New Hampshire Code of Administrative Rules
Env - Department of Environmental Services
Subtitle Env-Ws - Division of Water
Chapter Env-Ws 300 - NEW HAMPSHIRE DRINKING WATER RULES
Part Env-Ws 381 - CORROSION CONTROL TREATMENT, LEAD AND COPPER ACTION LEVELS
Section Env-Ws 381.03 - Lead and Copper Action Levels
Current through Register No. 13, March 27, 2025
(a) The lead action level shall be exceeded if the concentration of lead in more than 10% of tap water samples collected during any monitoring period conducted in accordance with Env-Ws 381.15 through Env-Ws 381.21 is greater than 0.015 mg/L, that is, if the 90th percentile as computed in (c) below, is greater than 0.015 mg/L.
(b) The copper action level shall be exceeded if the concentration of copper in more than 10% of tap water samples collected during any monitoring period conducted in accordance with Env-Ws 381.15 through Env-Ws 381.21 is greater than 1.3 mg/L, that is, if the 90th percentile as computed in (c) below, is greater than 1.3 mg/L.
(c) The 90th percentile lead and copper levels shall be computed as follows:
(See Revision Note at chapter heading for Env-Ws 300) #6521, eff 6-4-97, ss by #7734, eff 8-2-02