APPCOR12974

• Permit No: C1981041
• IBM Index Class Name: Application Correspondence
• Doc Date: 2/10/1982
• Doc Name: ROADSIDE CAMEO AND COTTONWOOD PERMIT APPLICATION SUBSIDENCE ASPECTS
• From: JIM PENDLETON
• To: JIM HERRON
• Media Type: D
• Archive: No

R~chartl D Lamm
Governor
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DEPARTMENT OF NATURAL RESOURCES
D. Monte Pascoe. Executive Dueclor
MINED LAND RECLAMATION DIVISION
DAVID C. SHEL70N Director
February 10, 1982 ..+~
TO: Jim Nerron
FROM: Jim Pendleton
RE: Roadside, C o Cottonwood Permit Application - Subsidence Aspects
Pursuant to your request, I have completed a review of the subsidence aspects
of the original Roadside and Cameo mine application, the supplemental addenda
thereto, and the adjoining Cottonwood lease amendment. I have determined
that several problems continue to exist, which I recommend be resolved prior
to the completion of a draft findings document.
The applicant indicates that several structures overlie the proposed under-
ground workings. The Ute Water District, which serves approximately 45,000
people, has a water treatment plant, several storage tanks, and a 24 inch
treated water distribution pipeline above the Roadside mine workings.
Several raw water collection pipelines also cross the Cottonwood lease. The
application does not indicate the existence of any renewable resource lands
within the combined permit areas. However, two intermittent stream drainages,
Cottonwood and Rapid Creeks, cross the permit area within the Cottonwood
lease. The application does not appear to contain sufficient descriptions
of these drainages to discount the existence of alluvial deposits and alluvial
aquifers. The applicant is required by Rule 2.05.6(6) to preclude material
damage to any renewable resource land.
The application should be amended to clarify the surficial geology and hydrology
of the Cottonwood Creek and Rapid Creek drainages, in order to determine
whether renewable resource lands exist within those drainages which may be
potentially affected by ground subsidence. If renewable resource lands are
determined to exist within those drainages, the application must be amended to
conform with the requirements of Rule 2.05.6(6)(b). In a similar situation
encountered at the I~serado mine, the applicant was required to monitor and
maintain the positive drainage of the potentially affected surface drainage
courses.
The applicant contains an extensive analysis of the stability of pillars
proposed to prevent subsidence damage to the overlying Ute Water District's
water treatment plant and collection and distribution pipelines (see Appendix
W). The application also contains several predictions of maximum subsidence
expected to occur if pillar failure follows cessation of mining in these areas.
Each of these analyses is prepared in accordance with the state-of-the-art
of subsidence prediction.
423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. [phone]