(a) Applicability.The requirements of sections 5-1.40 through 5-1.48 of this Subpart shall apply to all community water systems and nontransient, noncommunity water systems serving 15 or more service connections or serving 25 or more persons.
(b)Lead and copper action levels.(1)Analyte | Action Level1,2 |
Lead | 0.015 mg/L |
Copper | 1.3 mg/L |
(2) The lead action level is exceeded if the concentration of lead in more than 10 percent (90th percentile) of the tap water samples collected in accordance with section 5-1.42 of this Subpart during any monitoring period exceeds 0.015 mg/L.(3) The copper action level is exceeded if the concentration of copper in more than 10 percent (90th percentile) of the tap water samples collected in accordance with section 5-1.42 of this Subpart during any monitoring period exceeds 1.3 mg/L.(4) The 90th percentile lead and copper levels shall be computed as follows: (i) Place the results of all lead and copper samples taken during a monitoring period in ascending order from the sample with the lowest concentration to the sample with the highest concentration. Each sampling result will be assigned a number, ascending by single integers beginning with the number one for the sample with the lowest contaminant level. The number assigned to the sample with the highest contaminant level will be equal to the total number of samples taken.(ii) Multiply the number of samples taken during the monitoring period by 0.9.(iii) The contaminant concentration of the numbered sample obtained by the calculation in subparagraph (ii) of this paragraph is the 90th percentile contaminant level.(iv) For water systems serving fewer than 100 people that collect 5 samples per monitoring period, the 90th percentile is computed by taking the average of the highest and second highest concentration.(v) For a public water system that has been allowed by the State to collect fewer than five samples under section 5-1.42(a)(3) of this Subpart, the sample result with the highest concentration is considered the 90th percentile value.Footnotes
1, Analysis of lead and copper samples must be done by an approved laboratory as prescribed in section 5-1.74(a), that demonstrates the ability to achieve a Practical Quantitation Level (PQL) for lead equal to 0.0005 milligrams/Liter (mg/L) and a PQL for copper equal to 0.050 mg/L.
2 All lead and copper levels measured between the PQL and Method Detection Level (MDL) must be either reported as measured or one-half the PQL specified in note 1. All levels below the lead and copper MDLs must be reported as zero.
N.Y. Comp. Codes R. & Regs. Tit. 10 §§ 5-1.40
Amended New York State Register January 17, 2018 /Volume XL, Issue 03, eff. 1/17/2018