REV00011

• Permit No: C1980001
• IBM Index Class Name: Revision
• Doc Date: 8/19/2003
• Doc Name: Memo-Summary of Adequacy Review
• From: Tom Kaldenbach
• To: File
• Type & Sequence: TR41
• Media Type: D
• Archive: No

Pond Removal Checklist
Pond: Tipple Ponds 1, 2, 3, and 4 Technical Revision: 41
Mine: Edna Mine Date review completed: 8/19/2003
Permit No.: C-80-001 CDMG reviewer: Tom Kaldenbach

Requirements for removing a pond, Require-

Section 4.05.2(2) ,Went met
Comment
~
(Yes / No)
The Division has authorized the removal. Yes Removal is being authorized based on the following items in this checklist.
Adequate revegetation is indicated by the 1999, 2000,and 2001 vegetation cover data
The disturbed area has been revegetated and submitted by the operator and referred to in the TR-41 submittal. Stabilization has been
stabilized. Yes indicated by the operator's annual erosion reports. DMG has verified in the field the
reve etation and stabilization durin its re lar month] ins ections.
Premining sediment yield is unknown because the disturbed area (conveyor corridor)
draining to the Tipple ponds was disturbed prior to enactment of SMCRA. The TR-41
submittal contains a post-mining RUSLE calculation for the disturbed area. This
calculation was compared to a pre-redisturbance USLE calculation in the permit
application for the same area. Only the "C" factor was varied in the post-mining
The untreated drainage from the calculation, compared to they pre-redisturbance calculation.. The post-mining sediment
disturbed area does not contribute yield was calculated to be 55 /o of pre-redisturbance sediment yield. The variables used in
additional suspended solids above Yes the post-mining calculation appeared reasonable for making the comparison. The
calculation used vegetative cover data for the disturbed area collected in 1999, 2000, and
natwal conditions. 2001. The comparison; therefore, appears valid and indicates the untreated drainage,
currently, probably does not contribute more suspended solids than the just prior to
enactment of SMCRA. As a check, I independently calculated, post-mining sediment yield
for the disturbed area using the RUSLE, as follows: 30R X 0.30K X 3.53~s X 0.085c X
O.SOP = 1.4 tons/acre/year. This is a modest soil loss rate for steep-sloped rangeland in
northwest Colorado.
The Tipple Ponds discharge to Oak Creek in segment 7 of the Yampa River Basin. A list of
The quality of untreated drainage from the instream parameters applies to segment 7. The ponds discharge to Oak Creek via CDPS
disturbed azea meets the state water quality outfal1001, downstream from pond 4. CWQCD would have set the reporting requirements
standards for receiving streams that will be Yes and limitations for this outfall based on those pollutants in the discharge having a
applicable after the sedimentation ponds and reasonable potential for causing an exceedance of the instream standards. The ponds have
treatment facilities are removed, if any. discharged only a few times in recent years, only during springtime snowmelt/runoff. The
CDPS com Hance record indicates the dischar es have not caused a violation of the