Remedial Investigation / Design / Operation / Monitoring Brookdale North Service Area

The New Jersey Turnpike Authority (NJTA) operates the Garden State Parkway and maintains the Brookdale North Service Area as a public fueling facility. The NJTA initiated soil and groundwater investigations based upon reports of gasoline discharges from underground storage tank systems.

HMM implemented a phased approach to investigating the presence and extent of contamination as a result of the discharges.  The HMM team investigated soil quality using standard drilling and soil sampling methods, direct-push methods, and using a cone penetrometer and UVIF tool.  Groundwater contamination was investigated through direct-push sampling, the installation of monitoring wells and groundwater sampling, and through the collection of seep samples along the bank of the adjacent Third River.  Because the contaminant plume had migrated from the discharge locations to the river, surface water and sediment samples were collected.  The results of the investigation showed that a large area of gasoline free product is present, soil contamination is widespread, and groundwater contamination is present in separate shallow and deep plumes migrating in different directions.  Surface water quality was slightly impacted, but the sediments were widely impacted with lead from the previous use of leaded gasoline.

HMM completed pilot studies and prepared a remedial action workplan and a remedial design for an air sparging and soil vapor extraction (AS/SVE) system in the source areas, as well as a vapor control system for the service area building. 

However, continuous impacts to the surface water necessitate the need for additional remedial actions.  A baseline ecological evaluation has been completed, and a remedial action plan for the sediments will be proposed following the completion of an ecological risk assessment.

In order to design a remedial system to provide hydraulic control of the contaminant plume, HMM conducted aquifer tests, interpreted the data, and modeled groundwater flow and capture.  Based on this, a hydraulic sheet-pile barrier and groundwater recovery system has been designed.  The AS/SVE system will also be modified to include the use of ozone.  The proposed remedial actions were presented to, and approved by the NJDEP.  Plans and specification were prepared for public bidding.  HMM completed permit applications for the remedial systems.

HMM is responsible for operating and maintaining the AS/SVE system.  We conduct compliance monitoring of the system to ensure that it is operating within regulatory approvals, and make adjustments based on the results.  HMM also conducts groundwater compliance monitoring, and prepares progress reports for the client and the NJDEP.