The lab results of two site assessment soil samples determine,
what kind, and, how much, of an environmental clean-up is
required. There are six basic clean-up categories,
depending on the severity of contamination:
1) Clean Decommission (0-49 ppm diesel)
2) Soil Matrix Level 1 (50-499 ppm diesel)
3) Generic Remedy Level 1 (500-2,499 ppm diesel)
4) Generic Remedy Level II (2,500-2,499 ppm diesel)
5) Risk Based Corrective Action in-place (10,000+ ppm diesel)
6) Risk Based Corrective Action tank/soil removal (10,000+ ppm
CLEAN DECOMMISSION - When a tank has not leaked or
has leaked only a trace amount (<50ppm), it can be decommissioned
in the ground (in-place) with no further sampling. Please
note that if your tank has leaked a trace amount, it is highly
recommended that it be decommissioned. Trace amounts of oil
indicate that the tank has just begun to leak and will only become
a bigger and more expensive problem in the future.
SOIL MATRIX - If soil ample lab results indicate that
the contamination level in the soil is between 50-499 parts per
million of diesel, then the action required is called a Soil
Matrix clean-up. The tank can be decommissioned in place
with no further sampling.
REMEDY LEVEL 1 - If soil sample lab results indicate
that the contamination level in the soil is between 500-2,499
ppm diesel, then the tank can be decommissioned in-place,
however, additional sampling is required. Four or five
additional samples around the tank are required to delineate the
underground distribution of contamination.
REMEDY LEVEL 2 - If soil sample lab results indicate
that the contamination level in the soil is between 2,500 -
9,999 ppm diesel, then the tank might be able to be
decommissioned in-place, but it could also potentially require
removal. Additional samples are required and additional
lab analysis must be performed on the soil samples that test for
Benzene, Toluene, Ethylene, and Xylenes
(BTEX). If the concentrations of these hydrocarbons
are higher than allowable levels, then the site jumps to the
next level of clean-up requirements. The Risk Based
Corrective Action (RBCA) (see next
RISK BASED CORRECTIVE ACTION (RBCA) - If soil sample lab
results indicate that the contamination level in the soil is
10,000 ppm or greater, then further lab analysis is required.
A BTEX-PAH analysis must be performed on the site assessment
soil samples to determine the concentrations of a group of
regulated hydrocarbon contaminants. (Benzene, Toluene,
Ethylene, Xylenes, and Polynucleic Aromatic
Hydrocarbons). The BTEX-PAH analyses must be
performed within 14 days of the soil sample extraction date.
If it is determined that the concentrations of contaminants is
within allowable levels, then the tank may be decommissioned
in-place with additional sampling. If the contaminant
levels are too high, then tank and soil removal may be required.
RBCA TANK AND SOIL REMOVAL - If the BTEX-PAH analysis
shows petroleum contamination is at concentration levels that
are a threat to human health, then the tank, and as much
contaminated soil as possible, must be removed to avoid human
exposure to hazardous chemicals. An excavator is used
whenever possible; however, tanks and soil must sometimes
be removed by hand.
Integrity: ( ĭn-těģ-rĭ-tē)
possessing and steadfastly adhering to high moral principles, ethical codes,
or professional standards.