N.H. Admin. Code § Env-Dw 302.14

Current through Register No. 50, December 12, 2024

Section Env-Dw 302.14 - Proposal for Pumping Test

(a) The pumping test proposed pursuant to Env-Dw 302.08(i) shall be designed and conducted to gather site-specific information necessary to:

(1) Demonstrate that the permitted production volume is sustainable;

(2) Demonstrate the water quality of each proposed new well;

(3) Assess impacts from the proposed well on surrounding water resources and water uses;

(4) Address critical data gaps identified in the conceptual hydrogeologic model;

(5) Refine the conceptual hydrogeologic model and the estimated wellhead protection area and justify the selected refinement methodology;

(6) Develop a contamination control program for each known contamination source;

(7) Develop a wellhead protection program for all contamination sources identified in accordance with Env-Dw 302.13; and

(8) Demonstrate the system source capacity required by Env-Dw 402, Env-Dw 404 or Env-Dw 405, as applicable.

(b) A standard pumping test shall:

(1) Have an antecedent period, a pumping period, and a recovery period as described in (d), below;

(2) Pump and discharge water as described in (e), below;

(3) Measure groundwater as described in (f), below;

(4) Measure surface water as described in (g), below;

(5) Monitor wells as described in (h), below; and

(6) Track ambient conditions as described in (i), below.

(c) The pumping test proposal shall include the following:

(1) The proposed pumping test production rate;

(2) A site sketch showing locations of:

a. Each test well;

b. Each monitoring well;

c. Each surface water staff gauge or other water level measuring device;

d. All other monitoring and recording locations; and

e. Each discharge location;

(3) A description of and justification for monitoring well layout, construction, and screening;

(4) A description of borehole drilling and sampling techniques;

(5) A table showing the schedule for the collection of water level measurements;

(6) A table of the horizontal distance between observation points and each test well;

(7) A description of the construction of any surface water level staff gauges;

(8) Supporting information demonstrating the discharge location complies with (e)(1), below;

(9) A description of the method and equipment that will be used to ensure a constant pumping rate is maintained;

(10) A schedule for measurement of discharge;

(11) A copy of the notification letter that extends an offer to monitor water levels in wells identified in accordance with (h), below;

(12) A description of how any other of the system's wells will be operated during the pumping test program;

(13) The anticipated pumping test duration; and

(14) The construction details for each test well.

(d) The 3 required pumping test periods shall be as follows:

(1) The antecedent period shall be the 7-day period immediately preceding the start of pumping, during which non-pumping hydrologic conditions are monitored;

(2) The pumping period shall be as follows:

a. For large overburden production wells, 5 days or until the average change in water level in the pumping well, or in an observation well within 5 feet of the pumping well, is 0.5 feet or less over a period of at least 24 hours, except that the pumping period shall be no less than 3 days in duration;

b. For large bedrock production wells, 7 days or until the average change in water level in the pumping well is 0.5 feet or less over a period of at least 24 hours except that the pumping period shall be no less than 5 days in duration; or

c. For a new source for a large CWS that does not qualify as a large production well, not less than 72 hours; and

(3) The recovery period, during which the aquifer system recovers from the stress of pumping, shall begin immediately upon cessation of pumping and continue for:

a. A duration at least equivalent to the pumping period; or

b. The water level in the test well or the nearest well within 5 feet of the pumping well has recovered to 90% of the pre-pumping level, provided the recovery period monitoring is not less than 24 hours.

(e) The pumping of and discharge from each test well and the system's other production wells, if any, shall be as follows:

(1) The pumped water shall be discharged outside the estimated contributing area of the test wells so there is no effect on the pumping test results;

(2) The pumping rate in each test well shall be recorded at least as often as water level measurements, after the first 10 minutes of pumping;

(3) The discharge rate from the test well shall be measured using at least one of the following methods:

a. With a circular orifice weir, provided that:

1. A physical description of the weir is provided in the preliminary report; and

2. A table of gauge or manometer readings with calculated discharge rates is provided in the final report;

b. With a cumulative flow meter or other equivalent device provided that;

1. Each discharge measurement includes at least 2 meter readings that are collected over a period that is not greater than one minute; and

2. The meter has been calibrated in accordance with manufacturer specifications within one year prior to the pumping test; or

c. With a device that can be demonstrated to record measurements that are accurate to within 5% of the discharge rate;

(4) The discharge from other system wells shall be measured using cumulative flow meters or equivalent devices;

(5) Each test well shall be pumped at a single, constant rate that, when multiplied by 24 hours, produces the proposed permitted production volume; and

(6) The system's other wells shall be operated continually at their permitted production volumes or established capacities, unless data is provided to demonstrate that the wells will not affect aquifer response to pumping the proposed production well.

(f) Groundwater level measurements shall be made:

(1) To the nearest 0.01 foot;

(2) At the following locations:

a. Each test well;

b. Each of the water system's other production wells, if within the estimated area influence of the test well(s);

c. One background monitoring well located outside the expected influence of the test well(s);

d. For large overburden production wells, at least 4 monitoring wells within the expected area of influence of the test well(s);

e. For large bedrock production wells, at such locations as to gather sufficient site specific information such as that obtainable from monitoring wells or geophysical techniques;

f. Other water supply wells in accordance with (4), below; and

g. Such additional locations as are necessary to meet the objectives of the pumping test;

(3) During the antecedent period, twice daily in the background well, each test well and one selected monitoring well, when such wells are used in a pumping test;

(4) During the pumping period, beginning at one minute after the start of pumping until shut down, so that at least 10 data points per log cycle of time in minutes are recorded for each test well and each selected monitoring well; and

(5) During the recovery period, beginning at one minute after shut down of the pump until the end of the recovery period, so that at least 10 data points per log cycle of time, in minutes, are recorded for each test well and each selected monitoring well.

(g) Surface water levels in waters within 1,000 feet of the test wells shall be measured to the nearest 0.01 foot not less than once every 6 hours during the antecedent, pumping, and recovery periods, provided that the applicant shall propose a more frequent monitoring schedule if the surface water elevation is affected by a dam or other control structure.

(h) Water levels in private and public wells shall be monitored as follows:

(1) At least 14 days prior to the start of the pumping test program, the applicant shall send a written request for permission to monitor a well via certified mail, return receipt requested, or by another method that provides documentation that the notice has been delivered, to:

a. The owner of each private well and each public well located within 1,000 feet of the proposed new source; and

b. The owners of representative wells within 1,000 feet of the estimated cone of depression, determined based on the conceptual hydrogeologic model developed as required by Env-Dw 302.08(e);

(2) The applicant shall propose a schedule on which the water levels in the wells will be monitored and the method by which the water levels will be measured and recorded; and

(3) The applicant shall monitor the water levels in accordance with the approved preliminary report.

(i) Ambient conditions shall be monitored as follows:

(1) Rainfall shall be measured to the nearest 0.1 inch throughout the pumping test program at the proposed well site;

(2) If the aquifer is subject to confining conditions, barometric pressure shall be measured throughout the pumping test program at the proposed well site on a schedule consistent with water level monitoring performed on the production well; and

(3) Site activities and weather conditions shall be observed and logged daily throughout the pumping test program at the well site.

(j) For a large production well, the applicant may propose an alternative pumping test method provided the alternative:

(1) Meets the objectives stated in (a), above;

(2) Will provide the data necessary to refine the preliminary estimate of the wellhead protection area;

(3) Will produce results that are superior or equivalent to the results obtained using the method described in (d) through (i), above; and

(4) Will be justified in the final report based on observations collected during the pumping test.

(k) The proposal for an alternative pumping test shall include the information specified in (c), above, together with information demonstrating that the alternative meets the requirements specified in (j), above.

N.H. Admin. Code § Env-Dw 302.14

(See Revision Note at part heading for Env-Dw 302) #9008, eff 10-19-07

Amended by, Volume XXXVI Number 14, Filed April 7, 2016, Proposed by #11061, Effective 4/1/2016, Expires 4/1/2026.