Predicting the Quality of Cattle Feedlot Runoff and Holding Pond Contents

Abstract

ABSTRACT T is important to be able to predict the quality as well as the quantity of both feedlot runoff and retention basin contents if the wastewater is to be effectively utiliz-ed and if the pollution potential of various runoff control systems are to be evaluated. A procedure was devised to predict the quantity and quality of cattle feedlot runoff entering a runoff holding pond whenever precipitation occurs in excess of the sur-face holding capacity of the lot or whenever accumulated snow would melt. These predictions are based upon size and location of the feedlot, previous weather conditions, and daily climatic data. Runoff retention basin liquid content and quality are predicted on a daily basis which considers inputs and outputs as well as chemical and biological changes which are occurring on a continuous basis. The quality parameters which are predicted on a daily basis include: chemical oxygen demand (COD), total nitrogen (N), ammonia nitrogen (NH3-N), total phosphorous (P), total solids (TS), fixed dissolved solids (FDS), total coliforms (TC), fecal coliforms (FC) and fecal streptococcus (FS). A cattle feedlot in Illinois was sampled intensively to adjust the various coefficients of the predictive tool.