Introduction
Goleta Sanitary District uses what is called a blended secondary treatment process. It maintains the environment in a clean and healthful condition. It also requires a less costly facility, is more economical to operate, and produces less land and air pollution than the full secondary process.
Preliminary Treatment
The Treatment process begins with mechanical bar screens which remove large objects, dirt and grit.
Primary Treatment
The Primary Treatment process removes about 50% of the solids from the wastewater.
Our Primary Treatment process consists of the screened sedimentation tanks where solids that settle to the bottom or float to the top are collected and removed.
Secondary Treatment
The Secondary Treatment process removes about 85% of the solids.
A portion of the primary treated wastewater is sent to the Secondary Treatment process, which begins in the bio-filter. Here microorganisms literally consume the dissolved organic material in the wastewater. After bio-filtration, the water flows by gravity to another sedimentation tank where biological action causes solids to clump together and settle to the bottom of the tank for removal. The clear and clean surface water is secondary effluent.
Blending and Discharge
Goleta Sanitary District blends Primary and Secondary treated water for safe discharge to the ocean.
Primary and Secondary treated wastewater are first blended, and then chlorine is added to disinfect it and kill any remaining bacteria. The wastewater is then de-chlorinated to protect ocean life, is transported through a pipeline a mile out to sea, and safely discharged into the ocean environment.
Water Recycling
Our Tertiary Treatment creates super-clean recycled water that meets stringent quality requirements.
Recycled wastewater is produced by treating secondary effluent to the tertiary level. Secondary treated water is mixed with special chemicals that cause remaining particles to clump together. It is then filtered with carbon, and finally disinfected with chlorine to kill bacteria. Recycled water is used for irrigation, saving precious drinking water.
Bio-Solids Treatment
The solids removed from wastewater are treated so they can be safely reused as a soil amendment.
The solids from the wastewater treatment process are stabilized by treating them in a heated anaerobic digester for about six weeks. The stabilized solids are then treated in settling basins over a two-year period. Solids are dried in several stages to kill off any remaining bacteria. The end product has a dark, earthy color, is completely dry, nearly odorless and is available free to the public as a useful soil amendment.