TOTAL COLIFORM MONITORING 40 CFR 141.21 - PowerPoint PPT Presentation

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TOTAL COLIFORM MONITORING 40 CFR 141.21

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Title: TOTAL COLIFORM MONITORING 40 CFR 141.21


1
TOTAL COLIFORM MONITORING40 CFR 141.21
  • TRANSIENT NON-COMMUNITY PUBLIC WATER SYSTEMS

2
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

3
MONITORING FREQUENCYGroundwater System
CFR 141.21 (a) (3) (i)
Daily Population 25 to 1,000 Persons
  • 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

4
MONITORING FREQUENCYGroundwater System
(continued)
5
MONITORING FREQUENCY
Surface Water and GW Under Influence
6
ROUTINE SAMPLE INTERVALS
CFR 141.21 (a) (4)
  • 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 day
  • if they are taken from different sites.

7
ROUTINE SAMPLE COLLECTION
Helpful Hints
Always Collect - early in the week - early in
the month - early in the compliance period
Early collection allows time to collect repeat
samples, if routine sample is total coliform
positive.
8
FECAL COLIFORM OR E. COLI TESTING OF ROUTINE
SAMPLES
CFR 141.21 (e)
  • Any routine or repeat sample that is TC must be
    analyzed for the presence of fecal coliforms or
  • E. 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.

9
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.

10
REPEAT MONITORING
CFR 141.21 (b)
WHEN?
  • Collect repeats within
  • 24 hours of being notified
  • of positive routines (State may
  • extend on case by case basis.)
  • Collect all repeats
  • on the same day

11
REPEAT MONITORING
HOW MANY?
  • If PWS Collects One or Fewer Routines/Month
  • Collect four repeat samples for each TC routine
    sample
  • If PWS Collects gt1 Routine Sample/Month
  • Collect three repeat samples for each TC routine
    sample

12
REPEAT MONITORING
WHERE?
  • At least one repeat at tap
  • where original TC sample taken
  • At least one repeat sample within
  • five service connections upstream of original
    site

13
REPEAT MONITORING
WHERE? (continued)
  • At least one repeat sample within five service
    connections downstream of original site
  • Location of fourth sample collected at the
    discretion of the PWS

14
SYSTEMS WITH A SINGLE SERVICE CONNECTIONCFR
141.21 (b) (3)
  • Samples can be collected in a single large volume
  • or as 100ml samples in multiple containers
  • Collect all samples on the same day
  • OR
  • Collect samples over a four day period

15
RECOMMENDED REPEAT
COLLECTION METHOD
  • 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.

16
RECOMMENDED REPEAT COLLECTION METHOD
(continued)
  • Four separate samples recommended over a
  • single large volume sample because
  • Increases probability of capturing coliforms, if
    present, since contamination may be intermittent

17
POSITIVE REPEAT SAMPLES
CFR 141.21 (b) (4)
  • If one or more repeats is TC, then collect
  • a 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

18
ADDITIONAL ROUTINES
CFR 141.21 (b) (5)
If a system collects fewer than five
routine samples/month and has one or more
TC sample(s) which are not invalidated, it must
collect at least five routine samples during the
next month the system provides water to the
public. The State may waive this requirement on
a case-by-case basis.
19
STATE WAIVER FOR COLLECTION
OF ADDITIONAL ROUTINES
  • State may waive the requirement to collect five
  • routines the next month the system provides water
  • in one of the two following cases
  • 1. A State approved agent performs a detailed
  • site visit before the end of the next month the
  • system provides water to the public. The
  • inspecting agent cannot be an employee of the
  • water system.

141.21 (b) (5) (i)
20
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
21
MAXIMUM CONTAMINANT LEVEL(MCL) COMPLIANCE
DETERMINATION
CFR 141.21 (b) (7)
  • 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

22
(MCLs) FOR MICROBIOLOGICAL CONTAMINANTS
CFR 141.63
  • 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.

23
MCL COMPLIANCE CHART FOR MICROBIOLOGICAL
CONTAMINANTS
24
STATE INVALIDATION OF TOTAL
COLIFORM SAMPLES
CFR 141.21 (1) (c)(i - iii)
TC Samples Invalidated by State
  • 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

25
STATE INVALIDATION OF TOTAL COLIFORM SAMPLES
(continued)
  • If State invalidates because result is unrelated
  • to 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

26
LAB INVALIDATION OF TOTAL COLIFORM SAMPLES
CFR 141.21 (c) (2)
  • 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.

27
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 an underestimation of coliform numbers
or a false negative result.
28
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 SAMPLES FOR ALL OF THE ABOVE
CASES
29
PUBLIC NOTIFICATION (PN)CFR 141.32
A PN IS REQUIRED WHEN A SYSTEM
  • 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

30
PN REQUIREMENTS FOR FTM FOR TOTAL COLIFORMS
CFR 141.32
  • Within three months of the FTM, non-community
    PWSs 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

31
PN REQUIREMENTS FORNON-ACUTE MCL VIOLATIONS
CFR 141.32
  • Within 14 days of the TC non-acute violation,
    non-community PWSs 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

32
PN REQUIREMENTS FORACUTE MCL VIOLATIONS
CFR 141.32
  • Within 72 hours of the TC acute violation,
    non-community PWSs 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

33
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

34
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.

35
  • ALWAYS
  • DRINK UPSTREAM FROM THE HERD!!!
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