The U.S. Environmental Protection Agency announced Tuesday it has opened a civil rights investigation into whether Alabama discriminated against Black residents when handing out funding for wastewater infrastructure.

The Natural Resources Defense Council and the Center for Rural Enterprise and Environmental Justice filed the complaint this spring, arguing Alabama’s policies for distributing money have made it difficult for people — particularly Black residents in the state’s poverty-stricken Black Belt — to get help for onsite sanitation needs.

“Sanitation is a basic human right that every person in this country, and in the state of Alabama, should have equal access to. Those without proper sanitation access are exposed to illness and serious harm,” Catherine Coleman Flowers, founder of The Center for Rural Enterprise and Environmental Justice, said in a statement.