How Does the City Clean the Facility that Cleans Wastewater?
It’s summertime at the Water Resource Recovery Facility (WRRF) and that means a lot of cleaning!
Each summer, when Cal Poly students leave the area, the influent flow at the WRRF drops one third on normal flows.
These low flows allow the WRRF to operate at half capacity, taking the redundant processes offline for cleaning and inspection. The operations and maintenance staff takes advantage of this unique opportunity to empty one of the primary clarifiers, an aeration basin, and one of the final clarifiers. Once empty and clean, they will inspect the infrastructure and make the necessary repairs.
After the first tanks are clean and ready to put back in service, the operators will take the other half offline for its cleaning and inspection. Depending on the influent flows, half of the processes may remain offline until heavy rainfall in fall.
Summertime is an exciting and busy time at the WRRF and a great opportunity to see what the tanks look like when they are empty. Come down for a tour to check it out!
The top picutre shows a Primary Clarifier that is online, the picture on the bottom is what they look like when empty. The WRRF has two Primary Clairifiers.
These are Aeration Basins, one the top is a full basin and the bottom picture is a basin that has been drained. They are 18 feet deep and have aeration headers at the bottom to aerate the water as it passes through.
Here are Final Clarifiers. The top is a Final Clarifier that is working and the bottom picture is a Final Clarifier that is offline for summertime cleaning.