Urban Fish Ponds: Low-tech Sewage Treatment for Towns and Cities

In the mid 20th century, whole cities’ sewage systems safely and successfully used fish to treat and purify their water. Waste-fed fish ponds are a low-tech, cheap, and sustainable alternative to deal with our own shit — and to obtain high protein food in the process.

This entry originally appeared at solar.lowtechmagazine.com/2021/03/urban-fish-ponds-low-tech-sewage-treatment-for-towns-and-cities.html, and may be a summary or abridged version.