Shipped: July 12, 2021
W212 Preliminary results – Membrane Filtration
Sample Number Organism Total Colony Count - Group Means/Median (cfu/100mL)/MU%
Membrane Filtration Method
Total coliforms Thermotolerant coliforms E.coli
W212-1 Enterobacter spp. 58/55/18 0/0/0 0/0/0
W212-2 E.coli 56/60/18 54/54/19
54/58/21
W212-3 E.coli 33/33/17 35/33/17 32/32/17
W212-4 Enterobacter spp. 11/12/33 0/0/0 0/0/0
MU: measure of uncertainty
W212 Preliminary results – Enzyme Substrate
Sample Number Organism Total Colony Count - Group Means/Median (cfu/100mL)
Enzyme Substrate Method
Total coliforms Thermotolerant coliforms E.coli
W212-1 Enterobacter species 58/58 0/0 0/0
W212-2 E.coli 60/57 55/53 60/58*
W212-3 E.coli 39/38 39/38 40/40
W212-4 Enterobacter species 12/13 0/0 0/0
*outliers were not included in group mean/median/MU calculations
W212 Preliminary results – Most Probable Number (MPN)
Sample Number Organism Total Colony Count - Group Means/Median (cfu/100mL)
MPN Method
Total coliforms Thermotolerant coliforms E.coli
W212-1 Enterobacter species ≥23/≥23 0/0 0/0
W212-2 E.coli ≥23/≥23 ≥23/≥23
≥23/≥23
W212-3 E.coli ≥23/≥23 ≥23/≥23 ≥23/≥23
W212-4 Enterobacter species 9.4/9.2 0/0 0/0
W212 Preliminary results – Presence/Absence
Sample Number Organism Presence/Absence Method
Total coliforms Thermotolerant coliforms E.coli
W212-1 Enterobacter species Present Absent Absent
W212-2 E.coli Present Present Present
W212-3 E.coli Present Present Present
W212-4 Enterobacter species Present Absent Absent
H212 Preliminary results
Samples Organism Total Colony Count Group Means/Median MU%
H212-1 E.coli 186/191 18.5
H212-2 E.coli 196/197 15.7
H212-3 Blank *0/0 *0.0
H212-4 Enterobacter species *86/88 28.6
MU (%): Measurement Uncertainty in percentage outliers excluded in group means
*outliers were not included in group mean/median/MU calculations
ISO17043