Current through Register Vol. 39, No. 12, December 1, 2024
(a)
Required tests. If a public water system uses disinfectants or other chemicals
for the treatment of water, residual disinfectant tests and other applicable
water quality tests required by this Subchapter shall be made during every
oversight visit to the facility required by Rule .1303 of this Section.
Residual disinfectant concentrations shall be maintained in accordance with
15A NCAC
18C .2002 and
18C .2201 and shall be tested as
follows:
(1) Residual disinfectant tests at
the entry point. For systems providing treatment, residual disinfectant
concentrations shall be measured in the water entering the distribution system
by the operator during every visit required by Rule .1303(a) of this
Section.
(2) Residual disinfectant
tests in the distribution system shall be performed as follows:
(A) Residual disinfectant concentrations
shall be measured weekly at locations that represent maximum residence time of
the water in the distribution system or at other locations with high water age.
These locations shall be designated on the sample siting plan required under
15A NCAC
18C .1534. The number of required weekly
tests is shown in Table A below. Samples collected on the same day must be
collected from different locations.
Table A: Measurement Requirements for Residual Disinfectant
Concentrations and Chloramine Operational Parameters
|
Distribution System Classification according to
15A NCAC 18D
.0205(b)
|
Minimum Number of Samples Per Week
|
|
D
|
1
|
|
C
|
3
|
|
A and B
|
5
|
(B) Distribution systems classified as C or D
in Table A may request the Department to reduce the requirements for measuring
residual disinfectant concentrations in the distribution system at the
locations that represent maximum residence time or other locations with high
water age as required in Part (a)(2)(A) of this Rule. The request shall be in
writing and shall demonstrate to the Department that the residual disinfectant
concentrations measured at the entry point in accordance with Subparagraph
(a)(1) of this Rule are sufficient in providing the minimum residual
disinfectant concentrations required under
15A NCAC
18C .2002 and
18C .2201. The Department shall
consider the presence of continuous monitoring, size and configuration of the
distribution system, magnitude of disinfectant degradation and results of
performance studies.
(3)
Chloramine Operational Parameters. When ammonia and chlorine are applied
disinfectants, the system shall measure analytical parameters pertinent to the
operation as follows:
(A) Water entering the
distribution system. Parameters to be measured shall, at a minimum, include
total chlorine, monochloramine, free ammonia, and pH and shall be performed
daily, while the treatment facility is in operation.
(B) Water in the distribution system.
Parameters to be measured shall, at a minimum, include total chlorine,
monochloramine, free ammonia, and pH and shall be measured no less often than
denoted in Table A.
(b) Forms, Reports and Records. A public
water system shall report and retain records as follows:
(1) Test results shall be documented and
reported monthly on forms and in a format provided by the Department and shall
be signed by the ORC. Copies of report forms may be obtained from the Public
Water Supply Section. The monthly report shall be submitted by the
10th day of the following month to the Public Water
Supply Section.
(2) The forms and
reports shall be in an electronic format provided by the Department for water
systems owned or operated by local governments and all community water systems
serving 1,000 or more service connections or 3,000 or more individuals,
regardless of ownership, effective April 1, 2010. Community water systems
serving less than 1,000 service connections and less than 3,000 individuals and
all non-transient, non-community water systems shall report test results in an
electronic format provided by the Department effective October 1, 2010. The
Department may waive the requirement for electronic submission in accordance
with G.S. 130A-329. Requests for
waivers shall be submitted in writing to the Department no less than two months
prior to the deadline.
(3) Records
documenting compliance with Section .1300 shall be retained on the premises of
the water system for a minimum of three years.
Authority
G.S.
90A-29;
130A-315;
P.L.
93-523;
Eff. January 1,
1977;
Readopted Eff. December 5, 1977;
Amended Eff.
October 1, 2009; July 1, 1994; September 1, 1990; February 1, 1987; June 30,
1980;
Pursuant to
G.S.
150B-21.3A, rule is necessary without
substantive public interest Eff. November 23,
2015.
