Site Remediation Projects

Bayard Street Right-Of-Way Site

This site is a New Mexico Department of Transportation right-of-way that has been impacted by hydrocarbons from a leaking PST system.  After characterizing the nature and extent of contamination at the site, INTERA conducted demolition and excavation activities, including the removal of existing structures and paving, as well as the excavation and disposal of approximately 640 tons of petroleum-contaminated soil. We also provided turnkey services for the design, construction, and operation of a groundwater pump-and-treat system. The remediation system was designed to arrest the migration of contaminants toward an intermittent creek located adjacent and downgradient to the site. The remediation system includes pneumatic pumps, an air stripper, and granular activated carbon polishing. Treated water is discharged to the city sewer. Operation of the remediation system showed that it is effective at producing a pressure response across the design area and that the treatment system is effectively 100% efficient in treating extracted groundwater.

Chiltipin Creek Site

INTERA provided remedial design and remedial construction oversight at a site along the Gulf coast where petroleum crude oil was discharging into a creek adjacent to a residential area.  This included aquifer characterization, computer design simulations, remedial design, plans and specifications preparation, and construction oversight. Prior to completing the final design, we conducted engineering studies to determine the effectiveness and constructability of an interceptor trench.  INTERA conducted multi-phase simulations of the crude oil and groundwater flow to validate the basic design concept and ensure that a trench would effectively capture the oil. Once the relevant issues had been resolved, INTERA designed a passive interceptor-collector trench, and provided an engineering cost estimate and bid specifications.  The overall design package included construction and permanent roads, drainage features, decontamination, and soil handling as well as design of the trench. Construction was completed under the Engineer's estimate provided by INTERA, and the remedial system is currently functioning as designed.

North Railroad Avenue Plume Site

The NRAP site is a dry cleaning operation where the release of chlorinated solvents (i.e., PCE) has resulted in soil and groundwater contamination. Because this contamination has the potential to effect a public water supply, the site is listed on the Federal National Priority List. INTERA’s efforts have included: site assessments, designing and implementing data collection programs, monitor well installations, aquifer testing, data review and analysis, modeling ground water and surface water interactions, risk assessment, feasibility analysis, engineering design for remedial action, and engineer of record responsibilities during bidding and construction phases of the remedial action. We completed a feasibility study to evaluate multiple alternatives for remediating PCE contaminated soils and groundwater. The two major components of the remedy selected by EPA are in-situ flooding of the PCE source area with a surfactant/co-solvent mixture, and in-situ enhanced biodegradation of chlorinated ethenes in the downgradient plume. To design the remedy, INTERA used a groundwater model to design both the surfactant flood and bio-enhancement remedies. We assisted in the preparation of the bid documents and are currently overseeing the implementation of the remedial action by providing both engineering and on-site inspection support. Our duties include review of contractor submittals, drafting field orders, responding to requests for information, and providing design revisions as needed.

Hill Air Force Base

INTERA has provided Hill Air Force Base (HAFB) with a variety of NAPL characterization and remediation services at various Operable Units (OUs).  The primary purpose of our site characterization and site review work has been to provide detailed conceptual site models to support the formulation of remedial strategies at the OUs. The iterative methodology of these characterization activities involved incorporating field data followed by model projections for subsequent field tasks.  This approach provided an efficient and accurate site characterization for all of the OUs that INTERA has been involved with at HAFB.  At OU2, this method of site characterization has been specifically applied to source zone remediation. We have conducted pilot tests, demonstrations, and full-scale application of innovative remedial technologies, including cometabolic bioventing and surfactant flooding, to address groundwater and soils contaminated with NAPLs. Our efforts have included gathering additional site characterization data, developing geosystems models, designing and optimizing new and existing remediation systems through the use of numerical simulators, and system installation and operation.

North Garage Project

When environmental concerns were identified at a site being considered as a location for a new vehicle service center and garage facility, INTERA was retained to consult on the closure options under the Texas Commission on Environmental Quality (TCEQ) Voluntary Cleanup Program (VCP) and led the additional environmental assessment efforts.  The Phase II ESA identified impacts to both soil and groundwater. The contaminants of concern (COCs) at the site include RCRA metals, semi-volatile and volatile organic compounds, and total petroleum hydrocarbons. Our assessment and analyses efforts determined that there were four small areas of affected soil at the site that had reported concentrations of chemical constituents above the applicable protective concentration levels.  These soil areas were removed as part of the remedial actions for the site.  INTERA led the coordination and oversight of the remediation effort and prepared the Remedial Action Completion Report for the TCEQ. Additionally, affected groundwater that was indicated in two limited areas was addressed by groundwater monitoring based on the Response Action Plan that we prepared. INTERA coordinated this project with the TCEQ during the VCP review of the APAR, RACR and RAP.  The TCEQ accepted and approved each of these documents in an expedited fashion.  These activities supported finalizing the property transaction, demolishing the existing facilities, and obtaining federal funding for the new facilities. The TCEQ recently accepted our recommendation to discontinue groundwater monitoring and finalize environmental closure of the site.