PERMFILE108847

• Permit No: M1980020
• IBM Index Class Name: Permit File
• Doc Date: 11/5/1979
• Doc Name: LIMITED IMPACT 110 & SPECIAL TEN DAY 111 PERMIT APPLICATION FORM
• Media Type: D
• Archive: No

EXHIBIT "B" - Mining Plan
There is on site presently an existing mining operation. (At the
time the Board will consider this, the pit is operating under a Special
Permit - a governmental contract providing bedding material for the
Rampart Raw Water Transmission Line - Pahse II to the City of Aurora).
On Map "B" attached, the area designated with the blue perimeter is the
extent of present excavation and the floor of that excavation is 10 to
16 feet below the previous ground level (the 10 foot depth is found in
the North end of the pit, sloping up to the previous existing ground
level; the 16 foot depth at the South end). The red perimeter defines
the area that to date has been disturbed by the stripping of topsoil in
preparation for excavation. The green perimeter would be the fartherest
point in terms of excavatiorn for the pit and actual mining, that being 9
acres. The dotted green line on the West would be a disturbed area of
.75 acres occasioned by the necessity of a slope before the mining between
the West red and West green line could be effected. The blue perimeter
designates 6.3 acres, the area presently being mined, and the red perimeter
is 7.5 acres, which represents the disturbance at this point in terms of
stripping and sloping and where excavation will proceed from the blue
perimeter area.
The operation is a dry pit. There is no water involved, and the
water table is 30 to 40 feet below the existing floor of the gravel pit.
Core tests of the material on site show the existence of various grades
of sand, sand and gravel, silt, and intermittent clay to the depth of
the water table. Core tests further ind(cate the water table to be at
an approximate elevation of 5475 feet (present floor of mining operation
is 5514 feet in elevation). At present there is no processing on site,
i.e. no screening plants, no crushers. There could be in the future the
operation of a screening plant in which event operation of this piece of
machinery would not commence until NPDES Permit, if the same is necessary,
is procured.
For purposes of this Limited Impact Permit, the maximum area to
actually be mined would be the green perimeter line of 9 acres. The
disturbed area would be 9.75 acres, the fartherest point of either the
solid green perimeter line or the green dotted line on the West. Less
than 70,000 tons per year would be removed and the total depth of the
pit, if it were to be fully excavated to an elevation of 5508 feet or 6
feet below the lowest point that now exists, would result in 262,739
tons available for extraction. Within the parameters of 70,000 tons per
year, the life of the mine would be 3.75 years, if 70,000 tons per year
were processed. If one were to assume an average of 52,500 tons mined
per year, the life of the mine would be 5 years. Hence, the duration of
mining under the Limited Impact Permit, given the parameters of not more
than 10 acres affected and not more than 70,000 tons per year, would be
between 3 years and 9 months and 5 years. Reclamation as will be discussed
in Exhibit "E" would then be effected 6 to 12 months after the date of
final excavation, either 3 years and 9 months from now or 5 years from
now, as the case may be.
Mining for the purposes of this Limited Impact Permit will consist
of three phases:
1. The stripping of overburden, which is 3 to 5 feet of topsoil,
which will be stockpiled as additional stripping of topsoil is necessary
(this would be in the area between the red and the green perimeter as
shown on Map "B"). Once excavation proceeds to the solid green perimeter
line, then the stockpiles would be located on the slope between the
solid green line on the West and the dotted green line.
2. The excavation of the sand and gravel material by way of bulldozers
stockpiling the same.
EXHIBIT "B" - Mining Plan
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