Police raid Rosemont contractor over Mount Polley dam failure

Search warrants have been served on two engineering companies linked to the Mount Polley tailings dam collapse including AMEC Foster Wheeler, the lead designer of the proposed Rosemont copper mine’s massive dry stack tailings dump.

AMEC said Thursday its Prince George, British Columbia office had been served a search warrant in conjunction with the Mount Polley investigation, the Vancouver Sun reports. “We are co-operating fully with the regulatory authorities,” AMEC spokeswoman Lauren Gallagher said in a written statement.

The investigation by the B.C. Conservation Officers Service, Environment Canada, Fisheries and Oceans Canada and the RCMP is focused on offences related to B.C.’s environmental management act and the federal Fisheries Act, the Sun reports. The investigation could result in charges and fines.

Another search warrant was served on BGC Engineering, a Vancouver firm that was preparing to assume oversight of the Mount Polley tailings dam from AMEC last summer but the dam collapsed prior to the handover.

AMEC took over engineering responsibility for the dam in 2011 from Knight Piésold, which designed the dam in the early 1990s.

Mine owner Imperial Metals’ had its head office in downtown Vancouver, B.C. and its mine site 250 miles northeast of Vancouver raided Tuesday evening.

The Toronto Globe and Mail is reporting authorities have executed four search warrants in all.  The target of the fourth warrant remains unclear.

The British Columbia sponsored Independent Expert Engineering Investigation and Review Panel Report on the Mount Polley Tailings Storage Facility Breach “concluded that the dominant contribution to the failure resides in the design,” according to a media briefing.

The multinational engineering giant Knight Piésold’s design did not fully account for the presence of a glacial lake deposit beneath the tailings dam foundation, the Vancouver Sun reported.

Knight Piésold knew about the glacial till after it did boring tests, but decided the deposit was spotty and would “not adversely affect the dam stability”, the CBC reports.

“They misinterpreted the test results and didn’t really understand the nature of the strength, and the nature of how it could get weaker, and the nature how in fact, it did, fail,” Jack Caldwell, a leading North American expert in the field of tailings dams, told the CBC.

Knight Piésold has also done work on the proposed Rosemont tailings dump as an AMEC subcontractor.

The Arizona Department of Environmental Quality raised concerns over the design of Rosemont’s tailing facility in an April 14, 2010 letter to the Rosemont Copper Company. ADEQ requested additional testing after it determined that the previous “assessment of physical and engineering properties of the dry stack tailings…is inadequate.”

ADEQ was particularly concerned about the possible impact of shallow ground water on the stability of the tailings dump.

“The central portion of the Dry Stack Tailings appears to be situated just above the ground water level,” ADEQ stated. The state agency asked Rosemont to provide additional data to show how the shallow groundwater table would effect the “structural integrity of the tailings pile.

In response to ADEQ’s request for more information, AMEC hired Knight Piésold to conduct soil analysis of the materials that will be placed in the mine tailings waste dump.

Toronto-based Hudbay Minerals Inc. is seeking state and federal permits to construct the controversial Rosemont open-pit copper mine in the Santa Rita Mountains on the Coronado National Forest southeast of Tucson, AZ.

 

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4 Responses to Police raid Rosemont contractor over Mount Polley dam failure

  1. T J Stewart says:

    Good Golly Tree Huggers Why Would The Canadian Police Have Any Thing To Say About “Rosemont Copper Mine” On The Arizona Desert?? Tree Huggers Get A Real Job And Get Out Of A 21st Century Mining Company Progress!! This State And Country Need Copper, Plus The Rainfall On The Arizona Desert Is Almost Nothing, So If Mount Polley Dam Failure Is In Canada, Big Differance In Rainfall. God Bless America.

    • Cheryl Rennie says:

      If the State and County need copper so bad as you state, then it should be kept here for our use and National security. Truth is, copper supply exceeds demand on a worldwide basis and China’s economy is imploding.
      We need real sustainable jobs in Arizona not temporary construction jobs that this mine for the most part will bring along with your phony “economic multiplier impacts”. Sounds like you are using the same economic mumbo jumbo as Obama.
      Water is our most important economic resource and you people just don’t seem to get it.

  2. Andrew West says:

    Total alarmist BS, and misleading in the context of facts surrounding the Rosemount Project. The tailings system designed for Rosemont is a dry stack system, and completely different than the system designed for Mount Polley.

  3. Cheryl Rennie says:

    Yawn.