INSPEC39824

• Permit No: M1987064
• IBM Index Class Name: Inspection
• Doc Name: INSPECTION REPORT
• Inspection Date: 2/1/1995
• Media Type: D
• Archive: No

(Page 2)

MINE ID ~ OR PROSPECTING ID ~ M-87-066
INSPECTION DF~TE 2 1 95 INSPECTOR'S INITIALS TAS, SS
OBSERVATIONS
1. A site inspection was conducted with John Dillon on 2/1/95 and with David Dalton on
2/2/95.
2. The Dalton Land & Cattle operation ie permitted for in-stream mining of gravel for a
total disturbance of 67 acres. The current financial warranty ie a letter of credit for an
amount of S6,800. The poet-mining land use is wildlife habitat. The mining operation ie
located 5 miles north of Durango within the channel of the Animas River. The intent of the
operator is to practice "controlled" mining in order to remove the volume of sand and gravel
annually deposited above the level of the low flow channel water surface.
3. The operation ie permitted for extraction of gravel down to the elevation of the water
table that exists at the time of extraction. An assumption was made by the operator in the
permit application that the water table in the area of extraction and the water surface of
the adjacent Animas River are synonymous. This hydrologic relationship may not always be
true but certainly the surface of the Animas River ie expected to be at or above the
groundwater table in the area of extraction. Therefore, ensuring that all future excavation
ie at or above the elevation of the Animas River at the time of extractioa should aid the
operator in determining the maximum allowable depth of excavation. It ie incumbent upon the
operator to monitor this condition closely and to comply with the terms of hie mining permit.
On the day of inspection the depth of excavation appeared to be 4-6 inches lower than the
exposed groundwater table. The operator reported this difference to be due to daily
fluctuations in the water table. During future inspections the Division will consider Sandco
to be in violation of their permit if there is exposed water in the area of excavation during
active mining.
4. Sandco made a commitment in the mine plan to isolate the river from the work areas
through the use of temporary dikes and berme. The purpose of the temporary dikes and berme
is to confine any muddy water to the work area and to confine the Animas River to a single
channel during excavation. On the day of inspection there was a small volume of muddy water
flowing from the work area though a culvert and into the active channel of the Animas River.
The operator was cautioned to maintain the turbulent water in the work area unless he was
prepared to acquire an NPDES water discharge permit from the Colorado Department of Health,
Water Quality Control Division and comply with effluent standards. A copy of this report ie
being sent to the Colorado Department of Health, Water Quality Control Division.
5. Reclamation procedures for the river channel area consist of removing and grading all
isolation dikes, haul roads, and other surface irregularities created by mining act iv itiee
to conform with the undisturbed portions of the river channel. Reclamation procedures for
stockpile and processing areas consist of removing buildings, equipment, and stockpiles;
grading to czeate a smooth surface that conforms with the adjoining land; application of
available topsoil (2-3"); and seeding with a grass and clover seed mix recommended by the
local Soil Conservation Service.
Wildlife noted at or near the operation during the time of inspection included elk, mule
deer, bald eagles, Canada geese, great blue heron, and various waterfowl species. There ie
a stand of mature cottonwood trees on the east bank of the Animas River just outside of the
permit area which serves ae important habitat for hawks, bald eagles, and other raptors. The
east bank of f:he river near these trees ie approximately 8-10 feet high at a elope of 1:1 or
steeper. A shallow water table ie vital to the health and vigor of the existing cottonwood
trees. Therefore, the operator should be advised that any mining practices which result in
a lowering of the water table in the Animas Aiver floodplain can have a direct adverse impact
on adjacent aDttonwood trees.
6. A concern noted is that the reclamation plan does not clearly define the conditions to
which the river channel will be reclaimed. Since Rule 3.1.6 requires that disturbances to
the prevailine7 hydrologic balance as well as to the quantity and quality of surface water be
minimized and that damage to adjacent property be prevented, specific information such as the
width/depth ratios and channel elevations at the upstream and downstream permit boundaries
should be provided to establish a set of baseline criteria that can be used to evaluate the
suttees of reclamation and compliance with Rule 3.1.6. This information can easily be
obtained by conducting a channel survey which provides channel cross sections from east to
west bank and a longitudinal profile of the stream channel from the upstream boundary to the
downstream permit boundary. The Division requests that the operator address this concern