SITE:	Petroleum contaminated insitu soils and waters.
BIODEGRADED MATERIAL:	Gasoline
SITE SURVEY:	Site and geological surveys had revealed the sources of contamination were 4 UST’s from a former gas station located at the southwest corner of this vacant site. Groundwater was found at a depth of 17 feet below the surface and the groundwater ran up against the wall of the underground subway structure. Samples were obtained and the initial laboratory samples revealed that the levels of contamination were actionable. The soils encountered were primarily sand, silt, clay, and gravel.
METHOD:	Insitu bioremediation was selected to enable the site to be cleaned-up and put back into productive use with the least amount of disruption to the adjacent property, the clients business and the site itself. 16 monitoring wells were installed, each 2-inch slotted PVC, to an average depth of 20 feet. These were used to further define the project on and off site, amend the existing site assessment reports, to deliver remedial products, and to monitor and test the site during and after completion of the remedial project. A bio infiltration system was also installed. This consisted of installing 14 rows of 4 inch flexible PVC. Each row in the matrix was approximately 200 feet long and installed alternatively at approximately 5-10 feet deep. The matrix was spaced equally across the entire site. The H-10™ product placement was made via a matrix of borings. Once the Bio Rem H-10™ product was applied, there was no other addition of oxygen sources or other nutrients needed to remediate the site. The contaminated area was then tested after remediation. Readings were taken at periodic intervals with the use of a photo ionization detector (PID). The PID readings were taken from the borings/TVMPs placed in and around the contaminant plume. As readings indicated non-detect levels, soil and water samples were taken from those areas showing no contamination and sent for formal analysis by a certified, independent laboratory. The NYSDEC allowed the closure of all monitoring wells in the area where test results confirmed no contamination 3 consecutive times. There was residual contamination, which had migrated down gradient from the source area. Treatment was required to continue down gradient until the residual migrated contaminants in wells MW-6, MW-8, and MW-9 (MW-8 and MW-9 were also know as B-8 and B-9) were biodegraded below actionable levels.   The treatment with Bio Rem H-10™ bacteria began on May 1999 to June 1999. The samples were analyzed progressively in July 2000 by an independent lab confirmed that the site is below NYSDEC action levels for soil and groundwater. The results of the laboratory analysis were obtained using U.S. EPA Method 602 as required by the NYSDEC.
COMMENTS:	The NYSDEC has issued a "no further action" status for this site. The property has no tie to a disposal site, eliminating any future liabilities. After remediation a new Walgreen’s Drug Store was built on this location.

 

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