Increasing attention has been given in recent years to the use of reclaimed municipal wastewater for groundwater recharge. What may look like sewage to flush away to a layperson is, to the eyes of a resource manager, water to treat and conserve.
Recycled water is municipal wastewater which, as a result of specified treatment, is suitable for beneficial use. Currently approved uses of recycled water in California include non-potable uses, such as irrigation of turf and landscaping, agricultural uses, dust control and industrial cooling. Recycled water that has received additional treatment can be used to recharge groundwater aquifers and to prevent seawater intrusion into underground drinking supplies.
In the near future, the State Water Board will develop regulations to authorize the addition of highly treated recycled water to drinking water reservoirs.
Municipal Recycled Water: Resource Management StrategyCWP-RMS-Ch-11-Municpal_Recycled_Water_July2016
Issue Brief: Water Reuse Potential in California
From the NRDC and the Pacific Institute:
There is tremendous opportunity to expand water reuse in California. In most urban areas, water is used once, treated, and disposed of as waste. Reuse provides a reliable, local water supply that reduces vulnerability to droughts and other water-supply constraints. It can also provide economic and environmental benefits, for example, by reducing energy use, diversions from rivers and streams, and pollution from wastewater discharges.
Some progress is being made. An estimated 670,000 acre-feet of municipal wastewater is already beneficially reused in the state each year (SWRCB and DWR 2012). Onsite reuse—including the use of graywater—is also practiced in communities across California, although data are not available to estimate these volumes. More can and should be done.