Municipalities in and upstream of the Delta increasingly use the estuary as a TOILET BOWL for their sewage discharges.

With each flush comes increased pollution, including toxic contaminants such as ammonia, heavy metals, and even pharmaceuticals. As population continues to increase in the region, so will wastewater discharges and their impacts on the estuary.


Consider the following:

  • There are at least 52 wastewater discharge sites in the Delta and an additional 25 stormwater discharge sites, each contributing to the pollution of the estuary.
  • The Sacramento region is a large polluter and each day discharges millions of gallons of partially treated sewage into the Delta. Contained in this wastewater are significant concentrations of ammonia. On a monthly basis, Sacramento adds high levels of ammonia to the Delta – far more than any other source. These discharges are believed to have a significant impact  on Delta Smelt and other threatened and endangered species.
  • In addition to Sacramento, another dozen municipalities each day flush millions of gallons of treated sewage directly into the heart of the Delta. These discharges have grown substantially over the past 30 years as populations have expanded.
  • The Stockton wastewater treatment plant has been repeatedly cited for illegal discharges of toxic contaminants. A recent lawsuit identifies over 1,500 sewage spills in Stockton over the past 5 years, endangering human health and the environment.
  • Millions of gallons of treated sewage is discharged each day by some 300 additional communities upstream of the Delta.
  • A 2008 investigation by the Associated Press revealed the presence of pharmaceuticals in the drinking water of major metropolitan areas. Scientific evidence suggests even small amounts of such substances – including estrogen, antibiotics and heart medications – may adversely affect habitat and fish species. A 2014 study detected concentrations of pharmaceuticals, including carbamazepine, fluoxetine, and trimethoprim, within the vicinity of the Sacramento Wastewater Treatment Plant in concentrations that could be chronic to aquatic organisms within the Delta.
  • As a result of Coalition efforts, Sacramento Regional Sanitation District is in the process of updating their wastewater treatment facilities.

Sources: Sacramento Bee, Associated Press

*Information related to the Major NPDES dischargers in the Sacramento/San Joaquin Delta Watershed was retrieved from the California Integrated Water Quality System Project (CIWQS) Regulated Facilities Report available on the website of the State Water Resources Control Board as well as the respective NPDES permits issued to each facility.