The Los Osos Wastewater System provides wastewater collection, treatment, and recycled water services to properties within the designated service area in the community of Los Osos. The service area generally encompasses the urbanized portions of Los Osos and is shown on the boundary map below. The dotted areas on the map designate exceptions from the zone - properties within these areas are not in the designated service area.
Property owners, developers, and other interested parties may use the boundary map or the GIS map to determine whether a property is located within the Los Osos Wastewater System service area. For questions regarding service availability, new sewer connections, or development requirements, please refer to our Will Serve Request page. If your property is within the boundary and needs a will serve without a permit number, please submit a request and we will evaluate if the property qualifies for a statement of eligibility.
Los Osos Wastewater System
Our mission is to protect public health and environmental resources by providing safe, reliable, and sustainable wastewater collection, treatment, and recycled water services to the Los Osos community. Through responsible stewardship, regulatory compliance, infrastructure investment, and exceptional customer service, the County is committed to maintaining a resilient wastewater system that serves the community today and into the future.

Sewer rates and charges support the ongoing operation, maintenance, and long-term sustainability of the Los Osos Wastewater System. The resources below provide information about current rates and charges, property tax billing, capacity fees, financial assistance, and available water conservation rebate programs.
For additional information about how Los Osos wastewater rates and charges are established and billed, please review the Los Osos Wastewater Finance FAQ.
- Current Rates and Charges Ordinance No. 3413
- Property Tax Billing Information
- View your property tax bill at San Luis Obispo County Tax Collector - Information Search
- Los Osos Capacity Fee Board of Supervisors Agenda Item
- Los Osos Low Income Financial Assistance Program
- Los Osos Water Conservation Rebate Program - Homeowner Installation
- Los Osos Water Conservation Rebate Program - Plumber Installation
The Los Osos Wastewater System produces high-quality recycled water for beneficial reuse within and adjacent to the community of Los Osos. The Recycled Water Program supports the sustainable management of local water resources by providing an alternative water supply for approved uses, including landscape irrigation, agricultural irrigation, and construction water.
Recycled water use is reviewed and approved by the County on a case-by-case basis to ensure compliance with applicable public health, water quality, and system requirements. Current and prospective recycled water users can find program requirements, approved uses, application information, and user responsibilities in the Rules and Regulations Governing the Distribution and Use of Recycled Water.
Los Osos Washout Station: The County is planning a new washout station at the Los Osos Water Recycling Facility for material collected during routine wastewater system maintenance. The facility will allow sewer cleaning trucks to unload and wash out on site, improving maintenance efficiency and reducing off-site hauling.
The Los Osos Water Recycling Facility was awarded the 2023 Small Plant of the Year by the California Water Environment Association (CWEA), recognizing the facility's achievements in regulatory compliance, innovative practices, cost effectiveness, and superior plant performance. The facility first received the Plant of the Year award from the CWEA Tri-Counties Section before advancing to the statewide competition, where it earned first place in the small plant category. This achievement reflects the dedication and expertise of Wastewater Utilities staff and their commitment to providing high-quality wastewater service to the Los Osos community.
Los Osos Water Recycling Facility wins the CWEA Tri-Counties Small Plant of the Year
In a community that might once have been considered highly contentious to their wastewater system, the Los Osos Water Recycling Facility is exceeding effluent discharge requirements and leveraging that effluent to reduce groundwater pumping, to slow saltwater intrusion, and reduce residual nitrates from past septic operations in the Los Osos groundwater basin. Dedicated staff focus Operations and Maintenance efforts on service to the community and long-term equipment reliability. There is a healthy sense of pride in the plant’s quality of operation and appearance. We are grateful for our staff that diligently work to provide wastewater service for our community.
Los Osos Staff with the CWEA Small Plant of the Year Trophy (Stephen, Marcus, Luis, Harbans, Eric, Sean L., Teddy, Greg,)
Los Osos Wastewater System continues to monitor COVID to gain community insights
Our team has recently partnered with the CDC NWSS Program managed by Biobot Analytics for COVID surveillance in wastewater systems. This free program will give the Los Osos Community valuable and actionable public health insights.
ARPA Funding for Los Osos Projects
The County received Federal funding through the American Rescue Plan Act (ARPA) to execute projects in the Public Works Department. Projects in Los Osos that are funded by ARPA include installing variable frequency drives (VFDs) at the Los Osos Water Recycling Facility (LOWRF), installing a flow meter at the Broderson Leach Field, procuring a vacuum truck and installing a washout facility, and installing a chlorine analyzer at the LOWRF. The VFDs will provide energy savings for the LOWRF by controlling the effluent pumps more efficiently. The flow meter at the Broderson Leach Field will improve the reporting accuracy and assist with optimizing the use of recycled water in the community. The vacuum truck and washout bins are critical pieces of infrastructure for the operations staff to maintain the Los Osos Wastewater System. The chlorine analyzer will allow the LOWRF to optimize the chlorine addition into the recycled water system to continue to protect the health and safety of the County’s recycled water customers.
Recycled Water Connections
The Los Osos Water Recycling Facility (LOWRF) produces recycled water that can be utilized within the Los Osos groundwater basin. The County provides recycled water to irrigation, agricultural, construction, and urban water users. Customers using recycled water consist of Sea Pines Golf Course, the Los Osos Valley Road median, and construction and agricultural users. The County is working with the San Luis Coastal Unified School District to develop an agreement for the schools to use recycled water for irrigation. The school sites would be Los Osos Middle School, Baywood Elementary School, Monarch Grove Elementary School, and at the Sunnyside Elementary site. The County is working internally to provide recycled water for the Los Osos Community Park to irrigation. Recycled water that is not used for irrigation is sent to the Broderson and Bayridge Leach Fields.