Seymore Quartz safety assessment.docx

Seymour Quartz minesite

The east Seymour Quartz adit is supported with competent timber and steel beams and is periodically used by the claimant. The claimant no longer needs access to this adit and is willing to allow the Forest Service to close the workings. Bedrock at the site is steeply dipping and moderately jointed schist. The adit trends N450E and is accessible for about 400 feet where partially collapsed back and ribs and rotten collapsed timbers indicate the working are too dangerous to continue any further. There are several dangerous features in this working. There is incompetent bedrock at the portal and colluvial material on the hillslope sloughing into the portal area. Approximately 200 feet into the adit is a winze that is the width of the adit from rib to rib, about 10 feet across and reportedly 100+ feet deep and is flooded up to the floor of the adit. The only way across the flooded winze is to walk across two rails that are lying on the bedrock surrounding winze and supported by only a few inches of bedrock. There is a partially collapsed drift that goes around this flooded winze and has standing water about 6 inches deep. The flooded winze intersects the drift at an incline to the surface that probably served as a haulage way to the surface. There is an incompetent wooden ladder that leads up to the surface. Air quality was good throughout the workings. We discussed portal closure options including building a new gate and reinforcing the existing gate using the existing timbers and steel.

The incline to the surface from the east Seymour Quartz adit is a surface hazard since the surface opening is about 14 feet across with unstable banks. The claimant has placed steel pieces across the decline as a temporary safety measure but this is inadequate as a long-term solution. We discussed closure options but did not identify a preferred method. The options for a closure method for this decline need to be assessed. There appears to be waste rock available on site to partially fill the winze. There does not appear to be competent bedrock to anchor metal netting or to use to anchor a culvert lowered into the hole. A steel culvert could be lowered into the decline and then packed with the waste rock at the site, but the long-term stability of this type of placement is questionable. The site is accessible by heavy equipment but may require walking the equipment into the site from the Kanaka Creek bridge.