Nutrients in a Playa Wetland Receiving Wastewater

We determined nutrient sequestration differences in soil and vegetation within two regions of a playa wetland that receives agricultural runoff and secondarily treated wastewater. Playas are small, topographically closed, ephemeral wetlands that serve as catchments for surface runoff in the Southern High Plains of the USA. The wetland studied received natural runoff and secondarily treated wastewater from the U.S. Department of Energy, Pantex facility near Amarillo, TX. Soil and aboveground biomass N, P, Cu, and Fe and water N and P were evaluated seven times during a 2‐yr period in cattail (Typha domingensis Pers.) and pink smartweed [Persicaria pensylvanica (Raf.) Nieuw.] dominated regions of the playa. Spatial and temporal variabilities were observed in water, vegetation, and soil‐nutrient concentrations. These variabilities were likely due to fluctuation of water depth and quality in the playa. Water was deeper (P < 0.05) in the cattail region compared with the smartweed region. Water quality [Total Kjeldahl N (TKN) and total P (TP)] was not effected (P > 0.05) by vegetation type. Soil concentrations of TKN, TP, Cu, and Fe were not significantly different (P > 0.05) between cattail and smartweed vegetative types. Cattail had significantly greater (P < 0.05) levels of TKN, TP, Cu, and Fe than did smartweed. Aboveground biomass was greatest in August. Based on nutrient sequestration this playa wetland functioned quite well as a receptor for added nutrients from runoff and the wastewater treatment facility.