Section Env-Wq 403.09 - Conceptual Hydrologic Model and Potential Impact Area(a) The conceptual hydrologic model of the withdrawal required by Env-Wq 403.06(a)(5) shall: (1) Be developed by a qualified professional;(2) Identify the sources of information used to develop the model; and(3) Be prepared as specified in (b) through (k), below.(b) The conceptual hydrologic model shall be based on information including but not limited to: (1) A summary of the results of any hydrogeologic investigations conducted on site to date;(2) Historical water level data;(3) Department records for existing water users and resources including testing and production reports, as available;(4) Published reports and maps;(5) Natural Resource Conservation Service maps, as applicable;(6) Hydrogeologic mapping information such as surficial material, lineament, and bedrock or other remote sensing analysis; and(7) Geophysical data, if available.(c) Where historical environmental data is used to develop the conceptual hydrologic model, such data shall be adjusted to account for any major land use changes that have occurred.(d) As required by RSA 485-C:21 (a) and (b), V-e, the conceptual hydrologic model pumping conditions shall be based on the assumption of 180 days of continuous operation of the withdrawal at maximum rates without direct recharge to groundwater from rainfall or snowmelt.(e) The conceptual hydrologic model shall include:(1) A description of the geology and geomorphologic history of the region including the governing hydrogeologic characteristics of the bedrock and surficial geologic formations, such as the chronology and mechanisms of origin and change, grain size distribution, and bedrock fracture characteristics;(2) Generalized geologic cross-sections through the region, including at least one through the well or withdrawal site, based on available information such as well logs, geologic reports, maps, and subsurface data; and(3) Delineated extents of the potential impact area and its components, and a description of how the delineated potential impact area meets the requirements of RSA 485-C:21, V-e.(f) The conceptual hydrologic model shall identify data needed to refine the model to complete the report required by Env-Wq 403.20.(g) Where data gaps are identified during the development of the conceptual hydrologic model, the model shall:(1) Identify the data gaps and their significance to understanding the potential impacts of the proposed withdrawal; and(2) Estimate the reasonably suspected hydrologic scenario(s) associated with the withdrawal that could occur given the known and unknown model parameters.(h) The estimated extents of the potential impact area and each of its components shall be presented on a map that: (1) Is at a scale of 1:24,000 or 1:25,000, or at a scale that gives greater detail;(2) Has as its base a United States Geologic Survey (USGS) topographic map or an original map depicting equivalent features and information; and(3) Shows a map legend that includes a map title, date, scale, and north arrow.(i) A description of the hydrologic cycle and a water budget calculation for the potential impact area shall be prepared that describes: (1) The amounts and timing of precipitation, runoff, storage, recharge, and discharge;(2) The distribution and availability of water necessary to maintain natural resources, existing water uses, and the proposed withdrawal; and(3) The location and amounts of natural and artificial loss of water, consumption, discharge, and recharge of water to and from the potential impact area.(j) A comprehensive description of the groundwater flow regime for the potential impact area that describes hydraulic boundaries, recharge characteristics, and the interaction of water bodies associated with the withdrawal shall be prepared that includes: (1) Hydrologic conditions at the water table, in any confining or semi-confining layers of the overburden aquifer, and in the bedrock;(2) The occurrence of groundwater flow both in horizontal and vertical directions, under average, non-pumping, and conceptual hydrologic model-based operating conditions;(3) The magnitude and direction of vertical and horizontal hydraulic gradients, under average, non-pumping, and conceptual hydrologic model-based operating conditions;(4) Hydraulic influences of regional groundwater flow from all aquifers and surface water bodies, or other water resources in hydraulic communication with the proposed withdrawal; and(5) Preferential groundwater flow pathways caused by the properties of the deposits or bedrock.(k) The conceptual hydrologic model and the estimated extents of the potential impact area shall be refined in accordance with Env-Wq 403.17 and presented in the report required by Env-Wq 403.20 based on results from withdrawal testing performed in accordance with Env-Wq 403.16.N.H. Admin. Code § Env-Wq 403.09
(See Revision Note at part heading for Env-Wq 403) #9569, eff 10-17-09
Amended by Volume XXXVIII Number 15, Filed April 12, 2018, Proposed by #12493, Effective 3/21/2018, Expires 3/21/2028.