The U.S. government and Wal-Mart reached a settlement May 12 for alleged stormwater violations under the federal Clean Water Act at 24 construction sites in nine states. Wal-Mart, based in Bentonville, Ark., agreed to pay a $3.1-million penalty, the largest for stormwater violations at a construction site.

The retail giant also agreed to reduce stormwater runoff at its sites by instituting better control measures, thereby setting an industry standard for developers and contractors, according to the Environmental Protection Agency and the Dept. of Justice. The government also alleged that Wal-Mart failed to obtain permits before starting construction, failed to develop a plan to control polluted runoff from those construction sites, and failed to adequately install sediment and erosion controls on the sites.

Wal-Mart is one of the largest commercial developers in the U.S., building more than 200 stores each year. “Developers like Wal-Mart must share responsibility with their construction contractors to ensure compliance” with the Clean Water Act, said Thomas L. Sansonetti, assistant attorney general in DOJ’s environment and natural resources division.

Under the settlement, Wal-Mart will comply with permitting requirements, and provide rigorous oversight of its 150 contractors at its construction sites across the country. The retailer also will spend $250,000 on an environmental project that will help protect wetlands or waterways in one of the affected states: California, Colorado, Delaware, Michigan, New Jersey, South Dakota, Tennessee, Texas and Utah.