Works and Days


"sewage treatment"

Reed Winter Externship Reflections 14: Number twenty-seven, Sewerage Agency of Southern Marin, Kathleya Strode

Sewage treatment isn’t exactly what we would call a ‘sexy science’, but it is a job for a true environmentalist. I learned this when I spent about a week shadowing chemist Liz Falejczyk at the Sewerage Agency of Southern Marin (SASM) in the north San Francisco Bay area.

 I arrived on Sunday and drove with Liz to her home in Sonoma County, which is way north of Marin – as we drove, we passed the SASM building (which is just north of the Golden Gate Bridge) and a lot of gorgeous farmland. I took the opportunity of arriving on a non-working day to visit the Armstrong Redwoods State Natural Reserve and take a look at all of the gorgeous trees. I had never seen redwoods before, so it was a huge treat.

Monday morning we woke up early and arrived at the plant just in time to see the sun rise. I got a tour of the entire grounds, beginning where the sewage enters the plant in a room that is referred to as the headworks. Just as the sewage plant was built in the lowest area in the valley so that most of the pipes can flow with gravity, the headworks are underground in the lowest point of the plant. Sewage is then screened to remove plastic and other non-processable items and pumped through another room up to ground level.

Reed Winter Externship Reflections 14: Number twenty four, SASM, Ilana Novakoski

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.