A total of 18 junior and senior Chester High School students from the AP environmental science class, along with their teacher Mrs. Ludington, visited the Chester Public Utility District (CPUD) lab and wastewater treatment plant and ponds Tuesday, March 6.
Upon arriving at the lab, CPUD Lead Supervisor Andy Capella gave an overview of the wastewater system, and introduced Clint Tissot, CPUD field supervisor, and Allan Homme, CPUD operator, to the students.
Tissot led the tour of the facility, explaining the route that wastewater takes once it leaves the home.
The first stop was the intake where the influent (dirty wastewater) comes into the treatment facility. After passing through a screening system, the wastewater goes into the first or second of six ponds at the wastewater plant.
It’s there where the wastewater starts the natural breakdown of the waste solids by bacteria.
After some time, the wastewater continues on to ponds 3, 4, 5 and 6.
The first four ponds act to break down the waste. The last two ponds are called the polishing ponds.
As the wastewater goes from pond to pond it becomes naturally “cleaner” and by the time it gets to pond six it is called “effluent” wastewater.
After the trip through the ponds the wastewater is sent through a serpentine tank, where chlorine is added to kill any remaining bacteria.
After traveling through the serpentine tank, sulfur dioxide is added to remove the chlorine.
Once the bacteria and chlorine are removed, the effluent flows through a “flume,” which measures the amount of the treated water before being released into nearby wetlands for disposal. Here it percolates into the ground or is evaporated. It takes approximately nine months from entering the treatment plant to arriving at the wetlands ponds.
The students seemed very interested in the process. They did not like the smell and several wondered if employees ever got used to it.
They asked many good questions about the treatment system. Some of the questions were about capacity and did the ponds ever overflow.
Tissot and Capella assured the students that the way the treatment plant and the ponds were set up that they would not overflow.
“There are alarms built into the system to notify us of any problems,” said Capella. “Measures can be taken to mitigate a large influx of wastewater.”
Even with all the tourists visiting in the summer, any potential problems are more likely to occur in the winter and spring, he said, when there is a big influx of rain and groundwater that enter the wastewater system.
Another question from a student was, “When the wind blows is that a problem blowing water over the edge of the ponds?”
Tissot replied that, “No, the wind is a big help. There is a lot more evaporation when the wind blows. This actually reduces the level in the ponds.”
The average amount of wastewater that enters the facility on a daily basis is about 100,000 gallons, Capella noted. That can rise to 500,000 gallons a day in the summer months.
Not all wastewater systems are alike, observed Capella. “We are very fortunate to have a simpler, natural system at CPUD.”
Becoming a wastewater/drinking water operator is a very good field to get into for any student interested in a career with CPUD or other wastewater facility, Capella added.