TOTAL COLIFORM MONITORING40 CFR 141.21

TRANSIENT NON-COMMUNITY PUBLIC WATER SYSTEMS

COLIFORM SAMPLINGCFR 141.21 (a)

• Routine Monitoring– Written sample siting plan

• Sites must represent water throughout distribution system

• Plans subject to State review and revision

Daily Population: 25 to 1,000 Persons

MONITORING FREQUENCYGroundwater System

• Monitor each calendar quarter when water served to public– Monthly monitoring suggested

• State can reduce monitoring to once/year– System must be free of sanitary defects

CFR 141.21 (a) (3) (i)

MONITORING FREQUENCYGroundwater System (continued)

*40 CFR 141.21 (a) (2)

Population Served (average daily)

MinimumSamples/Month*

22,501 to 3,300 33,301 to 4,100 4

1,001 to 2,500

MONITORING FREQUENCY

*40 CFR 141.21 (a) (2)

Population Served (average daily)

MinimumSamples/Month*

25 to 1,000 11,001 to 2,500 22,501 to 3,300 3

Surface Water and GW Under Influence

ROUTINE SAMPLE INTERVALS

• PWS must collect samples at regular time intervals throughout the month, except GW systems serving 4,900 and fewer. Those systems may collect all required samples on a single dayif they are taken from different sites.

CFR 141.21 (a) (4)

ROUTINE SAMPLE COLLECTION

Always Collect - early in the week - early in the month- early in the compliance period

Helpful Hints

Early collection allows time to collectrepeat samples, if routine sample istotal coliform positive.

FECAL COLIFORM OR E. COLI TESTING OF ROUTINE SAMPLES

• Any routine or repeat sample that is TC+ must be analyzed for the presence of fecal coliforms orE. coli.– If FC+ or EC+, the system must notify the State by the

end of the day when the system is notified of the result, unless the State office is closed at that time. In such a case, the State must be notified before the end of the next business day.

CFR 141.21 (e)

FC OR EC COLIFORM TESTINGCFR 141.21 (e) (continued)

• State may waive fecal or E. coli testing if the system assumes the TC+ sample is also FC+ or EC+.

– State waiver is made on a case-by-case basis

– System must notify State by the end of the day when the system is notified of the result, unless the State office is closed at that time. In such a case, the State must be notified before the end of the next business day.

REPEAT MONITORING

• Collect repeats within24 hours of being notifiedof positive routines (State mayextend on case by case basis.)

• Collect all repeatson the same day

WHEN?

CFR 141.21 (b)

112

2

3

4567

8

9

1011

REPEAT MONITORING

• If PWS Collects One or Fewer Routines/Month– Collect four repeat samples for each TC+ routine

sample

• If PWS Collects >1 Routine Sample/Month– Collect three repeat samples for each TC+ routine

sample

HOW MANY?

REPEAT MONITORING

• At least one repeat at tapwhere original TC+ sample taken

• At least one repeat sample withinfive service connections upstream of original site

WHERE?

REPEAT MONITORING

• At least one repeat sample within five service connections downstream of original site

• Location of fourth sample collected at the discretion of the PWS

WHERE? (continued)

SYSTEMS WITH A SINGLE SERVICE CONNECTION

CFR 141.21 (b) (3)

• Samples can be collected in a single large volumeor as 100ml samples in multiple containers

– Collect all samples on the same day OR

– Collect samples over a four day period

RECOMMENDED REPEAT

• Ideal method is to collect samples over a four day period.

• If unable to collect over four days, then collect four separate samples spaced throughout a single day.

COLLECTION METHOD

RECOMMENDED REPEAT COLLECTION METHOD

• Four separate samples recommended over asingle large volume sample because:

– Increases probability of capturing coliforms, if present, since contamination may be intermittent

(continued)

POSITIVE REPEAT SAMPLES

• If one or more repeats is TC+, then collecta set of four repeats for each TC+ sample.– Repeat process until no detection of TC in one

set of repeats or the MCL is exceeded and State has been notified

• Collect samples within 24 hours of being notified of positive results.– State may extend on case-by-case basis

CFR 141.21 (b) (4)

ADDITIONAL ROUTINES

If a system collects fewer than five routinesamples/month and has one or more TC+sample(s) which are not invalidated, it must collectat least five routine samples during the nextmonth the system provides water to the public.

The State may waive this requirement on a case-by-case basis.

CFR 141.21 (b) (5)

STATE WAIVER FOR COLLECTION

State may waive the requirement to collect fiveroutines the next month the system provides waterin one of the two following cases:

1. A State approved agent performs a detailedsite visit before the end of the next month thesystem provides water to the public. Theinspecting agent cannot be an employee of thewater system.

OF ADDITIONAL ROUTINES

141.21 (b) (5) (i)

STATE WAIVER (continued)

2. The State determines the cause of the TC+ sample and establishes that the system has corrected the problem before the end of the next month the system serves water to the public. If so, the State must

a. Document the waiver in writing b. Approve and sign the document

c. Make document available to EPA and public

MAXIMUM CONTAMINANT LEVEL(MCL) COMPLIANCE DETERMINATION

• All valid routine and repeat results must be included in determining compliance with the MCL for total coliforms.

• Invalidated TC+ samples do NOT count toward compliance

CFR 141.21 (b) (7)

(MCLs) FOR MICROBIOLOGICAL CONTAMINANTS

• The MCL is based on presence/absence of total coliforms in a sample.

• Systems collecting fewer than 40 samples/month are in compliance with the MCL for TC, if no more than one sample collected during a month is TC+.

• Systems collecting at least 40 samples/month are in compliance, if no more than 5.0% of the samples collected during a month are TC+.

CFR 141.63

MCL COMPLIANCE CHART FOR MICROBIOLOGICAL CONTAMINANTS

Routine Results Repeat Results In Compliance?TC FC/EC TC FC or

ECMCL

violationAcute

violation- NA NA NA NA NA

+ - - NA NO NO

+ - + - YES NO

+ + - NA NO NO

+ + + - YES YES

+ + + + YES YES

+ - + + YES YES

STATE INVALIDATION OF TOTAL

• Lab establishes improper analysis caused result OR

• Repeat sample(s) at original TC+ tap are positive, all others negative (not so for single service connections) OR

• Positive result is unrelated to water quality in distribution system

COLIFORM SAMPLES

TC+ Samples Invalidated by StateCFR 141.21 (1) (c)(i - iii)

STATE INVALIDATION OF TOTAL COLIFORM SAMPLES (continued)

• If State invalidates because result is unrelatedto water quality– Decision, rationale and corrective action must

be in writing– Approved and signed by supervisor– Document available to EPA and public– Water system must still collect all repeat samples and

use them to determine compliance with the MCL

LAB INVALIDATION OF TOTAL COLIFORM SAMPLES

• A lab must invalidate a total coliform sample (unless TC+) if test results reveal heterotrophic interference (HI).– System must collect a replacement sample from the

same location as the original sample. Collection must be within 24 hours of being notified of the HI.

CFR 141.21 (c) (2)

HETEROTROPHIC INTERFERENCE

Non-coliform bacteria which are better than coliforms at surviving in the environment may be present in the sample. If these organisms are given a chance to grow, they may out-compete coliforms during analysis and may limit the analysts ability to detect coliforms. The effect of HI is anunderestimation of coliform numbers or a false negative result.

REASONS SAMPLES MAY BE REJECTED FOR ANALYSIS

• Old sample (received after 30 hours)

• Container broken in transit

• Insufficient quantity

• No date/time of collection

• Frozen

• Leaked

COLLECT REPLACEMENT SAMPLESFOR ALL OF THE ABOVE CASES

PUBLIC NOTIFICATION (PN)CFR 141.32

• Fails to Monitor (FTM) for Total Coliforms– Routine monitoring– Repeat monitoring– Additional routine monitoring the month following a

TC+ routine• Exceeds the MCL for Total Coliforms

A PN IS REQUIRED WHEN A SYSTEM:

PN REQUIREMENTS FOR FTM FOR TOTAL COLIFORMS

• Within three months of the FTM, non-community PWS’s must– Continuously post the notice in a conspicuous

place for as long as the violation exists, or– Directly deliver the notice by hand

• Repeat hand delivery every three months for as long as the violation exists

CFR 141.32

PN REQUIREMENTS FORNON-ACUTE MCL VIOLATIONS

• Within 14 days of the TC non-acute violation, non-community PWS’s must– Continuously post the notice in a conspicuous

place for as long as the violation exists, or– Directly deliver the notice by hand

• Repeat hand delivery every three months for as long as the violation exists

CFR 141.32

PN REQUIREMENTS FORACUTE MCL VIOLATIONS

• Within 72 hours of the TC acute violation, non-community PWS’s must– Continuously post the notice in a conspicuous

place for as long as the violation exists, or– Directly deliver the notice by hand

• Repeat hand delivery every three months for as long as the violation exists

CFR 141.32

GENERAL CONTENT OF PNCFR 141.32

• The PN must provide– A clear explanation of the violation– Potential adverse health effects– Population at risk– Corrective steps taken by the PWS– The need to seek alternative water supplies, if any– Preventative measures the consumer should take– Name and number of a contact person

PN REPORTING REQUIREMENTSCFR 141.31

• The PWS, within ten days of completion of each public notification, shall submit to the State a copy of each type of notice that was made available to the persons served by the system.

• ALWAYS– DRINK UPSTREAM FROM THE HERD!!!