| (ii) If the laboratory report indicates that a valid
analytical result could not be reported, the laboratory report must
be accompanied by a request to collect a replacement sample.
(B) The results must be submitted within ten days of
their receipt by the public water system and no later than ten days
after the end of the first month following the month that the sample
was collected.
(C) The results and any additional information must
be mailed to the Water Supply Division, MC 155, Texas Commission on
Environmental Quality, P.O. Box 13087, Austin, Texas 78711-3087.
(c) Treatment technique requirements. A system that
treats surface water or groundwater under the direct influence of
surface water must meet minimum treatment technique requirements before
the water reaches the entry point to the distribution system.
(1) The combination of pathogen removal and disinfection
processes used by a public water system must achieve at least a 4.0-log
removal/inactivation of viruses.
(2) The combination of pathogen removal and disinfection
processes used by a public water system must achieve at least a 3.0-log
removal/inactivation of Giardia lamblia.
(3) A public water system that is required by subsection
(b) of this section to conduct raw surface water monitoring must comply
with the requirements of this paragraph.
(A) The average Cryptosporidium level
and bin classification shall be determined in accordance with the
requirements established by 40 CFR §141.710.
(i) For systems that collect a total of at least 48 Cryptosporidium samples, the average concentration
is equal to the arithmetic mean of all sample concentrations.
(ii) For systems that collect a total of at least 24
samples, but not more than 47 Cryptosporidium samples,
the average concentration is equal to the highest arithmetic mean
of all sample concentrations in any 12 consecutive months during which Cryptosporidium samples were collected.
(iii) For systems that serve fewer than 10,000 people
and monitor for Cryptosporidium for
only one year (i.e., collect 24 samples in 12 months), the average
concentration is equal to the arithmetic mean of all sample concentrations.
(iv) For systems with plants operating only part of
the year that monitor fewer than 12 months per year under 40 CFR §141.701(e),
the bin concentration is equal to the highest arithmetic mean of all
sample concentrations during any year of Cryptosporidium
monitoring.
(v) If the monthly Cryptosporidium
sampling frequency varies, systems must first calculate a
monthly average for each month of monitoring. Systems must then use
these monthly average concentrations, rather than individual sample
concentrations, in the applicable calculation for bin classification
in paragraphs.
(B) Unless otherwise specified in this paragraph, the
combination of pathogen removal and disinfection processes must achieve
the removal/inactivation of Cryptosporidium
parvum specified in the following table titled "Treatment Technique
Requirements for Cryptosporidium," beginning
36 months after being assigned a bin classification by the executive
director.
Attached Graphic
(i) A system that conducts the first round of special
raw surface water monitoring according to the schedule contained in
subsection (b)(4)(A) of this section must comply with the requirements
of this paragraph no later than the date shown in the following table,
titled "Compliance Date for Existing Sources."
Attached Graphic
(ii) A system that conducts the first round of special
raw surface water monitoring according to the schedule contained in
subsection (b)(4)(B)(i) of this section must comply with the requirements
of this paragraph no later than six years after beginning the first
round of monitoring on the new source.
(iii) The executive director may allow a system making
capital improvements an additional two years to comply with the treatment
requirement of this paragraph.
(C) A system that has been assigned to Bin 3 or Bin
4 must achieve at least 1.0-log removal/inactivation of Cryptosporidium using one or a combination
of the following: bag filters, cartridge filters, chlorine dioxide,
membranes, ozone, or ultraviolet light (UV).
(D) Prior to the effective date of subparagraph (B)
of this paragraph, the combination of disinfection and filtration
processes used by a public water system to treat for Cryptosporidium must achieve at least a
2.0-log removal/inactivation of Cryptosporidium
parvum.
(4) The combination of disinfection and filtration
processes at plants that do not monitor each source in accordance
with the requirements of subsection (b) of this section must achieve
at least a 5.5-log removal/inactivation of Cryptosporidium
parvum.
(5) The executive director may require additional levels
of treatment in cases of poor source water quality.
(6) The executive director may establish minimum design,
operational, and reporting requirements for watershed control programs
and treatment processes used to meet the treatment technique requirements
of this subsection.
(d) Microbial inactivation requirements. A system that
treats surface water or groundwater under the direct influence of
surface water must meet minimum disinfection requirements before the
water is supplied to any consumer.
(1) Inactivation table. The disinfection process must
achieve the minimum microbial inactivation levels shown in the following
table.
Attached Graphic
(A) The disinfection process at treatment plants not
described in the Microbial Inactivation Requirements table must provide
the level of disinfection required by the executive director.
(B) The executive director may require additional levels
of treatment in cases of poor source water quality.
(C) The executive director may reduce the inactivation
requirement for plants that meet the individual filter effluent performance
criteria contained in subsection (g)(1) of this section and have been
assigned a Bin 1 classification under the provisions of subsection
(c)(3) of this section.
(D) A system that fails to meet the inactivation requirements
of this section for a period of longer than four consecutive hours
commits a nonacute treatment technique violation. A system that fails
to conduct the additional testing required by paragraph (2)(C) of
this subsection also commits a nonacute treatment technique violation.
(E) A system that has a plant assigned a Bin 2, 3,
or 4 classification under the provisions of subsection (c)(3) of this
section and uses UV disinfection facilities to meet the treatment
technique requirements for Cryptosporidium must
meet the inactivation requirements of this subsection in at least
95% of the water treated each month.
(2) Monitoring requirements for chemical disinfectants.
Public water systems must monitor the performance of the disinfection
facilities to ensure that appropriate disinfectant levels are maintained.
All monitoring conducted pursuant to the requirements of this subsection
must be conducted at sites designated in the public water system's
monitoring plan.
(A) The disinfectant residual, pH, temperature, and
flow rate of the water in each disinfection zone must be measured
at least once each day during a time when peak hourly raw water flow
rates are occurring.
(B) Disinfection contact time will be based on tracer
study data or a theoretical analysis submitted by the system owner
or their designated agent and approved by the executive director and
the actual flow rate that is occurring at the time that monitoring
occurs.
(C) Treatment plants that fail to demonstrate an appropriate
level of treatment must repeat these tests at four-hour or shorter
intervals until compliance has been reestablished.
(3) Monitoring requirements for UV disinfection facilities.
Public water systems must monitor the performance of the UV disinfection
facilities.
(A) A system must continuously monitor and record UV
intensity as measured by a UV sensor, lamp status, the flow rate through
the unit, and other parameters prescribed by the executive director
to ensure that the units are operating within validated conditions.
(B) A system with a plant that has been assigned a
Bin 2, 3, or 4 classification under the provisions of subsection (c)(3)
of this section must also monitor and record the amount of water treated
by each UV unit each month and the amount of water produced each month
when the unit was not operating within validated conditions.
Cont'd... |
