Located in Monterey, Monterey One Water is the public wastewater treatment agency for northern Monterey County. The Agency receives wastewater from the following: areas: Boronda County Sanitation District, Castroville Community Services District, Del Rey Oaks, Marina Coast Water District, Monterey, Pacific Grove, Salinas, Sand City, Seaside, and the unincorporated sections of Monterey County. Each member entity governs the Agency through a Joint Powers Authority.
Monterey One Water (M1W)
Process Description:
Primary Treatment:
Solids Handling:
Secondary Treatment:
Tertiary Treatment:
Advanced Water Purification Facility:
“Over the past three years, Monterey One Water (M1W) has demonstrated environmental compliance, operational innovation, management efficiency, and cost-effective performance at the Regional Treatment Plant (RTP), the Salinas Valley Reclamation Project (SVRP), and the PureWater Monterey facility (AWPF). Through process control, maintenance, and a safety and quality culture, M1W has delivered reliable wastewater treatment, tertiary treatment, and advanced purification that safeguard the environment.”
Recent Improvements: Pure Water Monterey Expansion (2023–2025) A $16.4 million project adding new MF/RO trains, UV-AOP reactors, and ozone liquid-air separators delivered ahead of schedule and under budget, expanding potable reuse capacity to more than 4,000 acre-feet per year. Co-Digestion and Renewable Energy Integration: The new Food Waste Receiving Facility and digester mixer project enhances biogas production and offsets natural gas consumption, advancing toward carbon neutrality.
Other notable achievements include innovation drives that support M1W’s operational excellence. These include advanced automation and SCADA redundancy, plant-wide PLC and RIO modernization, improved reliability, and shorter response times. Thin-client terminals now provide operators with secure access across facilities. SENTRY microbial monitoring was installed in the trickling filter and biofloc systems to provide real-time data on microbial activity.
M1W distinguishes itself through industry-leading innovation in process optimization, renewable energy, and integrated water management. The Organics Polishing Station and Digester Mixer Modernization Project expanded co-digestion and biogas recovery, providing up to 80% of plant energy through cogeneration while diverting organics from landfills. Upgraded PLCs, SCADA visualization, and thin client automation enhanced operational reliability, while the Pure Water Monterey Advanced Water Purification Facility set a statewide benchmark for indirect potable reuse using microfiltration, reverse osmosis, UV/AOP, and stabilization. Laboratory collaboration with Operations and Source Control ensures rapid detection of anomalies from events such as the Salinas Industrial Wastewater release, which are translated into process and communication improvements. Through technological advancements, renewable energy generation, and strong cross-department coordination, M1W continues to lead the industry in sustainability, operational efficiency, and environmental stewardship.
CWEA is now accepting nominations for the 2026–27 Awards Program. Nominate an outstanding agency, project, team, or wastewater professional whose work deserves statewide recognition.
All nominees must be CWEA members. Some award categories begin at the Local Section level, so check with your Section for its nomination deadline and eligibility requirements.
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