| (I) The executive director shall not decrease the quarterly
sampling requirement until a groundwater system has taken a minimum
of two quarterly samples.
(II) The executive director shall not decrease the
quarterly sampling requirement until a surface water system has taken
a minimum of four quarterly samples.
(5) Asbestos monitoring frequency. Community and nontransient,
noncommunity water systems shall monitor for asbestos at the following
frequency.
(A) A public water system shall routinely monitor for
asbestos once during the first three years of each compliance cycle.
(B) The executive director may waive the routine monitoring
frequency requirements for asbestos.
(i) When determining if a waiver should be granted,
the executive director shall consider:
(I) the potential for asbestos contamination of the
water source;
(II) the use of asbestos-cement pipe for finished water
distribution; and
(III) the corrosivity of the water.
(ii) If the executive director grants a waiver, it
shall be made in writing and shall set forth the basis for the determination.
The determination may be initiated by the executive director. The
executive director shall review and, where appropriate, revise the
waiver of monitoring frequency when other data relevant to the system
becomes available.
(iii) The term during which the waiver is effective
shall not exceed one compliance cycle (i.e., nine years).
(C) The executive director may increase the monitoring
frequency for asbestos.
(i) A system that exceeds the MCL for asbestos shall
sample quarterly beginning in the next quarter after the violation
occurs.
(ii) After the initiation of quarterly sampling, the
executive director may return a system to the routine monitoring frequency
if monitoring shows that the system is reliably and consistently below
the MCL.
(I) The executive director shall not decrease the quarterly
sampling requirement until a groundwater system has taken a minimum
of two quarterly samples.
(II) The executive director shall not decrease the
quarterly sampling requirement until a surface (or combined surface
water and groundwater) water system has taken a minimum of four quarterly
samples.
(6) Nitrate monitoring frequency. All public water
systems shall monitor for nitrate at the following frequency.
(A) Routine nitrate monitoring frequency. All public
water systems shall routinely monitor for nitrate.
(i) All public water systems shall annually sample
at each groundwater entry point to the distribution system.
(ii) A community or nontransient, noncommunity water
system shall sample quarterly at each surface water entry point to
the distribution system.
(iii) A transient, noncommunity water system shall
sample annually at each surface water entry point to the distribution
system.
(B) Reduced nitrate monitoring frequency. The executive
director may reduce the monitoring frequency for community or nontransient,
noncommunity water systems using surface water sources by granting
a waiver to the routine monitoring frequency.
(i) To be considered for a waiver, a system shall demonstrate
that the nitrate concentration in each sample collected during the
previous four consecutive quarters was less than 50% of the nitrate
MCL.
(ii) If the executive director grants a waiver, it
shall be made in writing and shall set forth the basis for the determination.
The determination may be initiated by the executive director. The
executive director shall review and, where appropriate, revise the
waiver of monitoring frequency when other data relevant to the system
becomes available.
(iii) A system that receives a waiver to the routine
nitrate monitoring frequency must sample annually for nitrate. The
annual sample must be collected in the quarter that previously resulted
in the highest nitrate concentration.
(C) Increased nitrate monitoring frequency. The executive
director may increase the nitrate monitoring frequency for community
or nontransient, noncommunity water systems using groundwater sources.
(i) A system that is sampling annually shall begin
quarterly nitrate sampling if the nitrate concentration in any sample
is equal to or greater than 50% of the nitrate MCL. Quarterly sampling
must begin the first quarter after the elevated nitrate level was
detected.
(ii) After the initiation of quarterly sampling, the
executive director may return a system to the routine annual nitrate
monitoring frequency if quarterly sampling shows that the system is
reliably and consistently below the nitrate MCL for a minimum of four
consecutive quarters.
(7) Nitrite monitoring frequency. All public water
systems shall monitor for nitrite at the following frequency.
(A) All public water systems shall routinely take one
nitrite sample during each nine-year compliance cycle. All public
water systems shall monitor at the time designated by the executive
director during each compliance period during each nine-year compliance
cycle. New entry points will be scheduled for nitrite sample collection
during the first year of operation, and then every nine years thereafter
unless increased nitrite monitoring is required in accordance with
this paragraph.
(B) The executive director may reduce the monitoring
frequency for nitrite by granting a waiver to the routine monitoring
frequency.
(i) To be considered for a waiver, a system shall demonstrate
that the nitrite concentration in the initial sample was less than
50% of the nitrite MCL.
(ii) If the executive director grants a waiver, it
shall be made in writing and shall set forth the basis for the determination.
The determination may be initiated by the executive director. The
executive director shall review and, where appropriate, revise the
waiver of monitoring frequency when other data relevant to the system
becomes available.
(iii) A system that receives a waiver to the routine
nitrite monitoring frequency must sample at a frequency specified
by the executive director.
(C) The executive director may increase the monitoring
frequency for nitrite.
(i) A system shall sample quarterly for at least one
year following any sample in which the nitrite concentration is greater
than or equal to 50% of the MCL.
(ii) The executive director may allow a system to return
to the routine monitoring frequency after determining the system is
reliably and consistently less than the MCL.
(8) Confirmation sampling for all IOCs. The executive
director may require a public water system to confirm the results
of any individual sample.
(A) If a sample result exceeds the MCL, a public water
system may be required to collect one additional sample to confirm
the results of the initial test. If an additional sample is required:
(i) Confirmation samples must be collected at the same
entry point to the distribution system as the sample that exceeded
the MCL;
(ii) Confirmation samples for IOCs except nitrate and
nitrite shall be collected as soon as possible after the system receives
the analytical results of the first sample; and
(iii) Confirmation samples for nitrate and nitrite
shall be collected within 24 hours of the system's receipt of notification
of the analytical results of the first sample. Systems unable to comply
with the 24-hour sampling requirement must immediately notify the
consumers served by the public water system in accordance with subsection
(f) of this section. Systems exercising this option must take and
analyze a confirmation sample within two weeks of notification of
the analytical results of the first sample.
(B) The executive director may require a confirmation
sample for any sample with questionable results.
(9) More frequent monitoring. The executive director
may require more frequent monitoring than specified in paragraphs
(4) - (7) of this subsection.
(d) Analytical requirements for IOCs. Analytical procedures
shall be performed in accordance with §290.119 of this title
(relating to Analytical Procedures). Testing for inorganic contaminants
shall be performed at a laboratory certified by the executive director.
(e) Reporting requirements for IOCs. The owner or operator
of a public water system shall ensure that 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. The copies must be mailed to the Texas Commission
on Environmental Quality, Water Supply Division, MC 155, P.O. Box
13087, Austin, Texas Cont'd... |
