HYDRO30213

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

The Permit requires monitoring of all aquifers overlying the mining zone as a means of
detecting potential fluid movement out of the cavity and monitoring to detect potential
subsidence. The Permittee is also requved to carry out continuous monitoring of the gas cap
placed in the cavity and continuous monitoring of the inflow and outflow streams to ensure that
the well and cavity have mechanical integrity. The EPA has determined that the revised
monitoring plans incorporated into the Permit aze adequate to assess the ground-water quality of
the aquifers and to detect any problems associated with the cavities. The monitoring schedule is
such that any cavity failure will be detected quickly, thereby allowing the operator sufficient time
to initiate rededication measures before there is any threat to any USDW. Given the geologic
setting and the adequacy of the construction elements, the monitoring program, and the operating
requirements, EPA believes the Permit conditions will protect USDWs.
Comments regarding the accuracy of the ground-water data were evaluated along with the
comments regarding the need for more baseline data, and these are addressed specifically in
Response 5. As explained in the Response, EPA believes that collection of additional baseline
water quality data is not needed prior to issuance of the permit. EPA has determined that the
geologic and hydrologic data (including water quality data) aze sufficient to evaluate the request
for a permit. EPA does agree, however, that additional baseline water quality and water level
data are needed prior to commencing commercial operation. EPA has determined that the Permit
provisions regarding an active ground-water monitoring program, including 5 quarters of baseline
monitoring prior to commencement of commercial operation, are adequate to ensure that the
monitoring will detect problems associated with solution mining activities in the azea of the active
mine cavities.
EPA considers the concerns relating to the potential impact of this project on the financing
of future projects and other similar issues to be speculative and beyond the scope of the SDWA
jurisdiction. As a result, no specific response will be provided on issue 8 of this group of
comments.
Based on a review of all comments, EPA does not believe that there are grounds for
denial of the Permit. EPA believes that the Final Permit conditions are adequate to
address the potential for contamination as result of the project. Therefore, EPA has made
a decision to proceed with issuance of the Permit.
Comment 2: The EPA has not complied with its NEPA responsibilities regardine the need for a
separate or supplemental EIS.
The following ten (10) paraphrased comments discussed the issue of the need for an EIS
relating to EPA's proposed Permit for the Yankee Gulch Project:
1. EPA should have prepazed its own EIS, or supplemental EIS in order to comply with NEPA.
The statutes that EPA administers directly require the consideration of environmental
consequences of EPA's action and calls for public participation.
6