Ja. Entry et al., The influence of vegetation in riparian filterstrips on coliform bacteria:I. Movement and survival in water, J ENVIR Q, 29(4), 2000, pp. 1206-1214
Swine (Sus scrofa) wastewater was applied to three separate 4 m wide x 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 ttl m maidencane (Panicum hemitom
on Schult,) in Southern Georgia during each season. Total and fecal colifor
m numbers in the applied wastewater pulse did not decline as water moved do
wnslope regardless of vegetation type or season. The pulse of applied waste
water did not move beyond 15 m in any treatment in autumn or summer (dry se
asons) and only moved beyond 7.5 m in the 20 m grass-10 m forest treatment
in the summer. Total and fetal coliform numbers in soil water and shallow g
round water declined by approximately 10-Fold every 7 d for the First 14 d
regardless of vegetative treatment or season. Soil temperature and soil moi
sture correlated with total coliform bacteria in both 1.5 m wells (r(2) = 0
.89) and 2.0 m wells (r(2) = 0.89), and with fecal coliform bacteria in 1.5
(r(2) = 0.82) and 2.0 m (r(2) = 0.76) wells. Animal production operations
may need to locate in warm-dry climates so animal waste can be applied to l
ands to help ensure enteric bacteria input to surface and ground water will
not occur.