The pipe system depends largely on gravity. A gentle slope in increasingly larger pipes moves wastewater to the plant. Tanker trucks bring septic wastes to the plant for treatment. Each day these two sources contribute 18 million gallons of wastewater to the plant, which also accommodates additional water during storms. The screened wastewater next enters grit tanks where sand and gravel are settled out and removed for hauling to landfill.
Sedimentation tanks allow lighter materials, such as grease, to float to the top and be skimmed off.
Heavier material, called primary sludge, falls to the bottom. Both are pumped to anerobic digesters. Here solids are digested in a biological process similar to food digestion in our stomachs. Digestion produces methane gas that is used to fuel engines that produce power and heat for the plant. After primary treatment, the wastewater proceeds to large, flow equalization basins.