Table 2. Distribution of MeCl in Paradise Irrigation District Water Samples Collected December 2018–May 2020 (N = 5056).
| samples |
detections
N (%) |
over MCL (5
μg/L)% |
flagged samples excludeda |
||||||
|---|---|---|---|---|---|---|---|---|---|
| type | N | all samples | flagged samples excludeda | all samples | flagged samples excludeda | mean | median | max | SD |
| main line | 2391 | 47 (2%) | 29 (1%) | 6 (0.3%) | 2 (0.08%) | 2.97 | 1.2 | 28.1 | 5.55 |
| appurtenance | 448 | 14 (3%) | 10 (2%) | 1 (0.2%) | 0 | 1.38 | 1.11 | 2.4 | 0.81 |
| service line: standing structure | 1569 | 167 (11%) | 41 (3%) | 68 (4%) | 6 (0.4%) | 3.53 | 1.8 | 26 | 5.1 |
| service line: destroyed structure | 622 | 96 (15%) | 48 (8%) | 47 (8%) | 18 (3%) | 6.22 | 2.35 | 34 | 8.03 |
| service line: unknown structure status | 25 | 4 (16%) | 2 (8%) | 2 (8%) | 0 | 1.62 | 1.62 | 2.6 | 1.39 |
| all | 5056 | 328 (6%) | 130 (3%) | 124 (2%) | 26 (0.5%) | 3.80 | 1.5 | 34 | 6.08 |
a
A total of 198 samples collected by PID in June 2019 were flagged for possible contamination because they were collected using a galvanized steel riser.