PERMFILE50384

• Permit No: M2001051
• IBM Index Class Name: Permit File
• Doc Name: WATER INFORMATION
• Section_Exhibit Name: EXHIBIT G
• Media Type: D
• Archive: No

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EXHIBTT G
WATER INFORMATION
The proposed operation will have impacts on groundwater in the immediate area of the
affected land. Mining and reclamation plans have been designed to minimize and
mitigate these impacts. A substitute water supply plan has been prepared and will be
submitted to the Colorado State Engineer's Office for review.
Section 1-Surface Water
Although the site is located near the Cache La Poudre River, no part of the site is located
within any regulated floodplain or floodway. Historically, no conveyances other than
local imgation ditch laterals have crossed the site. The proposed mining activity is
expected to have little or no impact on surface water systems in the vicinity of the site.
Section 2 -Ground Water
Soil bores in the vicinity of the site indicate groundwater levels at an average of
approximately 5 feet. The site lies within an unconfined riparian aquifer associated with
the Cache La Poudre River. This aquifer extends to the bedrock at 20-25 feet below
ground surface. In order to mine the site dry, dewatering will be required. Groundwater
modeling done by Tuttle Applegate, Inc., indicates that dewatering is likely to lower the
water table in the immediate vicinity of the site by as much as five to six feet west of the
site and two to four feet on the east side. The extent of these impacts range from
approximately 1800-2400 feet fora 1' drawdown.
In accordance with DMG Construction Materials Rule 3 (Section 3.1.7), a groundwater
monitoring program has been designed and will be implemented by the applicant to
determine baseline conditions and observe changes in groundwater levels. If levels in
monitoring wells show a significant drop, mitigation efforts will be initiated on a case-by-
case basis as described in the monitoring protocol.
The reclamation plan for the site is to create unlined water ponds. It is believed that
groundwater conditions will effectively return to pre-mining conditions once reclamation
is complete. A substitute water supply plan will be filed with the State Engineer's Office
for mining operations as well as post-mining augmentation requirements. This plan will
be approved prior to exposure of groundwater.
Water Commissioner George Varra has completed field inspections of the vicinity and
identified several wells within 600 feet of the pit boundary. Two wells on the east of the
site, one owned by Dave Slatten, another by Darwin Roe, are located within 600 feet of
the boundary. One well on the west side of the site, owned by William Seaworth, is also
located within 600 feet. Seaworth's and Roe's wells are not registered with the State
Engineer's Office, but were identified by Commissioner Varra as in use and needing
protection or mitigation from negative impacts. A copy of SEO well registration
documents for the general area are included in Appendix G-1.