CAHOKIA HEIGHTS, Ill. (AP) — The U.S. Environmental Protection Agency has ordered officials in a southwestern Illinois city to address problems with the community’s sewers blamed for nearly 30 sewer overflows since January.

The EPA’s order, issued Monday, mandates that the city of Cahokia Heights submit plans to control sanitary sewer overflows, which can cause water to back up, fouling residents’ homes and yards.

The Belleville News-Democrat reports that the federal agency’s order states that since Jan. 26, at least 28 sewer overflows have occurred in the city. Cahokia Heights is located in St. Clair County just across the Mississippi River from St. Louis.