The Department’s Wastewater Division collects, treats and disposes of all of the City’s sewage at the San Luis Rey Wastewater Treatment Plant and the La Salina Wastewater Treatment Plant. All sewage is treated to levels set by the Environmental Protection Agency. The San Luis Rey (SLR) plant, constructed in 1972, treats wastewater to the secondary level by conventional biological treatment flowed by clarification. SLR serves areas east of I-5, and treats sewage from the Rainbow MWD and a portion of the City of Vista. The La Salina plant was constructed in 1949 and treats sewage from areas west of I-5, downtown and along the coast. La Salina also treats waste to the secondary level by conventional biological treatment followed by clarification. Both plants discharge treated effluent through the Oceanside Ocean Outfall. Flows from Fallbrook Public Utilities District and Camp Pendleton are also discharged through the Oceanside Ocean Outfall.
The department also reclaims wastewater at the San Luis Rey Wastewater Treatment Plant and uses it to irrigate the Oceanside Municipal Golf Course.