Current through September 17, 2024
In addition to the reporting and recordkeeping requirements
in 179 NAC
13-008, a public water system subject
to the requirements of 179 NAC 17 that provides conventional filtration
treatment or direct filtration must report monthly to the Department the
information specified in 179 NAC 17-007.01 and 17-007.02 beginning January 1,
2002. In addition to the reporting and recordkeeping requirements in 179 NAC
13-008, a public water system subject
to the requirements of this chapter that provides filtration approved under 179
NAC 17-005.02 must report monthly to the Department the information specified
in 179 NAC 17-007.01 beginning January 1, 2002. The reporting in 179 NAC
17-007.01 is in lieu of the reporting specified in 179 NAC
13-008.02A.
007.01 Turbidity measurements as required by
179 NAC
17-005 must be reported within 10
days after the end of each month the system serves water to the public.
Information that must be reported includes:
1. The total number of filtered water
turbidity measurements taken during the month.
2. The number and percentage of filtered
water turbidity measurements taken during the month which are less than or
equal to the turbidity limits specified in 179 NAC 17-005.01 or
17-005.02.
3. The date and value of
any turbidity measurements taken during the month which exceed 1 NTU for
systems using conventional filtration treatment or direct filtration, or which
exceed the maximum level set by the Department under 179 NAC
17-005.02.
007.02
Systems must maintain the results of individual filter monitoring taken under
179 NAC
17-006 for at least three years.
Systems must report that they have conducted individual filter turbidity
monitoring under 179 NAC
17-006 within 10 days after the end
of each month the system serves water to the public. Systems must report
individual filter turbidity measurement results taken under 179 NAC
17-006 within 10 days after the end
of each month the system serves water to the public only if measurements
demonstrate one or more of the conditions in 179 NAC
17-007.02A to
17-007.02D.
Systems that use lime softening may apply to the Department for alternative
exceedance levels for the levels specified in 179 NAC
17-007.02A to
17-007.02D if
they can demonstrate that higher turbidity levels in individual filters are due
to lime carryover only and not due to degraded filter performance.
17-007.02A For any individual filter that has
a measured turbidity level of greater than 1.0 NTU in two consecutive
measurements taken 15 minutes apart, the system must report the filter number,
the turbidity measurement, and the date(s) on which the exceedance occurred. In
addition, the system must either produce a filter profile for the filter within
seven days of the exceedance (if the system is not able to identify an obvious
reason for the abnormal filter performance) and report that the profile has
been produced or report the obvious reason for the exceedance.
17-007.02B For any individual filter that has
a measured turbidity level of greater than 0.5 NTU in two consecutive
measurements taken 15 minutes apart at the end of the first four hours of
continuous filter operation after the filter has been backwashed or otherwise
taken offline, the system must report the filter number, the turbidity, and the
date(s) on which the exceedance occurred. In addition, the system must either
produce a filter profile for the filter within seven days of the exceedance (if
the system is not able to identify an obvious reason for the abnormal filter
performance) and report that the profile has been produced or report the
obvious reason for the exceedance.
17-007.02C For any individual filter that has
a measured turbidity level of greater than 1.0 NTU in two consecutive
measurements taken 15 minutes apart at any time in each of three consecutive
months, the system must report the filter number, the turbidity measurement,
and the date(s) on which the exceedance occurred. In addition, the system must
conduct a self-assessment of the filter within 14 days of the exceedance and
report that the self-assessment was conducted. The self assessment must consist
of at least the following components: assessment of filter performance;
development of a filter profile; identification and prioritization of factors
limiting filter performance; assessment of the applicability of corrections;
and preparation of a filter self-assessment report.
17-007.02D For any individual filter that has
a measured turbidity level of greater than 2.0 NTU in two consecutive
measurements taken 15 minutes apart at any time in each of two consecutive
months, the system must report the filter number, the turbidity measurement,
and the date(s) on which the exceedance occurred. In addition, the system must
arrange for the conduct of a comprehensive performance evaluation by the
Department or a third party approved by the Department no later than 30 days
following the exceedance and have the evaluation completed and submitted to the
Department no later than 90 days following the exceedance.
007.03 Additional Reporting Requirements
1. If at any time the turbidity exceeds 1 NTU
in representative samples of filtered water in a system using conventional
filtration treatment or direct filtration, the system must inform the
Department as soon as possible, but no later than the end of the next business
day.
2. If at any time the
turbidity in representative samples of filtered water exceeds the maximum level
set by the Department under 179 NAC 17-005.02 for filtration technologies other
than conventional filtration treatment, direct filtration, slow sand
filtration, or diatomaceous earth filtration, the system must inform the
Department as soon as possible, but no later than the end of the next business
day.
