Thailand announces the effluent standard for housing estates 
Ministry of Natural Resources and Environment announced two notifications regarding the effluent standard for housing estates in the Royal Gazette on 19 July 2021 by virtue of the Enhancement and Conservation of National Environmental Quality Act, B.E. 2535 (1992). The notifications are;
- the Notification of Ministry of Natural Resources and Environment on Specification of the effluent standards for developed land B.E. 2564 (2021),
http://www.ratchakitcha.soc.go.th/DATA/PDF/2564/E/161/T_0047.PDF and - the Notification of Ministry of Natural Resources and Environment on Designation of the developed land as a point source which shall be regulated of the wastewater to be discharged into the public waterways or environment B.E. 2564 (2021)
http://www.ratchakitcha.soc.go.th/DATA/PDF/2564/E/161/T_0050.PDF.
Effluent standard
The developed land is classified into three types as follows;
- Type A is a land with more than 500 sections/units or an area of more than 100 Rai.
- Type B is a land with 100 to 499 sections/units or an area of 19 to 100 Rai.
- Type C is a land with 10 to 99 sections/units or an area of less than19 Rai.
* A rai is a unit of area equal to 1,600 square meters
The effluent standard for each type of housing estate is set as shown in the following table.
|
Parameter |
Unit | Standard | |||
| Type A | Type B |
Type C |
|||
| 1. | pH | – |
5.5-9.0 |
5.5-9.0 |
5.5-9.0 |
| 2. | BOD (Biochemical Oxygen Demand) |
mg/l |
20 |
30 |
40 |
| 3. | TSS (Total Suspended Solids) |
mg/l |
30 |
40 |
50 |
| 4. | TDS (Total Dissolved Solids) |
mg/l |
1000 |
1000 |
1300 |
| 5. | Sulfide |
mg/l |
1.0 |
1.0 |
1.0 |
| 6. | TKN (Total Kjeldahl Nitrogen) |
mg/l |
35 |
35 |
35 |
| 7. | Oil and Grease |
mg/l |
20 |
20 | 20 |
Each type of developed land shall provide a necessary wastewater treatment system to meet the standard before discharging to the environment. Dilution is not permitted. The new standard has been effective since the next day of publication, namely 20 July 2021, for Type A and Type B lands while one year of grace period has been given to Type C lands.
