• Non-community water systems serving more than 1,000 persons during any 

month must sample at regular time intervals throughout the month except for 

ground water systems that serve 4,900 persons or less.

Ground water systems serving 4,900 persons or less may collect all required 

samples on a single day if they are taken from different sites.

• You must sample at the sites in your distribution system identifi ed in your primacy agency reviewed sampling plan.

• The number of samples you collect depends on the number of people you serve 

(see Table A).

If you take 4 or fewer routine samples every month or quarter, you are required 

to take 5 routine samples in the month following a total coliform (TC) positive 

result, even if you are on a quarterly schedule. For example, if you took 3 routine 

samples in June and 1 sample was TC-positive, you must take 5 routine samples 

in July.

• If a repeat sample is positive, you must continue to collect repeat samples, per repeat monitoring 

instructions, until TC is no longer positive or until there is an MCL violation. If a repeat sample is 

TC-positive, it must also be analyzed for either fecal coliform or E. Coli.

• If you have 2 or more TC-positive samples in 1 month (including both repeat and routine samples), 

your system has a monthly MCL violation.

• If you have any fecal coliform or E. Coli positive repeat samples or have a 

fecal coliform or E. Coli positive sample followed by a TC-positive repeat sample, your system has 

an acute MCL violation.

Besides sampling, what else are we required to do?

There are also requirements on what you report to the primacy agency every month, and requirements on how and when to notify your customers if you have a violation. Contact your primacy 

agency to make sure you are providing them with all the information that is required.

Population # of Routine Samples per Month

1,001 – 2,500 2

2,501 – 3,300 3

3,301 – 4,100 4

4,101 – 4,900 5

4,901 – 5,800 6

5,801 – 6,700 7

6,701 – 7,600 8

7,601 – 8,500 9

8,501 – 12,900 10

Where can I fi nd more information on the 

Total Coliform Rule? 

You can fi nd more information on the Total Coliform 

Rule by calling EPA’s Safe Drinking Water Hotline at: 

1.800.426.4791; or you can visit EPA’s Total Coliform Rule 

Web site: 

http://www.epa.gov/safewater/disinfection/tcr/

index.html. 

Total Coliform Rule Monitoring Requirements 

Noncommunity Water Systems Serving 1,001 - 10,000 People*

ROUTINE 

MONITORING

POSITIVE REPEAT SAMPLES AND 

MCL VIOLATIONS

Offi ce of Water (4606M) www.epa.gov/safewater January, 2008

Table A: TCR Routine Monitoring*

EPA 816-F-08-006

• You must collect repeat samples whenever you are notifi ed of a TC-positive sample. The positive routine sample 

must also be analyzed for either fecal coliform or E. Coli. 

• You must take at least 3 repeat samples for every TCpositive sample; for example if you had 2 TC-positive 

samples, you must take at least 6 repeat samples.

• If you have more than 1 service connection, you must 

collect repeat samples within 24 hours of learning about 

the positive results (unless your primacy agency gives 

you more time).

• If you have only 1 service connection, your primacy 

agency may give you approval to collect repeat samples 

within 4 days of learning of the positive result.

You must collect at least 1 repeat sample from each of the 

sites identifi ed below:

* The tap where the routine TC-positive was taken.

* A tap within 5 service connections upstream of the tap 

where the routine TC-positive was taken.

* A tap within 5 service connections downstream of the 

tap where the routine TC-positive was taken.

REPEAT MONITORING

* Requirements for systems serving <1000 are summarized on a separate 

Placard (EPA 816-F-08-007)

Primacy Agency___________________________

 (contact name and phone number)