Section Env-Ws 381.27 - Reduced and Additional Monitoring of Water Quality Parameters(a) A water system owner maintaining the range of values for the water quality parameters reflecting optimal corrosion control treatment during each of 2 consecutive 6-month monitoring periods under Env-Ws 381.26 shall continue monitoring at the entry point(s) to the distribution system as specified in Env-Ws 381.25(c).(b) Such system owner shall collect 2 tap samples for applicable water quality parameters from the following reduced number of sites as stated in Table 381-3 during each 6-month monitoring period: Table 381-3
Reduced Number of Sites for Testing Water Quality Parameters
| Number of People Served | Reduced Number of Sites for Water Quality Parameters |
| >100,000 | 10 |
| 10,001 - 100,000 | 7 |
| 3,301 - 10,000 | 3 |
| 501 - 3,300 | 2 |
| 101 - 500 | 1 |
| Less than or equal to 100 | 1 |
(c) A water system owner maintaining the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the department under Env-Ws 381.10(e) and (f) during 3 consecutive years of monitoring within each 6 month period, may request that the department reduce the frequency with which it collects the number of tap samples for applicable water quality parameters specified in (a) above from every 6 months to annually.(d) A water system owner maintaining the range of values for the water quality parameters reflecting optimal corrosion control treatment specified in Env-Ws 381.10(e) and (f) during 3 consecutive years of annual monitoring under this section, may reduce the frequency with which it collects the number of tap samples for applicable water quality parameters specified in (a) above, from annually to every 3 years.(e) A water system owner may reduce the frequency with which tap samples are collected for applicable water quality parameters specified in Env-Ws 381.27(a) and (b) to every 3 years if the system demonstrates that:(1) During 2 consecutive monitoring periods that its tap water lead level at the 90th percentile is less than or equal to 0.005 mg/L, the practical quantitation level (PQL) for lead;(2) The tap water copper level at the 90th percentile is less than or equal to 0.65 mg/L for copper as specified in Env-Ws 381.03(b); and(3) The system has maintained the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the department under Env-Ws 381.10.(f) A water system owner conducting sampling annually shall collect the sample(s) evenly throughout the year so as to reflect seasonal variability.(g) A water system owner subject to reduced monitoring frequency that fails to operate at or above the minimum value or within the range of values for the water quality parameters specified by the department under Env-Ws 381.10(e) and (f) for more than 9 days in any 6-month period specified in Env-Ws 381.10(j) shall resume distribution system tap water sampling in accordance with the number and frequency requirements in Env-Ws 381.26.(h) A water system owner in (g) above: (1) May resume annual monitoring for water quality parameters at the tap at the reduced number of sites specified in (a) and (b) above after having completed 2 subsequent consecutive 6-month rounds of monitoring that meets the criteria of Env-Ws 381.27(a) and (b); or(2) May resume triennial monitoring for water quality parameters at the tap at the reduced number of sites after demonstrating through subsequent rounds of monitoring that it meets the criteria of:a. Paragraphs (c) and (d) above; or(i) The results of any monitoring conducted in addition to the minimum requirements of this section shall be considered by the system owner and the department in making any determinations, determining concentrations of water quality parameters, under this section or Env-Ws 381.09 and Env-Ws 381.10.N.H. Admin. Code § Env-Ws 381.27
(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; amd by #9598, eff 11-21-09