Section Env-Dw 305.11 - Preliminary Estimate of the Wellhead Protection Area and Proposed Refinement(a) The estimate of the wellhead protection area shall be derived for small overburden production wells, except those in confined aquifers, by drawing a circle with a 4,000 foot radius around the well or, when sufficient data is available, by using the method as specified in (c)(1), below.(b) For small bedrock production wells and small overburden production wells in confined aquifers, the estimate of the wellhead protection area shall be derived by drawing a circle around the well with a radius based on the proposed permitted production volume, as set forth in Table 305-2: Table 305-2: Wellhead Protection Area Radii
Permitted Production Volume (gallons per day) | Radius (feet) |
0 to 7,200 | 1,300 |
7,201 to 14,400 | 1,500 |
14,401 to 28,800 | 2,050 |
28,801 to 43,200 | 2,850 |
43,201 to less than 57,600 | 3,600 |
(c) The wellhead protection area refinement method required by Env-Dw 305.08(h) for small overburden production wells, except those in confined aquifers, shall be one of the following: (1) An analytical or numerical model that identifies the contributing area of the well based on assuming180 days of continuous pumping without recharge from precipitation, provided that the model's assumptions are not violated and conservative estimates of aquifer parameters are used; or(2) A circle centered on the well having a radius of 4,000 feet.(d) The wellhead protection area refinement method required by Env-Dw 305.08(h) for small bedrock production wells and small overburden production wells in confined aquifers shall be the same methodology used in (b), above, based on the permitted production volume established by the pumping test performed in accordance with Env-Dw 305.19.N.H. Code Admin. R. Env-Dw 305.11
Adopted by, Volume XXXVI Number 14, Filed April 7, 2016, Proposed by #11062, Effective 4/1/2016, Expires 4/1/2026.