OPERATIONAL EVALUATION OF A PASSIVE BEEF CATTLE FEEDLOT RUNOFF CONTROL AND TREATMENT SYSTEM

Abstract

Nutrients from feedlot runoff can infiltrate beneath longterm storage ponds. Pond embankments wetting anddrying cycles facilitate infiltration paths as does weed growth that form roots channels. The research objectives were toconstruct and evaluate a passive runoff control system to reduce or eliminate longterm liquid storage. Runoff volumes,nutrient totals, and peak discharge were estimated using the Nutrient Fate Model for Beef Cattle Feedlots (Eigenberg et al.,1995). A vegetative filter strip was sized based on these estimated values. A flatbottom terrace was constructed to collectrunoff, provide temporary liquid storage, and accumulate settable solids, while distributing the nutrient laden liquid fractionuniformly across a vegetative filter strip. No runoff from the vegetative filter strip was recorded during the study period thatlasted from 1999 through 2001, indicating that the basin discharge was effectively utilized for grass production. The volumeof water remaining in the basin that was available for deep infiltration was greatly reduced when compared to traditionallongterm runoff storage systems. This reduction was evident as the solids storage system began to accumulate solids, therebyreducing the total liquid storage volume of the basin. The passive beef cattle feedlot runoff treatment system appeared to bean improvement to traditional storage systems.