From the Proceedings of the 1972 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 5-6, 1972, Prescott, Arizona / Sewage effluent for irrigation is well established. This study determines the capacity of selective turfgrass-soil systems to purify municipal sewage effluent and to measure the degree of utilization of nitrogen in the effluent by turfgrass. Chlorinated secondarily treated sewage effluent from the city of Tucson was applied to turfgrass grown on sandy loam, silt and loam, under three levels of irrigation under laboratory conditions of duplicate pots. Each pot had 2 suction probes to estimate soil moisture tensions and to allow soil water sampling. The study operated from September to March, 1972, for 30 weeks. Purification efficiency, nitrogen utilization and percent recharge were calculated. Turfgrass can be irrigated with sewage effluent at common rates without hazard of nitrogen pollution to groundwater. Purification efficiency exceeded 90 percent for all irrigation levels on sandy loam and silt. Nitrogen utilization was greater over sandy loam. Turfgrass-soil systems can utilize nitrogen and purify waste water.

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / This study investigated the potential of a soil-turf filter to renovate secondary effluent applied in excess of consumptive use. Lysimeter plots were filled with a sand and a sand mix, and seeded to winter ryegrass. In spring, plots were scalped and seeded to bermudagrass. Plots were drip irrigated twice a week with secondary effluent at rates of 10, 17, 22, 34, and 43 mm/day. Leachate and effluent were analyzed for NH -N, NO,-N, and organic-N. Grass clippings were oven dried, weighed, and analyzed for organic -N. Percent of leachate available for groundwater recharge was 50% at the lowest rate and 68% at the highest rate when values were averaged for both soils. The amount of nitrogen removed by the soil-turf filter using sand was 42 to 87% and 52 to 90% on the mix, decreasing as application rate increased. The highest nitrogen removal and utilization occurred at the lowest application rate. Turf utilization of nitrogen was 10 to 28% on sand and 18 to 36% on mix, decreasing as rate of application increased. The sand-turf filter renovated 22 mm/day and the mix-turf filter renovated 43 mm/day, yielding leachate averaging less than 10 ppm NO₃-N.