Can data centers contaminate wells and other water sources? | Fact brief - Portland Press Herald

Maine lawmakers have passed a bill, LD 307, aimed at imposing a temporary moratorium on the approval of new data centers within the state. The legislation, which would bar data centers with loads of 20 megawatts or more, is intended to pause development until November 1, 2027. During this period, a state-appointed council would study the effects of data centers on ratepayers, grid reliability, and the environment. The bill addresses concerns regarding the potential for data centers to contaminate water sources. The article cites a 2025 Congressional Research Service report highlighting the common use of backup diesel systems with underground fuel storage tanks, which the U.S. Environmental Protection Agency identifies as a common source of groundwater contamination. Additionally, a February 2026 University of California, Berkeley, report indicates that wastewater from data center cooling systems, containing concentrated minerals and chemical additives, could contaminate groundwater if improperly discharged. As of April 22, Governor Janet Mills had not yet signed the bill, with a deadline of April 25 to act.