Total trihalomethane concentrations (μg/l) by quarter and sampling point for 84 sites reporting for four quarters; Information Collection Rule database 1997–1998
| ICR time period | Sampling point | Mean | SD | Median | Range |
|---|---|---|---|---|---|
| Quarter 1 (Oct–Dec 97) | DSE | 39.20 | 22.33 | 33.30 | ND–108.9 |
| AVG1 | 41.24 | 23.44 | 35.95 | ND–130.8 | |
| AVG2 | 42.41 | 23.15 | 38.10 | ND–104.4 | |
| MAX | 48.76 | 25.35 | 42.35 | ND–129.0 | |
| Quarter 2 (Jan–Mar 98) | DSE | 30.91 | 16.59 | 28.35 | 3.8–74.8 |
| AVG1 | 32.82 | 18.76 | 28.30 | 5.9–96.1 | |
| AVG2 | 32.91 | 16.26 | 31.30 | ND–80.5 | |
| MAX | 38.71 | 21.09 | 34.20 | 3.6–108.5 | |
| Quarter 3 (Apr–Jun 98) | DSE | 45.17 | 27.37 | 39.15 | 1.1–136.0 |
| AVG1 | 47.56 | 26.59 | 39.80 | 7.2–133.1 | |
| AVG2 | 48.10 | 28.34 | 42.05 | 3.2–136.0 | |
| MAX | 54.68 | 28.68 | 48.60 | 4.3–136.4 | |
| Quarter 4 (Jul–Sept 98) | DSE | 56.19 | 35.31 | 47.35 | ND–193.0 |
| AVG1 | 58.15 | 33.65 | 50.40 | 1.2–188.0 | |
| AVG2 | 61.12 | 38.31 | 53.00 | ND–222.0 | |
| MAX | 67.75 | 35.99 | 58.90 | ND–204.7 |