摘要:The purpose of this study was to determine whether the effluent of the Ash Flat Wastewater Treatment Plant changes the water quality or aquatic macroinvertebrate community structure of North Big Creek. Weekly water samples were analyzed for pH, N, P, COD, TSS and fecal coliform bacteria from 17 June to 19 August 1992. Aquatic macroinvertebrates were collected biweekly using a Turtox Indestructible™ Dip Net, and density indices were calculated. Station 1, above the effluent, was a spring habitat. Fecal coliform, N, P, TSS and COD values were higher at this station, while the aquatic macroinvertebrate community was relatively simple. The effluent impact upon Station 2 was most obvious from the persistent presence of foam and filamentous algae. Moderating water temperature and enhanced nutrient supply has resulted in a more complex aquatic macroinvertebrate community with a lower numerical standing crop.