The Indiana Department of Environmental Management (IDEM) is the state’s environmental regulator and reviews all data center proposals for compliance with state and federal environmental laws covering air, water, and land quality.
Before construction, projects developing one or more acres must obtain a Construction Stormwater General Permit, which requires a Notice of Intent and a Stormwater Pollution Prevention Plan to protect Indiana waterways from construction runoff. If a project affects a protected wetland, an Isolated Wetland Permit may also be required.
For water quality, IDEM’s Office of Water Quality issues National Pollutant Discharge Elimination System (NPDES) permits for facilities discharging cooling water directly into streams, lakes, or other water bodies. Facilities discharging into a municipal sewer system must notify the receiving wastewater treatment plant, which then coordinates with IDEM to determine whether its own NPDES permit needs to be updated.
For air quality, backup generators and cooling towers typically require air permits from IDEM, with the specific permit type depending on the facility’s potential to emit, its location, and the capacity of the equipment.
For land quality, data centers must follow state rules for the storage and disposal of solid, hazardous, and electronic waste. Projects sited on properties with historical contamination may fall under Indiana’s Brownfields Program, which can carry ongoing obligations such as soil management, stormwater controls, or preservation of existing protective barriers.
For more information, please see the IDEM Fact Sheet