The latest updates from San Elijo JPA.
Reports Show Exceptional Water Treatment
March 14, 2023
The San Elijo JPA is treating wastewater to levels that far exceed requirements set by the state and federal government.
That is the finding of summary reports for a five-year period presented recently to San Elijo JPA’s Board of Directors.
One report, which presents data from ocean effluent sampling in the fall of 2022, identifies San Elijo JPA’s “exceptional water treatment” as shown by two key indicators: Carbonaceous Biochemical Oxygen Demand (CBOD) and Total Suspended Solids (TSS).
CBOD is a kind of test that measures the amount of oxygen that will be consumed by the decomposition of organic matter in sewage; TSS refers to waterborne particles greater than two microns in size.
State and federal regulations require a minimum of 85% removal of CBOD and TSS. San Elijo JPA data shows treatment levels at 98.8% and 99.3%, respectively. Data in a 13-month snapshot show similarly-high levels of treatment month-to-month since September 2021.
About 70 percent of the influent wastewater that arrives to San Elijo JPA’s water campus was recycled for industrial and irrigation uses in 2022.
A second study analyzes discharges from San Elijo JPA’s 8,000-foot-long ocean outfall off of Cardiff State Beach.
Prepared by Michael Baker International, the Plume Tracking Field and Model Analysis employed boat-based sensors and automated underwater vehicles to gather data from nearly 1,000 acres of ocean surrounding the outfall.
The report concluded that San Elijo JPA’s “diffuser system is very effective in mixing the discharge water with ambient ocean water.”
“The San Elijo Ocean Outfall discharge,” the report states, “has no potential to impact water quality in nearshore and surf zone waters.”