GENERAL39591

• Permit No: M1994117
• IBM Index Class Name: General Documents
• Doc Date: 3/27/1995
• Doc Name: PERMIT APPICATION ADEQUACY REVIEW GOLD HILL MILL FN M-94-117
• From: DMG
• To: COM INC
• Media Type: D
• Archive: No

~~ •
Gold Hill Mill 6 March 27, 1995
implemented at the impoundment, which is obviously not the case since the
only embankment at the site is the original starter dam. As a point of
clarification, COM, Inc. should provide a statement that the existing
impoundment was not built by the upstream method.
19. The application states that the starter dike was built as a zoned
embankment that has an upstream gradation into sand. The Division does
not believe that this type of construction actually occurred, and cannot
conceive of a reason to employ this type of construction since the
upstream face of the starter dike is lined. The application states that
the starter dike was initially built to between 4 and 6 feet in height and
11 and 17 feet in width, and was built with an outslope of 2.8:1. Based
on the Division's field observations of the existing embankment, and on
the MSHA inspection report mentioned previously, it is obvious that the
dimensions for the starter dam provided in the application are grossly
inaccurate. As you will see in adequacy comments provided below, the
Division will require substantial information on the existing impoundment
in order to approve this application. Please clarify the inaccuracy of
the starter dam dimensions as provided in the application as submitted to
date.
20. The application states that seepage is collected below the tailing
impoundment, and is then piped to the Hazel A adit. To the Division's
knowledge, this is not occurring and would not be necessary since the
impoundment is lined. Please clarify this statement in the application.
21. The application states that soda ash, pine oil, and xanthate are the
chemicals used in the in the milling process. COM, Inc. should
acknowledge that if any changes to this list of chemicals is anticipated,
that a technical revision would have to be filed with the Division. It
is further stated that no more than 200 gallons of these chemicals would
be stored at the mill at any time. Please provide a break-down of the
quantity of each chemical that may be stored. You should refer to the
quantity of soda ash to be stored in pounds rather than in gallons.
22. Please provide a containment plan for the mill building itself. The
building will have to be modified such that the maximum potential spill
of water or tailing would be contained within the building. The maximum
potential spill would occur if the thickener tank were to fail, amounting
to 75,000 gallons requiring containment.
23. As discussed previously, each diversion ditch at the site must be
accurately located on the Mining Plan map. Please also provide the
following information on the ditches:
(a) divide the ditches into distinct reaches, the boundaries of
which will be defined by changes in pertinent ditch parameters,
depict the reach boundaries on a map;
(b) provide a ditch cross-section for each reach that is defined,