Table 1.
Average concentration of total enterococci and vancomycin-resistant enterococci (VRE) by wastewater treatment plant and treatment step across all sample collection dates.
| Total Enterococci (CFU/100 mls) | VRE (CFU/100 mls) | Percentage of VRE | |
|---|---|---|---|
| Mid-Atlantic WWTP1 | |||
| Influent (n=3) | 7.17×106 | 1.93×104 | 0.3 |
| Activated Sludge Reactor (n=3) | 4.64×105 | 1.89×105 | 40.7 |
| Secondary Clarifier (n=3) | 1.49×103 | 9.60×101 | 6.5 |
| Effluent (n=3) | 1.04 | 0 | 0.0 |
| Mid-Atlantic WWTP2 | |||
| Influent (n=2) | 1.73×106 | 8.56×104 | 4.9 |
| Activated Sludge Reactor (n=2) | 2.19×105 | 1.32×104 | 6.0 |
| Secondary Clarifier (n=2) | 1.86×104 | 8.46×102 | 4.6 |
| Effluent (n=2) | 5.00×10−2 | 0 | 0.0 |
| Midwest WWTP1 | |||
| Influent (n=3) | 1.21×106 | 4.03×104 | 3.3 |
| Post Aeration (n=3) | 6.34×104 | 8.55×102 | 1.3 |
| Secondary Clarifier (n=3) | 6.63×103 | 1.03×103 | 15.5 |
| Effluent (n=3) | 1.56×101 | 3.29a | 21.1 |
| Midwest WWTP2 | |||
| Influent (n=4) | 5.30×105 | 2.52×103 | 0.5 |
| Cell B (n=4) | 5.08×102 | 0 | 0.0 |
| Effluent (n=4) | 6.05×101 | 0 | 0.0 |
| Total | 1.14×107 | 3.52×105 | 3.1 |
a
Sample collected in October 2010 when chlorination was not taking place.