| (i) The groundwater system must maintain the executive
director-approved minimum specified disinfectant residual every day
the groundwater system serves water from the specified groundwater
source to the public. If there is a failure in the continuous monitoring
equipment, the groundwater system must conduct grab sampling every
four hours until the continuous monitoring equipment is returned to
service.
(ii) The system must resume continuous residual disinfectant
monitoring within 14 days.
(B) Groundwater systems serving a population of 3,300
or fewer must monitor the disinfectant residual in accordance with
the analytical methods specified in 40 CFR §141.74(a)(2) in each
disinfection zone at least once each day that water from the specified
groundwater source is served to the public during either a time when
peak hourly raw water flow rates are occurring or at another time
specified by the executive director. The system must record and maintain
the disinfectant residual every day the system serves water from the
groundwater source to the public. The system must collect a daily
grab sample during the hour of peak flow or at another time specified
by the executive director. If any daily grab sample measurement falls
below the executive director-approved minimum specified disinfectant
residual, the groundwater system must collect follow-up samples every
four hours until the residual disinfectant concentration is restored
to the executive director-approved level. Alternatively, a groundwater
system that serves 3,300 or fewer people may monitor the residual
disinfectant concentration continuously and meet the requirements
of subparagraph (A) of this paragraph.
(C) 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.
(D) Groundwater 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.
(2) Monitoring and operating requirements for commission-approved
alternative treatment, including ultraviolet light (UV) disinfection
facilities, membrane systems, and other methods that can obtain 4-log
inactivation or removal of viruses.
(A) Public water systems shall monitor the UV intensity
as measured by a UV sensor, lamp status, the flow rate through the
unit, and other parameters prescribed by the executive director as
specified in §290.42(g)(5) of this title (relating to Water Treatment)
to ensure that the units are operating within validated conditions.
(B) Public water systems shall monitor and record membrane
system performance in accordance with executive director specified
requirements.
(3) Analytical requirements. All monitoring required
by this section must be conducted at a facility approved by the executive
director and using methods that conform to the requirements of §290.119
of this title (relating to Analytical Procedures).
(A) The pH analysis must be conducted using a pH meter
with a minimum accuracy of plus or minus 0.1 pH units.
(B) The temperature of the water must be measured using
a thermometer or thermocouple with a minimum accuracy of plus or minus
0.5 degrees Celsius.
(C) The free chlorine or chloramine residual (measured
as total chlorine) must be measured to a minimum accuracy of plus
or minus 0.1 milligrams per liter (mg/L). Color comparators may be
used for distribution system samples only. When used, a color comparator
must have current reagents, an unfaded and clear color comparator,
a sample cell that is not discolored or stained, and must be properly
stored in a cool, dark location where it is not subjected to conditions
that would result in staining. The color comparator must be used in
the correct range. If a sample reads at the top of the range, the
sample must be diluted with chlorine-free water, then a reading taken
and the resulting residual calculated.
(D) The chlorine dioxide residual must be measured
to a minimum accuracy of plus or minus 0.05 mg/L using one of the
following methods:
(i) Amperometric titrator with platinum-platinum electrodes;
or
(ii) Lissamine Green B.
(E) The ozone residual must be measured to a minimum
accuracy of plus or minus 0.05 mg/L using an indigo method that uses
a colorimeter or spectrophotometer.
(F) Membrane system integrity monitoring shall be conducted
in accordance with executive director specified requirements.
(4) Recordkeeping requirements for microbial inactivation
and removal treatment. Groundwater systems, including wholesale, and
consecutive systems, regulated under this subsection must comply with §290.46
of this title (relating to Minimum Acceptable Operating Practices
for Public Drinking Water Systems).
(d) Reporting requirements. Groundwater systems conducting
4-log treatment instead of conducting raw groundwater source monitoring
or required corrective action in response to a fecal indicator positive
source sample, or a significant deficiency, must report to the executive
director in accordance with this subsection.
(1) A groundwater system required to conduct compliance
monitoring for chemical disinfectants must complete a Groundwater
Treatment Monthly Operating Report (commission Form 20362) for groundwater
disinfection facilities monthly. Groundwater systems must maintain
the reports on site and make them available to the executive director
upon request.
(2) A groundwater system must provide written notification
to the executive director that it is not required to meet the raw
groundwater source monitoring requirements under §290.109(d)(4)
of this title because it provides at least 4-log treatment of viruses
for a specified groundwater source and must begin compliance monitoring
in accordance with subsection (c) of this section. The notification
must include engineering, operational, and other information required
by the executive director to evaluate the submission.
(3) A groundwater system required to complete corrective
action under subsection (b) of this section must notify the executive
director within 30 days of completing the corrective action.
(4) If a groundwater system is subject to the triggered
source monitoring requirements of §290.109(d)(4)(A) of this title
and does not conduct source monitoring, the system must provide written
documentation that it was providing 4-log treatment of viruses for
the specified groundwater source or that it met the criteria set out
in §290.109(d)(4)(D) of this title within 30 days of the positive
distribution coliform sample.
(5) A groundwater system conducting compliance monitoring
under subsection (a) of this section must notify the executive director
any time the system fails to meet any executive director-specified
requirements (including, but not limited to, minimum residual disinfectant
concentration, and alternative treatment operating criteria) if the
operation in accordance with the criteria or requirements is not restored
within four hours. The system must notify the executive director as
soon as possible, but no later than the end of the next business day.
(6) A groundwater system required to conduct integrity
monitoring for membrane systems shall complete the executive director
specified reports. The reports shall be maintained in accordance with
executive director specified requirements.
(e) Compliance determination. In accordance with this
subsection, the executive director shall determine compliance for
groundwater systems required to conduct corrective action within 120
days, or pursuant to a groundwater corrective action plan.
(1) A groundwater system is in violation of the treatment
technique requirement if it does not complete corrective action in
accordance with the executive director-approved corrective action
plan or any interim measures required by the executive director.
(2) A groundwater system is in violation of the treatment
technique requirement if it is not in compliance with the executive
director-approved corrective action plan and schedule.
(3) A groundwater system subject to the requirements
of subsection (c) of this section that fails to maintain at least
4-log treatment of viruses is in violation of the treatment technique
requirement if the failure is not corrected within four hours. The
groundwater system must notify the executive director as soon as possible
but no later than the next business day if there is a failure in maintaining
the 4-log treatment for more than four hours.
(4) A groundwater system that fails to conduct the
disinfectant or membrane system integrity monitoring required under
subsection (c) of this section commits a monitoring violation.
(5) A groundwater system that fails to report the results
of the disinfectant or membrane system integrity monitoring required
under subsection (c) of this section commits a reporting violation.
Cont'd... |
