Draft Odor Standards for Solid Waste Disposal Sites and Designation of Pollution Sources

Public Hearing Period: October 27 – November 25, 2026

Background:

1. Solid Waste Situation and Issues (2025)

  • Thailand has a total of 2,048 solid waste disposal sites nationwide.

  • Only 119 sites operate in compliance with engineering and sanitary standards.

  • The remaining 1,929 sites operate improperly; most rely on open dumping or surface/pit landfilling without low-permeability liner materials (such as compacted clay or HDPE geomembranes) and suffer from severe odor nuisance.

  • Most solid waste disposal facilities fall under the jurisdiction of Local Administrative Organizations (LAOs).

2. Complaints and Impacts

  • Data from the Traffy Fondue platform over the past 4–5 years (2021–2025) indicates that “foul odor” has consistently been the most frequently reported pollution issue, rising from 22 cases in 2022 to 38 cases in 2025 (the peak during that timeframe).

  • Odor nuisances originating from solid waste disposal sites constitute the second most prevalent complaint, adversely impacting public health and quality of life while triggering persistent community disputes.

3. Remedial Actions and Limitations

  • The Pollution Control Department (PCD) has conducted site visits to monitor operations and provide technical recommendations to LAOs for facility upgrades and performance improvements.

  • Budget allocations have been driven through provincial operational plans since 2018 for at least 712 sites, along with formal upgrade recommendations issued for 588 non-compliant sites since 2022.

4. Current Legal Gaps and Standards

  • Currently, only the Notification Prescribing Odor Concentration Standards for Exhaust Air Discharged from Animal Husbandry Facilities, B.E. 2556 (2013) exists as a reference guideline, but it applies strictly to livestock facilities.

  • There are currently no specific odor concentration standards designated for solid waste disposal sites, nor have these sites been formally designated as pollution sources subject to air emission controls under Section 68 of the Enhancement and Conservation of the National Environmental Quality Act, B.E. 2535 (1992).

5. Future Directions and Proposed Regulations

  • The PCD has prepared the Draft Notification of the Ministry of Natural Resources and Environment Prescribing Odor Concentration Standards for Exhaust Air Discharged from Solid Waste Disposal Sites, B.E. ….

  • The standard caps the allowable odor concentration at no more than 30 Odor Units (OU).

  • The draft establishes clear, standardized parameters for sampling locations, sampling timeframes, collection and transport protocols, sensory testing methods, and phased grace periods—taking into account the scale and operational readiness of facilities to reduce environmental impacts, grievances, and disputes with local communities.

Key Substance:

1. Legal Authority

  • The Draft Notification Prescribing Odor Concentration Standards is issued under Section 55 of the Enhancement and Conservation of the National Environmental Quality Act, B.E. 2535, upon the recommendation of the Pollution Control Committee and with the approval of the National Environment Board.

  • The Draft Notification of the Ministry of Natural Resources and Environment Designating Solid Waste Disposal Sites as Pollution Sources Subject to Odor Concentration Control for Exhaust Air Discharged into the Atmosphere, B.E. …. is issued under Section 68 of the Enhancement and Conservation of the National Environmental Quality Act, B.E. 2535, upon the recommendation of the Pollution Control Committee.

2. Definitions

  • “Solid Waste Disposal Site” means an area or facility used for solid waste disposal via open dumping or landfilling, whether operated sanitary or unsanitary.

  • “Odor Concentration” means a metric representing odor strength, expressed as the dilution ratio of an odorous exhaust air sample diluted with odor-free clean air.

  • “Odor Panelist” means an assessor tasked with sniffing to determine odor concentration, who must be officially registered and rostered with the Pollution Control Department, Ministry of Natural Resources and Environment.

3. Designation of Pollution Sources and Air Emission Controls

4. Odor Concentration Standards

  • The odor concentration must not exceed 30 Odor Units (OU).

5. Prescribed Odor Measurement and Testing Methods

6. Effective Enforcement Dates

  • The Draft Notification of the Ministry of Natural Resources and Environment Prescribing Odor Concentration Standards for Exhaust Air Discharged from Solid Waste Disposal Sites, B.E. …. shall come into force on the day following its publication in the Royal Gazette.

  • The Draft Notification of the Ministry of Natural Resources and Environment Designating Solid Waste Disposal Sites as Pollution Sources Subject to Odor Concentration Control for Exhaust Air Discharged into the Atmosphere, B.E. …. shall take effect upon the expiration of 360 days from the date of its publication in the Royal Gazette.

Public feedback and comprehensive details are accessible at [Link]. For further inquiries, contact the Pollution Control Department at +66 2 298 2086.