Renovating Secondary Sewage By Ground Water Recharge With Infiltration Basins

A field project demonstrated the feasibility of renovating secondary sewage effluent by ground water recharge with infiltration basins. Maximum loading rates were obtained. With the schedules the system could infiltrate 300-400 ft/year using a water depth of 1 ft. Grassed basins had higher infiltration rates, and a gravel covered basin had a lower infiltration rate than a bare soil basin. Essentially complete removal of BOD and fecal coliform, and significant removal of phosphorus, nitrogen and fluoride were obtained. Hydraulic properties of the aquifer were evaluated by analog from the response of piezometric heads in the ground-water system to infiltration. These properties were then used in the design of a prototype system, which would yield renovated water at an estimated total cost of about $5 per acre-foot at the pump.