Sewage farm

Suspended solids may be converted to humus by microbes and bacteria in order to supply nitrogen, phosphorus and other plant nutrients for crop growth.

Some of the nutrients and organic solids in wastewater can be usefully incorporated into soil and agricultural products rather than fouling natural aquatic environments.

[1] Polluted runoff may occur from sewage irrigation of fields when entering wastewater and precipitation exceed evaporation and percolation capacity.

[2] Sewage is usually generated at a relatively constant rate, but irrigation is required only during dry weather, and is useful only while temperatures are high enough to promote plant growth.

During the Middle Ages this was accomplished with hand-carried buckets, but as local populations grew, during the Industrial Revolution sanitary sewer systems were built.

[5][failed verification] In Wales, it was the common means of sewage treatment when cess-pits became unusable as the population grew in towns during the industrial revolution.