UTILIZING GEOLOGIC MAPS AS TOOLS TO EVALUATE INITIAL PROJECT FEASIBILITY IN NORTHERN NEW ENGLAND

Geologic maps are valuable resources for individuals interested in earth processes, materials, and landform history. These maps, whether basic or specialized, contain a wealth of data pertaining to surface and subsurface earth conditions. This information can then be employed in a variety of ways to determine the feasibility of small and large scale projects in the private and public sectors alike. Examples from recent development and remediation projects in northern New England are utilized to showcase the potentials and pit falls associated with applications of geologic mapping.

Detailed examination of geologic maps, in addition to other resources, can help answer complex questions for a variety of different project types, and judge whether the intents of the projects are feasible or defensible. For example, evaluation of geologic maps can help address environmental concerns at sites with known or suspected contamination, as well as enabling interpretation of contaminant migration trends and potential impacts to sensitive receptors. Surficial, bedrock and aquifer maps are important when evaluating the likelihood of developing a viable and sustainable groundwater supply, whether within bedrock or overburden deposits. Detailed aquifer maps can aid in the prediction of the saturated thickness, transmissivity, and potential yield at a given location, and bedrock lineament maps and orthophotographic imagery can help resolve well siting challenges. Bathymetric and historical maps can assist in interpretation of previous site uses, landscape alterations, or rates of sediment accretion. Site suitability relative to borrow or mineral extraction can be evaluated with the aid of surficial mapping. Topographic, FEMA flood, and coastal geologic maps can also be used to evaluate the feasibility of development in high risk areas.

Utilizing geologic maps in these ways during initial planning stages can help determine whether a project can proceed with the probability of a positive outcome, or whether it should be postponed or reevaluated prior to expenditure of significant project resources. Surficial, bedrock, and aquifer maps published by the Maine Geological Survey, New Hampshire Geological Survey and USGS demonstrate the quality in local mapping and the continued need to resolve details to a finer scale.