AWWA REUSE52089

The city of Yelm is located 65 miles south of Seattle, in the shadow of magnificent Mount Rainier. The prairie soils in Yelm are very porous and the groundwater table is quite shallow. Yelm draws its drinking water from this shallow aquifer. In the mid-l980s, routine testing revealed that nitrate levels were rising in the drinking water. Studies indicated the nitrates were coming from high densities of septic tank leach fields; the soil structure simply could not keep up with the densities, and it was no longer providing adequate treatment prior to the effluent reaching the groundwater. As an immediate fix, the City constructed a new Septic Tank Effluent Pump system and aerated lagoon treatment facility that discharged to the Nisqually River. In an effort to protect this pristine river, the City explored ways in which to stop discharging wastewater into the river. This paper describes Yelm's solution to this problem which includes a reclaimed water wetland park, a state-of-the-art treatment facility and a reclaimed water distribution system.