Animal Waste, Water Quality and Human Health

172Animal Waste, Water Quality and Human HealthTable 5.6 (Continued)Indicator organismTreatment levels andspecific typesn c GeometricmeanBase-flow conditions High-flow conditionsLower 95%CIUpper 95%CIn c GeometricmeanLower 95%CIUpper 95%CIFAECAL COLIFORMSUntreated 252 1.7 × 10 7 *(+) 1.4 × 10 7 2.0 × 10 7 282 2.8 × 10 6 *(–) 2.3 × 10 6 3.2 × 10 6Crude sewage discharges d 252 1.7 × 10 7 *(+) 1.4 × 10 7 2.0 × 10 7 79 3.5 × 10 6 *(–) 2.6 × 10 6 4.7 × 10 6Storm sewage overflows d 203 2.5 × 10 6 2.0 × 10 6 2.9 × 10 6Primary 127 1.0 × 10 7 *(+) 8.4 × 10 6 1.3 × 10 7 14 4.6 × 10 6 *(–) 2.1 × 10 6 1.0 × 10 7Primary settled sewage 60 1.8 × 10 7 1.4 × 10 7 2.1 × 10 7 8 5.7 × 10 6 – –Stored settled sewage 25 5.6 × 10 6 3.2 × 10 6 9.7 × 10 6 1 8.0 × 10 5 – –Settled septic tank 42 7.2 × 10 6 4.4 × 10 6 1.1 × 10 7 5 4.8 × 10 6 – –Secondary 864 3.3 × 10 5 *(–) 2.9 × 10 5 3.7 × x10 5 184 5.0 × 10 5 *(+) 3.7 × 10 5 6.8 × 10 5Trickling filter 477 4.3 × 10 5 3.6 × 10 5 5.0 × 10 5 76 5.5 × 10 5 3.8 × 10 5 8.0 × 10 5Activated sludge 261 2.8 × 10 5 *(–) 2.2 × 10 5 3.5 × 10 5 93 5.1 × 10 5 *(+) 3.1 × 10 5 8.5 × 10 5Oxidation ditch 35 2.0 × 10 5 1.1 × 10 5 3.7 × 10 5 5 5.6 × 10 5 – –Trickling/sand filter 11 2.1 × 10 5 9.0 × 10 4 6.0 × 10 5 8 1.3 × 10 5 – –Rotating biological 80 1.6 × 10 5 1.1 × 10 5 2.3 × 10 5 2 6.7 × 10 5 – –contactorTertiary 179 1.3 × 10 3 7.5 × 10 2 2.2 × 10 3 8 9.1 × 10 2 – –Reedbed/grass plot e 71 1.3 × 10 4 5.4 × 10 3 3.4 × 10 4 2 1.5 × 10 4 – –Ultraviolet disinfection e 108 2.8 × 10 2 1.7 × 10 2 4.4 × 10 2 6 3.6 × 10 2 – –ENTEROCOCCIUntreated 254 1.9 × 10 6 *(+) 1.6 × 10 6 2.3 × 10 6 280 4.9 × 10 5 *(–) 4.2 × 10 5 5.6 × 10 5Crude sewage discharges d 254 1.9 × 10 6 *(+) 1.6 × 10 6 2.3 × 10 6 79 8.9 × 10 5 *(–) 6.7 × 10 5 1.2 × 10 6Storm sewage overflows d 201 3.8 × 10 5 3.2 × 10 5 4.5 × 10 5Primary 128 1.3 × 10 6 1.1 × 10 6 1.7 × 10 6 14 9.8 × 10 5 4.4 × 10 5 2.2 × 10 6