Gary Wastewater System
WSN worked with the City of Gary, population 201, to find an affordable wastewater collection and treatment system. Gary sits on 12 feet of fine sand which lies on top of more than 200 feet of heavy clay. Located near a shoreline of ancient Lake Aggasiz, there is very little slope. Consequently, precipitation soaks into the sand layer and is trapped above the clay. During snowmelt, the water table is at or within one foot of the surface, causing drain fields to fail, and untreated wastewater flows on the surface to shallow ditches along the streets where it stays until it can soak in.
WSN prepared a Preliminary Engineering Report (PER), which examined three treatment options: aerobic treatment, constructed wetlands, and stabilization ponds. The City chose stabilization ponds and gravity sewers—a system in which the collected wastewater flows to a pump station located near the center of town where it then pumps to a two-cell stabilization pond system located ½ mile south and ½ mile east of Gary. The treated effluent is then discharged to County Ditch 75 and eventually flows into the Wild Rice River.