Table 2.
Monitoring data for indicator organisms during 14 years as part of conventional monitoring of drinking water microbial quality by responsible authorities based on infrequent quarterly (Q) (2002–2012) and monthly (M) (2013–2015) grab sampling in Spring A, displayed in Figure 1.
| Samples >0 cfu 100 ml−1 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Concentration | ||||||||||||
| Detected organisms | Number of samples analyzed | Number of positives | Median | Average | Std. dev. | Maximum | ||||||
| Q | M | Q | M | Q | M | Q | M | Q | M | Q | M | |
| Enterococcus | 63 | 37 | 18 (29%)a | 9 (24%)a | 3.0 | 3.0 | 26.3 | 7.8 | 60.3 | 10.5 | 250.0 | 34.0 |
| E. coli | 63 | 37 | 14 (22%)a | 8 (22%)a | 1.5 | 2.0 | 16.3 | 13.3 | 42.0 | 31.4 | 160.0 | 91.0 |
| Both | 63 | 37 | 9 (14%)a | 4 (11%)a | – | – | – | – | – | – | – | – |
a
Percentage of samples >0 cfu 100 ml−1 in all samples analyzed.