Olivenhain Municipal Water District’s 4S Ranch Water Reclamation Facility Named as California’s Plant of the Year

Encinitas, CA—Today, Olivenhain Municipal Water District’s 4S Ranch Water Reclamation Facility was awarded California Water Environment Association’s statewide 2022 Plant of the Year Award at CWEA’s Annual Conference in San Diego. The award acknowledges the facility’s accomplishments to increase water supply reliability by reducing imported water demand and plant operations. In addition to the honors as California’s plant of the year, the facility received the same designation at the local level earlier this year from CWEA’s San Diego Section.

“OMWD is honored to be selected as the Plant of the Year by CWEA in the statewide competition,” said Board President Christy Guerin. “The 4S Ranch Water Reclamation Facility is celebrating its 20-year anniversary this year, and this award recognizes the plant’s long-standing contribution to the communities we serve by producing a drought-resilient, sustainable water supply.”

OMWD serves up to 15 percent of its overall demand from recycled water treated through its 4S Ranch facility and agreements with neighboring recycled water providers. As California’s water supply becomes more affected by unpredictable swings in weather, so does the need for innovative and diversified approaches to help reduce demand for valuable drinking water supply. OMWD provides and distributes recycled water for non-potable uses in portions of its service area for landscape irrigation at schools, parks, golf courses, streetscapes, and homeowner association common areas.

CWEA’s award program recognizes professional achievements within the wastewater industry and stimulates public awareness of the importance of wastewater treatment to public health and the environment. 4S WRF operators maintain over 85 miles of sewer collection system pipelines, lift stations, a 410-acre-foot storage pond, and a one-million-gallon reservoir to provide wastewater and recycled water services.

Founded in 1927, the California Water Environment Association is a not-for-profit association of 9,000-plus professionals in the wastewater industry. The association trains and certifies wastewater professionals, disseminates technical information, and promotes sound policies to benefit society through the protection and enhancement of our water environment. For more information, visit

OMWD receiving 2023 Plant of the Year from CWEA