Orange County Sanitation District

The Orange County Sanitation District (OCSD) is a wastewater treatment facility that serves Orange County, California. It consists of two operating plants, referred to as Plant No. 1 located in Fountain Valley and Plant No. 2 located in Huntington Beach. It is the third largest wastewater treatment facility west of the Mississippi River. Orange County Sanitation District is commonly referred to as OCSD, though not to be confused with Orange County Sheriff's Department that shares the same acronym.^[1]

History

In 1954 County Sanitation District of Orange County began operating and took over the duties of the Orange County Joint Outfall Sewer (JOS), which was the sewage outfall system that extended into the Pacific Ocean. The name was changed from County Sanitation District of Orange County to Orange County Sanitation District or OCSD in 1998.

Facilities

Plant No. 2

At Plant No. 2 there are several facilities that operate to treat wastewater and dispose of solids.

Trunklines

Wastewater enters into Plant No. 2 via five trunklines: Miller-Holder, Bushard, Coast, Districts 5 and 6, and Interplant. Once inside Plant No. 2, the flow is measured in each of the trunklines via venturi flow meters.

Headworks

The trunklines connect into a common discharge channel located at the Headworks C facility. The wastewater flows through five operating bar screens, which scrape out large material, like rags and sanitary products, and drop the material onto a conveyor belt that transports it into a large metal bin. Once full, the bin is transported to an offsite facility for disposal. Once through the barscreens, main sewage pumps (commonly referred to as a MSP) located at the Headworks C and Headworks B facilities pump the wastewater into eight grit chambers. The grit chambers inject air through diffusers into the wastewater to freshen the water to decrease septicity and to help settle out grit material. The grit material is transported to an offsite facility for disposal. Grit material consisting of inorganics, like eggshells, corn, and sand and dirt, is removed from wastewater to prevent damage to pumps and disruption of other processes like sludge digestion by consuming unnecessary space. From the grit chambers, the wastewater flows into three splitter boxes where ferric chloride (FeCl₃) is injected into the wastewater to increase sludge settling in the primary clarifiers. Bleach (NaOCL) is also added into B and C splitter boxes for disinfection and to work with ferric chloride (FeCl₃) to assist in sludge settling. The splitter boxes are used to control the amount of flow, measured in millions of gallons per day (MGD) that flows into the three distribution boxes, which further separate wastewater for treatment in primary clarifiers.

Primary Clarifiers

Wastewater flows from the Headworks facility into three distribution boxes. The wastewater flows from each distribution box into designated primary clarifiers. The distribution of the wastewater is as follows: "A" distribution box dispenses water to D, E, F, and G primary clarifiers, "B" distribution box dispenses water to H, I, J, K, and L primary clarifiers, and "C" distribution box dispenses water to M, N, O, P, and Q primary clarifiers. This distinction between the different distribution boxes is important in the later processes of activated sludge wastewater treatment, disinfection, and outfall pumping.

References

1. ^ 1.Orange County Sanitation District About Us page

External links

• Orange County Sanitation District website