Section Env-Ws 381.16 - Lead and Copper Sample Collection Methods(a) Each tap sample for lead and copper collected in accordance with this part, with the exception of lead service line samples collected under Env-Ws 381.13, and samples collected in accordance with (g) below, shall be first-draw samples.(b) Each first-draw tap sample for lead and copper shall be one liter in volume and have stood motionless in the plumbing system of each sampling site for at least 6 hours but no longer than 10 hours, in accordance with the following:(1) First-draw samples from residential housing shall be collected from the cold-water kitchen tap or bathroom sink tap; and(2) First-draw samples from a non-residential building shall be collected from an interior tap from which water is typically drawn for consumption.(c) First-draw samples may be collected by the system owner or the system may allow residents to collect first-draw samples after instructing the residents of the sampling procedures specified in this section(d) If a system owner allows residents to collect water samples: (1) Acidification to first-draw samples may be performed up to 14 days after the sample is collected to avoid resident(s) handling nitric acid; and(2) The system shall not challenge, based on alleged errors in sample collection, the accuracy of sample results.(e) After acidification to re-dissolve the metals, the sample shall remain in the original container for the time specified in the approved EPA method before the sample is analyzed.(f) Non-first draw samples collected in lieu of first-draw samples pursuant to Env-Ws 381.17 shall be one liter in volume and collected at an interior tap from which water is typically drawn for consumption.(g) Each service line sample shall be one liter in volume and have stood motionless in the lead service line for at least 6 hours but no longer than 10 hours.(h) Lead service line samples shall be collected using one of the following 3 methods: (1) At the tap after flushing the volume of water between the tap and the lead service line with the volume of water calculated based on the interior diameter and length of the pipe between the tap and the lead service line;(2) By tapping directly into the lead service line; or(3) If the sampling site is a building constructed as a single-family residence, by allowing the water to run until there is a change in temperature which would be indicative of water that has been standing in the lead service line.(i) A system owner shall collect each first-draw tap sample from the same sampling site from which it collected a previous sample. If, for any reason, the system owner cannot gain entry to a sampling site in order to collect a follow-up tap sample, the system owner may collect the follow-up tap sample from another sampling site in its sampling pool as long as the new site meets the same targeting criteria and is within reasonable proximity of the original site.N.H. Admin. Code § Env-Ws 381.16
(See Revision Note at chapter heading for Env-Ws 300) #6521, eff 6-4-97, ss by #7734, eff 8-2-02; amd by #8351, eff 5-14-05