Site Description - BTEX & MTBE Contamination
 

Location - Southeast USA - Treatment (In Situ)

 
FDEP Facility # 508514224
This project is located in West Palm Beach, Florida at the site of a former gas station. This location is currently operating as a maintenance facility. An old leaking gasoline tank had been removed but the contaminated soil surrounding the tank was left in place. As a result this had also affected the groundwater.
 
The site was reported to have moderate levels of contamination in the soil and groundwater. BioWorld treated to a depth of 30 feet. The delineated groundwater contamination was estimated to be approximately 12'x100'x30' and soil contamination at 50'x40'x10'. The lithology of the site consisted of sandy soil.
 
Contaminant
Gasoline
 
Treatment Method
In-Situ
 
Remediation Time Frame
10 months
 
BioWorld initiated the remediation of this site utilizing 30 specialized high-pressure rod injections to treat the soil. 1 month later, the groundwater was treated using 22 injection wells installed to a depth of 30 feet, screened 10' to 30'. Subsequent similar groundwater treatments took place, at 3 additional times with a month interval between each.
  Starting Contaminant Levels
Sampling Point Benzene Toluene EB Xylene MTBE Total Nap
HM-1 161 111 130 151 17 18.7
HM-9 1,070 2,850 415 3,160 25.1 8.1
HM-10 101 4 42.7 190.9 8 8.1
MW-12 BDL BDL BDL BDL BDL BDL
 
BDL - below detection levels
 
Testing standards
All tests were performed by an independent 3rd party laboratory.
Methods
5030/8021B - VOA (602) Compounds in Water by G.C)
3510/8270C - PAHs (610) in Water by GC/MS (ion trap)
 
Five months after the project started, analytical data indicated that the above treatments had apparently broken loose pocket/s of contamination that were at much higher levels than previously identified. This resulted in the total contamination increasing radically in several monitoring wells. In the most contaminated monitoring well, HM-9, the levels exceeded 40,000 ug/l.
 
BioWorld determined that a more aggressive treatment schedule would be implemented to combat these elevated levels. As a result BioWorld treated the site every week, for a seven week period.

Results

The soil and groundwater was cleaned up to levels specified by the Florida Department of Environmental Protection (FDEP). The project was completed in ten months.

Ending Contaminant Levels

Sampling Point Benzene Toluene EB Xylene MTBE Total Nap
HM-1 BDL 1.18 22 8.69 BDL 222.6
HM-9 BDL 1.49 BDL 2.05 BDL BDL
HM-10 BDL BDL BDL BDL BDL BDL
MW-12 BDL BDL BDL BDL BDL BDL