REV106044

• Permit No: C1982057
• IBM Index Class Name: Revision
• Doc Date: 8/2/2007
• Doc Name: Adequacy Review Memo
• From: Mike Boulay
• To: Dan Mathews
• Type & Sequence: TR59
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 275
denver
Colorado 80203 C O L O R A D O
, DIVISION o e
Phone: [phone] RECLAMATION
FAX: [phone] M I N I N G
Sc-
SAFETY
Bill Owens
INTEROFFICE MEMORANDUM Governor
Russell George
Executive Director
Ronald W. Cattany
Division Director
TO• Dan Mathews Natural Resource Trustee
FROM: Mike Boulay 1'~g
DATE: August 2, 2007
SUBJECT: Seneca II-W, Permit No. C-82-057
Technical Revision No. 59 (TR-59) Adequacy Review
As requested, I have reviewed the TR-59 application from Seneca Coal Company (SCC)
regarding postmine channel designs and Pond 005 sediment capacity revision. Since we
have recently reviewed similar revisions for the Yoast and Seneca II Mines TR-30 and
TR-42, respectively, many of the adequacy issues have been resolved with regard to the
use of turf reinforced mat for channel design and the design/modeling for increased
sediment pond storage capacity. This TR-59 submittal reflected the issues that have been
worked out with these former revisions regarding these items. I have the following
adequacy comments which primarily concern the presentation of design information.
In the revised SEDCAD run for 005 Gulch, the Structure Networking and the
Structure Routing Details were missing from the revision application. This was
previously given on page 20-1-4 but this page is missing from the TR-59
application. Please provide page 20-1-4 with the appropriate networking and
routing details for Postmine Channels 005 Gulch and 005-E1.
2. In the revised SEDCAD run for PM-2 System, the model indicates that both PM-2
and PM-2A flow to Culvert J-2. On revised Exhibit 20-2, it shows that Culvert
PM-2A flows to Culvert K-1 and also branches off and joins Channel PM-2 at
point EEE. Also, in the cover letter to this revision, SCC indicates that Channel
PM-2A and PM-2 are separate and distinct channels and the flows do not join
until the channels both reach Culvert J-1. The information presented in the
SEDCAD demonstration and Exhibit 20-2 Postmining Topography and Drainage
are not consistent. Please revise the SEDCAD demonstration for PM-2 System
and Exhibit 20-2 as needed to be consistent and accurate regarding the culvert
designation and the routing of Channels PM-2 and PM-2A.
Office of Office of
Mined Land Reclamation Active and Inactive Mines