Behind Dana Anderson’s home in central Alabama, a plastic pipe carries waste from her toilet through her backyard, discarding it outdoors. Three or four times a year, a spell of heavy rain forces the excrement back up into the house. It is a plight that has long plagued residents across Alabama’s Black Belt, a stretch of largely rural counties so named for its dark soil and history of slavery. Cotton flourished in the region for the same reasons that conventional septic tanks fail there: The soil is dense and holds on to water. Today there are more than 50,000 people in the region who pipe raw sewage into open trenches and pits. Now, a seeming solution to the public health problem has been stymied by an unlikely force: the Trump administration’s war on diversity, equity and inclusion programs.…