HYDRO30213

• Permit No: M1999002
• IBM Index Class Name: Hydrology
• Doc Date: 2/10/2000
• Doc Name: UIC INFO
• Media Type: D
• Archive: No

Response: The comments, both oral and written contained numerous questions regazding the
validity of the data submitted as part of the Permit application. EPA has reviewed these data and
has consulted with the Colorado Division of Minerals and Geology (CDMG), the U. S. Geological
Survey (USGS) and the BLM regarding this issue. American Soda collected and analyzed
ground-water samples a number of times during 1997 and 1998 from four wells representing
water quality in the alluvium, upper aquifer, lower aquifer, and the Dissolution Surface. Concerns
were raised regarding these data, which mainly focused on the assertion that analytical results did
not conform to ground-water quality trends noted in previous studies of the Piceance Basin (i.e.,
water quality appeared to be worse in the vicinity of American Soda's wells than regional data
suggested it should be). There were also some problems with data entry for some wells.
It is important to emphasize that EPA's permit action does not imply that the water
quality of the initial area to be mined is representative of the water quality elsewhere in the
basin. Additionally the construction, operating and monitoring requirements are designed
to prevent migration of fluids out of the injection zone into any aquifers regardless of their
quality. They are also designed to detect any migration that may occur.
To address these concerns, American Soda subsequently contracted a known expert in
ground-water conditions within the Piceance Basin Dr. George Saulnier, a former USGS
employee, to review and comment on ground-water data collected by the applicant. Dr. Saulnier
prepared a report to document his findings ("Groundwater Quality in Piceance Creek Basin", G.J.
Saulnier, Jr., September 1999). This report was supplied to the Rio Blanco County Planning and
Zoning Commission in September 1999, with a copy to EPA This report will be considered part
of the administrative record. Dr. Sauhder concluded that past activities unrelated to solution
mining in the vicinity of American Soda's project had the potential to cause, and may have caused
cross-contamination of aquifers in the area. He specifically noted activities by Shell in
construction of their in-situ oil shale test cavity, the US Bureau of Mines at the Horse Draw test
mine site, and improper plugging and abandonment of mineral and oil and gas exploration
boreholes in the area (including borehole 20-1 on American Soda's leasehold) as likely sources of
cross contamination. He suggested that these prior activities likely contributed to the total
dissolved solids (TDS) anomalies observed in American Soda ground water monitoring wells.
Conclusions in his report are supported by his presentation and interpretation of specific
conductance readings taken in monitoring wells installed by American Soda for the pilot project.
It is important to note that EPA believes that the Permit conditions relating to corrective action
(plugging the 20-I well and resolving downhole conditions in 17-1), well construction, operating
criteria, process monitoring and ground-water monitoring will minimize the potential for future
contamination that might be related to the Yankee Gulch project.
In addition to contracting Dr. Saulnier to review past activities in the immediate area of
their Leases, the applicant developed a comprehensive monitoring plan in order to collect
additional, more technically sound data that would supplement their early ground-water quality
data. An important component of this monitoring plan is that the additional baseline data
collection must occur prior to the commencement of injection under this Permit. Furthermore,
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