Total Coliform Rule
Overview of the Rule
 | View the original EPA source document. |
| EPA Total Coliform Rule website. |
| Title | Total Coliform Rule (TCR) 54 FR 27544-27568, June 29, 1998, Vol. 54, No. 124 |
| Purpose |
Improve public health protection by reducing fecal pathogens to minimal levels through control of total coliform bacteria, including fecal coliforms and Escherichia coli (E. coli). |
| General Description | Establishes a maximum contaminant level (MCL) based on the presence or absence of total coliforms, modifies monitoring requirements including testing for fecal coliforms or E. coli, requires use of a sample siting plan, and also requires sanitary surveys for systems collecting fewer than five samples per month. |
| Utilities Covered | The TCR applies to all public water systems. |
Click hereWhat are the Major Provisions?
 | How to take a sample. |
| How to take repeat samples. |
ROUTINE Sampling Requirements
Total coliform samples must be collected at sites which are representative of water quality
throughout the distribution system according to a written sample siting plan subject to state
review and revision.
Samples must be collected at regular time intervals throughout the month except groundwater
systems serving 4,900 persons or fewer may collect them on the same day.
Monthly sampling requirements are based on population served (see table on next page for the
minimum sampling frequency).
A reduced monitoring frequency may be available for systems serving 1,000 persons or fewer
and using only ground water if a sanitary survey within the past 5 years shows the system is
free of sanitary defects (the frequency may be no less than 1 sample/quarter for community
and 1 sample/year for non-community systems).
Each total coliform-positive routine sample must be tested for the presence of fecal coliforms or
E. coli.
If any routine sample is total coliform-positive, repeat samples are required.
REPEAT Sampling Requirements
Within 24 hours of learning of a total coliform-positive ROUTINE sample result, at least 3 REPEAT
samples must be collected and analyzed for total coliforms:
One REPEAT sample must be collected from the same tap as the original sample.
One REPEAT sample must be collected within five service connections upstream.
One REPEAT sample must be collected within five service connections downstream.
Systems that collect 1 ROUTINE sample per month or fewer must collect a 4th REPEAT sample.
If any REPEAT sample is total coliform-positive:
The system must analyze that total coliform-positive culture for fecal coliforms or E.coli.
The system must collect another set of REPEAT samples, violated and the system has notified the state.
Public Water System ROUTINE Monitoring Requirements
| Population | Minimum Samples/Month | Population | Minimum Samples/Month | Population | Minimum Samples/Month |
| 25-1,000* | 1 | 21,501-25,000 | 25 | 450,001-600,000 | 210 |
| 1,001-2,500 | 2 | 25,001-33,000 | 30 | 600,001-780,000 | 240 |
| 2,501-3,300 | 3 | 33,001-41,000 | 40 | 780,001-970,000 | 270 |
| 3,301-4,100 | 4 | 41,001-50,000 | 50 | 970,001-1,230,000 | 300 |
| 4,101-4,900 | 5 | 50,001-59,000 | 60 | 1,230,001-1,520,000 | 330 |
| 4,901-5,800 | 6 | 59,001-70,000 | 70 | 1,520,001-1,850,000 | 360 |
| 5,801-6,700 | 7 | 70,001-83,000 | 80 | 1,850,001-2,270,000 | 390 |
| 6,701-7,600 | 8 | 83,001-96,000 | 90 | 2,270,001-3,020,000 | 420 |
| 7,601-8,500 | 9 | 96,001-130,000 | 100 | 3,020,001-3,960,000 | 450 |
| 8,501-12,900 | 10 | 130,001-220,000 | 120 | >= 3,960,001 | 480 |
| 12,901-17,200 | 15 | 220,001-320,000 | 150 | ||
| 17,201-21,500 | 20 | 320,001-450,000 | 180 |
What are the Other Provisions?
| Systems collecting fewer than 5 ROUTINE samples per month . . . | Must have a sanitary survey every 5 years (or every 10 years if it is a non-community water system using protected and disinfected ground water). |
| Systems using surface water or ground water under the direct influence of surface water (GWUDI) and meeting filtration avoidance criteria . . . | Must collect and have analyzed one coliform sample each day the turbidity of the source water exceeds 1 NTU. This sample must be collected from a tap near the first service connection. |
How is Compliance Determined?
Compliance is based on the presence or absence of total coliforms.
Compliance is determined each calendar month the system serves water to the public (or each calendar month that sampling occurs for systems on reduced monitoring).
The results of ROUTINE and REPEAT samples are used to calculate compliance.
What are the Public Notification and Reporting Requirements?
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| For a Monthly MCL Violation | The violation must be reported to the state no later than the end of the next business day after the system learns of the violation.4 The public must be notified within 14 days. |
| For an Acute MCL Violation | The violation must be reported to the state no later than the end of the next business day after the system learns of the violation. 4 The public must be notified within 72 hours. |
| Systems with ROUTINE or REPEAT samples that are fecal coliform- or E. coli-positive . . . | Must notify the state by the end of the day they are notified of the result or by the end of the next business day if the state office is already closed. |
