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What is essential for the decentralized waste water

management ? – Experience of Japan, Malaysia, India –

April 2, 2015 Kazushi HASHIMOTO

Adviser Japan Sanitation Consortium

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Decentralized Wastewater Treatment System (DEWATS) ①

• Septic Tank

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Decentralized Wastewater Treatment System (DEWATS) ②

• BORDA DEWATS

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Decentralized Wastewater Treatment System (DEWATS) ③

• Packaged Aerated Wastewater Treatment Plant (PAWTP – Johkasou in Japan)

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Comparison of DEWATS

Septic Tank BORDA DEWATS PAWTP (Johkasou)

Treatment Process

Anaerobic (Electricity not

required)

Anaerobic (Electricity not

required)

Aerobic (Electricity required)

Effluent Water Quality (BOD)

100-200 mg/l 50 mg/l 20 mg/l

Nitrogen removal

Not removed Not removed Removed

CAPEX per person in developing countries

US$ 80-150 US$ 90-100 US$ 210-380

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What happens, if DEWATS is not regularly desludged?

Any wastewater treatment system ceases to treat and becomes a pollution source.

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What happens, if Septic Tank is not regularly desludged ? ①

If the septage volume exceeds one-third the capacity of the tank, solid-liquid separation decreases since the retention time of the wastewater decreases. BOD removal is hampered since the inflow of wastewater agitates the accumulated sludge causing inflow wastewater to pass through the tank without treatment. Moreover, a part of the accumulated sludge in the tank flows out together with the untreated wastewater, leading to further deterioration in the water quality of the effluent of the septic tank.

(Source : USAID) 7

What happens, if Septic Tank is not regularly desludged ? ②

Volume (㎥)

Usage (persons)

Effluent water quality Remarks

BOD COD

mg/l mg/l Black water only type 1

6.0 15 145 421 Desludged once a year.

Black water only type 2

2.2 4 231 622 Desludged twice a year.

Black water only type 3

2.9 4 217 544 Never desludged.

Black & Grey type – 1

7.4 4 206 419 Not desludged (4 years)

Black & Grey type – 2

10.0 40 162 367 Not desludged (3 years)

Black & Grey type – 3

10.0 18 213 401 Not desludged (3 years)

No septic tank meets the effluent standard established by the Governor of Jakarta City Government for household septic tank (BOD75mg/l, COD100 mg/l). Irregular desludging may be one of the causes.

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What happens, if PAWTP (Johkasou) is not regularly desludged ? ①

Sludge accumulates quickly in a PAWTP since its wastewater treatment efficiency is high. It must be desludged once a year to maintain its performance standard.

After one year After three years

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What happens, if PAWTP (Johkasou) is not regularly desludged ? ②

A research, conducted in 1984 for 70 PAWTPs (black water only type) in Japan, revealed that 24.6% of them had not been 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.

0

20

40

60

80

100

120

140

160

<6 Month 6-12Month 12-18Month

BOD

COD

SS

NH4-N

NO2,3-N

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BORDA DEWATS

I wonder how to desludge this system ??

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What is essential for the decentralized wastewater management ?

• Introduction of regular desludging system.

• Proper disposal of the sludge removed from DEWATS.

Septage Management !

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What is essential for the introduction of regular desludging system ?

• Desludging must be the legal obligation of all the owners of any DEWATS.

• There must be the trained good desludging operators. Formalize them, if there are existing desludging operators. Let them make companies. Establish the licensing system and training system.

• Data base of all DEWATS in the City. Both the municipality and the desludging operators should have it.

• Use vacuum truck for the more efficient and hygienically safer de-sludging operation.

• Use the sludge relay tank to shorten hauling time. • Improve the DEWATS for the efficient desludging.

Necessity of Regulatory Framework for Septage Management

Residents do not worry about the septic tank unless it becomes full of sludge, overflow and their toilet becomes unusable. Communication strategy is necessary but not enough. Regulation is necessary.

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For good Septage Management, these peoples are the most important !!!

PAWTP De-sludging Technician PAWTP Inspector

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Existing desludging operators in Mizoram State, India, who are conducting desludging of septic tanks using a pump and a water tank mounted on a truck.

Economics of Regular Desludging

• The most expensive item for septage management is not the DEWATS itself but the cost for desludging. Desludging of one septic tank (3 ㎥) costs US$30 in Jakarta, US$50 in India, US$70 in Malaysia, US$250 in Japan.

• In Japan, the desludging is considered not a profitable business unless at least 4 PAWTPs can be desludged by one vacuum truck. Efficiency matters.

• In Japan, many desludging operators cover 7 PAWTPs daily and make money.

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Technology for the efficient Septage Management ①

Use of Vacuum Truck will ensure the efficient and hygienically safe desludging operation.

Vacuum Truck Truck + pump

Time required for emptying

Septic tank (3㎥) – 40 minutes PAWTP (5PE) – 30 minutes

Septic tank (3㎥)－2 hours

Discharge of the sludge

10 minutes －Quick because the caliber of the hose is bigger (45-65mm)

30 minutes －Slow because the caliber of the hose is smaller (32mm)

Possibility of the human contact with the pathogen

None Possible at the time of connecting and disconnecting the hose to the tank.

These vacuum trucks shall be leased to the existing desludging operators.

(Photo taken in Mizoram State, India)

Technology for the efficient Septage Management ②

Sludge relay tank will improve the efficiency of desludging operation by shortening the hauling time.

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DEWATS must be desludging friendly

• It must be reachable for the desludging operators.

(1) It must be installed in the open air space.

(2) It must have manholes.

• It would be the most convenient if the partial desludging could effectively remove all the sludge without removing the water contents.

In case of septic tank, you need to remove all the contents of the tank.

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In case of PAWTP, the partial desludging effectively removes all the sludge. The water contents of the tank

does not need to be removed.

Proper disposal of the sludge removed from DEWATS

(1) Local municipality’s obligation to develop septage/sludge treatment facility. Central government’s obligation to provide financial support to Local municipalities.

(2) Sludge drying bed is an appropriate method if land is available.

(3) If there is a Sewage Treatment Plant (STP) nearby, co-treatment at the excess sludge treatment section of a sewage treatment plant is the best option. Proper pre-treatment facility is required to minimize the adverse effect on the operation of STP.

(4) Independent septage/sludge treatment facilities - In Japan, there are 1,100 independent night soil/sludge treatment plants of various technologies.

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Warning !

Establishing a workable Septage Management may be the most difficult development agenda.

Only two countries have a nation wide Septage Management System.

• Japan

• Malaysia (partial success)

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Septage Management System based on PAWTP (Johkasou) Technology in Japan

In Japan, PAWTPs (black water only type) had been widely difused since 1960s. In 1970s – 1980s, water pollution of rivers and oceans had become a big issue. Particularly, the cause of eutrophication occurred in lakes and inland bays was attributed to the poor performance and maintenance of PAWTPs (black water only type).

Only after the promulgation of PAWTP (Johkasou) Act in 1983, the maintenance of PAWTPs in Japan improved and eutrophication of lakes and inland bays in Japan stopped.

The new installation of PAWTP (black water only type) was banned and PAWTP (both black water and grey water type) has become the standard DEWATS in Japan.

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Main points in the PAWTP Act (1983) (1) Item What does the PAWTP Act stipulate?

Manufacturing and Installation of PAWTPs

The PAWTP (black + gray water type) is the standard on-site wastewater treatment facility in Japan. PAWTPs shall meet the technical standards for effluent water quality and the structural standards prescribed in the Building Standard Law.

Maintenance of 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 can outsource the work related to PAWTP management to a PAWTP vendor and/or a PAWTP desludging vendor.

Desludging of PAWTPs

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

Inspection of PAWTPs

The PAWTP Manager shall make the PAWTP receive an inspection for its water quality annually by the Specified Inspection Agency.

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Main points in the PAWTP Act (1983) (2)

Item What does the PAWTP Act stipulate?

Desludging Business

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

Maintenance Business

A corporate body that intends to join the PAWTP maintenance business 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 a training course conducted by a designated training agency, to the PAWTP maintenance work.

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Number of people engaged in the Septage Management Business in Japan

People with qualification (Number of registrants)

PAWTP Operators

72,521 Operation and maintenance

PAWTP Installation Workers

83,205 Installation/ Construction

PAWTP Technical Supervisors

26,658 Management of PAWTP with 501 PE or more

PAWTP Desludging Technicians

15,117 Desludging

PAWTP Inspectors

1,210

Total 198,711

Number of vendors

Specified inspection agencies

65 PAWTP inspection and water quality examination

PAWTP manufacturers

27 Research, development and manufacture

PAWTP maintenance vendors

12,871 Operation and maintenance

PAWTP desludging vendors

5,375 Desludging

PAWTP installation vendors

33,593 Installation/ construction

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Malaysia’s effort toward establishing effective Septage Management System ①

In 1993, Sewerage Services Act (SSA) federalized the sewerage assets, thus empowering the Malaysian Government to regulate this industry. SSA also provided the fundamental policies for septage management.

In 1994, Indah Water Konsortium (IWK) was created as the private concessionaire who was responsible for O/M of all sewerage facilities, and septage management. By these reforms,

・Sewerage coverage ratio : 25% (1993) ⇒ 70% (current)

・Desludging coverage ratio : 1% (1993) ⇒ 12.4% (1999)

On the other hand, the newly introduced sewerage charges (including desludging charges) for individuals and businesses caused complains from the Malaysian population and refusal to pay. As a result, tariffs were reduced at a level too low to cover operation expenditures.

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Malaysia’s effort toward establishing effective Septage Management System ②

In 2000, IWK was nationalized.

In 2006, SSA was replaced by the Water Service Industry Act (WSIA). National Water Services Commission (SPAN) was created to regulate water and sewerage services.

In the area of Septage Management, the IWK’s responsibility for the desludging and maintenance of the individual septic tank was transferred to the owner or residents of a premise, who are legally responsible for engaging IWK (Service licensee) or a license permit holder – both regulated by SPAN – to desludge and maintain their septic tanks.

Fines up to US$ 15,000 was established against the non-compliance, which have not been imposed yet.

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Malaysia’s effort toward establishing effective Septage Management System ③

The number of desludged septic tanks has substantially decreased since 2008.

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0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

No IST

Year

IST SCHEDULED DESLUDGING

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

No IST

Year

IST DEMAND DESLUDGING

Total Attempted Total Unsuccessful Total Desludged

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148208

135982

146524

37018 47056

58406

68548

70170

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

2005 2006 2007 2008 2009 2010 2011 2012

Jumlah Tangki Septik yang dinyahenap cemarNo. of IST desludging done Desludging Campaign at:- a) Taiping, Perak b) Kangar, Perlis c) Melaka d) Yong Peng, Johor e) Simpang Renggam, Johor

Desludging Campaign at:-

a) Muar, Johor

b) Temerloh, Pahang

c) Kubang Pasu, Kedah

d) Port Dickson, Negeri Sembilan

e) Sungai Besar, Selangor

No

. of

IST

Year

Malaysia’s effort toward establishing effective Septage Management System ④

Desludging campaigns are being organized to incite septic tank owners/users to desludge within the legal interval.

Malaysia’s effort toward establishing effective Septage Management System ⑤

Ms. Y. B. Dato’ Noriah Kasnon, Deputy Minister for Energy, Green Technology, and Water, joined a desludging campaign organized by SPAN and IWK and operated the lever of vacuum track.

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RIVER WATER QUALITY BASED ON BIOLOGICAL OXYGEN DEMAND

Malaysia’s effort toward establishing effective Septage Management System ⑥

Decrease of desludging activities has been affecting the river water quality.

Lessons from experiences of Japan and Malaysia

• Any on-site wastewater treatment facility becomes pollution source without proper Septage Management.

• In order to do Septage Management, you must be real serious. 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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