The Olivenhain Municipal Water District’s 4S Ranch Water Reclamation Facility (4S WRF) was named the statewide 2024 Plant of the Year (small division) by the California Water Environment Association at its recent annual conference in San Diego. The award recognizes the facility’s innovation, regulatory compliance, and cost-effective operation.

In addition to being named California’s plant of the year, the facility received the same designation at the local level in February from CWEA’s San Diego Section.

The 4S Ranch Water Reclamation Facility is a repeat winner, winning this statewide recognition as Plant of the Year five times since 2019.

“There are over a thousand wastewater treatment plants in California, and our district is honored to have 4S WRF named as CWEA’s Plant of the Year at the state level for the second time in three years,” said Matthew R. Hahn, OMWD board president.

CWEA president Gilbert Barela (far right) presents the award to Olivenhain Municipal Water District employees John Onkka, recycled water program supervisor, and Jason Emerick, water reclamation operator. Photo: Olivenhain Municipal Water District

“The successful operation of the 4S WRF is a direct result of the support and collaboration across all areas of the District, including the Board of Directors, senior management, the 4S WRF operators, and all OMWD departments,” said John Onkka, recycled water program supervisor at the 4S Water Reclamation Facility.

Innovation Drives High Quality, Saves Treatment Costs for Ratepayers

Innovative practices at 4S WRF over the past several years include the installation of monitoring equipment that makes immediate adjustments in the treatment process, which stood out to the CWEA judges. The equipment not only keeps the facility in regulatory compliance but also reduces treatment costs for ratepayers. In addition, to obtain higher water quality and reduce energy costs, OMWD installed a more efficient ultraviolet disinfection system.

OMWD meets up to 15 percent of its overall demand with recycled water. 4S WRF can transform up to two million gallons of wastewater to recycled water each day. This alternative water supply reduces the use of drinking water for the irrigation of golf courses, parks, schools, streetscapes, and homeowner association common areas.

OMWD Expands Access to Recycled Water in 2025

Construction is nearly complete at three sites in the cities of Encinitas and Carlsbad to install 5,600 feet of new recycled water pipelines. Photo: Olivenhain Municipal Water District

Currently, OMWD is expanding access to its recycled water by identifying opportunities to connect more customers to its recycled water distribution system.

Construction is nearly complete at three sites in the cities of Encinitas and Carlsbad to install 5,600 feet of new recycled water pipelines. The completion of the pipeline extensions later this year will result in the conversion of 28 water meters from potable to recycled water, saving more than 12.5 million gallons of imported drinking water annually.

Founded in 1928, the California Water Environment Association is a not-for-profit association of 10,000-plus wastewater industry professionals. The association trains and certifies wastewater professionals, disseminates technical information, and promotes safe and effective work practices.