2008-07-15_ENFORCEMENT - C1994082 ‎(2)‎

• Permit No: C1994082
• IBM Index Class Name: ENFORCEMENT
• Doc Date: 7/15/2008
• Doc Name: Memo Regarding Recommendation to Extend Abatement Beyond 90 Days
• From: Sandy Brown
• To: Ron Cattany
• Violation No.: CV2008001
• Email Name: SB1
• Media Type: D
• Archive: No

c,.
sNor Seneca Coal Company
July 7, 2008
RECED
ED
Mr. Dan Mathews 'Alt 09

Division of Reclamation, Mining and Safety
d 20
p W
101 South 3,
, Suite 301 46* of
Grand Junction, CO 81501 "u'8
[phone]
RE: Yoast Mine Permit No. C-94-082
NOV CV-2008-001: Abatement Step 2 - Time Extension Request
Mr. Mathews,
Seneca Coal Company (SCC) is providing information regarding Abatement Step 2, as stated in the "Attachment to
NOV CV-2008-001, Extension of Time for Abatement", that extends the time deadline to submit a complete technical
revision application from June 30, 2008 until July 31, 2008.
Step 2. No later than &.& 31.2UD8. provide a complete technical revision application, which will include a slide remediation plan
prepared by a qualifiedgeotechnical engineer. The remedial plan will identify and assess the factors that contributed to the failure, will
include specific remealial measures to be impkmented to repair the slide and effect comptwoce with the applicable requirements of Rule
4.14, and shall include ageotechnicalstabi/ity analysis demonstraAing that the remedial plan will result in a final slope that will comply
with Rule 4.14.2(1)(b). The application will also address both short term and longterm measures that will betaken to provide
adequate sediment controls in the Pond 12 watershed, consistent with long term mass stability of the failed slope. Short term measures
may include cleanout of Pond 12, if the geotechniaal nport demonstrates that such ckanout can be accomp&bed without compromising
slope stability. The application will include a schedulefor implementaAion of the slide mmediation plan, including the short term and
long term sediment control measures for the Pond 12 watershed
Response: The Yoast Mine is located at an approximate average elevation of 7,700 feet. At this elevation the ground
conditions remain wet in the drainage bottoms throughout the spring and early summer (probably into July especially
given the extreme snowfall experienced over the 2007-2008 winter season). Equipment, such as that needed to evaluate
-the root cause of the'situation, cann6t even-access the area until considerable drying/dewatering has occurred
SCC retained a qualified geotechnical engineering firm (NWCC) to conduct a slide evaluation and geotechnical
investigation of the Pond 012 area. Following is the scope of work to conduct the evaluation and investigations,
submitted by NWCC:
SAW:
1) Advance 7 to 8 test holes across the slide area situated north/northeast of the existing Pond 12 with an all terrain drill rig. In
addition, S to 6 test pits will be excavated with a trackhoe. The depth of the test holes will be determined in the field as the drilling
and excavationsprogreu and as the subsoil pmfeks become evident. We have assumed that the test hoks will be dulkd to a
minimum depth of 20 to 40 feet and the test pits will be excavated to depths ranging from 10 to 20 feet, depending on the
subsurface conditions encounterrd The test holes and pits will be advanced to investigate the subsurface profiles, to obtain samples
for laboratory testing, to estimate the groundwater level and the depth to bedrock Slotted PVC pipe will be installed in several
Seneca Coal Company • P.O. Box 670 • Hayden, Colorado 81639
Telephone [phone] • FAX [phone]