| (B) The executive director may return a system on increased
quarterly monitoring to routine monitoring after at least four consecutive
quarters if the LRAA for every monitoring location is less than or
equal to 0.060 mg/L for TTHM and less than or equal to 0.045 mg/L
for HAA5.
(C) A system that is on increased monitoring under §290.113
of this title must remain on increased monitoring until the system
qualifies for a return to routine monitoring under subparagraph (B)
of this paragraph. The increased monitoring schedule must be conducted
at the Stage 2 monitoring locations approved under paragraph (1) of
this subsection, beginning on the date identified in subsection (a)(2)
of this section.
(5) IDSE requirements. All community systems of any
size and nontransient, noncommunity systems that serve at least 10,000
people must comply with these IDSE requirements.
(A) The executive director may grant a VSS IDSE monitoring
waiver to systems that serve fewer than 500 people. Systems that receive
a VSS IDSE monitoring waiver are not required to do IDSE monitoring.
Systems must be compliant with all of the Stage 1 monitoring requirements
of §290.113 of this title to be eligible for a VSS IDSE waiver.
(B) The executive director may grant a 40/30 IDSE monitoring
waiver to IDSE monitoring to systems with levels for TTHM less than
0.040 mg/L and levels for HAA5 less than 0.030 mg/L. Systems that
receive a 40/30 IDSE monitoring waiver are not required to do IDSE
monitoring. Systems must be compliant with all of the Stage 1 monitoring
requirements of §290.113 of this title to be eligible for a 40/30
IDSE waiver. The timing of samples that all need to be less than 0.040
mg/L and 0.030 mg/L respectively for TTHM and HAA5 are given in the
following table, titled "Timing of Stage 1 Samples Evaluated for 40/30
Initial Distribution System Evaluation (IDSE) Waiver."
Attached Graphic
(i) To qualify for a 40/30 IDSE waiver a system must
certify to the executive director that every individual sample taken
under §290.113 of this title were less than 0.040 mg/L for TTHM
and less than 0.030 mg/L for HAA5, and must have not had any TTHM
or HAA5 monitoring violations during the period specified in subsection
(a) of this section.
(ii) To qualify for a 40/30 IDSE waiver, a system must
submit compliance monitoring results, distribution system schematics,
and recommended Stage 2 compliance monitoring locations to the executive
director upon request. The executive director may require a system
that fails to submit the requested information to perform IDSE sampling.
(iii) The executive director may still require a system
that meets the 40/30 IDSE waiver or VSS IDSE waiver requirements to
do IDSE sampling under subparagraph (C) of this paragraph.
(C) Systems that must perform IDSE sampling must submit
any needed documentation for waivers, produce an IDSE Plan, do IDSE
sampling, and report the IDSE results to the executive director on
the schedule in the following table titled "Initial Distribution Schedule
Evaluation (IDSE) Schedule."
Attached Graphic
(i) The IDSE plan has required elements.
(I) The IDSE plan must include a schematic of the distribution
system (including distribution system entry points and their sources,
and storage facilities), with notes indicating locations and dates
of all projected standard monitoring, and also Stage 1 compliance
monitoring under §290.113 of this title.
(II) The IDSE plan must include justification of IDSE
monitoring location selection and a summary of data used to justify
IDSE monitoring location selection.
(III) The IDSE plan must include the system type and
population served by the system.
(ii) Systems must do required IDSE sampling in accordance
with this clause.
(I) Systems must monitor at the number and type of
sites indicated in the following table titled "Number and Type of
Initial Distribution System Evaluation (IDSE) Sample Sites:"
Attached Graphic
(II) Systems must collect dual sample sets at each
monitoring location. One sample in the dual sample set must be analyzed
for TTHM. The other sample in the dual sample set must be analyzed
for HAA5.
(III) IDSE sample locations must be different than
the existing Stage 1 monitoring locations established under §290.113
of this title.
(IV) IDSE sample locations must be distributed throughout
the distribution system.
(V) Systems must monitor at the frequency indicated
in the following table titled "Frequency of Initial Distribution System
Evaluation (IDSE) Monitoring:"
Attached Graphic
(VI) The IDSE monitoring frequency and locations may
not be reduced.
(iii) The IDSE report must comply with the elements
in this clause.
(I) The IDSE report must include all TTHM and HAA5
analytical results from Stage 1 compliance monitoring under §290.113
of this title and all IDSE sample results and locational running annual
averages presented in a tabular or spreadsheet format acceptable as
described in Texas Commission on Environmental Quality regulatory
guidance number 384: "How to Develop a Monitoring Plan for a Public
Water System."
(II) If changed from the IDSE plan submitted under
clause (ii) of this subparagraph, the IDSE report must also include
an updated distribution system map, documentation verifying the population
served, and an updated list of sources including their water type.
(III) The IDSE report must include an explanation of
any deviations from the approved IDSE plan.
(IV) The IDSE report must recommend and justify Stage
2 compliance monitoring locations consistent with paragraph (1) of
this subsection. The recommended Stage 2 compliance monitoring locations
must be listed in a Stage 2 sample plan as part of the system's monitoring
plan.
(V) The IDSE report must include recommendations and
justification for when Stage 2 samples should be collected.
(iv) The executive director may approve a system specific
study that meets the requirements in 40 CFR §141.602 to comply
with IDSE sampling requirements. The commission hereby adopts the
requirements of 40 CFR §141.602 by reference.
(D) The executive director may require a system to
perform IDSE sampling or a system specific study for any reason. The
executive director may require a system to perform IDSE sampling or
a system specific study even if the system meets the criteria for
an IDSE waiver. The executive director may require new systems and
systems with a change in population or system type to perform IDSE
sampling or a system specific study.
(d) Analytical requirements for TTHM and HAA5. Analytical
procedures required by this section shall be performed in accordance
with §290.119 of this title (relating to Analytical Procedures).
Testing for TTHM and HAA5 shall be performed at a laboratory accredited
by the executive director.
(e) Reporting requirements for TTHM and HAA5. Public
water systems must submit reports related to TTHM and HAA5 to the
executive director. Reports must be mailed to the Water Supply Division,
MC 155, Texas Commission on Environmental Quality, P.O. Box 13087,
Austin, Texas 78711-3087.
(1) The owner or operator of a public water system
must ensure the executive director is provided with a copy of the
results of any test, measurement, or analysis required by this subsection.
The copies must be submitted within the first ten days following the
month in which the result is received by the public water system,
or the first ten days following the end of the required monitoring
period as provided by this subsection, whichever occurs first.
(A) The owner or operator of a public water system
is responsible for reporting the following information for each monitoring
location to the executive director within ten days of the end of any
quarter in which monitoring is required:
(i) number of samples taken during the last quarter;
(ii) date and results of each sample taken during the
last quarter;
(iii) arithmetic average of quarterly results for the
last four quarters for each monitoring location (LRAA), beginning
at the end of the fourth calendar quarter that follows the compliance
date and at the end of each subsequent quarter;
(iv) whether the MCL was violated at any monitoring
location; and
(v) any OELs that were exceeded during the quarter
and, if so, the location and date, and the calculated TTHM and HAA5
levels.
Cont'd... |
