The City of San Luis Obispo (City) is undertaking a series of upgrades to the Water Resource Recovery Facility (WRRF) located on Prado Road in San Luis Obispo. These upgrades, collectively referred to as the WRRF Project, represent a significant community investment and will help the City implement its long-term strategy for resource management.
The WRRF currently treats over three million gallons of wastewater per day. A portion of the treated water is recycled for irrigation use within the City and the remaining flow is discharged to San Luis Obispo Creek. San Luis Obispo Creek has been identified as having many beneficial uses that require protection by the Central Coast Water Board (CCWB). The City’s WRRF effluent meets the criteria for all of these uses except Municipal and Domestic Water Supply (MUN).
The MUN designation is the main driver for treatment upgrades at the WRRF. These new requirements have been placed in the WRRF’s recently revised National Pollutant Discharge Elimination System (NPDES) permit to meet nutrient and disinfection by-products limits. Compliance with the new limits is detailed through a Time Schedule Order (TSO) which requires the City to submit a time schedule outlining the planned actions for achieving compliance. A TSO was adopted with the WRRF’s permit and requires compliance by November 30, 2019.
The new permit limits are the primary reason for the WRRF Project. However, there are other drivers for the project including:
1. Future increases in flow in alignment with the City’s General Plan.
2. Ability to provide treatment to peak wet weather flows.
3. Addressing aging and out-of-date equipment and processes.
4. Incorporating features that embrace the value of the WRRF as a community asset.
5. Process redundancy to allow operational efficiency.
6. Odor control.
7. Maximizing recycled water production.