Hampton Airfield Hydrogeologic Study

Hampton and North Hampton, New Hampshire

PROBLEM | The Hampton Airfield, a grass runway airfield primarily used for small propeller planes and helicopters, needed to grow and modernize to meet greater demand. The project included paving a portion of the landing strip, taxiways, and access roads in addition to overhauling the stormwater management system at the site. However, the airfield site is within the North Hampton and Hampton Aquifer Protection Districts and aquifer recharge zones and is therefore subject to the town Aquifer Protection Ordinance Regulations. Additionally, a major public water supply utility, Aquarion, maintains two gravel packed wells that draw water from the sand and gravel aquifer located downgradient of the airfield.

SOLUTION & METHOD | The airfield area is underlain by a stratified drift deposit composed of sand and gravel that also underlies a large area of North Hampton and Hampton, NH. TruslowRC was brought in to coordinate and complete a hydrogeologic study to determine existing and potential impacts to groundwater quality and aquifer recharge from the proposed project. Phase I of the study was completed in April 2015 and included a site visit, review of existing private and USGS reports, and evaluation of NHDES Onestop data. We also mapped registered wells, potential contamination sources, and aquifer and surface water characteristics. The existing Stormwater Pollution Prevention Plan, emergency response measures and pre-and post stormwater drainage modeling were also reviewed to understand spatial and total changes in recharge to the aquifer and potential water quality impacts.

The report and findings were presented to area planning boards in support of the project, which was ultimately approved. Additional monitoring well installation and water quality sampling was completed in 2015 with follow-up monitoring later in 2015 and 2016. Since the end of this initial project, a planned expansion of the on-site café, airfield office, and classroom training area was submitted to the local planning board in 2016. We were again engaged to provide an update to the hydrogeologic study in support of this new planning board application. As additional hydrologic concerns arise we continue to provide hydrogeologic consulting support to the airfield owners as needed.