HDR, Ott Constructability, Dan Brown Visit and boat tour of Rouchleau pit ◦ Access better than potrayed ◦ Challenging geotechnically Viewed drilling operation
E-1a and E-2 have similar conditions (fill over rock) Large boulders (unknown size) and some of the hardest rock in the world No experience drilling in this material How long it will take to install foundations Need to determine best foundation type and cost
All work on E-1a haul road One 8’ diameter drilled shaft ◦ Can it be constructed ◦ No load test (2) 16” and 24” drilled pile ◦ 2 locations previously drilled ◦ Load test one 16” pile July 25 th letting Cost $3.5-5 million Pre-bid meeting – July 9
Minimize number of piers for any option HDR to develop conceptsand cost estimates E-1a ◦ Steel ◦ Concrete ◦ Delta Frame Arch E-2 ◦ Steel ◦ Concrete ◦ Arch ◦ Delta Frame Arch
Geological Mapping of faces Boring at possible arch locations Cost
MPCA, MnDOT & FHWA Perpetuate current drainage patterns Collect water across pit ◦ Permit to mine (no impact to Cliffs NPDES permit) ◦ MDH requirement for drinking water Infiltration ponds on east side ◦ MDH – no infiltration ponds near drinking water ◦ May add to TDS issue in pit from chemicals Need to review groundwater flow All de-icing chemicals may create an issue
PAC Meeting – July 2 Pending issues ◦ Notification of Elected officials ◦ Cost Range $240-$460 million (tie to alternatives?) FAQ’s ◦ Will be the road be closed? ◦ What is the new timeline? ◦ Where will the money come from?
MnDOT & Cliffs working together Common Goals ◦ Move road in timely manner ◦ Maintain direct connectivity ◦ Minimize resource encumbrance Technically challenging -geotechnical Schedule – unknown at this time, quick, plan of action Awaiting Cliffs comments on talking points.
Commissioner’s Staff – June 16 Air Quality – June 17 Cliffs Negotiations– June 19 PAC – July 2 Coffee & Conversation – July 3 Test Foundations Pre-Bid – July 9 Needed meetings Utilities DNR School Trust