Hydrogeologic (Ground Water) Investigations

Charter Oak hydrogeologists possess 40 years of combined hydrogeologic investigation experience in a wide array of oftentimes complex environmental settings including; glacial till and stratified drift aquifers typical of New England;  bedrock aquifers; large alluvial aquifers typical of the Rocky Mountains and the Great Basin; and, extreme arid environments such as the Great Sahara Desert.  Charter Oak personnel have performed hundreds of hydrogeologic investigations in projects ranging in size from less than one acre to tens of square miles and to depths in excess of 500 feet.  Charter Oak’s hydrogeologic investigation services include ground water contamination investigations, water resource and water supply evaluations, well-head protection services, aquifer test design and implementation and numerical ground water flow and contaminant transport modeling. Charter Oak’s hydrogeologic investigation expertise includes:

  • Design and installation of monitoring wells and aquifer test pumping wells utilizing a variety of drilling and exploration methods tailored to specific project needs including hollow-stem auger, spun casing, air rotary, mud rotary and cable tool drilling methods
  • Interpretation of geophysical data to assist in hydrogeologic interpretation
  • Design, implementation and analysis of aquifer tests ranging in size from slug tests of individual wells to multi-well / multi-day pumping tests
  • Development of Drinking Water Source Protection Plans in accordance with state law
  • Collection of soil, surface water and ground water samples
  • Two and three-dimensional numerical ground water flow and mass transport modeling
  • Negotiation of work plans with regulatory authorities;
  • Technical reporting
  • Routine ground water monitoring and reporting

Two representative hydrogeologic investigation projects are described below.

Charter Oak hydrogeologists participated in the investigation of an aerospace manufacturing company where ground water was found to contain chlorinated solvents and hexavalent chromium.  The project site is underlain by a stratified drift aquifer confined by an aquaclude at about 35 feet below grade.  Charter Oak successfully demonstrated that solvents detected in the lower portion of the aquifer did not result from site releases, but were caused by an off-site source.

Charter Oak hydrogeologists are leading a fourteen year investigation of ground water impacts related to an active explosives manufacturing site in Utah.  Over thirty-five monitoring wells have been constructed to depths of more than 500 feet using a variety of drilling technologies.  In addition to these monitoring wells, over twenty private and municipal water supply wells are included in an extensive ground water monitoring program. The hydrogeologic investigation resulted in the construction and operation of a ground water recovery and treatment system having a design capacity of 2,500 gpm.