Fig. 1. Effects of water content and manure level on populations of Escherichia coli O157:H7 ATCC 43895, and indigenous generic E. coli and total coliforms in feedlot soils during storage at room temperature. Water content was maintained by daily addition of deionized distilled H₂O. The minimum detection level is marked by dashed lines and was 1.00 log₁₀ colony forming units (CFU) g^–1 of dry feedlot surface material (FSM). The standard errors of the least squares means were 0.15, 0.20, and 0.18 for E. coli O157:H7, generic E. coli, and total coliforms, respectively.