Total Coliform Rule Monitoring Requirements 

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

• All public water systems 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, you are required to take at least 5 

routine samples in the month following a total coliform (TC) positive result that is not 

invalidated by your primacy agency. For example, if you took 3 routine samples in June 

and one sample was TC- positive, you must take at least 5 routine samples in July.

• You must collect repeat samples within 24 hours of being 

notifi ed of a TC- positive sample. Any TC-positive routine 

or repeat sample must also be analyzed for either fecal 

coliform or E. Coli.

• You must take at least 3 repeat samples for every 

TC-positive sample; for example, if you had 2 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 result (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.

• 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 (as defi ned below). 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. 

ROUTINE MONITORING REPEAT MONITORING POSITIVE REPEAT SAMPLES AND 

MCL VIOLATIONS

Table A: TCR Routine Monitoring*

Offi ce of Water (4606M) EPA 816-F-08-004 www.epa.gov/safewater January, 2008

* Requirements for Systems serving <1000 are

summarized on a separate Placard (EPA 816-F-08-005)

Primacy Agency___________________________

 (contact name and phone number)