HomeMy WebLinkAboutNotes, Work PLANNER 7/12/2004
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Memo to File
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July 12,2004
To:. ZON2004-00006 (MTGATE QUARRY FILE)
Date:
From: Jim Donovan, DSD Planner II I
Subject: July 12, 2004 Initial Test Blast Field Report
Deputy Fire Marshall Joe Wicks, State Deputy Fire Marshall Kristina Deschaine and I
attended the initial test blast at the Mountai'nGate quarry site. The work was perfonned in
accordance with the Discretionary Use Approval, the approved blasting plan, and state
and federal regulations. !
Field conditions were 85 degrees with cleat skies. On hand were Mike Evans, Project
Manager for the owner, Dick Daniel of Explosive Technology Service as consultant, Kris
Jeremiah as site superintendent and Shaun Rimmington as Blaster in Charge for BJ
Equipment, blasting contractors. Site prep~ation included the excavation contractor
removing loose soil and rock from the bottom of the quarry/detention pond site and
grading a protective berm ofJarge rock along the south side of the work site,
approximately 50 yards north of the property line. Notice had been sent out to neighbors,
access controls at both entrances to the site and Weyerhaeuser Road were in place.
Seismic and air pressure monitors were set' at four locations (SUB water tank site, two
neighboring property lines directly south along Weyerhaeuser Road and at 571h and Mt.
Vernon Road). '
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Kris Jeremiah gave a brief overview of the' blast preparations. The blast area was located
at the east end of the pond bench which is partially excavated, leaving an exposed face to
the north, facing-the main quarry wall. A matrix of 60 vertical holes had been drilled and
loaded. The matrix was a 6x I 0 pattern over an area approximately 20 yards wide by 40
yards long. The 14-20 foot deep holes were loaded with 2" diameter unigel explosive,
reduced to 1.5 inch diameter near the top and stemmed or capped with aggregate to
reduce noise. The intent was to fracture approximately 900-1000 cubic yards of material
under seismic and air pressure monitoring !for calculating patterns and charges for future
blasts on the scale of 5000 cubic yards. ]
At 12:45 Mike Evans, Joe, Kristina and I tetreated to a vantage point approximately one
quarter mile away (Weyerhaeuser earthen benn south east of the quarry site) to observe
the blast. Joe called 911 to alert the call centcr of the impending work (NOTE: Kris will
do this for all blasts.) Five slow horn blasts were sounded 5 minutes before the blast, a
radio check indicated all preparations werb complete. At I minute prior to blast,S rapid
horns were sounded and a radio check ocdurred. After radio countdown from 10 seconds
the call of FIRE IN THE HOLE was anno~nced by Geri Betz and the blast was triggered.
The surface raised 4-6 feet and slumped irl place with minimal dust and a low "humph"
sound. Minor reverberation was noted offithe quarry face, but at very low pitch. After an
"All Clear" from the blaster, visual inspection revealed a pile ofrock in varying sizes up
to approximately 1.5 cubic yards. All chafges had detonated and the test had gone exactly
as planned. Monitor readings will be incotporated in future blasts.
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Date Received:
Planner: ~ 1-0 !J~
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