United States
Environmental Protection
Agency
Total Coliform Rule Monitoring Requirements
Community Water Systems Serving 1,001 - 10,000 People*
ROUTINE MONITORING
• 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 identified 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.
Table A: TCR Routine Monitoring*
Population
1,001-2,500
2,501-3,300
3,301-4,100
4,101-4,900
4,901 - 5,800
5,801 - 6,700
6,701 - 7,600
7,601 - 8,500
8,501-12,900
# of Routine Samples per Month
2
3
4
5
6
7
8
9
10
' Requirements for Systems serving <1000 are
summarized on a separate Placard (EPA 816-F-08-005)
REPEAT MONITORING
•You must collect repeat samples within 24 hours of being
notified of a TC- positive sample. Any TC-positive routine
or repeat sample must also be analyzed for either fecal
coliform or £ 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 identified 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.
POSITIVE REPEAT SAMPLES AND
MCL VIOLATIONS
• 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 defined below). If a repeatsample isTC-posi-
tive, it must also be analyzed for either fecal coliform or £ Co//.
• If you have 2 or more TC-positive samples in 1 month (including both re-
peat and routine samples), your system has a monthly MCL violation.
• If you have any fecal coliform or £ Coli positive repeat samples, or have a
fecal coliform or £ 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. Contactyour primacy agency to make sure you are
providing them with all the information that is required.
Where can I find more information
on the Total Coliform Rule?
You can find more information on the Total Coli-
form 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.
Primacy Agency.
(contact name and phone number)
Office of Water (4606M)
EPA816-F-08-004
www.epa.gov/safewater
January, 2008
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