing these institutional changes to
ensure sustainability of sewerage operation. Now Institutional Development
Consultancy is over and following activities have been performed.
(i) Development of Complaint management System, Drainage Property
Connection System and Asset Management System using webERP
Computer based Property Connection management system was developed and is inoperation satisfactorily. Commencing from the origin of the sewer system in the city,
records of connections given are computerized to enhance efficiency and
effectiveness of service provision. In parallel public complains on sewer failures,
collapses handling system was established. Complains received are entered into the
system and attendance of complains is monitored on-line. Objective of developing
computer based systems is to enhance transparency and accountability of the
Colombo Municipal Council in service provision and also to have efficient and
effective database management system which is required for system improvement. .
The Asset Management system development of 3 numbers of pumping stations which
are not planned to rehabilitate under the Project has been completed. Required onthe-job training for data collection and scoring based on the risk assessment of assets
etc. has been completed.
Sewer network asset management system is being developed under sewer
rehabilitation contract as a part of condition assessment of 125kilometer length of
sewers.
A dash board view of the Complaint
Management system developed showing
the
numbers
of
complains
received/attended by relevant Districts for
monitoring by the management.
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A screen view of the Property connection
database.
This ensures transparency,
accountability of the service provider.
(ii) Development of Financial Management and Accounting System
Financial and Accounting system for the accounting work of the sewerage activities is
developed. Accounting data based on cost centers is segregated and entered. The
objective of having cost centers is to ring-fence the expenditure to introduce
performance based budgeting system. .
(iii)Supply and Installation of Computer Systems for Drainage Division
In order to support the computer based systems developed necessary Hardware was
procured and installed under the Project. Required training on Micro Soft Project
Server is being carried out under with the support of a Technical Assistant grant of
ADB.
(iv) Environmental Regulatory Compliance Monitoring
Colombo Municipal Council requires ensuring the compliance of environmental
regulations when disposing sewage. Several studies were carried out to collet effluent
levels and pollution levels in water ways by engaging third party laboratory agencies.
In order to assist period monitoring of effluent quality, a laboratory will be
established. Construction of the laboratory building is nearly completion. Required
laboratory equipment have been identified and procurement of equipment is in
progress. Training for sample collection for monitoring and for testing was provided
to identified staff of the Drainage Division to ensure the sustainability of the
compliance monitoring.
(v) Community Participation and Public Awareness Programme
This programme is carried out through a Non-Governmental Organization and
through School Education programme using in-house staff. A baseline survey to
educate the sewerage users’ roles and responsibilities was carried out by engaging the
NGO. Based on the lessons learned a Street Drama was produced by the NGO and
was shown using Forum Theater concept in large number of community groups. This
included the population living in Under Served Settlements in the city, institutions,
establishments and social groups.
The School Education Programme is carried out every year in the first term of the
year. Project staff together with the staff of the Drainage Division of Colombo
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Municipal Council, with the blessings of the Ministry of Education, visits Schools and
explains the students and teachers on the aspects related to sanitation and sewerage
system. So far the programme has been carried out in 66 numbers of schools
and16705 numbers of students have attended the programme.
School education and Public Awareness Programme. School children actively participated at
programmes. Street Drama produced by the NGO attracted large crowds and participation of
the viewers on discussion was encouraged suing the Forum Theater concept.
Gathering of school children at school education programmes.
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A leader from a Community Based Organizations shares his views at a forum held to
discuss the mechanisms to strengthen the links established under the CPPE
Programme. The elected body; Council members attended the forum with the staff of
the council.
8.0 Status of Component 3: Project Management and Implementation
Support
This component will support project management and implementation, including
incremental administration and operations associated with Project Management Unit.
Consulting service is provided to the Project Management Unit for the design and
supervision of sewerage infrastructure works.
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09- Investment Plan 2016
No.
1
1.1
Main Activity / Sub Activity
Sewerage infrastructure is upgraded
Rehabilitation of Main Sewerage System -Pumping Stations,
Pumping Mains, Fine Screens
1.2
Rehabilitation of Gravity Sewers
1.3
Upgrading of Wanathamulla Gravity Sewer network
1.4
Rehabilitation of Sea Outfall
Sub Total
2
2.1
3045
2126
9.6
48
5228.6
Strengthening Institutional and Operational Capacity
Equipment for institutional Support
Sub Total
3
Allocation for
2016 Rs. Mn.
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15
Project Management and Implementation Support
3.1
Design, Supervision and Management Consultant
100
3.2
Training and Workshop
100
3.3
Project Administration in CMC
50
Sub Total
250
5493.60
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