INSPEC14469

• Permit No: M1983030
• IBM Index Class Name: Inspection
• Doc Name: MINERALS PROGRAM INSPECTION REPORT
• Inspection Date: 3/21/1996
• Media Type: D
• Archive: No

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MINE ID # OR PROSPECTING ID # M-83-030
INSPECTION DATE 3/21196 INSPECTOR'S INITIALS WHE
This complete inspection of the Twin Canyon Mine mill site was conducted by Wally Erickson from the DMG field office in Durango,
1474 Main Avenue, Room 207, Durango, CO 81301-5162,phone [phone]. Westley Potts and Jim Potts, Potco Milling &
Mining, accompanied the DMG inspector through out this inspection. The mill is located behind the residence of Mr. Westley Potts,
approximately 1.5 miles south of Mancos, 8115 CR 41, in the S 1 /2 of the S 112 of the SW 1 l4, Section 33, T36N, R13W, NMPM,
Montezuma County. ~ This inspection resulted from a request submitted by Mr. Westley Potts for an on-site meeting to discuss plans
for tailings pile containment structures, to be reviewed and finalized in TR-01.
Mine identification sign was posted at the entrance to the mill site. Mine identification sign was clearly visible from the access road
and displayed the information required by Rule 3.1.12111. Affected area perimeter markers were posted and clearly delineated the
affected area, as per Rule 3.1.12121. Several cattle were observed within the affected area and may create a maintenance problem
for the signs, should the cattle utilize the signs as scratching posts.
Milling operation were not active during the time of this inspection. Description of the mill operations was recorded in DMG
12113195 inspection report and in TR-01, submitted by the operetor on 2/16/96. Conditions of the mill operations appeared
unchanged since DMG 12113195 inspection except that barrel of surfactant had been removed. No chemicals, fuels or lubricants
were observed within the affected area. The operator stated that a household liquid detergent may be utilized in small quantities
as a dispersant in milling operations.
Tailings pond contained water. Water level was approximately 2-Teel below discharge level, algae and aquatic vegetation was
established along the waterline of the pond. Pond inslopes did not appear to be steeper than 3H:1 V slope. Water was not observed
to be entering the pond. No discharge was noted. Operator indicated that the pond depression had been incised into the Mancos
shale strata.
Tailings stockpile appeared unaltered from DMG 12113195 inspection. Operator indicated that the shallow layer of topsoil had been
stripped down to shale bedrock prior to mill operations and that the tailings stockpile was located on the shale strata, Topsoil
stockpile was observed adjacent to the tailings stockpile. Vegetative cover of the stockpiled tailings was sparse and consisted of
various grasses and annuals, operator indicated that stockpile had not been seeded. Evidence of erosion was not observed on the
stockpiled tailings. Sediment containment structures were not observed for the tailings stockpile area, and are addressed as an
adequacy concern of TR-01, currently being reviewed by DMG staff.
DMG inspector discussed with the operator, Harry Posey's review of the ore assay, dated 3/7/96. Mr. Posey indicated in his 3/7/96
memo, that the ore assay submitted by the operator did not contain sufficient information to determine, with certainty, whether the
ore and resulting tailings are a potential acid or toxic metal source. However, DMG experience with similar operations, in similar
stratigraphic locations has shown low acid generating and toxic producing potential. Given the minimal quantities of ore stockpiled
and tailings generated by this operation, the fact that no chemicals or toxic substances are utilized by the operation, and the
relatively impermeable shale strata which underlies the entire milling operation, DMG has determined that additional sampling and
leach testing of the tailings is not necessary et this time. DMG inspector discussed with the operator, the following three issues
regarding containment of tailings and drainage from the milling operation:
1. construction of a sediment containment ditch around the lower side of the tailings stockpile area to contain surface drainage
from the tailings and convey drainage to the tailings pond;
2. construction of an upland diversion ditch/berm around the upper side of the operation to isolate mill operations from surface
drainage; and
3. establish vegetative cover on tailings stockpile to minimize erosion and potential off-site transport of tailings by wind.
I & E Contact Address
NAME
OPERATOR
STREET
CITY/STATE/ZIP
Mr. Westley Potts
Potco Milling & Mining
8115 County Road 41
Mancos. CO 81328
cc: Tom Gillis, DMG
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