Coliform Monitoring Frequency Required at Public Water Systems Based on Population
The table below indicates the number of total coliform samples a community water system must take each month based on the population served. For example, a water system that serves a population of 9,200 must take at least 10 total coliform samples each month.
Monthly Coliform Samples Required for Community Water Systems
Population Range |
# samples per month |
25 to 1000 |
1 |
1001 to 2500 |
2 |
2501 to 3300 |
3 |
3301 to 4100 |
4 |
4101 to 4900 |
5 |
4901 to 5800 |
6 |
5801 to 6700 |
7 |
6701 to 7600 |
8 |
7601 to 8500 |
9 |
8501 to 12900 |
10 |
12901 to 17200 |
15 |
17201 to 21500 |
20 |
21501 to 25000 |
25 |
25001 to 33000 |
30 |
33001 to 41000 |
40 |
41001 to 50000 |
50 |
50001 to 59000 |
60 |
59001 to 70000 |
70 |
70001 to 83000 |
80 |
83001 to 96000 |
90 |
96001 to 130000 |
100 |
