The effects of vegetative filter strips on remediation of feedlot runoff

Feedlots are fenced areas of land that are highly concentrated with livestock. In the process of raising livestock, large volumes of animal waste are produced. Through the hydrologic cycle, this animal waste containing harmful substances can enter water sources as non-point source pollution.;The vegetative filter consists of a six by ten metre plot with a distribution pipe at the upper end and a collection trench at the lower end. Sixteen parameters (solids, nutrients and microorganisms) were tested at five different application rates through the VFS; a total of fifteen experiments were performed. Each of the five application rates was tested three times to ensure reproducibility.;Pollutant treatment efficiencies were highly affected by application rates. As the application rates decreased in general the mass of pollutants removed increased. As the application rate decreased the mass removal increased at a faster rate. The most effective removal also occurred at the lowest experimental application rate. At the lowest experimental application rates effluent was not reaching the collection trench.;The first tank applied to the VFS for each test run had the largest volume of wastewater removed by the VFS. Each additional tank added to the VFS resulted in deterioration of treatment efficiencies from the previous tank. The VFS became less effective as subsequent tanks were added. A two day rest period between tests appeared to provide the VFS sufficient time to recover.;A vegetative filter strip (VFS) was designed and constructed west of Innisfail, Alberta, Canada. The project was located at Little Red Feeders Ltd. This particular feedlot on average houses 3500 commercial head of cattle per year.;Weather conditions affected the amount of wastewater removed due to infiltration and evaportranspiration. It was noticed that higher temperatures correlated to greater test water removal.