1. (a) For well source(s) constituting a large groundwater withdrawal as defined in RSA 485-C:2, the owner shall apply for and receive a large groundwater withdrawal permit in accordance with Env-Wq 403 prior to submitting part II of the design review application required by 406.09. Where the requirements of (b) through (h) below conflict with the requirements of Env-Wq 403, the stricter requirement shall apply.
2. (b) For all non-community water systems having a design flow of 13,500 gpd or greater, the owner shall demonstrate adequate source capacity by performing a sustained 48-hour pumping test at a constant rate for all wells proposed to be connected to the PWS. The pumping test shall meet the requirements of (c) through (h) below and demonstrate stabilized drawdown for at least the last 12 hours of the test. Stabilization is defined as a drawdown of less than one inch in 2 hours. If stabilization is not achieved, the pumping test shall continue and the department shall be contacted.

3. (c) The owner shall submit data documenting the pumping test on a pumping test log sheet that includes the following items:

   1. (1) Well depth, in feet;
   2. (2) The date of the pumping test;
   3. (3) The pumping rate, in gallons per minute (gpm);
   4. (4) The level of water in the well prior to pumping in feet below top of casing;
   5. (5) The drawdown level during pumping, in feet below top of casing;
   6. (6) The time the test was initiated and concluded and the total hours of the test;
   7. (7) Water levels in the PWS’s existing wells as required by (g) and (h) below, where applicable; and
   8. (8) On-site weather condition observations during pumping.
4. (d) Each log sheet shall be identified by project name, well number or name, location, and submittal date.
5. (e) Readings for water level and pumping rate shall be taken at least every hour so long as the change in drawdown exceeds 2 feet per hour. Thereafter, readings may be taken at appropriate intervals not to exceed 4 hours. Readings shall be direct measurements and not inferred from pump curves or other inferential methods.
6. (f) Where proposed wells are within 150 feet of each other, the pumping tests shall be run simultaneously.
7. (g) For an existing PWS, water levels in the PWS’s other well(s) shall be recorded before the pumping test starts, during the pumping test at intervals no greater than once every 4 hours, and just after the pumping test ends.
8. (h) For an existing PWS with one or more existing wells that will continue to be used even if the proposed well is approved, each other well shall be operated as usual to demonstrate system capacity requirements as defined in Env-Dw 406.12.
9. (i) Upon completion of the pumping test, the department shall determine the well capacity based on the constant pumping rate at which stabilization is demonstrated.
10. (j) For all non-community water systems having a design flow less than 13,500 gpd, the capacity of all wells connected to the PWS shall be determined by either a pumping test performed pursuant to (b) above or the well completion report submitted by a licensed well driller in accordance with We 801.

Source. (See Revision Note at part heading for Env-Dw 406) #10613, eff 6-1-14; ss by #14158, eff 12-25-24 (formerly Env-Dw 406.13)