sam winer motors technical outreach support for communities michigan state university east lansing,...
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Sam Winer Motors
Technical Outreach Support for Communities
Michigan State UniversityEast Lansing, MI
November 29, 2001
TOSC Program Provides assistance to communities
affected by polluted sites Enables citizens to participate in
cleanup decisions Inform, educate and empower Funded by U.S. EPA Agreement with CCAIC
Agenda Introduction Focus of investigations Where is the contamination? Is the contamination moving? Residential well sampling Conclusions & Recommendations
What has TOSC done? Reviewed documents produced by
Ohio EPA and U.S. EPA Produced reports, including
recommendations for further actions
Published TOSC and AGENCY documents on the Web
Our Goals Tonight Build greater sense of
understanding and participation Provide expert opinion Gather comments to be provided
to EPA
Site cleanup process Site characterization Risk assessment, both human
health and ecological Options for site remediation
Agenda Introduction Focus of investigations Where is the contamination? Is the contamination moving? Residential well sampling Conclusions & Recommendations
Focus of the investigation
Focus of the investigation
Contaminants Chemicals from petroleum (gasoline)
Toluene Benzene
Metal Degreasers Trichloroethane Tetrachloroethane
Plasticizers “phthalates”
Others
Where is the contamination?
Where is the contamination?
Where is the contamination?
Where is the contamination?
Site Geology
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0 200 400 600 800 1000 1200
Concentration (ppm)D
epth
(fe
et b
gs)
Approximate BTEX
FID Reading
Sandstone/Shale Bedrock
Glacial Till
Non-Native Fill
Where is the contamination?
North/South Cross Section
0.00
2.00
4.00
6.00
8.00
10.00
12.00
De
pth
(ft
)
BTEX
Naphthalene
Where is the contamination?
East/West Cross Section
0.00
2.00
4.00
6.00
8.00
10.00
12.00
De
pth
(ft
)
BTEX
Naphthalene
Where is the contamination?
Concentration (g/kg soil)
Contaminant MW-1S4 to 6 ft. bgs
MW-1S12 to 14 ft bgs
N-nitrosodiphenylamine 460,000 1,600,000
Bis(2-ethylhexyl)phthalate 550,000 1,500,000
1,2-Dichlorobenzene 7,400 39,000
Isophorone 4,300 3,600
Di-n-butylphthalate <LOD 4,900
Phenol 4,300 5,700
Is the contamination moving?
On-site sampling from sandstone/shale aquifer has not revealed any contamination.
Once contaminants reach the groundwater, significant migration is possible.
Determining if these chemicals will reach the aquifer is difficult.
Is the contamination moving?
Is the contamination moving?
Monitoring Wells Installed by U.S.EPA
0
20
40
60
80
100
120
140
MW-1S MW-1D MW-2D MW-3D MW-4D
Fe
et
Be
low
Gro
un
d S
urf
ac
e
Screening Depth
Depth of Casing
Is the contamination moving?
Difficult to answer due to potential problems associated with the U.S.
EPA monitoring wells. No screening at top of aquifer
Screening over different depths
Measurements made only on January 3,
2001.
Estimating how long until the groundwater is contaminated Assume chemical is in non-native fill Glacial till conductivity
Estimate range between 2.0x10-7 ft/min (silt) 2.0x10-9 ft/min (clay)
Vertical Gradient Estimated from MW-1S & MW1D
0.733 ft/ft Assume 10% porosity
Between 20 and 2,000 years
Residential Well Sampling EPA sampling focused on VOCs and
“Base Neutral Compounds” Gasoline Plasticizers Pesticides
Performed September 12 & 13, 2001
Residential Well Sampling Chemicals not found
Acrolein Cyclohexanone BTEX
Chemicals found Butyl benzyl phthalate: 0.20-0.26 ppb Di-n-butylphthalate: 1.1-2.5 ppb Bis(2-ethylhexyl)phthalate: 0.33-11
ppb
Agenda Introduction Focus of investigations Where is the contamination? Is the contamination moving? Residential well sampling Conclusions & Recommendations
Recommendations Further sampling of residential
wells is warranted. Due to the presence of a number of
phthalates in several residential wells Due to the presence of DEHP in one
well at concentrations greater than the recommended value provided by U.S. EPA for drinking water
Recommendations Determine the hydrogeology of the glacial till
layer Necessary to determine rate of vertical
migration of water through this layer into the sandstone/shale aquifer
This will determine the migration of chemicals present from the non-native fill layer to the sandstone/shale aquifer
Will require measurements to be made during different seasons and after varying rainfall events
Recommendations Determine the hydrogeology of
the sandstone/shale aquifer Necessary to determine rate of
horizontal movement of water and chemicals off-site
Will require measurements to be made during different seasons and after varying rainfall events
Recommendations Additional sampling is necessary to
delineate contamination The U.S. EPA report states that
“concentrations decrease an order of magnitude from 4-6 ft bgs and … another order or two of magnitude [sic] from 12-14 bgs to 20-22 ft bgs”.
The data does not support this conclusion.
Recommendations The decision to close the site with no
further action must be revisited. The presence of several chemicals (n-
nitrosodiphenylamine, bis-(2-ethylhexyl) phthalate and total petroleum hydrocarbons at concentrations in the g/kg level is cause for concern.
The lack of understanding of the groundwater hydrology further necessitates revisiting this decision.