Summary
- The regulator wants a detailed Muhos water management plan by 5 November.
- Preparatory work at Muhos and Kajaani-Otanmäki has been suspended during unfinished environmental assessments.
- The Muhos police referral is confidential and establishes neither a charge nor guilt.
Finland’s environmental regulator has demanded additional drainage controls at the planned Google data centre in Muhos and confirmed that it has referred a separate, undisclosed matter associated with the project to police. The latest intervention follows an earlier order to suspend significant site preparation while environmental assessments remain unfinished.
The Finnish Licensing and Supervision Authority issued its further requirements on 22 October to Tuike Finland Oy, the Google subsidiary responsible for the developments at Muhos and Kajaani-Otanmäki. The company told the authority on 14 October that it had complied with the previous instruction and suspended preparatory work at both sites.
The immediate new deadline is 5 November. By then, Tuike must submit a detailed water management plan for Muhos, identifying proposed protective structures, their locations, an implementation timetable and water monitoring undertaken by an independent party. The regulator has specifically asked the developer to consider exceptional runoff caused by heavy rainfall and snowmelt.
Its concern centres on local geology as well as the scale of earthworks. The Muhos site lies in an area affected by black shale and material capable of producing acidity when sulphide-bearing soil or rock is exposed to oxygen. Drainage and excavation can allow acidic runoff and dissolved metals to reach surrounding waters if protective measures are ineffective.
According to the authority, monitoring already submitted by Tuike has shown changes indicating acidification. The regulator did not accept that measures described in the company’s drainage notification would control the risk with sufficient certainty. Proposed soil liming and lime filtration dams were judged inadequate on their own, while the design and effectiveness of surface filtration areas remained uncertain.
The drainage scheme includes approximately nine kilometres of new ditches. The company submitted its drainage notification on 18 September, when most of those ditches had already been constructed, according to the regulator’s account. The authority said the notification should have been filed at least 60 days before work began.
Because the area does not have a legally effective detailed local plan, the regulator determined that the drainage work requires a permit under the Finnish Water Act. That is a separate approval issue from the wider environmental impact assessment, which has not been completed.
The regulator’s earlier suspension instruction prohibits activities that materially change the natural environment, landscape, terrain or water balance. It covers activities such as clearing trees, stripping topsoil, excavation, rock blasting, crushing and the construction of site roads or drainage. Low-impact surveys and measurements were not automatically barred by that instruction.
While work is suspended, Tuike must also explain what maintenance, safety and environmental protection activities it believes are necessary at both Muhos and Kajaani-Otanmäki. That submission is due by 5 November and must show that any such activities will not create further environmental impacts during the assessment process.
The authority is separately examining a submission concerning excavated soil and rock, and has asked about the condition of a protected moor frog breeding and resting area at Muhos following work on the site. The Kajaani-Otanmäki drainage notification is being handled separately, rather than treated as part of the Muhos permit determination.
The police investigation request concerns Muhos. The regulator said confidentiality rules prevent it from explaining the subject of the referral. A request for investigation is not a finding that an offence occurred, and the released information provides no basis for identifying a suspected offence or individual responsibility.
If the requested water measures are not taken, the authority says it may consider administrative enforcement under the Water Act, potentially backed by a conditional fine. That is a prospective regulatory remedy, distinct from the confidential police referral.
Large data centre campuses can alter drainage across an extensive site long before servers, substations or cooling plant are commissioned. Roads, excavations and temporary water arrangements influence how runoff reaches neighbouring land and watercourses. The Finnish case demonstrates the practical importance of the preliminary construction phase: completing early civil works does not remove the obligation to assess their effects or obtain permits where required.
The required water permit and protective design have not yet been resolved.
Both Google-related projects remain subject to unfinished environmental impact assessments. The regulator’s immediate requirements concern controlling the works already undertaken, establishing a permissible water management design and identifying which protective activities may continue while those broader assessments proceed.
