INSPEC20975

• Permit No: M1973021
• IBM Index Class Name: Inspection
• Doc Name: MINERALS PROGRAM INSPECTION REPORT
• Inspection Date: 6/26/2001
• Media Type: D
• Archive: No

D1INE ID # OR PROSPECTING ID#: M-1973-021 PAGE: 2
INSPECTION DATE: 6-26-01 INSPECTOR'S INITIALS: ACS
following the development of a slope failure on the east highwall of
the central quarry, the Morrison Quarry adopted an observational method
i:or the mining and reclamation of the quarry benches. This method
involves a rigorous series of interactive steps of excaval=ing rock,
observing the condition of the rock mass and the behavior of the rock
:;lopes, and refining the bench and highwall design based on the updated
__nformation. From a regulatory standpoint, the performance standards
of the Mined Land Reclamation Board require that "If not eliminated,
till highwalls shall be stabilized," (Rule 3.1.5(3), Construction
P4aterials Rules and Regulations). The observational method of quarry
development was incorporated into the Morrison Quarry mined land
reclamation permit through the approval of permit amendment AM-03 in
:L994 and has been carried through in the approval of :subsequent
~~mendments AM-04 and AM-O5. As a condition to the approval of the
observational method at the Morrison Quarry, the Division of Minerals
and Geology receives a geotechnical addendum to each annual reclamation
report. These addenda update the status of the ongoing geotechnical
Lnvestigations and the development of highwalls and benche:> based on
the information gathered during the investigations. The primary
f~urpose of this inspection was to observe the condition of the pit
:alopes relative to the volume of data and analysis provided in the
annual geotechnical addenda provided since the approval of AM-03 in
1994. Certain other observations germane to the mined land reclamation
f~ermit were made during this inspection, and are described below.
'.Chis was the first inspection of the Morrison Quarry specifically
related to pit slope stability since a series of inspections conducted
Ln 1992 and 1993 at the time of the slope failure on the ea:~t wall of
the central quarry. However, some observations of the slope failure
~srea were recorded in a report of a general monitoring :inspection
conducted 10-26-94. At that time the east highwall failure had not
teen repaired because the Operator was still finalizing the Jefferson
('ounty process to increase affected land needed to complete the slope
i'_ailure mitigation. The Division of Minerals and Geology conducted an
~ierial inspection of the quarry and photographed the quarry walls on
._0-6-98; in addition, inspections of the quarry unrelated to slope
:stability were conducted in 1998 and 1999.
~'he first stop of this inspection was at the top edge on the south side
of the central quarry pit. From this vantage point it wa:; observed
ghat the entire circumference of all central quarry benches show no