Inger Gas Station
Site Eligibility Determination
TO: Jane Neumann, Program Manager
U.S. EPA Region 5
Mail Code MCG 10J
77 West Jackson Blvd.
Chicago , IL 60604-3507
FROM: Diane Thompson, Hazardous Waste Manager
Division of Resource Management (DRM)
Leech Lake Band of Ojibwe (LLBO)
6530 Hwy 2 NW
Cass Lake , MN 56633
Introduction
This memo is written to support the 128 Brownfields cooperative agreement
requirements for USEPA notification and review of specific sites prior the issuance of a
loan. Specifically, information is provided to support that the Inger Site meets the
definition of a Brownfields and that the current owner (LLBO) has no affiliation with any
contamination onsite.
Owner:
Leech Lake Band of Ojibwe
Division of Resource Management
6530 Hwy 2 NW
Cass Lake , MN 56633
Site Name: Inger Store Property, Inger , MN
This community is approximately twenty-seven miles north of the town of Deer River
and thirteen miles south of the town of Squaw Lake , MN
Operational History:
The site has been used as a Grocery Store/Gas Station, Dilapidated House, Shed and
Garage that was on these 2.87 acres of land.
Title search clearly indicates that the Leech Lake Band of Chippewa Indians is the clear
legal owner of the property subject to the contract of deed interest of the Ahlmans .
On 10-20-88 Leech Lake Band of Chippewa Indians gave full payment on the contract
for deed sale to Mr. And Mrs. Ahlman , former owners of the Inger Store.
This site is currently vacant and has been for quite some time. There has been a Phase I
Environmental survey completed on 7-22-91 (see attached copy of that survey). No
environmental cleanup has occurred.
Environmental
A remedial investigation was performed July 1996 by Itasca Environmental of Bemidji,
MN.
A removal of the first gasoline tank (1000 lbs capacity) was completed on 8/25/95 ; the
age of tank was unknown and its condition was poor. The second 550 lbs gasoline tank,
which was removed on the same date, was also in poor condition. Similarly, the third 500
lbs kerosene tank was removed and found to be in poor condition. Two suction pumps
remain at the site. The source or suspected source of the release to the unsaturated soil
and groundwater system was attributed to tank overfill. According to the reports the
volume of release and the date of the releases are unknown.
There has been no soil excavated off-site, but there were soil borings conducted in or
immediately adjacent to all likely source areas. All soil borings were completed to the
required depth, with one boring extending to 20 feet below the water table. A hollowstem auger was used for drilling.
The underlying geology consists of sand and clayey sand. Bedrock underlies the site
approximately 228 feet below grade. Depth to groundwater is approximately 5 feet below
grade. The Bowstring River borders the site to the northeast and lows northwest. The
river elevation is approximately seven feet below site grade. A wetland exists behind the
site to the west. Based on the aquifer characteristics, the shallow aquifer provides good
indication for acting as a source of water supply, though it is in contact with
contaminated soil. There is another resource aquifer approximately 267 feet below grade
according to unique well no. #524484.
Monitoring well construction:
Well numbers
MW-1 578688 date installed 9-12-96
MW-2 578690 date installed 4-16-96
MW-3 578689 date installed 4-17-96
MW-4 582367 date installed 4-16-96
There are no deep monitoring wells completed at the site. According to the initial site
evaluation, groundwater contamination does not extend beyond site boundaries and does
not appear to have impacted the river. Dissolved concentrations of petroleum are
extremely high; benzene is 2000 times its recommended allowable limits in the worstcase well.
There are property owners within 500 feet of the nearest edge of the contaminant plume,
with only one private well located within 500 feet of the contaminant plume. This well is
on a private residence on the opposite side of Highway 35 from the site. It supplies the
Inger Store and the attached house.
The well located across the street which supplies the site was sampled for VOCs 465D
and GRO; concentrations of these parameters were not detected. The risk that this well
will be impacted from the release at the site is very low because the contaminant plume
appears to migrating toward the river and the well is located upgrading from the
contaminate source, the Bowstring river is approximately 30 feet from the edge of the
contaminant plume. The potential risk of impact to the river is very high.
The Discussion, the risks associated with the remaining soil contamination is very high
contaminant concentrations remain is soils returned to the excavation and may represent a
possible contaminant source for groundwater contamination. The risks associated with
the impacted ground water is high risk of impact to the Bowstring River exists due to the
high concentrations of petroleum constituents detected in a groundwater sample collected
from MW-1.
Conclusions and recommendations for the site is active cleanup, contamination may
impact surface water quality, quarterly monitoring beginning in March 1997. If active
cleanup is proposed, then MPCA staff will review this RI report at a higher than normal
priority to determine if active cleanup is required. We will respond with either a request
for proposal for additional monitoring or a Corrective Action Design report. Indicate
below what cleanup technology they are considering at this time.
Contaminated soils returned to the UST basin should be excavated for treatment.
Contaminated groundwater should be remedied using oxygen release compound mixed in
slurry and injected into the contaminated zones; ORC may also be used as an oxygen
barrier to restrict contaminant migration toward the river. I have the lab results from the
Itasca Environmental if you need to review.
Wenck Associated, Inc P.O. Box 693 Biwabik , MN 55708 (218) 865-0120 as took over
responsibility of the annual monitoring report because Itasca Environmental of Bemidji,
MN has closed business. The last report I have received from Wenck was dated
September of 2003.
On September 30, 2003 Joseph Palo, P.E. sent a memo to Larry Olsen -MPCA regarding
recommendation for corrective action and feel that the best step is to utilize in-place
treatment. The use of Oxygen Release Compounds is recommended with a condition that
it will work based on some additional sampling and analysis.
According to Wenck an Annual monitoring of the site has been completed since 2001 and
the data has been included in this annual report. Results indicate that impacts in the
monitoring well at the source remain elevated, but decreasing. The impact to the
surrounding downgrading wells has not occurred and is not anticipated, because of the
confining characteristics of the soil subsurface. The extents of the groundwater impacts
were defined in a groundwater Geoprobe investigation completed in 2001 and are shown
on the attached figures. The groundwater samples were collected using standard
Geoprobe equipment and techniques. Results from the groundwater samples are located
in the report that can be requested for review in the Leech Lake Division of Resource
Management Environmental Office.
Property Specific Determination:
Current Owners: Leech Lake Band of Ojibwe
Petroleum Contamination: yes annual monitoring report available
Process of Ownership Environmental Responsibility:
Common Elements Among the Brownfields Amendments Land Owner Provisions
All Appropriate Inquiry:
No Affiliation Demonstration:
Compliance with land use restrictions and institutional controls:
Taking Reasonable Steps:
Compliance with Information requests and administrative subpoenas:
Providing legally required notices: