Active contracted with the homeowner to conduct an investigation of an underground storage tank in conjunction with closure of the tank. Significant contamination was evident in the soils surrounding the UST, and the client’s insurance carrier was notified. The insurance carrier hired a consultant to conduct a third party coverage investigation related to Active’s findings concerning the UST.

Active completed tank removal activities, and the insurance carrier’s consultant conducted plume delineation activities. Active then assumed contracting and consulting responsibilities for the completion of the remedial action performed at the property. A Remedial Action Workplan (RAW) was prepared and submitted to the NJDEP for review and approval. The RAW proposed that contaminated soils would be excavated and on site treatment and discharge of petroleum contaminated ground water would be performed under On Scene Coordinator (OSC) authorization.

The limits of the proposed excavation required the use of substantial structural support of the dwelling. Active installed helical pile foundation support, and safely and efficiently removed approximately 920 tons of contaminated soils from the site. Post excavation soil sampling and ground water monitoring were completed. Active prepared a Remedial Action Report (RAR) for submittal to the NJDEP, resulting in a case closure and a No Further Action (NFA) Determination by the NJDEP.

Delineation at this site was conducted by another environmental consulting firm. Findings indicated that a substantial portion of the contaminant plume had migrated beneath the dwelling and onto the neighboring property. The scope of the project quickly exceeded the other firm’s level of capabilities, and Active was contracted by the homeowner’s insurance carrier to assume consulting and contracting activities and execute the remediation effort. The project presented challenging issues requiring creative remedial strategies.

The house was slab-on-grade construction and the slab contained copper pipes from a radiant heating system. Active developed a plan to support the dwelling and conduct compartmentalized excavation beneath the slab, utilizing a pit and pile technique. This technique proved to be a highly cost effective means of removing contaminated soils by eliminating the need to disturb the slab and damage the floor and heating system within. Remediation of the neighboring property was completed simultaneously, utilizing similar methods.

The pit and pile excavation technique allowed for the “surgical” removal of bulk contamination from beneath the dwelling, alleviating the potential for vapor intrusion into the home. Active was able to remove less material from the site resulting in significant cost savings for the client. Ground water contamination remains at the site and rather than install and operate a costly ground water treatment system, Active is taking measures to obtain No Further Action (NFA) determination through reclassification of the local ground water aquifer.

Active conducted a Third Party Coverage Investigation and subsequent Remedial Action at the property. Access to the area of concern (AOC) was limited by an inground swimming pool located just beyond the boundaries of the contaminant plume as delineated. Active successfully removed the contaminated soils without the need for the costly demolition and reconstruction of the pool.

Upon completion of the excavation activities, one (1) permanent permitted monitoring well was installed at the site, and ground water samples were collected and analyzed. A Remedial Action Report (RAR) was prepared and submitted to the NJDEP for review. Based on information contained within the RAR, NJDEP requested that several additional samples be collected down gradient of the AOC.

Active successfully negotiated with the NJDEP regarding placement of the requested additional sampling locations. Active’s plan involved conducting Enhanced Fluid Recovery (EFR) from the existing monitoring well and installation of several borings down gradient of the AOC to confirm that the contamination had been successfully removed from the site, and did not migrate past the swimming pool. A NJDEP geologist observed and directed the sampling events. A supplemental letter addendum to the RAR was submitted to the NJDEP and written NFA determination was received.

Active completed a Third Party Coverage Investigation to aid the homeowner’s insurance carrier with coverage determination. Soil and ground water samples collected indicated third party impact and the carrier triggered coverage. Client subsequently authorized Active to conduct remedial investigation activities, including a complete delineation of the contaminant plume, both exterior and interior to the dwelling.

Delineation at the site indicated the presence of commingling plumes, as the UST on the neighboring property had also leaked and migrated toward the subject property. Both plumes were sufficiently delineated, and a remedial action plan was developed that entailed completing the remediation of both sites simultaneously. The plan involved utilizing Active’s capabilities in helical pile structural support, on-site treatment of waste water, and limited access soil excavation.

Contaminated soils were excavated and removed from the site, and impacted ground water was treated on site and discharged to the storm sewer under On Scene Coordinator (OSC) authorization from NJDEP. The carrier insured both properties and Active conducted Cost Allocation Breakdown Analysis to aid the carrier in assigning proper costs for each claim. A Remedial Action Report (RAR) was prepared and submitted to the NJDEP; final No Further Action (NFA) determination is pending.