The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

Regulations and standards on decentralized
domestic wastewater treatment in Thailand
Presented byAsst. Prof. Dr. Wilasinee Yoochatchaval
Department of Environmental Engineering
Kasetsart University wilasinee.y@gmail.com

1/23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

Introduction• Surface water quality in Thailand• Number and capacity of municipal wastewater treatment system• Domestic wastewater management and constrain• Law and Regulation on onsite treatment• Septic tank management and constrains

2 /23The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

3 /Asia Pacific Water hotspots

Water Hotspots in Asia Pacific
Deteriorating water quality countries:
Thailand, Indonesia, Phillipines,Malaysia, Pakistan

Source: Unescap statistic yearbook 201123

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

4 /Surface water quality in Thailand

Water quality in Bangkok in 2016 (298 sampling points)• BOD < 4 mg/l : 2 points• BOD >4-20 mg/l : 230 points• BOD > 20 mg/l : 66 points

Source: Thailand state of pollution report 2016

Source : Annual Report 2016 by Department of Drainage and sewerage

23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

5 /Number and capacity of municipal wastewater
treatment system• Sewage volume =9.6 million m3/day• Treatment capacity = 2.7 m3/day (28%)• The overall nationwide WWTP = 101 plants , in used 88plant• 68 plants belong to Local Administrative Organization
8 plants belong to Bangkok Metropolitan Administration
25 plants belong to Wastewater Management Authority• Treatment Technology ; Stabilization pond, Aerated lagoonand Activated Sludge

Source: Thailand state of pollution report 201623

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

Constraints in domestic wastewater management in Thailand• Appropriated municipal wastewater management• Understanding in wastewater problem and awareness to protect theenvironment• LAO capacity for managing of wastewater and treatment plant(including treatment cost)• budget for construction of collection system and treatment facilities

6/23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

Domestic wastewater treatment management system• Central wastewater system• Cluster wastewater system• Onsite wastewater system

Decentralized system

7/23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

8/

Central wastewater treatment system
In Bangkok has 8Centralized system thetotal capacity is about 2.8
million cu.m/d only 1.2
million cu.m/d go toWWTP.

Bangsue WWTP , Bangkok

Dindang WWTP , Bangkok

WWTP , Chachoengsao province

23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

9/

Cluster wastewater treatment system

Pitsanulok Province

Udtaradit Province

Udtaradit Province
However, construction of centralization system is sometime not so appropriate in some areas.
Thus, decentralization is better solution. For example, a group of housing. So it called “Cluster WWTP”

23The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

10 /Onsite wastewater system (household)One cesspool

Two cesspool

Source: http://farmtaveepol.blogspot.com/2013/04/

Septic Tank

Source: Compendium of Sanitation Systems and Technologies 2nd Edition

Commercial septic Tank

Source: http://www.premier-products.co.th23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

Onsite wastewater system (Condominium, Apartment)

Source: http://www.envire.co.th

Source: http://www.iseehomecomplex.com/2015/04/condo-water-supply.html

11 /23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

12 /Domestic WW production
8%

13 %
63 %

SepticLegal
87 %10% Toilet
0.98 million cu.m

X2,100mgBOD/L

Illegalcesspoolx450mgBOD/L

SludgeTreatment
Plant

Land disposal

90 %Groundwater

90% Gray water
8.83 million cu.m73%

x 80 mgBOD/L

27%

x 20 mgBOD/L
sewerage

WWTP
Modified from Chongrak Polprasert 2017

Water reservoir

Surface water quality

23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

13 /Characteristics of Influent (black water)
Parameter

Type of on-site sanitation
One cesspool

Two cesspool

Commercial
package

Japanese
JohkasouTS (mg/L)

8,800

11,000

11,54025,000-32,000

TCOD (mg/L)

15,00020,70017,5808,000-15,000

BOD5 (mg/L)

3,900

5,600

5,940

4,000-12,000

TN (mg/L)

930

1,330

2,710

TP (mg/L)

480

183

440

Fecal coliform(MPN/100 mL)

2.85E+09

4.21E+09

1.20E+08

E.coli (MPN/100 mL)

1.90E+09

2.07E+09

3.88E+07

Source: Organic Waste Recycling, Chongrak Polprasert and Thammarat Koottatep 4th Edition

800-1,200

1E+06-1E+07

23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

14 /Law and regulation on decentralized wastewater treatment
Ministry of Natural
Resources and Environment

Ministry of Public
HealthNational Environmental
Quality Act 1992

Public HealthAct 1992

••
•
•
•
•

PolicyEnvironmental fundStandards
Laws
Educations
Trainingo Sewage tariffs

Effluent quality control
Modified from Chongrak Polprasert, 2017

• Standards• Lawso Septage collectionand charging
system(250THB/m3)

Septage control

Ministry of Interior

Building Control Act1979

Decentralization
Act 1999• Standards• Laws• Budgeting• Lawso Classified building into o Wastewater Tariff
type A, B, C, D and E
o Onsite treatment
installation

Construction

Tariff, Fine, Control

23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

15 /Effluent Standard - National Environmental Quality Act 1992
Ministry of Natural Resources and Environment(MNRE)
Notification on Community Wastewater
Treatment Plant Effluent Standard 2010

Notification on Housing Estate Effluent
Standard 2005

Domestic Wastewater Treatment
Plant

Housing estate no. of land > 100unit

pHBOD (mg/L)
SS (mg/L)
TDS (mg/L)
Settleable Solids (mg/L)

5-9< 20< 30-

5.5-9.0< 30< 40
< 500
< 0.5

TKN (mg/L)
Organic Nitrogen (mg/L)<20 (Total N)
-

< 35-

Ammonia Nitrogen (mg/L)--< 5.0-< 20< 1.0

Laws/Regulations
Applicable to Household

Oil and Grease (mg/L)
Sulfide (mg/L)

23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

16 /23Effluent Standard - Building Control Act
Building 100- <500
rooms, Hotel 60- <200rooms, Hospital 10-<30
beds, Institute 5,000<25,000 m2

Building <100,Hotel <60 rooms

Dormitory 10-<50
rooms, Hospital < 10beds, Institute < 5,000
m2, Department store<1,000 m2, market 500-<1,000 m2,Condominium < 2,000m2

Restaurant < 100 m2

5-9< 20< 30
< 500
< 0.55-9
< 30
< 40
< 500
< 0.55-9
< 40
< 50
< 500
< 0.55-9
< 50
< 50
< 500
< 0.55-9200<60-< 35< 10< 35< 10< 45< 15< 40< 15---25< 25-< 201.0< 201.0< 203.0< 20< 4.0

100

Building > 500
rooms, Hotel>200 rooms,
Hospital > 30
beds, Institute>25,000 m2
pH
BOD (mg/L)
SS (mg/L)
TDS (mg/L)
Settleable Solids(mg/L)
TKN (mg/L)
Organic Nitrogen(mg/L)
Ammonia Nitrogen(mg/L)
Oil and Grease (mg/L)
Sulfide (mg/L)

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

Decentralization Act 1999

17 /Online monitoring
system for WWTP

Propose to decentralize responsibility and authority to localities
and municipalities for planning, managing and solving
problems in the areas

Local organization
Provincial Administrative Organization

Bangkok

Tambon Administrative Organization

PattayaMunicipality

http://mews.onep.go.th/wwt_province.aspx?id=023

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

18 /Sewage Tariffs in Thailand• The National Environmental Quality Act, B.E. 2535 (NEQA 1992)- Polluter Pay Principle• Decentralization Act 1999

Delay
Development of Draft Tariff Regulations by LGAs
Review and Approval by PCD

Review and Approval by National Environmental Board

ImplementationSuccessExcluding : Bangkok and Pattaya city
3.5-11.2 THB/m323

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

19 /23Operation and monitoring of septic tank in Thailand
Public Health Act, B.E. 2546
Septage must be properly collected and treated
before disposal

TISI;Thailand Industrial
Standard Institute-Plastic Physical STD(TISI-816)-Standard for testing
SepticIllegallicensedUn-licensed

No requirement for regular maintenanceof on-site treatment facilities

cesspool• Local Government Organizations (LGOs)(office of Public Health and Environment or private sector)• Bangkok Metropolitan Authority (BMA)  Department of Environment• Pattaya city  Department of Environment

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

20 /Constrain on septic tank management system• Thailand has no enforcement on septictank operation and maintenance• No standard for commercial septic tankdesign criteria• No monitoring program on septic tankeffluent quality

http://www.naibann.com/house-checklist-review-bysatan-boat/

For larger scale onsite treatment systems i.e. those in Condominium, the effluent havebeen controlled by Building Code 1979 Act and Notification on Building Effluent
Standard 1994

23

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

Conclusion

Decentralization Act

Individual Household-Building/Hotel/
Condominium-House21 /Community/Cluster
Installation of onsite treatment
Effluent quality-Housing Estate-Community
Wastewater
Treatment Plant

TISI-816
Installation of septic tank-National Environmental Quality Act 1992
Building Control Act

Public Health Act-Notification on Housing Estate Effluent
Standard 2005
-Notification on Community Wastewater
Treatment Plant Effluent Standard 201023

The 5th Workshop on Decentralized Domestic Wastewater Treatment in Asia

Thank you for your attention

22 /23