DOMESTIC WASTEWATERMANAGEMENT IN SRI LANKA

ENG G
ENG.
G.A.
A KUMARARATHNA
ADDL. GENERAL MANAGER (SEWERAGE)
NATIONAL WATER SUPPLY & DRAINAGE BOARD

History

CONTENT Developments of Major Sewerage Infrastructure Subsequent Developments of Other Sewerage Infrastructure Key Legislative Instruments

Discharge Standards
Sewerage Development Goals
Present Status of Sewerage in Sri Lanka
 Coverageg Treatment Plants
 Wastewater Disposal Projects (ongoing and pipe-in-line)

Future Plans & Direction
Major issues

1History of Sewerage Worksin
Sri Lanka

History:
Development of Major Sewerage Infrastructure

Introduction:
A sewer network with pump stations and twotreatment plants,
plants (located at Madampitiya andWellawatta) were constructed during 1905‐
1910

2

Vystwyke

HarbourMadampitiya
Treatment
Plant
Maligawatta

Wanathamulla

Slave Island

Pollwatta

BorellaThimbirigasyaya

Bambalapitiya

Wellaw atta
Treatment
Plant

Sewer Network:1910

History: Continued..
Around 1956, Madampitiya TP was abandoned due
to Operational problems and Wellawatta TP wasabandoned due to complaints from community overnuisance and bad‐odour
 In 1972, a master plan was prepared by a British
C
Consultancy
lt
Fi
Firm
(H
(Howardd Humphrey)Hh ) with
ith thethassistance of UNDP for the rehabilitation of Greater
Colombo Sewerage System

3

History: Continued..
1983‐1987: Greater Colombo Sewerage System
rehabilitated with World Bank and Saudi Assistanceand two sea outfalls of 1500mm diameter wereconstructed at Mutwal and Wellawatta.
Wellawatta

Vystwyke

Madampitiya

Mutwal Sea Outfall
Maligawatta
Harbour
Wellampitiya

St. Jones Market

Meetotamulla
Kolonnawa

Slave Island
Wanathamulla

Pollwatta

BorellaFrom Sri
Jayawardhanapura
Kotte

Thimbirigasyaya

Bambalapitiya

Wellawatta Sea
OutfallPeterson Lane

Sewer Network
:1987

To
Wellawatta

Wellawatta

Dehiwala

Mt. Lavinia

4History: Continued..
 1993 : Updating of Wastewater Master Plan for the Greater Colombo area by

an American Consultancy Firm with the assistance of World Bank 1998‐2000: Preparation of feasibility study for the Greater Colombo area

including immediate works by Atkins with the assistance of British funding 2000:Beira Lake Restoration Project implemented with World Bank
Assistance (New PS at Slave Island and diversion of wastewater flow) 2006‐2008: Rehabilitation of Northern Catchment (Construction of new PS

at Madampitiya and 7.4 km line rehabilitation)
 2008‐2010:

Colombo Sewerage Rehabilitation Project (SouthernCatchment): (Construction of new PS at Wellawatta and 7.7 km line
rehabilitation)

Vystwyke

Madampitiya

Mutwal Sea Outfall
Maligawatta

Harbour

Wellampitiya

St. Jones Market

Meetotamulla
Kolonnawa

Slave Island
Wanathamulla

Pollwatta

BorellaFrom Sri
Jayawardhanapura
Kotte

Thimbirigasyaya

Bambalapitiya

To
Wellawatta

Wellawatta Sea
OutfallPeterson Lane
Wellawatta

Dehiwala

Sewer Network: since 2000

Mt. Lavinia

5History:

Subsequent Developments of Other Sewerage
Infrastructure
1980 - 2012:
Numbers of Small Scale Centralized WWTP were constructed totreat domestic waste of housing schemes and tourism
associated townships
Mattegoda Housing Scheme

Digana
Digana Village Housing Scheme

Soysapura Housing Scheme

Kataragama Sewerage Scheme

Raddolugama Housing Scheme

Hikkaduwa Sewerage Scheme

Hantana Housing Scheme

Modarawile Sewerage Scheme

History:

Subsequent Developments of Other Sewerage
Infrastructure Cont…
1980 ‐ 2012:
Other WWTPs
Jayawardenagama Housing Scheme
Maddumagewatte Housing Scheme
Maligawatte Housing Scheme
Crow Island Housing Scheme
Stace Road Housing Scheme

6

History:

Subsequent Developments of Other Sewerage
Infrastructure (Continued..)1980 ‐ 2012: Several WWTPs were constructed for the treatment of WW effluentsfrom Industries established in dedicated Export Processing Zones (EPZ)
monitored by BOI.
 Biyagama EPZ: 13,000 m3/day

 Seethawaka EPZ: 9,900 m3/day

 Katunayake EPZ: 3,000 m3/day

 Mirigama EPZ: 400 m3/daypEPZ
 Wathupitiwala: 900 m3//dayy Polgahawela EPZ: 450 m3/day

 Koggala EPZ: 675 m3/day

 Kandy EPZ: 1,000 m3/day

 Mawathagama EPZ: 500 m3/day

 Horana EPZ: 1,000 m3/day

History:

Key Legislative Instruments to be considered in Sewerage
Disposal(Note: not limited to sanitation only) Municipal Councils Ordinance No 29 of 1947
National Water Supply & Drainage Board Act No 2 of 1974
Urban Development Authority Law No 37 of 1978
National Environmental Act No 47 of 1980
 Coast Conservation Act No 57 of 1981
Water Resources Act 1994
Fisheries and Aquatic Resource Act 1996
 Archaeological Impact Assessment Act 2000
 Marine Pollution Prevention Act No 35 of 2008
 SLS 745 Part 2: 2009 – Code of Practice for Design and Construction of Septic
Tanks and Associated Effluent Disposal Systems

7

History:

With the progress in Industrial and Commercial activities
Key Legislative Developments for Issue of Environmental
Protection License for Emission or Disposal of Wastewater
were neededd d ini viewi
off protectingt ti drinking
d i ki watert sources.
National Environmental Policy:
1980 :GOSL passed National Environmental Act (NEA No 47 of 1980)

 1982 :Created Central Environmental Authority (CEA) as the national
regulatory and enforcement agency

 2001 :Set up Ministry of Environment and Natural Resources (MENR) 2003 :Formulated National Environment Policy (NEP)

Discharge Standards:

As per the Sec (1) of the Gazette Extraordinary 9No.1534/18)
of the Democratic Socialist Republic of Sri Lanka(01.02.2008), the Following Discharge Standards Exist.
T lToleranceli i for;limitsf

The discharge of industrial waste into inland surface water
bodies,Industrial waste discharged on land for irrigation purpose,Industrial and domestic waste discharged into marine coastal
areas,



Waste from rubber factories being discharged into inlandsurface waters,

8

Discharge Standards (Cont..)

As per the Sec (1) of the Gazette Extraordinary (No.1534/18)
of the Democratic Socialist Republic of Sri Lanka((01.02.2008),) the Following
g Discharge
g Standards Exist.
Tolerance Limits for;

Waste from textile industry being discharged into inlandsurface waters,

Waste being discharged from tanning industries,

Discharge of wastewater effluents into public sewers
with central WW treatment plants,

Development Goals of Sewerage
In Sri Lanka

9Development Goals of Sewerage
Millennium Development Goals (MDG) Access to adequate sanitation for 90% of population of Sri

Lanka by 2015 and 100% by 2025,
 Piped Sewerage systems to major urban areas and selected

growth centers, Availability of Standard On-site sanitation to all those notconnectedt d tto a sewer system,t

Development Goals of Sewerage
GOSL Goals (Mahinda Chinthanaya)
 Provision of Pipedp Sewerageg systemsyto major
j urban areas andselected growth centers, Facilitate for Standard On-site sanitation to all those notconnected to a sewer system, Sri Lanka Government Targets for Pipe Borne Sewerage(Mahinda Chinthanaya 2010,2010 P61-62)
P61 62)

Year

2005

2009

2015

2020

Pipe borne sewerage coverage (%)

2.0

2.5

3.0

7.0

10

Present Status of Sewerage In Sri
Lanka

Present Scenario of Sanitation Coverage
Sanitation Type

Estimated Population Coverage

Piped Sewerage (Offsite)

507,435 (02.5%)

Onsite Sanitation

16,887,200 (83.2%)

Without Proper Sanitation((Includes Typeyp Unknown/Other,/, Pit Latrines))

2,902,500 (14.3%)(Projection as at end of 2010 based on sources from NWS&DB, Census and Statistical Data Publication 2001
& Annual Health Bulletin 2006-2007 )Piped Sewer (85,102 Connections)
Safe Onsite Sanitation (Water sealed
type with septic tank and soakage
pit)Type Unknown
Type Other (Shared, etc.)

9.4%

Pit Latrines (Direct absorption to

2.5%

1.0%
3.9%

83.2%

11

Population coverage by Piped Sewerage
MAJOR CITIES

Total Population

Estimated Population coverage

Colombo city

City

715,000

435,615

Dehiwala / Mt. Lavinia

112,000

10,790Kolonnawa

60,0006,380

Kataragama

20,0004,500

Hikkaduwa
Total

30,0003,000

937,000

460,285

HOUSING SCHEMES

Housing Scheme

No. of Connections

Population Covered

Soysapura Housing Scheme

2,368

Matthegoda Housing Scheme

1,240

6,200

850

4,250

Jayawadanagama Housing Scheme
Maddumagewatta Housing Scheme

11,840192

960

Raddolugama Housing Scheme

2,100

10,500

Maligawatta Housing Scheme

1,510

7,550

Crow Island Housing Scheme

294

1,470

Stace Road Housing Scheme

240

1,200

Hantana Housing Scheme

385

1,925

Digana Village Housing Scheme
Total

250

1,250

9,429

47,150Wastewater Treatment Systems at BOI assisted Export Processing Zones
No.

Export Processing
Zone

Capacity3
m /day1

Biyagama

13,000Wastewater Treatment System

Extended Aeration system with Mechanical ly
Aerated Lagoon system (Flow through type)

Remarks
Proposed to augment3
up to 20,000 m /day

2

Seethawaka

9,900

Extended Aeration System

Proposed to augment3
up to 12,900 m /day3

Katunayake

3,000

Mechanical Aerated Lagoon (Flow through type)

Completed

4Mirigama

400

Package Plant

Completed

5

Wathupitiwala

900

Package Plant

Complete

6

Polgahawela

450

Extended Aeration System

Completed

7

Koggala675

Extended Aeration System

Proposed to augment3
up to 2,000 m /day

8

Kandy

1,000

Extended Aeration System

Under construction

9

Mawathagama

500

Extended Aeration System

Completed10

Horana1,000

Package Plant (Rotating Biological Contactors)

Completed

Total of Capacities

30,82512Natural Wastewater Treatment System
at Hikkaduwa (Waste Stabilization Ponds)

Locations of Sewerage Schemes in Colombo Cityand Suburbs
MutwalOut FallKolonnawa
Raddoulawa

CMC
Jayawadanagama
Wellawatte
Out FallDehiwala /Mt. Lavinia
Soysapura

Maddumagewatta
Kolonnawa
Mattegoda

Jayawadanagama

C.M.C
Dehiwala/
Mt. Lavinia

Maddumagewatta
Mattegoda
Soysapura

13

Locations ofMajor Wastewater
Treatment Plants
in Operation

Hantana
Katunayake EPZ

Biyagama EPZ

Raddolugama
Colombo City

Seethawaka EPZ

Soyzapura STP

Mattegoda STP

Hikkaduwa STP

Kataragama

Koggala EPZ

Wastewater Disposal Projects in Sri
Lanka

14

Major Projects
 Ongoing Major Projects (Mobilized)
 Ja Ela/Ekala – Ratmalan/Moratuwa Wastewater Disposal Project Kandyy Cityy Wastewater ManagementgProjectj GPOBA Greater Colombo Wastewater Management Project Jaffna Municipality Sewerage Project Colombo Sewerage Rehabilitation Project ‐ Southern Catchment :(Completed) Projects in Bidding Stage Jayawardana Pura/ Kotte Wastewater Disposal Project Hambantota Wastewater Disposal Project Kataragama Wastewater Disposal Project Kurunegala Water & Wastewater Project

Major Projects …. Contd.
 Projects in Pipeline Ratmalana
Ratmalana‐‐Moratuwa & Jaela/Ekala ‐ Phase II Wastewater Disposal Projectp Sewerageg Coverageg Expansionp Dehiwala// Mt. Lavinia Piped Maharagama and Boralesgamuwa Wastewater Disposal System Negombo WW Disposal System
 Chilaw Piped Sewerage System Puttalam Piped Sewerage System Galle WW Disposal System
 Kattankudy WW Disposal System Gampaha Sewerage Project Batticaloa WW Disposal System
 Improvement to WW Disposal System of Cancer Hospital (Design Stage)
 Improvement to WW Disposal Systems of Government Hospitals
 Data Collection Survey for 13 Towns by JICA

15

Locations of Major Sewerage Projects (On-going and Pipe Line)
Jaffna SP

Projects in Pipe LineOn going Projects

Puttalam WWTS
Chillaw WWTS
Kurunagala SP
Negombo SP
Batticaloa SP

Ja – Ela / Ekala SP – Phase II
Gampaha SP
Ja – Ela / Ekala SP – Phase I GPOBA

Kattankudi SP

GPOBA - Kolonnawa
Kandy SP

Akkaraipattu SP

GC WW Management Project
Sri Jaya’pura Kotte SP

Dehiwala/Mt. Lavinia Unsewered Area
GPOBA -Dehiwala/Mt. Lavinia
Ratmalana/ Moratuwa SP – Phase I
GPOBA – Rat / Moratuwa

Kalmunai SP

Maharagama Boralesgamuwa
UC Area

Kataragama SP
Hambanthota SP

Galle SP

Ratmalana/ Moratuwa SP – Phase II

Details of On Going Piped Sewerage Projects
SCHEMEPOPULATION COVERAGETOTAL ESTIMATED COST (Rs.
Mn.)

1Colombo Sewerage Rehabilitation
Project – Southern Catchment

180,000

Total – 2,222[F‐ 1,585
L‐ 6,37]

2

Wastewater Disposal Project forR
Ratmalana/l/ Moratuwa
M
andd JJaelal / EkEkalalAreas ‐ Phase I

80,000Total – 16,155[F‐ 11,033 :L– 5,122]

3

Kandy City Wastewater Disposal Project

55,000 + 150,000 Floating
population

Total – 22,591[F– 18,317 :L – 4,274]

4

GPOBA ( The Global Partnership on
Output Based Aid )76,400Total – 1,197[F – 636 :L – 561]

5

Jaffna Municipality Sewerage Project

100,000

4,500

6Greater Colombo Waste Management
Project ‐ NWSDB

150,000

1,012

7

Greater Colombo Waste Management
Project – CMC

600,000

12,300TOTAL

1,391,400

59,97716

Details of Projects In Pipe Line … Contd.
PROJECT

POPULATION

TEC / RS. M

07

Negombo WW Disposal System

86,7006,700

08Chilaw Pipedp Sewerageg System
y

4,700
4,7

2,445
,445

09

Puttalam Piped Sewerage System

7,200

2,605

10

Kattankudy WW Disposal System

79,0003,194

11

Galle WW Treatment System

34,6002,248

12Expansion of Piped Sewerage Coverage to Dehiwala/ Mt.
Lavinia

138,000

7,446

13

Batticaloa WW Disposal System

64,2001,960

14Gampaha Sewerage Project

25,000803

15Cancer Hospital•Connects to Ratmalana /Moratuwa wastewater treatment
plant
TOTAL

2,000

238

742,000

76,786

Details of Projects In Pipe LinePROJECT

POPULATION TEC / RS. M

01

Kurunegala Water & Wastewater Project

32,0008,283

02Hambantota WW Treatment System

30 40030,400

6 782
6,782

03

Sri Jayawardenepura Kotte Sewerage Project

138,300

22,06004

Wastewater Disposal Project for Ratmalana‐Moratuwa &Jaela/Ekala ‐ Phase II

49,6008,462

05

Augmentation of Kataragama Sacred City Sewerage Project

23,0001,324

06

Waste Water Disposal System for Maharagama andBoralesgamuwa UC Area

27,3002,281

17

Future Plans andDirection
Technical Approach, Design Principles,
Di
Disposall Methods
M th dTechnical Approach (cont..)

Historical approach: Domestic Wastewater (Urban, Sub
Sub--urban, Rural areas)
Prior to 1960’s
1960 s , only pit latrines,
latrines
1960--1970’s, Cess1960
Cess--pits, septic tanks + soakage pits, in UC,
MC areas, Individual WW Treatment systems in Hospitals, Hotels,
Major Gov. Institutions, Housing Schemes
1970--1980’s, Tricking filters, waste stabilization ponds,
1970
1980 – 1985’s, Activated sludge process with extended
aeration by mechanical aeration,
1985 onwards, deep Sea
Sea--outfall, activated sludge process,
RBC, mechanically aerated waste stabilization ponds

18Technical Approach (cont..)
 Present and Future:

-

-

-

On
On--Site Systems

In MC areas Mostly preferred Option:
Septic Tanks + Soakage pits after building approval by
MC + UDA, if pipe sewerage is not available,
Rural areas Preferred Options: Septic Tanks + Soakage
pits, Cess Pools (if GW table permits) after buildingpp
byy UC or Pradeshiya
y Sabawa,,
approval
Additional Treatment for Effluents from septic tanks
followed by anaerobic filters for needy “Clustered
Housing”,
Dry Compose Toilets in Dry, well drained soil conditions,Technical Approach, Design
Principles (cont..)
At Present and Future in OffOff-Site Systems:Design principles
All flows by gravity and capacity of pumping stations will be-phased out,
Extremely deep sewers (> 4.5 m) will be avoided,
Full treatment of WW with natural systems is adopted whereverlands are available,
Compactpfacilities for systemsywith limited land availabilityy andfor small systems,
Discharge of fully treated effluent to inland water bodies or byshort sea out fall,
Discharge of the unun-treated WW by deep sea outfall,Effluent quality requirement is achieved,

19

Future Plans and Direction in WW
Management (cont..)

Wastewater in Townships with Institutional and Commercial
areas will be disposed either by
Individual sewer Systems comprising full treatment , the effluent

discharged to Inland water body /or short sea out fall ,Individual system comprising partial treatment , the effluent
discharged to wetlands /or short sea out fall,
Individual system with no treatment , the effluent discharge tolong sea out fall,
fall
 Wastewater in housing schemes in subsub-urban settings will be disposedwith appropriate low cost WW treatment methods (waste
stabilization ponds, combination of septic tanks / anaerobic filters,
simplified small bore sewer system)

Future Plans and Direction in WW
Management ( cont..)Industrial Wastewater
Dedicated Centralized sewer Systems comprising full treatment
located within the industrial zones , the effluent discharged toInland water body or Central public WW collection system,20

Major Issues
Technical, Social, Environmental,
Economical

Urban Sewerage Infrastructure
Specific Planning Issues
 Land Constraints
–








Rapid urban developments plans without due
consideration to WW disposal infrastructure andnuisance buffer zones take up much land,
Higher Environmental Standards which are not practicablein certain circumstances,
Risks of Water Resource Contamination– Possibilities
P
bloff sewage overflows
flwithinh water catchmentshVisual Impacts and public objection due to odor
Costly alternatives subsequent to town / housing / roaddevelopment projects
Laying of sewer reticulation through highly congested areas.

21Planning for Long Term Needs ofWastewater Management
Need to address major issues:






Adequate and timely provision of sewerage facilities tomeet future needs,
Enhance and prolong the life of existing sewer reticulation
system,Provide adequate safe guard to the environment by installingsewerage infrastructure in par with the other developments,
Establishingg and maintain Monitoringg and surveillancesystems for industrial WW effluents,
Recognizing the priority of the development needs in thesewerage infrastructures,

Environmental and EconomicalIssues Public objection to sewerage infrastructure due to odor anddevaluation of adjacent real state economic values, High maintenance cost of infrastructure and inability torecover at least the O & M cost, Sustainability of systems due to low affordability of theconsumers,
 Restrictions on sludge disposal sites by regulators,
 PracticalPl llimitations in implementingleffluentfflddischargehregulations, Practical limitations in maintaining large numbers of
scattered individual WW systems in Hospitals, Housing
schemes etc

22Social and Institutional Issues
Limitations of skill work force to maintain the systems,
 Low Social recognition for sanitation workers,
 Difficult work environment and lack of incentives for workers,
 Consistent maintenance of workers safety standards,
 High investment needs for the plant and equipments tosustain the sewerage infrastructure, Lack of awareness of the public about sanitations and healthrisks.
Thank You23