REP18710

• Permit No: C1981044
• IBM Index Class Name: Report
• Doc Date: 6/15/1982
• Doc Name: REVIEW OF INSPECTION REPORT FOR EMPIRE ENERGYS COAL PROCESSING WASTE PILE
• From: MLRD
• To: SANDRA EMRICH
• Permit Index Doc Type: Waste Pile/Fill Report
• Media Type: D
• Archive: No

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STATE OF COLORADO AIC HAFfI D. L~MM. env non n~ ~~11 ~II ~I~~II 111 III
DEPARTMENT OF NATURAL RESOURCES 111 7I 11I II
D. Monte Pascoe. Executive Director 999
11'IIlVED LAND RECLARIATION
423 Cenlen nlal Building. 1373 Sherman Street
Denver, Colorado 80203 Tel. [phone]
David C. Shelton
June 15, 1982 DIfe C10T
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TO: Sandra Emrich `\~._
FROM: Jim Pendleton /~~W'~`~'""`""--
RE: Review of Ins~ectio Report for Empire Energy's Coal Processing
Waste Pile C__.
Pursuant to your request, I have reviewed the inspection report prepared by
CTL/Thompson, Inc., presenting their observations concerning the foundation
preparation and subsurface drain installations at Empire Energy Corporation's
coal processing waste pile at the Eagle mine. This document presents a
clear description of the construction process, including photography of the
activities described.
The consultant's observations indicate that several aspects of the construction
remain to be resolved:
(1) "Due to some variance between the topography used for design and
actual field conditions, a portion of surface ditches around the waste bank
had been directed toward the northern end of the disposal area. Empire Energy
has constructed a sedimentation pond, northeast of the processing waste bank
for treatment of water collected by the north-flowing ditches." Empire Energy
should be required to amend the approved plans and surface drainage designs
appropriately. The consultant further recommends that the diversion ditches
be analyzed to verify the adequacy of their cross-sectional sizing. Further,
the rip-rap ditch armorment had not been installed at the time of CTi,/Thompson's
last site. observation on May 6, 1982.
(2) Waste has been placed and compacted over roughly the southern half of
the approved disposal area. The consultant observes; ...., that the subgrade
be recompacted as the disposal area expands beyond its cur:^ent I~imits prior
to placing additional processing waste." In keeping with Lhe regulations of
Rule 4.10..1, as well as the consultant's recommendations, the foundation sub-
grade and processing waste should both be compacted to at least 90~ of stanr?ard
Proctor maximum dry density (ASTM D-698).
(3) The consultant recommends that; ... initially a soils engineer be
present during compaction (of the processing waste) and theft density tests should
also be taken periodically during construction of the waste bank to confirm that
the materials be properly compacted." Compaction certification is required by
Rule 4.10.4(3)(b), on a quarterly frequency.