Every day each one of us turns 100 gallons or so of water into sewage. That’s a lot of sewage, requiring a lot of treatment–and very little of it is poop.
“We’re like a nation of 1-year-olds throwing everything in the toilet.”
Scientific American offers a relaxed ten page synopsis on sewers, How Does Sewage Treatment Work?
By 1500 BC the palace of Knossos had an actual flush toilet–a seat, a pan, and a slave to pour water into a sluice.
Cesspits and privies were so offensive, in 1844 Boston tried to pass a law requiring a doctor’s order for every bath.
Most blockages are caused by grease or roots, but memorable clogs are mops, golf clubs or firewood pulled out of manholes. A refrigerator. Once a carpet remnant…
The system is not flawless–biosolids sometimes contaminate water; grease clogs cause sewage spills or system failures; heavy metals, pharmaceuticals, and personal care products build up in biosolids–but overall it works splendidly.
“It gets in your blood,” said a senior engineer and inspector… the rest of the way gravity does the work.