BIO REM^® USA, INC.

"Soil & Water Decontamination Specialists"

ENVIRONMENTAL PRODUCTS & SERVICES

Property Description:

    The results of Environment and Ecology's, Inc. (E&E) contamination assessment at the Courthouse BP/Hopkins site indicate petroleum-related soil and groundwater contamination exists beneath both facilities.  Free floating product has been reported at the BP Courthouse facility.  One and possibly a second potential source has contributed to the groundwater contaminant plume that has migrated laterally north and west of the site and vertically to a depth of 38 feet BLS.

    Excessively contaminated soil is present along the northern edge of the two facility properties.  Headspace readings in excess of 50ppm (kerosene group criterion) were observed from 6 to 27 feet BLS.  Because of the observed water level fluctuations (approximately 9 feet), the vertical extent of contaminated soil is difficult to define.  The depths to water during the initial site assessment ranged from approximately 7 to 16 feet BLS in the shallow zone and 45 feet BLS in the intermediate zone.  Six to seven months later, the depths to water had dropped 5 to 9 feet, with some wells being completely dry.

    The water level variability across the site is attributed to the complex subsurface lithology, different monitoring well depths and screening intervals, and the wet/dry seasonal conditions.  Based on the water levels measured in June/July 1993, a downward vertical hydraulic gradient appears to exist between the shallow and shallow-intermediate zones.  The groundwater flow direction was generally toward the west throughout the E&E's site assessments, although a southwesterly flow direction was noted in the vicinity of the Courthouse BP UST area in response to water level elevations calculated during June/July 1993.

    Extremely elevated concentrations of petroleum-related groundwater contaminants are present in the shallow and shallow-intermediate zones (to a depth of 38 feet BLS).  The contaminants detected include BTEX, EDB, MTBE, 1,2-dichloroethane, naphthalenes, and total lead.

    The lateral extent of petroleum-related groundwater contamination in the shallow zone is present from 3rd Street west to 2nd Street (encompassing almost the entire block).  The distribution of contaminants is attributed to the presence of permeable, sandy layers between 15 and 38 feet BLS where groundwater flow is less restricted.

    The petroleum-related soil and groundwater contamination at the Courthouse BP/Hopkins site has likely resulted from at least one known discharge release that occurred at the Courthouse BP facility, and possibly from a second source release that occurred near the kerosene UST at the Hopkins facility.  Only the Courthouse BP facility releases are known to have occurred at the Hopkins (a former TTFS convenience store/service station) facility.

    The vertical extent of the petroleum-related groundwater contamination has been defined beneath the FSI area of the Hopkins facility within the shallow-intermediate zone (38 feet BLS); however, no groundwater contamination was detected in the intermediate zone (51 feet BLS).  Delineation of the lateral extent of shallow-intermediate zone contamination will require further investigation.

    As of 2002 it was found that the contaminants are primarily petroleum hydrocarbons in the soil and groundwater.  The sources of contamination was from on-site underground storage tank (UST) system and Island dispenser spillage.  The soil contamination is smeared in an area 3 to 8 feet deep in and around the area referenced as OSB-7.  The groundwater plume to be treated is calculated 210' long x 120' wide.  The effected groundwater begins at a varying approximate depth of 7' to 16' at the soil groundwater interface.  The effected areas to be treated begin predominately on-site but the plume has migrated north of the site under the roadway and onto the neighboring property.

Project Scope:

    Bio Rem, Inc. installed and provided the necessary H-10™ product in order to bio remediate the defined insitu petroleum contaminated soil and ground waters.  The insitu petroleum contaminated ground waters to be remediated are defined by the Subsurface Investigation Report along with drawings and laboratory analytical provided by Omega Environmental Services, Inc. (OES).  The drawings and analytical tables were prepared and provided by OES designate the specific area to be remediated.

Bioremediation:

    The H-10™ product placement will be made via a previous remedial system and a monitoring well point system currently located on the site.  The system will now be used as an H-10™ remedial application and analytical monitoring system.

    Approximately 28 individual irrigation wells currently installed on the site will be utilized to install the H-10™ product application.  The irrigation wells will be selected from these existing that will most efficiently allow the H-10™ applications to migrate across the contaminated soil and groundwater areas of the property.  Bio Rem, Inc. will advise OES Environmental, Inc. as to the specific locations of these wells.

    It has been determined that it is necessary to modify the application system at the site.  It will be necessary to replace 6 wells previously destroyed.  Add 5 new wells to replace those being used and assigned for monitoring only.  We will also add a minimum of 4 new vertical well points, north of the site on the neighboring property.  Al vertical wells will be placed to a depth of groundwater.  It will also be necessary to add a minimum of 8 new horizontal borings, north of the site, under the roadway, at various locations, in order to insure that the applications reach all the affected areas.  Bio Rem, Inc. will provide direction for the location of the additional well points and borings.

    It is estimated that it will take approximately 6 to 12 weeks to make all the required H-10™ product applications. Once the Bio Rem H-10 product is applied, there will be no other addition of oxygen sources or other nutrients needed to remediate the site.  Based on the information provided, it is expected that the area of defined contamination will be fully biodegraded within 6 to 9 months from the date of the final product installation.  The project is a work in progress and is currently being monitored in order to track final results.

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