Down a long, flat road in the industrial zone of South Memphis, a newly occupied factory is humming with activity. It’s a low-level white building that spans the length of several football fields. Workers in florescent green vests excavate the surrounding land, and a parade of construction trucks comes and goes. More than a dozen generators steadily burn methane gas. This part of Memphis, Tenn., is known for its factories and smokestacks. Nearby are a handful of historically Black neighborhoods, where poor air quality has given residents elevated asthma rates and lower life expectancy. Now, they have a new neighbor:…