Denali Water Solutions LLC, based in Russellville, Arkansas, has agreed to a $610,000 civil penalty following a settlement with the federal government. This settlement addresses alleged violations of the Clean Water Act (CWA) in Arizona and southern California.
The U.S. Environmental Protection Agency (EPA) stated that Denali Water Solutions provides land application services for sewage sludge derived from wastewater treatment facilities, also known as biosolids. EPA Region 7 oversees all CWA biosolids cases nationwide.
Under federal regulations, biosolids must be applied at rates that limit nitrogen levels to what crops or vegetation can utilize. "EPA’s biosolids regulations protect wetlands, streams, rivers, and groundwater from harmful sewage sludge pollution," said EPA Region 7 Administrator Meg McCollister. "This settlement demonstrates EPA’s commitment to watershed and groundwater aquifer health, which in turn protects wildlife habitat and drinking water sources."
Since at least 2016, Denali allegedly applied sewage sludge to farm fields beyond the nitrogen needs of crops and failed to obtain necessary information for correct application rates. Such actions can lead to pollutants reaching groundwater or surface waters.
Excess nitrogen in water supplies poses risks such as harm to infants or livestock and ecological imbalances like algal blooms in aquatic environments.
In mid-2024, Denali ceased its land application activities in Arizona and California. The settlement requires adherence to a specific "Soil Sampling and Agronomic Rate Calculation Protocol" if operations resume. This includes sampling soil and calculating site-specific sludge applications without risking contamination.
The EPA estimates compliance will prevent the excess application of 5.8 million pounds of sewage sludge annually.
The proposed consent decree was filed with the U.S. District Court for the District of Arizona and is open for public comment over a 30-day period. Further details are available on the Justice Department’s Proposed Consent Decree webpage.
