Thai data centre board to review 80% cooling-tower wastewater reuse rule on November 27

Thailand is preparing rules that would require data centres to treat and reuse at least 80% of their monthly cooling-tower wastewater. The Data Centre Board, chaired by Deputy Prime Minister and Finance Minister Ekniti Nitithanprapas, is scheduled to consider the draft on November 27, 2026.

Deputy Interior Minister Polapee Suwunchwee, chair of the subcommittee on locations, urban planning, buildings and structures, is preparing to submit the draft ministerial regulation as part of the government’s oversight of a sector designated a national priority.

The proposed data centre regulation would be issued under the Building Control Act of 1979 and take effect 180 days after publication in the Royal Gazette. Board consideration would precede the formal process for issuing and publishing the regulation.

Draft would require 80% reuse of cooling-tower wastewater

Under Thailand’s draft data centre rules, operators would have to collect and treat water discharged from cooling towers, known as blowdown, and reuse at least 80% of the monthly discharge volume as makeup water to replenish the cooling system. Water circulating within the system, water treated repeatedly and water from other sources could not count towards the target.

Data centre wastewater that was not reused would have to meet discharge standards under the Ministry of Natural Resources and Environment’s 2024 notification. Operators unable to meet those standards would have to send the wastewater to a licensed treatment provider.

The data centre draft would prohibit discharging non-compliant wastewater or diluting it with clean water. Operators would have to install meters and produce monthly reports on water balances, water quality and pollution loads.

Generator and fuel-storage rooms at data centres would need ventilation, leak prevention, liquid containment barriers, emergency fuel shut-off systems and fire protection under the draft. Exhaust outlets must not cause a nuisance to neighbours, while noise and emissions would be controlled under environmental law.

Existing data centres would have one year for upgrades

Data centres licensed or operating before the regulation took effect would have one year to upgrade fire protection, emergency power and environmental measures, with private facilities also required to arrange insurance. The draft would exempt existing buildings from the building alignment and structural chapters unless operators later sought alterations or a change of use.

Private data centres would have to carry third-party liability insurance covering loss of life, bodily injury and property damage during both construction and operation. The draft would also require data centres to have a building inspector under Section 32 bis of the Building Control Act.

All data centres covered by the draft would need automatic fire suppression throughout the premises, meeting Department of Public Works and Town & Country Planning standards or other standards approved by the Building Control Committee. Fire alarms would be required on every floor, alongside lightning protection.

The draft’s structural provisions would require data centres to comply with the 2021 ministerial regulation on structural design, foundations and earthquake resistance. Main structural elements, walls and staircases would use non-combustible materials, while walls separating data centres from other building uses would need at least two hours of fire resistance.

Under the proposed data centre rules, emergency power systems, such as batteries or generators, would have to operate independently of normal supplies and activate automatically during an outage. These systems would have to supply exit signs, corridors, fire escape staircases and fire alarms for at least two hours.

Data centres would need building plans in Thai and English on every floor, backup lighting and escape signs under the draft. Portable fire extinguishers of at least 4kg capacity would be required, with one for each area of no more than 1,000 square metres and no more than 45 metres between extinguishers. Buildings with four or more storeys would need a fire escape staircase in addition to the main stairs.

Local officials would be able to order remedial work where a data centre could endanger life or property or cause environmental harm. Under the draft, operators would have to be given at least 30 days to comply.

Seven categories would determine building requirements

The draft would classify data centre buildings into seven categories based on electricity use or reserve fuel storage capacity. It defines a data centre as a building, premises or structure using electronic equipment and at least 0.5 megawatts (MW) of electricity to collect, store, process, host, receive or transmit data for the operator, affiliated companies or other users.

Under the data centre draft, electricity use means total facility load, although meeting documents call for a clearer definition. Fuel quantities would be measured by container capacity regardless of the amount actually stored.

• Category 1: Electricity use of 0.5 megawatts (MW) to below 1 MW, or reserve fuel storage capacity of 6,000 to below 12,000 litres.
• Category 2: Electricity use of 1 MW to below 5 MW, or reserve fuel storage capacity of 12,000 to below 60,000 litres.
• Category 3.1: Electricity use of 5 MW to below 10 MW, or reserve fuel storage capacity of 60,000 to below 90,000 litres.
• Category 3.2: Electricity use of 10 MW to below 20 MW, or reserve fuel storage capacity of 90,000 to below 180,000 litres.
• Category 3.3: Electricity use of 20 MW to below 50 MW, or reserve fuel storage capacity of 180,000 to below 600,000 litres.
• Category 4: Electricity use of 50 MW to below 200 MW, or reserve fuel storage capacity of 600,000 to below 2,400,000 litres.
• Category 5: Electricity use of 200 MW or more, or reserve fuel storage capacity of 2,400,000 litres or more.

Data centre buildings would become controlled-use buildings under Section 32(2) of the Building Control Act. The draft’s explanatory memorandum cites growing construction and specialised structures and equipment as reasons for tailored requirements covering structural integrity, safety, fire prevention, the environment, urban planning and public utilities to support digital infrastructure and economic development.

Standalone data centres in categories 1 to 3.2 would need setbacks of at least six metres on two sides and three metres on the remaining sides. For categories 3.3 to 5, the draft would require 10 metres on two sides and five metres on the others.

For data centres with reserve fuel tanks, the greater setback required by the draft building rules or fuel-storage regulations would apply. Facilities in industrial estates would follow industrial estate legislation. Meeting documents flag possible revisions to the wording on open space and to setback distances to account for noise, heat and effects on neighbouring communities.

Under the data centre draft, parking would be calculated at one space per 60 square metres of office space, and standalone buildings would need a fire engine access route at least six metres wide around the building. Wastewater treatment, water supply, refuse and lift systems would follow Ministerial Regulations Nos. 33 and 44, while electronic waste would be managed under environmental law.

The draft would require data centre construction, alteration, demolition and changes of use to comply with the regulation, local bylaws, planning law, factory law and other relevant legislation, with the stricter requirements taking precedence.

Investment incentives require Thai specialists and managers

Separate promotion conditions set by Thailand’s Board of Investment (BOI) require Thai nationals to make up at least 50% of specialist and management personnel in data centre projects. Operators must also work with educational institutions on workforce development and meet the conditions before claiming tax incentives.

Narit Therdsteerasukdi, BOI secretary-general, said the government’s data centre framework covers efficient electricity and water use, environmental impacts, suitable locations, and economic benefits through employment and domestic supply-chain links. BOI is coordinating with universities to accelerate specialist training.

Narit identified workforce development, domestic supply-chain integration and greater access to clean energy as parallel priorities for data centre investment. The aim is for Thailand to generate jobs and lasting economic value from the sector.

Source: Thansettakij