Table 1:
Geomean concentrations of indicators and norovirus in WWTP samples collected over a two-year period, 2009–2011. DOI: https://doi.org/10.1525/elementa.301.t1
| Site | Type of samplea | n | HB (CN L−1)b | Lachno2 (CN L−1)b | Enterococci (CN L−1) | E. coli (CN L−1) | G1 norovirus (GC L−1)c |
|---|---|---|---|---|---|---|---|
| Jones Island WWTP | Composite | 33 | 2.76 × 108 | 5.36 × 108 | 1.38 × 109 | 2.22 × 107 | 2.85 × 104 |
| Single | 16 | 2.08 × 108 | 6.30 × 108 | 8.75 × 108 | 3.19 × 107 | NDd | |
| All | 49 | 2.52 × 108 | 5.65 × 108 | 1.19 × 109 | 2.50 × 107 | 2.85 × 104 | |
| South Shore WWTP | Composite | 33 | 2.77 × 108 | 5.51 × 108 | 9.8 × 108 | 3.02 × 107 | 3.49 × 104 |
| Single | 16 | 3.70 × 108 | 8.08 × 108e | 7.89 × 108 | 3.46 × 107 | ND | |
| All | 49 | 3.04 × 108 | 6.2 × 108 | 9.13 × 108 | 3.16 × 107 | 3.49 × 104 | |
| Both WWTPs | All ± SDf | 98 | 2.77 × 108 ± 1.74 × 108 | 5.94 × 108 ± 1.70 × 108 | 1.04 × 109 ± 1.95 × 108 | 2.81 × 107 ± 1.58 × 108 | 3.18 × 104 ± 5.5 × 104 |
a
Seven-day composite samples and single-day samples from each wastewater treatment plant (WWTP).
b
Copy numbers (CN) per liter (per liter to compare with norovirus).
c
Genomic copies (GC) per liter.
d
ND indicates not determined.
e
Significantly higher than indicator concentrations in single South Shore WWTP samples (p < 0.05) compared to Jones Island WWTP composite (p < 0.05) and Jones Island WWTP single samples (p < 0.05); no other significant differences were noted.
f
SD of log-transformed data, as data are displayed as geomeans.