Lateral and vertical movement of water, nutrients, fecal coliforms, and somatic coliphages in soils dosed with wastewater by point and drip application methods

Point and drip application methods are being used to disperse sewage effluent. The objective was to compare the lateral and vertical movement of water, NH4-N, NO3-N, Kelowna-P, fecal coliforms (FC) and somatic coliphages (SC) in packed soil columns and in a field soil. Soil columns were dosed (once/day) for 60 and 90 days with diluted primary effluent (DPE) from Goldbar wastewater treatment plant. The point method created transient saturated flow but the drip method created transient unsaturated flow. FC only moved to a depth of 75 cm over 90 days but SC and nutrients were detected in soil leachates. DPE, with Brilliant Blue dye, was applied to field microplots (once/day) for 15 days. Wastewater was more evenly distributed in soil by drip versus point method. This also attenuated both organisms. The drip method provided a more effective treatment of wastewater than the point method. These methods need further field testing.