Wastewater is simply water that runs down the drain from your sink, shower, washing machine or dishwasher, or water that flushes down your toilet. After this water leaves your home, it must be treated before it can be safely discharged into the ocean. SOCWA treats all of South Orange County’s wastewater at its four treatment facilities, using an advanced process that protects public health and respects the environment.

Cleaning your wastewater is a three-step process, with an additional fourth step when recycling the water for irrigation and industrial uses:

Step 1: Preliminary Treatment
Before the wastewater is treated, we first must remove large solids and grit by running it through fine screens. The debris accumulated on the screens is removed for disposal, either to a landfill or incinerator.

Step 2: Primary Treatment
To begin treating the wastewater, it is first pumped into settling basins where any remaining smaller particles, such as sand or coffee grounds, are allowed to settle to the bottom and are removed. After settling, the water enters the heart of the treatment process: biological nutrient removal, also known as the activated sludge process. Here, nature’s process of breaking down organic materials is accelerated.
The activated sludge process is a biological treatment where microorganisms are used to consume bacteria and other organic material left in the water. Oxygen is pumped into the tanks to help support the process. A clarifier then separates the suspended solids from the treated wastewater, and the microorganisms are recycled back through the system to treat additional wastewater. The water is now safe to send to the ocean, but SOCWA goes further to better protect public health.

Step 3: Secondary Treatment
After the water goes through primary treatment it is pumped into a secondary clarification tank. Here the water sits for about two hours, allowing more of the solids to settle out. The water is now about 90 percent clean and called “secondary effluent.” SOCWA sends approximately 36 percent of South Orange County’s wastewater to the ocean following secondary treatment, through its two outfall pipes several miles off shore.

Step 4: Tertiary Treatment
The remaining wastewater goes through an additional step of treatment to make it ready for irrigation and other commercial uses as recycled water. The water is first filtered through layers of coal and sand, which mimics nature’s filtration of water as it percolates into underground aquifers. At this point, the water is 99 percent clean and crystal clear. The water is then disinfected to remove any bacteria or viruses that may still exist, and is treated to correct any pH imbalances. Now the water is ready to be sent through purple pipes to parks, greenbelts and commercial facilities throughout South Orange County.

View Treatment Process