EPA Finalizes Faster Groundwater Cleanup Plan at Former Nebraska Ammunition Plant

The U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers (USACE) have finalized a new groundwater cleanup strategy for the former Cornhusker Army Ammunition Plant in Grand Island, Nebraska, replacing an older extraction-based system with an accelerated bioremediation approach designed to reduce contamination more efficiently and at lower cost.

The updated plan, approved through a second Record of Decision Amendment, targets a contaminated groundwater plume linked to decades of military and industrial activity at the site. Instead of relying on groundwater extraction and treatment systems, the new method uses naturally occurring bacteria to break down pollutants underground.

To stimulate bacterial activity, the cleanup process will introduce carbon-rich organic materials including blackstrap molasses whey, vegetable oil, and corn steep into the groundwater system. Officials said these materials create conditions that help bacteria rapidly degrade harmful contaminants while restoring groundwater quality for future unrestricted use.

The amended remedy follows extensive remedial investigations and feasibility studies conducted by USACE, along with a public comment period held in February 2025. EPA Region 7 and the Nebraska Department of Water, Energy and Environment reviewed the proposal and confirmed support for its implementation.

The Cornhusker Army Ammunition Plant, a 12,042-acre facility built during World War II, once produced and stored munitions and included landfills, storage areas, fertilizer operations, and burning grounds used to destroy explosive-contaminated materials. Improper wastewater disposal and industrial operations later led to significant groundwater contamination that migrated beyond the property boundary.

Federal authorities said the new bioremediation approach is expected to accelerate cleanup timelines, lower long-term remediation costs, and continue protecting both public health and the environment while long-term monitoring and remediation activities remain ongoing.

Faster contaminated-site cleanup shapes long-term environmental-liability disclosure obligations for industrial operators, and it affects insurance and lender pricing of legacy-site risk. Our sustainability-due-diligence teams help clients evaluate what these cleanup frameworks mean for legacy-site risk and disclosure.