Wastewater

What is wastewater?

Wastewater (or sewage) can be thought of as "used" water. Most of this water is made up of water that has been used in sinks, showers, bathtubs, toilets, washing machines, and dishwashers before entering the SMWD sewer system. 

What can I flush or pour down the drain?

Many people utilize their toilets and sinks as a trash can. Medication, sanitary products, wipes, and oils are often flushed/poured down the drain which can cause pipes within your own home to clog. If this issue is multiplied by the 160,000+ customers that SMWD services, it is easy to see how this can cause major plumbing issues. Visit this site to learn additional info on what to flush.

Why treat wastewater?

SMWD is responsible for treating the wastewater of 160,000+ residents in order to protect public health and the environment. If the wastewater were to be discharged directly into the ocean, there could be significant negative impacts to both humans as well as the natural environment.

How do we collect wastewater?

SMWD's collection system is comprised of more than 600 miles of pipeline ranging from 8 to 30 inches. The sewer collection system was designed to utilize gravity as much as possible in order to reduce pumping costs. However in order to move the wastewater over the hills and valleys that are scattered throughout the service area, lift stations are required to pump it to a point where it flow via gravity. The final destination of the collected wastewater is a wastewater reclamation plant. The majority of Mission Viejo's flow goes to the Oso Creek Water Reclamation Plant or the 3A Water Reclamation Plant. The remaining portion of Mission Viejo, Rancho Santa Margarita, Coto de Caza, Talega, Ladera Ranch, Wagon Wheel, and Rancho Mission Viejo flow to the Chiquita Water Reclamation Plant for treatment.

In order to keep these pipelines free of obstructions and flowing, SMWD crews are constantly cleaning and checking the sewer lines for blockages. This YouTube video shows how the City of Los Angeles keeps their lines clean which is similar to SMWD does.  

How is wastewater treated?

The typical wastewater treatment process that SMWD follows is a four-step process. The first stage is Preliminary Treatment where items like rags, sticks, sand, gravel, eggshells, and other foreign objects are removed in order to prevent them from damaging equipment in the treatment process. Next, the wastewater undergoes Primary Treatment. This stage slows down the water so that heavier materials sink to the bottom and lighter materials rise to the top. These materials are removed from the wastewater and disposed of while the wastewater moves on to the next process. The Secondary Treatment process is a biological process where microorganisms feed on the organic solids in the wastewater. After the Secondary Treatment process, the wastewater is legally treated and can be discharged to the ocean. However, SMWD has a substantial recycled water distribution system that can utilize this treated wastewater if it's treated through a Tertiary Treatment process. This process further filters the wastewater and adds chlorine as a disinfectant. This water is known as recycled water and utilized to irrigate parks, golf courses, and medians throughout the District service area.

Wastewater, By the numbers

The District's Wastewater System:

  • 56,000 connections
  • Avg flows of 9 million gallons per day
  • 630+ miles of collections pipeline
  • 21 lift stations
  • Operate 3 water reclamation plants that produce recycled water