| (a) Applicability. All public water systems must produce
and distribute water that meets the provisions of this section regarding
microbial contaminants.
(b) Maximum contaminant levels (MCL) for microbial
contaminants. Treatment techniques and MCL requirements for microbial
contaminants are based on detection of those contaminants or fecal
indicator organisms.
(1) A public water system is in compliance with the
MCL for Escherichia coli (E. coli) unless
any of the following conditions occur:
(A) The public water system has an E. coli -positive repeat sample following
a total-coliform-positive routine sample;
(B) The public water system has a total coliform-positive
repeat sample following an E. coli- positive
routine sample;
(C) The public water system fails to take all required
repeat samples following an E. coli -positive
routine sample; or
(D) The public water system fails to test for E. coli when any repeat sample tests positive
for total coliform.
(E) The E. coli MCL
is defined as when a condition described in subparagraphs (A) - (D)
of this paragraph occurs.
(2) For public water systems required to collect raw
groundwater samples, the standard is no detection of fecal indicators
in a raw groundwater sample.
(c) Treatment technique triggers and assessment requirements
for microbial contaminants. All public water systems shall comply
with the requirements as described in this subsection. Public water
systems shall conduct assessments after exceeding any of the treatment
technique triggers as described in paragraphs (1) and (2) of this
subsection.
(1) Level 1 treatment technique triggers are:
(A) For a public water system which collects 40 or
more distribution samples per month, the treatment technique trigger
is defined as when more than 5.0% of samples collected in a month
are total coliform-positive.
(B) For a public water system which collects fewer
than 40 distribution samples per month, the treatment technique trigger
is defined as when two or more samples collected in a month are total
coliform-positive.
(C) When a public water system fails to collect all
required repeat samples after a total coliform-positive result.
(2) Level 2 treatment technique triggers are:
(A) An E. coli MCL
violation as specified in subsection (b)(1)(A) - (D) of this section
occurs.
(B) A second Level 1 treatment technique trigger occurs
as defined in paragraph (1) of this subsection, within a rolling 12-month
period. If the executive director has determined the reason that the
samples that caused the first Level 1 treatment technique trigger
were total coliform-positive and has established that the public water
system has corrected the problem, a public water system will not be
required to conduct and complete a Level 2 assessment. The public
water system shall have identified any sanitary defect and provided
adequate documentation to the executive director in the initial Level
1 assessment which established the reason that caused the first Level
1 treatment technique trigger and that the public water system corrected
the problem. If the executive director has determined that a public
water system is not required to conduct a Level 2 assessment based
on the occurrence of a second Level 1 treatment technique trigger
within a rolling 12-month period, the public water system shall still
conduct the required Level 1 assessment and shall complete and submit
the executive director-approved Level 1 assessment form.
(3) Treatment technique assessment requirements are:
(A) Level 1 and Level 2 assessments are conducted in
order to identify the possible presence of sanitary defects and defects
in distribution system coliform monitoring practices. The assessments
may also indicate that no sanitary defects were identified. When conducting
assessments, systems shall ensure that the assessor evaluates minimum
elements that include review and identification of inadequacies in
sample sites; sampling protocol; sample processing; atypical events
that could affect distributed water quality or indicate that distributed
water quality was impaired; changes in distribution system maintenance
and operation that could affect distributed water quality (including,
but not limited to water storage); source and treatment considerations
that bear on distributed water quality; and existing water quality
monitoring data. The system shall conduct and complete the assessment
in the format as prescribed by the executive director that tailors
specific assessment elements with respect to the size and type of
the system and the size, type, and characteristics of the distribution
system.
(i) Level 1 and Level 2 assessments shall be conducted
and completed by the public water system, licensed operators as required
under §290.46(e) of this title (relating to Minimum Acceptable
Operating Practices for Public Drinking Water Systems), or other parties
approved by the executive director. The public water system, licensed
operators, as required under §290.46(e) of this title, and other
parties approved by the executive director shall have also completed
training as required in clause (iii) of this subparagraph and any
additional training required by the executive director in writing,
upon notice to the public water system, licensed operators, and other
parties approved by the executive director.
(ii) Other parties approved by the executive director
include, but are not limited to:
(I) backflow prevention assembly testers and customer
service inspectors licensed under Chapter 30 of this title (relating
to Occupational Licenses and Registrations);
(II) plumbing inspectors and water supply protection
specialists licensed by the Texas State Board of Plumbing Examiners;
(III) licensed professional engineers licensed by the
Texas Board of Professional Engineers;
(IV) circuit riders or technical assistance providers
under contract with the executive director or other government agency
as approved by the executive director; or
(V) utility supervisor or manager supported by various
utility staff or other individuals that meet the assessment requirements
as described in this paragraph.
(iii) Assessors who have conducted Level 1 assessments
which were determined by the executive director to be insufficient
or inadequate may be required to complete additional training or obtain
certifications as prescribed by the executive director.
(B) The Level 1 and Level 2 assessments shall be conducted
and completed consistent with all directives set forth by the executive
director and with respect to the size, type, and characteristics of
the public water system. When conducting assessments, at a minimum,
public water systems shall ensure that the following items are evaluated:
(i) review and identification of inadequacies in sample
sites;
(ii) sampling protocol;
(iii) sample processing;
(iv) atypical events that could affect distributed
water quality or indicate that distributed water quality was impaired;
(v) changes in distribution system maintenance and
operation that could affect distributed water quality (including,
but not limited to water storage);
(vi) source and treatment considerations that bear
on distributed water quality, where appropriate;
(vii) existing water quality monitoring data; and
(viii) the possible presence of sanitary defects.
(C) A public water system shall conduct a Level 1 assessment
and complete the executive director-approved Level 1 assessment form
when the public water system exceeds one of the treatment technique
triggers in paragraph (1) of this subsection. The public water system
must note no sanitary defects were identified or describe sanitary
defects detected, corrective actions completed, and a proposed timetable
for any corrective actions not already completed in the Level 1 assessment
form. At the discretion of the executive director, the public water
system shall comply with any additional or expedited corrective actions
when there is a potential for an acute health risk.
(i) Both the Level 1 assessment and the executive director-approved
Level 1 assessment form shall be completed and the form submitted
to the executive director as soon as practical, but no later than
30 days after the public water system learns that it has exceeded
a trigger, or 30 days after all routine and repeat monitoring was
required to be completed for the calendar month in which the system
exceeded the trigger, whichever is earlier.
(ii) If the executive director determines that the
Level 1 assessment is not sufficient, the public water system shall
consult with the executive director and submit a revised assessment
form to the executive director within 30 days from the date of consultation.
(iii) The executive director will determine if the
public water system has identified the likely cause(s) of the trigger
and, if so, was the cause(s) corrected, or has an acceptable schedule
to correct the problem been included. The assessments may also indicate
that no sanitary defects were identified.
(D) A public water system shall ensure that a Level
2 assessment and the executive director-approved Level 2 assessment
form are conducted and completed consistently with all directives
set forth by the executive director if the public water system exceeds
one of the treatment technique triggers in paragraph (2) of this subsection.
The public water system shall comply with any expedited actions or
additional actions required by the executive director in the case
of an E. coli MCL violation.
(i) After any trigger in paragraph (2) of this subsection,
the public water system shall ensure that both the Level 2 assessment
and the executive director-approved Level 2 assessment form are completed
by the public water system, licensed operators as required under §290.46(e)
of this title, or by parties approved by the executive director and
the completed form submitted to the executive director as soon as
practical but no later than 30 days after the public water system
learns that it has exceeded a trigger in paragraph (2) of this subsection,
or 30 days after all routine and repeat monitoring was required to
be completed for the calendar month in which the system exceeded the
trigger, whichever is earlier.
(ii) If the executive director determines that the
completed Level 2 assessment is not sufficient or the proposed timetable
for any corrective actions not completed is not sufficient, the public
water system shall consult with the executive director. If any revisions
are required after consultation, the public water system shall submit
a revised assessment form to the executive director within 30 days
from the date of the consultation.
(iii) After the Level 2 assessment is submitted, the
executive director will determine if the public water system has identified
the likely cause(s) of the trigger and corrected the cause(s), or
has included an acceptable timetable for correcting the cause(s).
The assessments may also indicate that no sanitary defects were identified.
(E) Public water systems must correct sanitary defects
found through either Level 1 or Level 2 assessments described in this
subsection. For corrective actions not completed by the time of submission
of the assessment form, the public water system must complete the
corrective actions in compliance with a timetable approved by the
executive director in consultation with the public water system. The
public water system must notify the executive director when scheduled
corrective actions have been completed.
(F) At any time during the assessment or corrective
action phase, either the public water system or the executive director
may request a consultation with the other party to determine the appropriate
actions. The public water system shall consult with the executive
director on all relevant information that may impact its ability to
comply with a requirement of this subsection.
(d) Monitoring requirements for microbial contaminants.
Public water systems shall collect samples for total coliform, fecal
coliform, E. coli (or other approved
fecal indicator) at sampling sites and a sample collection schedule,
as designated by the public water system, which are subject to review
and revision as directed by the executive director. All compliance
samples must be collected at sampling sites and a sample collection
schedule that are representative of water throughout the distribution
system and shall be reflected in the public water system's Sample
Siting Plan and included with the public water system's monitoring
plan in accordance with §290.121 of this title (relating to Monitoring
Plans). All public water systems shall develop a written Sample Siting
Plan as described in paragraph (6) of this subsection.
(1) Routine microbial sampling locations. Public water
systems shall routinely monitor for microbial contaminants at the
following locations.
(A) Public water systems must collect routine distribution
coliform samples at a customer's premise, dedicated sampling station,
or other designated compliance sampling location at active service
connections which are representative of water quality throughout the
distribution system. Other sampling sites may be used if located adjacent
to active service connections.
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