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 WASTEWATER TREATMENT


Introduction

The Goleta Sanitary District discharges treated wastewater in accordance with a National Pollutant Discharge Elimination System (NPDES) permit issued by the Central Coast Regional Water Quality Control Board (CCRWQCB). This permit consists of waste discharge requirements specifying the amount of wastewater that can be discharged, sampling frequency, the types of testing and monitoring and sets limits of pollutant concentrations.

The District is currently operating under a 301(h) wavier permit which is jointly issued by the U.S. EPA and the CCRWQCB. This specific permit is defined under the Clean Water Act and allows for a less than Full Secondary treated wastewater to be discharged to the ocean. In September of 2013, the Goleta Sanitary District completed a major up-grade of its treatment facility and is now a Full Secondary Treatment Plant. The District will submit an application for a new Full Secondary Discharge NPDES Permit in 2015 to match upgraded plant treatment capability.

NPDES Permit Application 2009

Through the secondary treatment process, the District produces a higher quality effluent that protects the environment and public health. This means cleaner and clearer water is being discharged to the ocean, and new air quality requirements are ensuring cleaner air.

Preliminary Treatment
The waste water treatment process begins with (2) Micro-Screen Units that remove large and small inorganic objects (Rags, Plastics, Wood, Paper, etc.) and then through (2) grit chambers with coarse air bubble diffusors that thin the water out, allowing small heavy inorganics such as (tar, eggshells, rocks, etc.) to drop out and be removed.

All this inorganic material cannot be treated and is taken to a landfill.

Primary Treatment
The primary treatment process is a physical process utilizing gravity to remove about 69% of the Organic 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 from the water.


Secondary Treatment
The secondary treatment process is a biological process that removes about 85% of secondary solids from the wastewater.

Primary treated wastewater is sent to the Secondary treatment process which begins with (2) Bio-Filters, here micro-organisms in the Bio-Filters literally consume the dissolved organic material in the wastewater. After Bio-filtration the water flows by gravity to the (3) Activated Sludge Basins where further biological activity take place and breaks down organic material which then proceeds to two of (4) Secondary Sedimentation Tanks where solids settle to bottom for removal. The Clear and Clean surface water flows over weirs as Secondary Treated Effluent.

Discharge
The Secondary treated wastewater then proceeds to the Chlorine Contact Channel where Sodium Hypochlorite (Chlorine Bleach) is added to disinfect it and kill any remaining bacteria.

The Wastewater is then de-chlorinated with Sodium Bi-Sulfite to protect the Ocean life, this wastewater is called the Final Effluent and it flows through a pipeline to one mile off-shore and safely 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 the wastewater during all the processes are treated so they can be reused as a soil amendment.

The Primary Solids are mixed with Secondary Solids that have been collected and thicken by (2) mechanical sludge thickeners and then are stabilized by treating them in (3) large heated Anaerobic Digesters Tanks for about 30-35days.

The Digested solids are then further treated in (2) Stabilization (Lagoons) Basins, from 6 months up to 2 years. These solids are then harvested out to drying beds where solids are dried in several stages to kill off any remaining bacteria. A portion of these digested solids is sent to (2) Mechanical Screw Presses where the solids are de-watered and then trucked off site for land application. The harvested solids product has a dark earthy color, is completely dry, nearly odorless, and is available free to the public as a useful soil amendment. PLEASE NOTE: the availability of free Class A Biosolids is subject to various environmental factors. Please call first to confirm if and when Biosolids will be available for pick-up.

Process Diagram
Click here for Maps and Flow Charts

 

Emergency Contact Information
For sewer spills or open man hole covers call 805.967.4519.
Board Meeting Information
The GSD Board of Directors meets the 1st and 3rd Monday of every month at 6:30 pm at the GSD Board Room at One William  Moffett Place.