The Influence of Vegetation in Riparian Filterstrips on Coliform Bacteria: I. Movement and Survival in Water

Swine (Sus scrofa) wastewater was applied to three separate 4 m wide × 30 m long riparian filterstrips consisting of 20 m grass and 10 m forest, 10 m grass and 20 m forest, and 10 m grass and 20 m maidencane (Panicum hemitomon Schult.) in Southern Georgia during each season. Total and fecal coliform numbers in the applied wastewater pulse did not decline as water moved downslope regardless of vegetation type or season. The pulse of applied wastewater did not move beyond 15 m in any treatment in autumn or summer (dry seasons) and only moved beyond 7.5 m in the 20 m grass‐10 m forest treatment in the summer. Total and fecal coliform numbers in soil water and shallow ground water declined by approximately 10‐fold every 7 d for the first 14 d regardless of vegetative treatment or season. Soil temperature and soil moisture correlated with total coliform bacteria in both 1.5 m wells (r2 = 0.89) and 2.0 m wells (r2 = 0.89), and with fecal coliform bacteria in 1.5 (r2 = 0.82) and 2.0 m (r2 = 0.76) wells. Animal production operations may need to locate in warm‐dry climates so animal waste can be applied to lands to help ensure enteric bacteria input to surface and ground water will not occur.