TikTok data centre wins environmental permit in Lahti

A data centre being built in Lahti for TikTok has received an environmental permit, Yle reports. The authority withheld detailed emissions and stormwater documents, citing trade secrets.

Singapore-based DayOne is building the facility in Kiveriö, with operations due to begin in 2027. The Permit and Supervisory Agency (LVV) classified some application attachments as confidential. They included emissions information and stormwater plans.

The agency’s public interest oversight unit said in its statement that emissions data generally cannot be kept secret on grounds such as commercial confidentiality. It cited environmental protection legislation and the public’s rights to information, participation and appeal. The property company provided a table of noise and air emissions but said it had submitted more detailed figures confidentially to the agency, including generator fuel capacities and quantities.

The data centre will normally draw electricity from the local grid. Its backup generators will run on light fuel oil and are intended for power outages, although they may also be tested periodically. The permit requires the company to keep noise as low as possible and sets limits of 55 decibels during the day and 50 at night at affected locations, including for generator tests and related traffic. The permit notes that prolonged power cuts are rare in Lahti.

Nearby residents have already raised concerns about noise from construction. The city of Lahti is responsible for assessing construction noise. Once the facility is complete, water chillers and electrical substation transformers will also produce noise. Forty-eight water chillers are planned for the roof, with an enclosed noise barrier around them.

The facility’s cooling system will use refrigerants in a closed circuit. It is expected to use about 3,000 cubic metres of water a year, mainly in office and staff facilities. Heat pumps will recover heat from the cooling systems to warm the building.

The permit decision is available on the agency’s website, and appeals can be filed with the administrative court until 11 November.