I enjoyed learning about the workings of a sewage treatment plant. When I arrived, I was given a tour of the facility. First I saw the wet wells, where the raw sewage initially enters the plant. From there, the water travels through deep tanks where the solid waste can settle out. The water then trickles through giant towers where bacteria, grown on honeycomb-shaped sheets of plastic, break down dissolved towers. Not all sewage plants operate with the exact same format; during my time with SASM, I toured four treatment plant facilities. The plant in San Francisco was partially under the zoo. It also had facilities to treat its own odor. Another treatment plant was stacked on top of itself so that it took up as little space as possible. I watched the lab technician sample the effluent and observed the different tests run on the effluent to make sure it was fit to release into the bay. I also learned about the problem of leaking pipes and how the administration decides whose job it is to fix the various sewer lines. Finally, I shadowed an inspector as she looked at the grease traps of restaurants and commercial kitchens.