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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 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
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 4
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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
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 7
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
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 8
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) |
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 10
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 %
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 11
More than 50% of households do not desludge within one year
Government Support: Technical Guideline
| Manuals from Ministry of Natural Resources and Environment |
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 12
| 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
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 13
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
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 14
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
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 15
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
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 16
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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
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 17
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 %
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 18
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
Commercial package 519-3,075 1,783 658-1,157 849 204-4,030 1,461 64-356 220
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 19
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 |
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 20
Anaerobic digestion Sludge drying beds Oxidation pond
Transforming septage to fertilizer
The use of treated sludge as fertilizer is widely accepted throughout Thailand
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KEY ISSUES: Technical Aspect
Efficiency of adopted on-site treatment systems for domestic
wastewater is only 43 – 59 % removal of BODwastewater is only 43 – 59 % removal of BOD
Most of on-site treatment for domestic wastewater in
Thailand collect only “Black water”
“Grey water” management is the key need !!
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 21
Conclusions
No standard of products for commercial septic tanks.
Permitting control for construction and installation of septic tanks
are week.
No regulation for operation and maintenance of on-site treatment
Lack of monitoring system and water quality examination
Integrated management among institutions is needed
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 22
Subsidy system for upgrading on-site treatment is needed
Grey water management is the key need !!
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Thank you
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand
Building Effluent Standards
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 24Source: PCD
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Surface Water Quality
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 25Source: PCD, 2012
Sewer System
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 26Source: PCD, 2012
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Sewer System
Storm sewerSanitary
Combined Sewer
Canal
Interceptor chambers
sewer
Pumping station
Wastewater treatment plant
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 27
station
Chao Phraya river
Source: BMA
On-site Treatment
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 28Source: PCD, 2012
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On-site Treatment
Suwanna. K. Boontanon | Mahidol Univ. |On-site Treatmentt for Domestic Wastewater in Thailand 29Source: PCD, 2012