case studies

Contamination Assessment
Princeton, NJ
HES completed a subsurface investigation of an MTBE contaminated bedrock aquifer using rock coring drilling methods. We applied New Jersey Department of Environmental Protection (NJDEP) groundwater fate and transport modeling to bedrock aquifer using data collected from our investigation to determine groundwater flow regimes, and current and future impacts to the hydrogeologic system.

Contamination Assessment/Remedial Engineering
Bellmore, NY
HES was retained to conduct an assessment of a gasoline spill to the sole source aquifer on Long Island. Our investigation included an accelerated site characterization using a portable field laboratory, and determination of the vertical and areal extent of gasoline impacts to the underlying aquifer. The project included a remedial system design and implementation for site cleanup and long-term operation, maintenance and monitoring of the site.

White Plains, NY
HES led an assessment of the impact of a large gasoline spill for the New York State Department of Environmental Conservation (NYSDEC) Region 3 Office. This project included subsurface investigations of the overburden and bedrock aquifers beneath the site, pilot test studies and remedial system design for site cleanup. HES's remedial system design included the application of dual phase high vacuum extraction and pump and treat technologies. top

Port Jefferson, NY
To delineate the extent of hydrocarbon compounds in soil and groundwater beneath a former petroleum bulk storage facility in Port Jefferson, NY, HES installed 38 monitor wells at the site. Based on the results of the subsurface investigation and pilot testing, HES designed a suitable remediation system for the site. The system included two groundwater recovery wells, and two Soil Vapor Extraction (SVE) trench systems. HES interfaced and coordinated this project with the New York State Department of Environmental Conservation (NYSDEC) Region 1 Office regulatory personnel. top

Hastings-on-Hudson, NY
An innovative subsurface investigation program was designed by HES using the Geoprobe drilling method to determine the horizontal and vertical extent of No. 6 fuel oil and dense non-aqueous phase liquid (DNAPL) (chlorinated solvent) impact on soil and groundwater along the property boundary of a former petroleum bulk storage facility located in Hastings-on-Hudson, NY. Based on the results of the subsurface investigation, HES designed a remediation plan for the area affected by the No. 6 fuel oil. HES interfaced and coordinated this project with regulatory personnel from the New York State Department of Environmental Conservation (NYSDEC) Region 3 Office. top

Bayside, NY
HES directed an environmental investigation and UST removal in Bayside, which involved a Risk Based Corrective Action (RBCA) approach to site assessment and remedial determination. Based upon observations and data collected during site activities, HES determined that the most reliable remedial strategy was through the application of Soil Vapor Extraction (SVE) technology. top

Albany/Schenectady, NY
HES's offices have managed five projects for a major gasoline distributor/vendor related to remediation of hydrocarbon impacted groundwater through the use of vapor extraction, air sparging, and pump and treat remediation technologies. Additionally, HES conducts compliance groundwater sampling and reporting at such sites to determine the best course of action and ensure compliance with regulatory agencies. HES maintains continual contact with the New York State Department of Environmental Conservation (NYSDEC) during project activities. top

Water Supply
Putnam Valley, NY
Community leaders in Putnam Valley retained HES to create groundwater resource overlay maps and delineate aquifer protection zones on a town-wide basis. Maps were subsequently used to recommend zoning changes to the Town Code to promote environmentally sound development practices in designated aquifer protection zones. Our study was completed as part of the Town master plan. top

Rockaway Beach and New York City
HES has completed construction dewatering projects by calculating aquifer parameters to determine the number of wells and volume and duration of pumping during large construction projects. The calculations completed by HES allowed for accurate well placement and groundwater pumping so that building foundations, parking garages and waterproofing could be properly installed.

Water Supply/Remedial Engineering
Dobbs Ferry, NY
To address various geotechnical issues outlined by the Town of Dobbs Ferry Planning Department, HES conducted an environmental and subsurface investigation. The investigation included collection of groundwater samples to determine groundwater quality beneath the subject property, and collection of subsurface soil data to determine slope stability and the nature and areal extent of a former construction and demolition (C&D) debris landfill area. The C&D area was investigated to determine the feasibility of constructing proposed condominium units. HES assisted with the proposed construction design and soil vapor remediation methodologies, as well as interfacing the project with the Westchester County Department of Health (WCDOH) and the New York State Department of Environmental Conservation (NYSDEC) Region 3 Office. top

Environmental Insurance Claims
Gibbstown, NJ
HES completed environmental oversight during the remediation of a residential fuel oil spill on behalf of a major insurance carrier. Site activities included delineation of the fuel oil spill in the soil and groundwater beneath the site, remediation action oversite, soil and groundwater quality sampling, and reporting to the New Jersey Department of Environmental Protection (NJDEP) for project review.

Legal Support/ Surface Water Hydrology
Old Forge, NY
HES was retained to provide technical assistance to legal counsel for a private club in the Adirondack Mountains regarding a legal case over the navigability of a privately owned wilderness river. This project included calculating stream discharge from the historical record, application of fluvial geomorphological principles, and design and installation of a stream gauge on the river. top

Bethel, NY
The legal counsel for a private hunting and fishing club retained HES to provide expert testimony on behalf of the club regarding reservoir navigability rights to the general public. HES was retained to estimate historical stream flows on the streams tributary to an existing reservoir, prior to retaining dam construction. The project included setup of five field and gaging stations for data collection purposes, and application of hydrologic principles using available Geographical Information System (GIS) and stream profiling computer software. top