Primer

Constructed Wetlands for Wastewater

Constructed wetlands, when used to treat wastewater, can keep nitrogen and phosphorous from the water supply and cut costs by controlling the size of drainfields.

Conventional septic systems collect wastewater in a septic tank, where organic solids settle out and anaerobic bacteria begin the process of biological decomposition. From there the wastewater is piped to a drainfield and released slowly into the soil, where aerobic bacteria continue to break down the remaining organic matter and pathogens. Conventional septic systems do not remove nitrogen and phosphorus, which fertilize bodies of water, causing algae blooms that deplete oxygen and kill aquatic life (a process known as eutrophication).

Published July 30, 2009