Challenges and good practice ofdecentralized wastewater
management in Asia

1(Challenge 1) Septic tank is still a prevailing form ofwastewater management in many Asian countries
Septic tank coverage rate in selected Asian countries

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(Challenge 2) Septic tank is not functioning as aneffective wastewater treatment system
Actual effluent water quality of household septic tanks in DKI Jakarta (Source: JICA)(Effluent standard of household septic tank in DKI Jakarta : BOD75mg/l, COD100 mg/l)

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(Challenge 3) In many Asian countries, more stringenteffluent standard is applied for commercial buildings(Case of DKI Jakarta)• In Jakarta, there are about 4,000 commercial buildings (officebuildings, hotels/condos, shopping malls, etc.) which produces
25% of total wastewater generated in the area.
• In 2005, effluent standard for commercial buildings weretightened to BOD: 50mg/l, CODcr: 80mg/l, which was notachievable by septic tanks. Therefore, many commercial
buildings have replaced septic tanks by Individual Treatment
Plants (ITPs ‐ mostly aerobic system such as Packaged
Wastewater Treatment Plant (PAWTP ‐ Johkasou in Japan).
• In DKI Jakarta, effluent water quality of ITPs are periodicallymonitored by Environmental Management Agency (BPLHD) ofJakarta.
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(Challenge 4) Many countries lacks maintenancesystem for decentralized wastewater management
What is required forHouseholds’ SepticTanks?

What is required forCommercial buildings’ITPs?

• Regular
desludging system• Regular desludging
system• System to support
the operation andmaintenance of ITPs
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Remarkable Effect of Frequent Desludging of Septic Tank

Removalfunction• Skimming• Settling• DigestingBOD removal ratio (%)

100
y = ‐0.61 x + 90.59
R² = 0.817550250‐25050100150200

AnnualOnce‐per‐7‐year‐50 desludging
desludging
Specific non‐desluding
period (month・cap./m3)

Fig. BOD removal ratio (%) and BOD discharged excluding the effect of dilution(g/L); calculations were based on 12,000 mg-BOD/L, 6,000 mg-Cl-/L atexcretion• Long non‐desluding period even increase pollution• Annual desluding could remove 71% of BOD load compared tocurrent conditions(Source: ‘Better septic tank management: challenges and remarkable effects’ by Assistant Prof. Harada, Kyoto University)

What happens, if PAWTP (Johkasou) is not regularly
desludged ?
A research, conducted in 1984 for 70 PAWTPs (black wateronly type) in Japan, revealed that 24.6% of them had notbeen desludged for more than 1 year, and their average
effluent water quality (BOD) was worse than the ones which
had been desludged with less than 1 year intervals.
160
140
120
100
BOD

80

COD

60

SS
NH4-N

40

NO2,3-N

200<6 Month6-12Month(Note) PAWTP (blackwater only type) was anold type Johkasou. Its
standard effluent quality
was BOD 90 mg/l. Its
new installation wasbanned in Japan since2001.

12-18Month7

How to respond to these challenges?
Challenges
Prevailing inferior
DEWATS (septictanks)

Responses‐‐‐

Encourage technology development
Create a Performance Evaluation System for
DEWATS
Eliminate septic tanks by connecting tosewerage system

Bad performance ofseptic tanks‐

Establish Regular Desludging System

ITPs for commercial
buildings‐

Establishment of Regular Desludging
System would also help improve
performance of ITPs
Establish Standard for Maintenance for ITPs‐
Lack of proper
maintenance ofDEWATS‐‐

Create Sanitation Service Chain
Create Qualification System for
maintenance workers
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(Good practice 1) Technology development
BORDA DEWATS(SANIMAS)• No electricity use (Anaerobicsystem)• Effluent water quality can beclose to BOD 50mg/l, if it isproperly maintained (incl.
regularly desludged) by a goodoperator, which fulfils theeffluent standard forcommunity plants in Indonesia,
but does not fulfil thecorresponding standard inneighboring countries.
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(Good practice 2) Technology development
Anaerobic + Aerobic (RBC*) Treatment(APEX & Yayasan Dian Desa)`Rotating Biological Contactors• Easy operation and energy
saving aerobic treatment:
Electricity consumption is1/3 of Packaged Aerated
Wastewater Treatment
Plant (PAWTP – Johkasouin Japan).
• High effluent water
quality: BOD 30mg/l,
which is good because ofaerobic system.
• Space saving: require only
1/3 area compared withordinary anaerobic process.
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(Good practice 3) Technology development
Packaged Aerated Wastewater Treatment Plant(PAWTP – Johkasou in Japan)(Source: Ministry of Environment ‘Night Soil
Treatment and Decentralized Wastewater
Treatment in Japan’)• Aerobic. Required electric
power is 40W perhousehold of 5 familymembers.
• Mechanical maintenance bya professional maintenancevendor is required.
• Sludge must be removed
once a year (householdtype).
• Effluent water quality isequal to a modern WWTP
(BOD: less than 20 mg/l.
Nitrogen removal.
Disinfection.).
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(Good Practice 4) Performance Examination System for
PAWTP (Johkasou) in Japan
Authorization ofa new product(PAWTP)

Temperature
controlled
examination lab.

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(Good Practice 5) Guidance, Manual for Septage
ManagementRecently, many countries have issued guideline,manual, etc. on Septage Management, the core ofwhich is Establishment of Regular Desludging System.
• India: MOUD’s Advisory Note on Septage
Management in Indian Cities (January, 2013)• Philippines: National Sewerage and Septage
Management Program – Program Operation
Manual (March, 2013)• Indonesia is promoting Septage Management by
the inclusion of provisions for sludge treatment
facilities in Mid‐term Development Plan for 2015‐2019.
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(Good Practices 6) Example of Septage
Management in Asian cities(City level)• Philippines – Metro Manila, Dumaguete• Vietnam – Haiphong• Indonesia – Solo, Balikpapan, Tabanan, Tegal,Jakarta, Bandung (Pilot stage)• India – Mizoram State (Pilot stage)(National level)• Malaysia• Japan14

(Good Practice 7) Septage Management in Metro Manila‐ Manila Water Company (MWCI) ‐• Under the Concession Agreement, MWCI isgiven full responsibility on operating,
maintaining and managing the watersupply and sewerage system in the East
Zone of Metro Manila.
• MWCI employs a three‐pronged approachin addressing wastewater management. As
the first step, MWCI is building interceptor
sewer systems to intercept the wastewater
discharged from septic tanks to drains
before discharged to rivers, and to convey
it to the WWTPs, and providing septage
management service in the areas that are
currently non‐sewered.
• All customers pay 20% environmental
charge from the basic waster charge which
can be used for MWCI’s investment and(Source: ADB CASE STUDY NOTES‘Cleaning Up the Business of Septage
O/M of sewerage system and septage
Management)
management system.
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(Good Practice 8) Septage Management inDumaguete City (The Philippines)• The first government financed septage
management system in The Philippines which
is a model for other cities in the country.
• In 2006, the Ordinance for Septage
Management was passed by the City Council.
• The Dumaguete City Water District desludges
septic tanks of residences, businessestablishments and institutions andtransports the septage to the treatment
plant.
• The City Government operates the septage
treatment plant.
• The Dumaguete City Water District collects
the septage “user fee” as an add‐on to themonthly water bills.
• The regular emptying program had been
operating for 2 years but has recently shiftedback to on‐demand operation.

(Source: UNEP Local
Government‐Financed
Citywide Septage
Management System, World
Bank: Septage Management
Pilots and Capacity Buildingin Indonesia)
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(Good practice 9) Septage Management inHaiphong City (Vietnam)• The Haiphong Sanitation andSewerage Company (SADCo) havedivided the cities into regions,where one region is emptied in ayear and then they move to thenext region in the next year.
• For faster emptying of septic
tanks special type of accesscovers are provided.
• The citizens are provided free
septic tank emptying service once
every three years and in lieu ofthis a tax of around 15% of thewater bill (as a part of water bill)is levied on the properties.

Worker installing plastic cover tothe access hole after emptying
septage in Haiphong City
(Source: WEPA ‘URBAN DOMESTICWASTEWATER MANAGEMENT IN
VIETNAM’)(Source: PAS ‘Faecal Sludge and Sullage Management in Urban
Maharashtra’ Policy Brief)17

(Good practice 10) Septage Management in Malaysia
•

•

•

••

In 1994, Indah Water Konsortium (IWK) was createdas the private concessionaire who was responsible for
O/M of all sewerage facilities and septagemanagement.
Desludging coverage ratio increased from 1% to 12%(1999), but due to poor collection recovery, IWK was
taken over by the Government, through the Ministerof Finance Incorporated in year 2000.
In 2006, Water Service Industry Act was formed andliberalization was introduced where the owner,
management body or tenant is responsible
Desludging services was opened to IWK or Permit Eholders
The number of desludged septic tanks had
substantially decreased in 2008.
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(Good practice 10) Septage Management in Malaysia (continue)
In order to reverse such trend, desludging campaigns are being organized toincite septic tank owners/users to desludge within the legal interval. The
number of desludged septic tanks has increased gradually from year 2008 till
Desludging Campaign at:‐year 2012.
No.Tangkiof IST
desludging
doneJumlah
Septikyang dinyahenapcemara) Taiping, Perakb) Kangar, Perlisc) Melakad) Yong Peng, Johore) Simpang Renggam, Johor

160,000

148208146524140,000

135982

No. of IST

120,000

100,000

80,000

68548
70170

60,00058406
40,00037018

Desludging Campaign at:‐a) Muar, Johorb) Temerloh, Pahangc) Kubang Pasu, Kedahd) Port Dickson, Negeri Sembilane) Sungai Besar, Selangor

47056

20,0000
2005

2006

2007

2008

Year

2009

2010

2011

2012

(Source: SPAN)
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(Good Practice 11) Septage Management in Japan• In Japan, PAWTPs (black water only type) had been widely
diffused since 1960s. In 1970s – 1980s, water pollution ofrivers and oceans had become a big issue. Particularly, thecause of eutrophication occurred in lakes and inland bays was
attributed to the poor performance and maintenance of
PAWTPs (black water only type).
• In 1983, PAWTP (Johkasou) Act was promulgated. Since then,the maintenance of PAWTPs in Japan has improved andeutrophication of lakes and inland bays in Japan has stopped.

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(Good Practice 11) Septage Management in Japan (Continue)
Main points in the PAWTP Act (1983) (1)Item

What does the PAWTP Act stipulate?

(1) Manufacturing The PAWTP (black + gray water type) is the standard on‐site
and Installation of wastewater treatment facility in Japan. PAWTPs shall meet thePAWTPs
technical standards for effluent water quality and the structural
standards prescribed in the Building Standard Law.
(2) Maintenanceof PAWTPs

The owner of a PAWTP is designated as the ‘PAWTP Manager’
who is legally responsible for the maintenance of the PAWTP. The
PAWTP Manager shall make the PAWTP receive inspection,
maintenance and desludging. The PAWTP Manager canoutsource the work related to PAWTP management to a PAWTP
vendor and/or a PAWTP desludging vendor.

(3) Desludging ofPAWTPs

The PAWTP Manager shall ensure that the PAWTP receives
desludging service once a year.

(4) Inspection ofPAWTPs

The PAWTP Manager shall make the PAWTP receive an inspection
for its water quality annually by the Specified Inspection Agency.
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(Good Practice 11) Septage Management in Japan (Continue)
Main points in the PAWTP Act (1983) (2)Item

What does the PAWTP Act stipulate?

(5) Desludging
Business

A corporate body that intends to join the PAWTP desludging
business shall get the approval from the mayor of themunicipality for a limited period. The applicants need to conformto the standards for approval stipulated in the PAWTP Law.

(6) MaintenanceBusiness

A corporate body that intends to join the PAWTP maintenancebusiness shall register to the municipality concerned. The PAWTP
maintenance vendor shall assign its staff qualified as ‘PAWTP
Operator’ who has passed a national examination or completed atraining course conducted by a designated training agency, to the
PAWTP maintenance work.

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(Good Practice 11) Septage Management in Japan (Continue)
Number of people engaged in the Septage Management Business
People with qualification(Number of registrants)

Number of vendors

PAWTP
Operators

72,521 Operation andmaintenance

PAWTP
Installation
Workers

83,205 Installation/Construction

Specifiedinspection
agencies

65 PAWTP inspection
and water quality
examination

PAWTP
manufacturers

PAWTP
TechnicalSupervisors

26,658 Management ofPAWTP with 501
PE or more

27 Research,development andmanufacture

PAWTP
Desludging
Technicians

15,117 Desludging

PAWTP
Inspectors

1,210

Total

198,711

PAWTP
maintenancevendors

12,871 Operation andmaintenance

PAWTP
desludging
vendors

5,375 Desludging

PAWTP
installation
vendors

33,593 Installation/construction(Source: Ministry of Environment ‘Night Soil Treatment and Decentralized Wastewater Treatment in Japan’)23Lessons learnt• Any on‐site wastewater treatment facility becomespollution source without proper SeptageManagement.
• In order to do Septage Management, you must be realserious. It is a highly political issue.
• In Septage Management, without proper regulation,
nobody does the right thing.
• In Septage Management, the people who do the actual
work are the most important. Regulate them. Formalize
them. Respect them.
• Septage Management will create a lot of job opportunities.
It is good for the economy at national and local levels.

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Thank you for your attention !
http://www.jsanic.org/

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