New York Codes, Rules and Regulations
Title 10 - DEPARTMENT OF HEALTH
Chapter I - State Sanitary Code
Part 5 - Drinking Water Supplies
Subpart 5-1 - Public Water Systems
Control of Copper and Lead in Drinking Water
Section 5-1.43 - Monitoring requirements for water quality parameters

(i) Distribution system (tap) samples shall be representative of water quality throughout the distribution system, taking into account the number of persons served, the different sources of water, the different treatment methods employed by the system, and seasonal variability. Distribution system sampling under this section is not required to be conducted at taps targeted for lead and copper sampling under section 5-1.42(a) of this Subpart.

(ii) Entry point samples to the distribution system shall be from locations representative of each source after treatment. If a system draws water from more than one source and the sources are combined before distribution, the system shall sample at entry point(s) representative of normal operating conditions.

(i) A water system conducting standard monitoring shall collect two samples for applicable water quality parameters during each monitoring period specified in subdivision (b) of this section from the number of distribution system sampling sites listed in the table below under Standard Monitoring. A water system conducting reduced monitoring shall collect two samples for applicable water quality parameters during each monitoring period specified in subdivision (c) of this section from the number of distribution system sampling sites listed in the table below under Reduced Monitoring. Such reduced monitoring sites shall be representative of the sites required for standard monitoring

(ii) A water system conducting monitoring in accordance with paragraph (b)(1) of this section shall collect two entry point samples for each applicable water quality parameter at each entry point to the distribution system during each six-month monitoring period. A water system conducting monitoring in accordance with paragraphs (b)(2), (3), and subdivision (c) of this section shall collect one entry point sample for each applicable water quality parameter at each entry point to the distribution system, or each applicable entry point in accordance with subparagraph (b)(2)(iii) of this section, at the frequency specified in subparagraph (b)(2)(ii) of this section.

(i) Two samples shall be collected at taps in the distribution system for the following parameters: pH; alkalinity; calcium; and orthophosphate or silica, as appropriate to the corrosion control treatment used.

(ii) One sample shall be collected at each entry point: Except as provided in subparagraph (iii) of this paragraph, at least one sample no less frequently than every two weeks (biweekly) for pH; alkalinity (and a reading of the dosage rate of the chemical used to adjust alkalinity, when alkalinity is adjusted); calcium; orthophosphate or silica, as appropriate to the corrosion control treatment used; and a reading of the dosage rate of the corrosion control treatment chemical used.

(iii) A ground water system may limit entry point sampling described in subparagraph (ii) of this paragraph to those entry points that are representative of water quality and treatment conditions throughout the system. If water from untreated ground water sources mixes with water from treated ground water sources, the system shall monitor for water quality parameters both at representative entry points receiving treatment and representative entry points receiving no treatment. Prior to the start of any monitoring under this paragraph, the system shall provide to the State written information identifying the selected entry points and documentation, including information on seasonal variability, sufficient to demonstrate that the sites are representative of water quality and treatment conditions throughout the system.

(i) Any water system that maintains the range of State-specified values for the water quality parameters reflecting optimal corrosion control treatment during three consecutive years of monitoring in accordance with paragraph (1) of this subdivision may reduce the frequency with which it collects the number of distribution system samples for applicable water quality parameters specified in paragraph (1) of this subdivision from every six months to annually. This sampling shall begin during the calendar year immediately following the end of the monitoring period in which the third consecutive year of six-month monitoring occurs. Any water system that maintains the range of State-specified values for the water quality parameters reflecting optimal corrosion control treatment during three consecutive years of annual monitoring under this paragraph may reduce the frequency with which it collects the number of distribution system samples for applicable water quality parameters specified in paragraph (1) of this subdivision from annually to every three years. This sampling begins no later than the third calendar year following the end of the monitoring period in which the third consecutive year of monitoring occurs.

(ii) A water system may reduce the frequency with which it collects the number of distribution system samples for applicable water quality parameters specified in subdivision (c)(1) of this section to every three years if it demonstrates during two consecutive monitoring periods that its tap water lead level at the 90th percentile is less than or equal to the PQL for lead specified in section 5-1.40(b)(1) of this Subpart, that its tap water copper level at the 90th percentile is less than or equal to 0.65 mg/L for copper, and that it also has maintained the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the State under section 5-1.41(f) of this Subpart.

(iii) Monitoring conducted every three years shall be done no later than every third calendar year.