Orange County Coastkeeper celebrates judgment ruling for water quality improvements in Santa Ana River

Orange County Coastkeeper celebrates a recent court ruling to protect the community and native species from stormwater pollution flowing from Corona Clay Company into Temescal Creek, which drains to the Santa Ana River – Southern California’s largest river. The company based in Corona, CA manufactures clay materials for use in athletic tracks, infields, tennis courts and mud baths. This fine sediment of clay was found to flow into the Temescal Creek with high levels of metal, coating the bottom of the bank and causing harm to aquatic life in the area.

The judge issued the clay manufacturer a civil penalty of $3.7 million for its violation of the Clean Water Act and its lack of proper management of its industrial stormwater permit. This is among the largest of civil penalties in the history of California’s Industrial Storm Water Permit implementing the Clean Water Act.

When it rains in Riverside County, stormwater containing sediments and metals flows from the clay manufacturing facility into the Temescal Creek causing harm to local aquatic life including threatened and endangered species. With this judgment, Coastkeeper expects the Corona Clay Company to improve their best management practices necessary to prevent polluted stormwater from entering the creek, which would improve water quality for local aquatic life and residents.


  • 2017: Inland Empire Waterkeeper sent a letter to Corona Clay, the EPA and the state of California informing that Corona Clay routinely violated the Clean Water Act
  • 2018: Waterkeeper sued with evidence gathered by state regulators, Corona Clay’s own records, and with a team of Waterkeeper investigators
  • 2019: U.S. District Court Judge, David O. Carter affirmed Waterkeeper’s allegations and held Corona Clay’s stormwater best management practices and stormwater pollution prevention plan violated the Clean Water Act
  • 2020: Judge Carter issued a final judgment resolving the case, ordering Corona Clay to implement pollution controls necessary to comply with the Clean Water Act, revise their stormwater pollution prevention plan, and pay $3.7 million in penalties to the U.S Treasury

This article was released by Orange County Coastkeeper.