Sludge Is Sent to Digesters where Bacteria “Digest” It and Make Methane

Sludge from the clarifiers is sent to cylindrical concrete buildings where it is “digested” by bacteria that came from our guts. We keep the digesters at 98 degrees Fahrenheit because the microorganisms work best at body temperature. You can think of a digester as a giant concrete gut. We use some of our reuse water to keep the digesters warm. First the reuse water picks up heat from our CoGen Power Plant Facility where it cools down the engines. Then that heated water is pumped to the digesters to keep them at body temperature.

As the bacteria eat in the digesters, they create methane gas. Orange pipes carry that methane gas to our Cogen power plant where we use it to make electricity. When the bacteria have eaten everything they die, and what is left is called biosolids. We send the biosolids to our Soil Amendment Facility.