18/02/56 1 WEPA International Workshop | 2013 | Cambodia On-site Treatment for Domestic Wastewater in Thailand Suwanna Kitpati Boontanon Mahidol University February 18, 2013 Assistant Professor, Faculty of Engineering Background Thailand : 14 million m 3 /d of wastewater generated 3 million m 3 /d of treatment capacity 21 % of people access to sewerage system Bangkok : 2.6 million m 3 /d of wastewater generated 1 million m 3 /d of treatment capacity Suwanna. K. Boontanon | Mahidol Univ. | On-site Treatmentt for Domestic Wastewater in Thailand 2 40 % of people access to sewerage system
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On-site Treatment for Domestic Wastewater in Thailand
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WEPA International Workshop | 2013 | Cambodia
On-site Treatment for Domestic Wastewater
in Thailand
Suwanna Kitpati Boontanon
Mahidol University
February 18, 2013
Assistant Professor, Faculty of Engineering
Background
Thailand : 14 million m3/d of wastewater generated
3 million m3/d of treatment capacity
21 % of people access to sewerage system
Bangkok : 2.6 million m3/d of wastewater generated
1 million m3/d of treatment capacity
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 2
40 % of people access to sewerage system
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Background
Sewer service area30 % 70 %
70 % of collected night soil is disposed to environment
No sewer service area
21 %
Wastewater treatment facility
Night soil treat‐mentfacility
cultural field, w
aterw
ays
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 3
79 %
Landfills, agric
Key Contents of Presentation
Management and Institutional Aspect of On-site Treatment
Technical Aspect of On-site Treatment
Black water and Grey water
Septage Collection and Treatment
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Management and Institutional Aspect| Law | Regulation |
MOI MONRE MOPH
Building Control Act National Environmental Quality Act Public Health Act
Ministerial Regulation (2002)
Notification for Building Effluent
Notification for Building Effluent Standards (2005): Control building A
Notification for Building Effluent Standards (2005): Standards
Ministerial Regulation No. 51 (1998)
Ministerial Regulation No. 44 (1995)
Building Control Act
(1979)
National Environmental Quality Act
(1992)
Public Health Act
(1992)
•Classified building into
•Septage collection and charging system
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 5MOI: Ministry of Interior; MONRE: Ministry of Natural Resources and Environment; MOPH: Ministry of Public Health
Construction Effluent quality control Septage control
gStandards (2011): Control building B
•Classified building into type A, B, C, D, E
•On-site treatment installation
Stakeholders and Responsibilities
MOI MONRE MOPH
Oversee by law Oversee by law
We do not have “law or standards” for • Manufacture of septic tank• Installation of septic tank• Operation and maintenance• Annual water quality examinationy
Owner
D t f t ti O ti (b ) Effl t i t
Responsible for
Oversee by law
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 6
•Document for construction
•Construction / Installation
•Operation (by owner)
•Maintenance
•Effluent requirements
•Desludging
Related Stakeholders Related Stakeholders•Construction
company•Private company •Local government
•Private company
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Funding Mechanism
| Centralized and Cluster Treatment |
National Funding Sources
> 1 billion US for wastewater infrastructure in Bangkok since 1990s
> 500 million US for wastewater treatment plants outside of Bangkok from 1985 to 2000
Local Funding Sources
Funding supported through Provincial Environmental Action Plans
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Action Plans
| On-site Treatment |
Owners respond for the cost of installation, operation and maintenance Subsidy system may be needed for
upgrading on-site treatment system
Cost of Commercial Septic Tanks
| Septic – Anaerobic Filter |
Price (Baht) for 5 persons
| Aerobic biofilm / Activated sludge |
3,000 – 12,000
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30,000 – 60,000
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Surveys of Willingness to Pay
Surveys in 2013 for 300 households
Pay for Upgrading the on‐site
t t t
Not willing to pay
Either choice is OK75 % of this answer :
illi t t
Pay for connecting to sewerage system
77 %
treatment 11 %
Either choice is OK6 %
6 %willing to pay at
<15,000 Baht
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 9
Subsidy system is really needed for upgrading on-site treatment system
Septage Collection and Charging System
| Septage collection by Local Government Authorities (LGAs) |
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First cubic meter desludging : Charging 250 Baht/ m3
8 USD/ m3
Subsequent cubic meter (less than half) 150 Baht/ m3
(more than half) 250 Baht/ m3
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Surveys of Desludging Period
Surveys in 2013 for 300 households
54 %
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More than 50% of households do not desludge within one year
Government Support: Technical Guideline
| Manuals from Ministry of Natural Resources and Environment |
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| Manuals from Ministry of Public Health |
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KEY ISSUES : Management and Institutional Aspect
Manufacturing of septic tank
Septic tank installation
Operation and maintenance
DesludgingWater quality examination
1 2 3 4 5No standard of products for commercial septic tanks
1Permitting control for construction are week.
2No regulation for operation and maintenance
3
Subsidy system
6
Lack of monitoring system
4Integrated management between MONRE and MOPH is needed
5
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Subs dy systefor upgrading on-site treatment is needed
Technical AspectThailand | Black water and Grey water
Pollutant loads from grey water is much higher than black water
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Daily amount of domestic wastewater Pollutant loads (BOD) of domestic wastewater
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Targeted Wastewater : Blackwater and Greywater
Bathing / showering
To sewerage system
ToiletSeptic tank Anaerobic filter
tankCesspool tank
Seep into ground
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In PCD manual: Both black water and grey water are recommended to treat by on-site treatment system
Kitchen Screener Grease Trap Source: PCD, 2012
Existing Situation : only Blackwater
Grey water
Black waterOnly black water is collected to treat.Grey water management is the key issue
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On-site Treatment Systems Adopted
Cesspool (one unit or two units)
• Septage is collected in cesspool.
• Liquid waste is drained into soakage pit which allow liquid waste to seep into surrounding soil.liquid waste to seep into surrounding soil.
Septic Tank
• Septage is collected in septic tank until full and then sucked by suction truck.
• Liquid waste flows out to sewerage and drainage system
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Activated Sludge
• Activated sludge is used mostly in big buildings.
• Liquid waste flows out from activated sludge to sewerage
and drainage system.
Percentage of On-site Treatment Systems
C i l
One cesspool
69 %
Two cesspools
23 %
Commercial
package
8 %
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Source: Dulyakasem, S., et. al., 2013. Survey of Decentralized Wastewater Treatment System (DEWATs) in Thailand – Urban Areas
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Range Avg. Range Avg. Range Avg. Range Avg.
Once cesspool 705-4,520 2,289 123-3,000 946 68-11,685 2,998 8-2,115 470
BOD (mg/L)
Influent Effluent
SS (mg/L)
Influent Effluent
Water Quality : Influent and Effluent
Two cesspools 66-6,450 2,537 25-9,517 1,436 102-1,556 608 4-1,068 245
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Source: Dulyakasem, S., et. al., 2013. Determinations of Blackwater characteristics and sludge accumulation rates in Decentralized Wastewater Treatment Systems (DEWATs) in Thailand
Septage Treatment: LGAs
| Best Practice in Treatment – Nonthaburi Municipality |
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