The discharge happened sometime Saturday when the sewage was released from a manway, the Public Health Department announced in a news release.
The cause of the release is believed to be a sewer system blockage, but the origin of the obstruction has not been determined, according to the news release.
It is unclear how much of the sewage ended up in the creek.
The Public Health Department said the Regional Water Quality Control Board will have final say as to whether the discharge at CMC occurred legally.
The department said it was unlikely that the spill would be a serious concern to public health or safety, thanks in part to recent rainstorms.
“The sewage spill was responded to by CMC Correctional Wastewater Treatment Plant personnel who cleaned and sanitized the area and are determining the cause of the overflow,” the news release stated. Because of “current rain, the creek has abundant water flow.”
Public health officials are required by law to notify residents when hazardous substances or sewage enter the state’s waters “if it is necessary to safeguard public health and safety,” according to California Assembly Bill 800, which passed in 2007.
In December 2015, California Men’s Colony reported a sewage spill of about 72,000 gallons, though officials said it was not considered a public safety risk. At that time, 6,000 gallons of the spill ended up in the creek.
Mark Powell: 805-781-7915