_PERMIT FILE - M1974070 ‎(61)‎

• Permit No: M1974070
• IBM Index Class Name: Permit File
• Section_Exhibit Name: EXHIBIT D-MINING REPORT
• Media Type: D
• Archive: No

such as the deposits at Rocky Flats, the cap gravels found on
some hilltops, and the mountains themselves, but all of these
alternative deposits are inferior to the river gravels from
either a quality or a cost standpoint. The river gravels vary
from almost no useable gravel to depths of over twenty feet
with the preponderance of gravel depths being twelve feet or less.
Method
Sand and gravel mining operations across the country vary widely
in the methods used for extraction. This is due to topography
of the site, depth and thickness of the gravel deposit, height
of the water table, quantity and rate of material extraction and
equipment availability, and other considerations.
r
Most Flatirrn mining operations are open pit excavations. The
procedures and equipment to be used at this operation are as follows :
1. Scrapers will remove the topsoil and expose the aggregate
below. In this case overburden will be deposited at the outside
edge of the area to be mined.
2. Because the aggregate is mined dry, a backhoe will be used
at this stage. The backhoe will dig a dewatering trench around
the area to be mined . Gravel removed will be stockpiled inside
the trenched area.
3. A pump will be placed in the down stream end of the dewatering
trench to keep the pit dry.
I4. Two pieces of earth moving equipment will remove the aggregate,
front end loader and scraper or truck. Once the transporting
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