Table 3:
Summary of sampling sites subject to E. coli advisory under the U.S. EPA Recreational Water Quality Criteria Beach Action Value (235 MPN/100mL) and comparison of respective somatic coliphage and enterococci concentrations.
Site | n | >235 MPN | % Advisories | Somatic (PFU) p-value | Total Coliphage (PFU) p-value | Enterococci (CFU) p-value | |
---|---|---|---|---|---|---|---|
Edgewater (ED) | Composite | 66 | 24 | 36.4 | 0.1034 | 0.1027 | 0.0002 |
Historic | 66 | 11 | 16.7 | 0.0084 | 0.0105 | <.0001 | |
River | 67 | 35 | 52.2 | < 0.0001 | < 0.0001 | <.0001 | |
Grant Park (GP) | Composite | 71 | 12 | 16.9 | 0.0129 | 0.0114 | <.0001 |
Historic | 70 | 9 | 12.9 | 0.0135 | 0.0158 | < 0.0001 | |
River | 70 | 65 | 92.9 | 0.1109 | 0.1100 | 0.0140 | |
Washington Park (WP) | Composite | 64 | 6 | 9.4 | 0.0070 | 0.0062 | 0.0041 |
Historic | 64 | 10 | 15.6 | 0.0965 | 0.4212 | 0.0259 | |
River | 63 | 58 | 92.1 | 0.0309 | 0.0277 | 0.0030 |
‘n’ refers to total number of samples. ‘> 235 MPN’ indicates number of samples with E. coli concentrations greater than the U.S. EPA Recreational Water Quality Criteria Beach Action Value (235 MPN/100mL). Bolded p-values indicate no significant difference (p > 0.05) between respective mean indicator concentrations.