| (a) Applicability. All groundwater public water systems,
including such systems that use surface water or groundwater under
the direct influence of surface water (mixed systems), must comply
with one or more of the treatment techniques and corrective actions
of this section if a raw groundwater source sample was positive for
fecal indicators, if a significant deficiency was identified, or if
the system is not required to conduct raw groundwater source monitoring
because it provides at least 4-log treatment of viruses at each groundwater
source.
(1) 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(c)(4)
of this title (relating to Microbial Contaminants) because it provides
at least 4-log treatment of viruses for the specified groundwater
source and begin compliance monitoring in accordance with subsection
(c) this section. The notification must include engineering, operational,
and other information required by the executive director to evaluate
the submission. If the executive director determines and documents
in writing that 4-log treatment of viruses is no longer necessary
for a specified groundwater source or if the system discontinues 4-log
treatment of viruses before the first connection for any groundwater
source, the system must document this in writing and conduct raw groundwater
source sampling as required under §290.109(c)(4) of this title.
(2) A groundwater system that places a groundwater
source in service after November 30, 2009, that is not required to
meet the raw source monitoring requirements under §290.109(c)(4)
of this title because the system provides at least 4-log treatment
of viruses for a specified groundwater source must begin compliance
monitoring within 30 days of placing the source in service in accordance
with subsection (c) of this section. The system must provide written
notification to the executive director that it provides at least 4-log
treatment of viruses before the first connection for the specified
groundwater source. The notification must include engineering, operational,
and other information required by the executive director to evaluate
the submission. The system must conduct triggered source monitoring
under §290.109(c)(4) of this title until the executive director
provides written approval of the system's request to provide the 4-log
treatment. If the system discontinues 4-log treatment of viruses before
the first connection for a groundwater source, the system must conduct
raw groundwater source sampling as required under §290.109(c)(4)
of this title.
(b) Groundwater corrective action plan. All public
water systems using groundwater must submit a corrective action plan
and implement corrective action if a raw groundwater source sample
was positive for fecal indicators or if a significant deficiency was
identified.
(1) If a groundwater source sample was found to be
fecal indicator positive or if a significant deficiency was identified,
the system must consult with the executive director regarding appropriate
corrective action and have an approved corrective action plan in place
within 30 days of receiving written notification from a laboratory
of the fecal indicator positive source sample collected under §290.109(c)(4)
of this title or within 30 days of receiving written notification
from the executive director of the identification of a significant
deficiency.
(2) Within 120 days of receiving written notification
from a laboratory of the fecal indicator positive source sample or
receiving written notification from the executive director of a significant
deficiency, the system must have completed corrective action or be
in compliance with an approved corrective action plan and schedule.
(3) Any changes to the approved corrective action plan
or schedule must be approved by the executive director.
(4) The executive director may require interim measures
for the protection of public health pending approval of the corrective
action plan. The system must comply with these interim measures as
well as with any schedules specified by the executive director.
(5) Systems that are required to complete corrective
action must implement one or more of the procedures in this paragraph
and the details of the implementation must be specified in the approved
corrective action plan.
(A) The system may disinfect the groundwater source
where the fecal indicator positive source sample was collected following
the American Water Works Association (AWWA) standards for well disinfection
and start monthly fecal indicator sampling at that source within 30
days after well disinfection. The executive director may discontinue
the monthly source sampling requirement if corrective action is sufficient.
(B) The system may eliminate the groundwater source
that was found to be fecal indicator positive and provide an alternate
groundwater source if necessary. Eliminated groundwater sources must
be disconnected from the distribution system until the contamination
is corrected and the executive director approves it for use.
(C) The system may identify and eliminate the source
of fecal contamination followed by well disinfection according to
AWWA well disinfection standards and begin monthly fecal indicator
sampling within 30 days after well disinfection. The executive director
may allow the system to discontinue the monthly source sampling requirement
after making a determination that corrective action is sufficient.
(D) The system may provide treatment that reliably
achieves at least 4-log treatment of viruses using inactivation, removal
or an executive director-approved combination of inactivation and
removal before the first connection of the groundwater source.
(E) Correct all significant deficiencies.
(F) Assessment source monitoring for a period of 12
months or a time period specified by the executive director from the
raw groundwater source in accordance with §290.109(c)(4)(E) of
this title.
(c) Microbial inactivation requirements. A system that
treats groundwater in response to a fecal indicator positive source
sample, significant deficiency, or in lieu of the raw groundwater
source monitoring shall meet minimum disinfection requirements demonstrating
at least 4-log treatment of viruses before the water is distributed
to the first connection of the specified groundwater source.
(1) Monitoring requirements for chemical disinfectants.
Groundwater systems shall monitor the performance of the disinfection
facilities to ensure that appropriate disinfectant levels are maintained
every day the specified source serves the public. All monitoring conducted
pursuant to the requirements of this section must be conducted at
sites designated in the system's monitoring plan in accordance with §290.121
of this title (relating to Monitoring Plans).
(A) Groundwater systems serving a population greater
than 3,300 must continuously monitor the residual disinfectant concentration
in accordance with the analytical methods specified in 40 Code of
Federal Regulations (CFR) §141.74(a)(2) at a location approved
by the executive director and must record the lowest residual disinfectant
concentration every day the groundwater source serves the public.
(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 and other methods that can obtain 4-log inactivation of
viruses and can be properly validated. 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.
(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 must be
measured to a minimum accuracy of plus or minus 0.1 mg/L. Samples
tested using a colorimetric method must be analyzed using a colorimeter;
spectrophotometer; or, with the written permission of the executive
director, a color comparator.
(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.
(4) Recordkeeping requirements for microbial inactivation
treatment. Groundwater systems, including wholesale, consecutive,
and mixed 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 in lieu of the raw groundwater source monitoring or
required to conduct 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(c)(4)
of this title because it provides at least 4-log treatment of viruses
for a specified groundwater source and 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(c)(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(c)(4)(D) of this title within 30 days of the positive
distribution coliform sample.
Cont'd... |
