All four used a common construction contractor—which DOJ records indicate was initially Swinerton Renewable Energy and then became SOLV Energy in a 2021 corporate spinoff.

The contractor was not a party in the settlements, says DOJ, but neither SOLV nor EPA spokespersons would comment on whether the firm signed a separate settlement or faces any pending or upcoming enforcement related to site stormwater management.

All four owners violated their construction stormwater permits by failing to design, install and maintain proper stormwater controls, said EPA. They also failed to conduct regular site inspections, employ qualified inspectors or accurately report and address stormwater issues. Additionally, the agency said AL Solar and American Falls Solar allowed unauthorized discharges of excess sediment into waterways.

Prairie State Solar, with a planned 134-MW capacity, and Big River Solar at 215 MW, are both still under construction, an EPA spokesperson said. Settlement terms require the owners to ensure compliance going forward. Prairie State will pay a combined $225,000 to the U.S. and Illinois. Big River will pay $175,000.

AL Solar A was completed in November 2019 and has a 111-MW capacity. American Falls Solar was completed in November 2017 and has a 54-MW capacity.

Since they are complete, the owners will only pay a civil penalty under the terms of their settlements. AL Solar will pay a combined $500,000 to the U.S. and Alabama, while American Falls will pay $416,500 to the U.S.