Table 4.
Comparison of microbiological target abundance for 24-h grab sample average versus composite sample produced during the degradation experiments (1-3A). p values of the one-sample t-test <0.05 indicate that the mean of the grab sample was statistically different than the value of the corresponding composite sample.
| Molecular and Microbial Targets | SARS-CoV-2 (gc/L) | SIV (gc/L) | PMMoV (gc/L) | B2M (gc/L) | Fecal coliform by culture (FC) (CFU/L) |
|---|---|---|---|---|---|
| Sample Type | Experiment 1A – Building Scale | ||||
| Grab Average (n = 24) | 6.28 × 102 | 1.93 × 106 | 1.14 × 108 | 1.45 × 106 | 5.33 × 106 |
| Grab Median (n = 24) | 6.14 × 102 | 1.94 × 106 | 1.06 × 108 | 1.48 × 106 | 1.50 × 106 |
| Grab [Min-Max] (Std. Dev) |
[BDL⁎-2.1 × 104] (5.5 × 102) |
[6.3 × 105–3.4 × 106] (4.6 × 105) |
[8.0 × 106–2.7 × 108] (4.4 × 107) | [2.1 × 105–2.2 × 106] (3.8 × 105) | [BDL⁎- 2.8 × 107] (8.0 × 106) |
| Composite 1A | 1.09 × 103 | 1.82 × 106 | 1.32 × 108 | 1.38 × 106 | 1.20 × 107 |
| One-Sample t-test (p-value: two-tailed) | <0.001 ⁎values above detection limits p = 0.135 |
0.284⁎⁎ | 0.050⁎⁎ | 0.365⁎⁎ | <0.001 |
| Sample Type | Experiment 2A – Cluster Scale | ||||
| Grab Average (n = 24) | 5.79 × 104 | 7.12 × 105 | 1.01 × 108 | 3.63 × 105 | 2.31 × 107 |
| Grab Median (n = 24) | 5.83 × 104 | 6.11 × 105 | 1.02 × 108 | 3.62 × 105 | 9.00 × 106 |
| Grab [Min-Max] (Std. Dev) | [3.3 × 104–8.5 × 104] (1.2 × 104) | [3.2 × 105–2.8 × 106] (5.1 × 105) | [8.1 × 107–1.2 × 108] (9.3 × 106) | [2.7 × 105–4.9 × 105] (5.9 × 104) | [1.0 × 103–1.3 × 108] (3.2 × 107) |
| Composite 2A | 5.58 × 104 | 4.03 × 105 | 9.28 × 107 | 3.54 × 105 | 3.40 × 107 |
| One-Sample t-test (p-value: two-tailed) | 0.393⁎⁎ | 0.007 | <0.001 | 0.479⁎⁎ | 0.112⁎⁎ |
| Sample Type | Experiment 3A – Community Scale | ||||
| Grab Average (n = 24) | 3.16 × 103 | 8.92 × 105 | 8.81 × 107 | 1.17 × 105 | 1.13 × 108 |
| Grab Median (n = 24) | 3.11 × 103 | 4.05 × 105 | 9.03 × 107 | 1.18 × 105 | 1.09 × 108 |
| Grab [Min-Max] (Std. Dev) | [1.8 × 102–7.5 × 103] (1.9 × 103) | [2.3 × 105–4.5 × 106] (1.1 × 106) | [3.0 × 107–1.5 × 108] (2.2 × 107) | [7.7 × 103–2.1 × 105] (4.6 × 104) | [6.7 × 107–2.4 × 108] (3.7 × 107) |
| Composite 3A | 3.27 × 103 | 3.09 × 105 | 1.1 × 108 | 1.23 × 105 | 2.21 × 108 |
| One-Sample t-test (p-value: two-tailed) | 0.771⁎⁎ | 0.013 | <0.001 | 0.545⁎⁎ | <0.001 |
⁎
BDL = Below Detection Limits. Detection limit for SARS-CoV-2 was 1.0 × 102 gc/L. Detection limit for FC was 1.0 × 106 CFU/L.
⁎⁎
Denotes that average of grab and composite sample were statistically not different as per t-test.