Inventory of Municipal Wastewater Discharges to CA Coastal Waters (2018)


There is a significant source of water for up to 8 million Californians.

Heal the Ocean’s online interactive study, The Inventory of Municipal Wastewater Discharges to California Coastal Water Bodies, documents the 417 billion gallons of treated municipal wastewater discharged from treatment plants at fifty-seven locations directly into California coastal waters, including the Pacific Ocean and the San Francisco Bay, in the 2015 calendar year. Other than serving as a disposal method, direct municipal discharges to these coastal water bodies have no clear benefit to the environment or water supplies. If an aggressive 85% of 2015 municipal wastewater effluent from coastal treatment plants were recycled and used to offset or supplement drinking water supplies, 28.61% of urban water use in California’s coastal regions could have been supplied. If California had recycled 63.3% of total municipal wastewater flows to coastal waters in 2015, it would have made its 2020 recycled water production goal. Engineering feasibility and financial considerations will be significant factors in determining the viability of using existing coastal wastewater discharges for increasing recycled water production.