In the past week there were two major mine spills in international news which highlight the many intentional gaps in Maine’s 2011 statute and regulations An Aug 4 tailings impoundment breach at Mt. Polley ( British Columbia) appears not to have involved a release of any toxins but a breach of that proportionate scale at Bald Mountain, would likely have caused significant damage. Prior analysis by highly regarded experts had established it was not possible to attain water quality standards in holding ponds for the unusually toxic levels in the Bald Mountain deposit and its footwall.
Two other significant spills making news this week were from holdings ponds involved with heap leach operations.
At Buenavista Del Cobre , 25 miles south of the U.S. border a much more toxic mine than Mt. Polley with high levels of arsenic & acid as we have at Bald Mountain, extensive environmental damage and extensive loss of public drinking waters have resulted..
A 2nd smaller heap leach related spill releasing cyanide solution received less press but also occurred in Mexico
Maine’s statue prohibits heap leach processing but DEPs rejected rules would have permitted vat leaching and electro winning both of which involve containment of large volumes of toxic solutions bare ( not containing leached metals) and pregnant (containing leached metals and associated toxics which at Bald Mountain would include extraordinarily high levels of arsenic.
The intentional policy gaps on tailings dams and other “wet cover” in the DEP drafted BEP endorsed Maine mining rules if implemented would most likely have caused the people of Maine significant unfunded loss as well as risking permanent loss and damage to watershed systems of regional significance. The total cost of clean up of the Mt. Polley spill is $100 to $500 million.Security bonds in place at the time of the Mt. Polley spill were funded only to about $14 million out of an eventual required $38 million.. Imperial had only a $10 million per occurrence liability policy in place which would not, in any event have provided funding for clean up required by law or permit and is seeking $100 million at very high costs in capital markets. Imperial carries no environmental liability insurance. So effectively, B.C. government will be out of pocket for 85% all clean up costs with questionable hope of repayment from Imperial as required under the permit and by law. Imperials cost of funds in capital markets will be an astronomical 6%-12% and its stock has dropped 50% in value giving investors jitters and inviting speculation about possible bankruptcy.
.As all members of the DEP policy team and Cynthia Bertocci, Executive Analyst at BEP knew well through the whole process of rule writing the use of tailings dams or any wet cover permanent closures at Bald Mountain was identified as a possible fatal flaw in all earlier expert reviewed open pit plans. The eminent and universally respected Dr. David Chambers reaffirmed the findings of that earlier study of options in his work for Bowker Associates. Contrary to lobbyists insistence, no advances in technology have altered that fact at Bald Mountain. http://lindsaynewlandbowker.wordpress.com/2014/02/28/mountain-x-would-you-issue-a-permit-to-this-mine/
Witnessing the scale of destruction at Mt Polley and understanding its causes is especially instructive and extremely relevant to us here in Maine because this failure occurred in a mine permitted under the most complete and up to date regulatory standards in North America. It is soberingly noteworthy that this breach occurred during mine operations ( not post closure). (An early breach also occurred at the Callahan resulting in a mudslide of contaminated debris still at issue in the Callahan Superfund site in Brooksville Maine)
Here is Mining.coms coverage and my post there http://www.mining.com/canadas-mount-polley-disaster-sparks-concern-over-us-mines-74374/
“The causes of the breach are not yet known but Knight Piesold has commented publicly that they warned Imperial and B.C. authorities that the tailings dam was getting too big . Also in the rather big step up in operations there were many indicators that the tailings pond was being pushed beyond safe operating limits. There was a permit violation threatening breach in May as levels exceeded the minimum (2.8 m) freeboard Before that among several smaller violations was an incident of by passing required treatment .
This event is instructive to lawmakers and advocates at the Polymet and here in Maine where the worst mining statute ever written stands in place under poorly informed and written old rules that don’t match the new lobbyist written statute.. It is instructive because compared to the Polymet or to our very high risk VMS deposit here in Maine, Bald Mountain, Mt Polley is pretty tame and its impoundment waters were alkaline (above 8ph)..Here in Maine the siting and engineering of the impoundment would not have been to the very high standards of B.C. permitting, would not have had the frequent inspections Mt. Polley has had and the waters breach would not have been as benign as the water of Mt. Polley. The Mt Polley breach should send all lawmakers, regulators and advocates together back to their statutes and regulations to insure both proper standards for design and strong enforcement for proper operations. Dr. David Chambers in a work for Bowker Associates has offered technical GO/NO GO Criteria for mine permitting with two critical “NO-GO” standards for tailings impoundments. Not one state has these standards and Maine regulators, in writing rules rejected by our legislators, specifically ignored our submission of these guidelines.(see www.csp2.org).Mt. Polley tells us that this is the time to go back to basics and to advocate for all the NO GO standards in Dr. Chambers new work not to promulgate false and misleading information about what happened at Mt. Polley and why”
Although the cause of the failure is still under investigation, Knight Piesold, design engineers for Imperial until 2011 warned the British Columbia authorities and Imperial in their “exit letter” that the dam was getting too big. http://www.cknw.com/2014/08/09/engineering-firm-expressed-concerns-about-mount-polley-mine/ In the months leading up to the major breach this past Monday ( August 4th) Imperial had dramatically stepped up production at the mine. There was a permit violation in May in a different part of the dam as storage exceeded what is mandated as free board ( distance to top of the dam to water level). The tailings dam was brought into compliance by pumping water out into other holding areas. At the time of the major breach on August 4, permits were under review to allow increased levels of discharges. Prior to that there was a history of non compliance with permit conditions http://www.cknw.com/2014/08/05/44600/ which included a treatment by pass as operations stepped up. http://www.marketwatch.com/story/imperial-update-on-tailings-storage-facility-breach-at-mount-polley-mine-2014-08-05-91733516
The B.C.Minister of Mines denies that the breach at Mt. Polley is an environmental disaster and data reported on receiving waters and fish is not in conflict with that. Mines Minister Bennett acknowledges though that some serious mistakes were made by both B.C. oversight and Imperial ( offering no specifics). It was revealed today that the B.C. Commissioner of Information and Privacy is investigating whether B.C. regulatory officials had sufficient information of a possible breach to have a legal duty of notice to communities in the impact zone of the dam including Likely, the most severely affected local community.The water released was alkaline ( 8.6ph) but had a selenium level of 2.8 times drinking water standards. The impacted area is small in comparison to the size of the dam.
(update 8/18) It was reported in the Vancouver Sun on August 18th that the B. C. government”t inspected the dam 33 times after Knight Piésold raised its concerns, including a geotechnical survey in 2013 and eight inspections in 2014.” The article goes onto relay an identical chain of events before failure of a Knight Piesold designed tailings dam in Guyana. In both Knight Piesold voluntarily withdrew after designing a tailings impoundment and issued an exit warning letter. Knight Pesold has not spoken directly on the public record to concerns they may have had about overall policy and operations at the two mines.: http://www.vancouversun.com/news/Stephen+Hume+Mount+Polley+inquiry+must+independent/10126049/story.html#ixzz3Ak4U0YJb
Dr. Kendra Zamzow, an expert on release conditions that endanger fish and wild life , commented to Bowker Associates via email on August 11 ““It appears that the quoted concentrations (2.8 x a standard of 10 ug/L = 28 ug/L) were from water tested in the tailings pond. It will likely dilute out quickly in Quesnel lake. Testing would need to be done in the lake to see if the concentrations would impact fish or drinking water — I expect they would not.
The alkaline nature of the water and organic carbon (4 mg/L) should help to make the metals toxicity less than it might be otherwise (with less alkaline, low carbon water).”
Dr. Zamzows expectations were born out in samples of waters in the flooded area and in samples of fish.
Tailings Dam & Wet Cover Issues At Bald Mountain
Tailings Dam siting & risk issues were identified as a likely fatal flaw at Bald Mountain in two open pit schemes proposed by Boliden and evaluated by globally respected expert Andy Mac G. Roberston, then at SRK and the distinguished Linda Broughton. A tiny Gossan only open pit extraction proposed by Blackhawk in 1995 used the tailings dam site only for temporary storage of highly reactive mine materials and proposed returning all materials to the original pit with artifical flooding was also flagged as most likely fatally flawed as the water filled pit would eventually spill out into surrounding waters.
DEP and BEP systematically avoided and ignored all the earlier expert assessment of Bald Mountain and all the recommendations of global expert Dr. David Chambers in his major work for Bowker Associates developng new technical Go No Go crietra for permitting modern day metallic mines . This major new technical work had a signifiant focus on the risk assessment of tailings dams and was actually contradicted in the DEP’s insistent, false, fool hardy guidance to BEP on “wet cover”.
Here is Dr. Chambers work for Bowker Associates http://www.csp2.org/files/reports/Go-NoGo%20Zones%20-%20Chambers%202Jan14.pdf which was submitted to BEP via Cynthia Bertocci before BEP voted on final adoption of the rules as submitted to the maine legislature. Their rules, as submitted to the legislature , completely ignore best knowledge best science, best practice in assessing an aplicants proposed use and design of tailings dams.
Here are Dr. Chambers NO GO standards on Talings Dams
(1) Is it likely that a tailings dam can be engineered to withstand a maximum credible earthquake no farther than 10 kilometers from the dam site? Numerical modeling must be used to verify the seismic stability of the dam design. If a tailings dam location cannot located in a place that allows these design criteria to be implemented, then it would not be safe to proceed with a mine.
(2) During mining operations a tailings impoundment must be able to hold the maximum probable flood event, plus snowmelt (if any), and have adequate freeboard remaining to withstand wave action and storm surge at the same time. If a tailings dam location cannot located in a place that allows these design criteria to be implemented, then it would not be safe to proceed with a mine.
Neither of these standards appear anywhere in Maine’s legislatively rejected mining regulations. In fact without statutorily required additional public comment DEP/BEP further relaxed the seismic design standard even though aware that there are fault systems through and near the Bald Mountain deposit as well as earthquake hazards. DEP substituted a standard that is suitable for siting of a small residential home. Bowker Associates lengthy well documented submission on this unlawful change ( it required a 10 day public comment) was rejected as “not within a public comment period”
INHERENT & EXTRAORDINARY RISKS OF TAILINGS IMPOUNDMENTS CORE ISSUE IN PERMITTING STANDARDS
With the focus on Mt.Polley , a failure that occurred In the context of the highest permitting standards and frequent inspections by independent well vetted experts and highly trained government staff, Bowker Associates asked Dr. David Chambers for clarification on statements he made several years ago at a conference that he would not have done or recommended anything any different at Los Frailes, the worlds most dramatic and expensive tailings dam failure. With his permission I share his further comment on that with you.
“From a design and construction standpoint they did everything right. It was their geotechnical evaluation (failure to identify a potential zone of slippage) that led to the dam failure. This was a downstream-type design, the safest. The point I was hoping to make is that even when everything is nominally done perfectly, a dam failure (like Los Frailes) can still occur” Dr. David Chambers Via Email 8/11/14
Both expert comments underscore what the important takeaway message is from the Mt. Polley: that the unique and unpredictable risks of tailings failures ( even under sound design principles and the worlds best statutory and regulatory framework) require ultra conservative and clear standards including ultra conservative triggers authorizing intervention and action by regulators. ” Due process” (ie a process that does not immediately recognize and respond to perceived risk where the result could be catastrophic loss) as we see at Mt. Polley, doesn’t avert disaster. That is perhaps what B.C. Mines Minister Bennett was refrring to in his comments to the Vancouver Sun about the “lessons of Mt. Polley”
The key message, as I testified before BEP on October 17th is that
(1) compared to other human endeavors, mining involves a much higher level of uncertainty
(2) compared to other human endeavors the severity of possible loss is extreme
(3) compared to other human endeavors, the opportunity to control or prevent loss is more limited
(4) the lowest and most limited possibilities for external risk finance ( adequate insurance & bond markets)
Hence (from a Risk Management Perspective):
- need for the most ultra conservative design standards,
- need to consider maximum possible loss in siting and size standards, in operating limits/requirements, in independent inspections and
- authority for the most conservative regulatory action when anything occurs that pushes risk in the wrong direction( ie defining appropriate triggers for regulatory intervention and action
The approach DEP has urged in its poorly informed poorly framed mining regulations favors and derives directly from extraction industry funded ITRC of which our DEP Commissioner is a member. Maine DEP’s advocacy and policy positions come directly and almost verbatim in many instances from ITRC “guidance”.and advocacy. ITRC’s mission is to break apart all federal environmental oversight and market its legislative agenda and policies to states, primarily their environmental regulatory departments, ITRC approaches that favor the adoption and use of unproven new technologies. (see http://www.itrcweb.org/)
The mandate of Maine’s mining statute, albeit it abysmal and inadequate as a modern mining statute, nevertheless is clear in requiring proven technology.
FACTS AND MYTHS ON THE EFFECTIVENESS OF WATER COVERS TO SUPPRESS SULFIDE OXIDATION AND METAL LEACHING – FIELD AND LABORATORY EVIDENCE
This paper by YK John Kwong provides some fundamentals on wet cover ( that it does not work for all reactive waste as a permanent closure technology) as well as offering some insights that suggest land cover might be more appropriate than wet cover for control of arsenic, a major issue and possible fatal flaw at Bald Mountain ( because of the inherent risk at Bald Mountain, no matter what the benefication and extraction scheme.)
It also provides findings that are readily translatable into performance standards for permitting providing criteria that are not present in the legislatively rejected C200 guidance on wet cover as a permanent closure for waste rock and/or tailings. The phrase “perpetual anoxic conditions” for example seems especially useful in setting up a permitting process that can effectively evaluate the likely efficacy of a given applicant proposed “wet cover” system for permanent closure.
Of course Bald Mounatin has other problems like the siting limitations for any impoundment there. Andy MacG. Roberston who did the siting work reported that of 45 sites considered at Bald Mountain only 4 were at all viable environmentally and of those 4 only 1 was economically viable but had size constraints. It didn’t work out as adequate for a tailings impoundment even for the smaller 500 ft open pit ven for the smaller open pit )
Here are the Conclusions of Dr. Kwongs excellent technical paper on “wet cover”
“On the Reactivity of Sulfides under a Water Cover The assumption that reactive sulfides once placed underwater will become completely nonreactive is a myth”
“Only in the presence of a more efficient oxygen scavenger like organic matter will sulfide oxidation be completely arrested”
“Only under completely anoxic conditions will the base metal sulfides become stable and base metal leaching be arrested”
“. Depending on the detailed composition of the mine wastes and the environmental settings of the depository, an alternative disposal may be more advantageous than placement under water.”
“For reactive mine wastes enriched in base metals, it may be appropriate to employ subaqueous disposal if the depository is characterized by a high settling flux of organic matter to assure the development of perpetual anoxic conditions.”
Final Conclusions are:
“1. Although water covers are effective in reducing the rate of sulfide oxidation, the process is not completely eliminated in the absence of a more efficient oxygen scavenger like decaying organic matter.
2. With the progress of sulfide oxidation under water, the alkalinity balance in the water cover determines if net acidification is to occur or not.
3. Even under near-neutral to slightly alkaline conditions, metal leaching can still occur in submerged sulfidic mine waste through galvanic interaction.
4. Potentially deleterious trace elements like arsenic and antimony with multiple oxidation states are susceptible to remobilization under water with changing redox conditions.”
5. The choice of long-term disposal options managing reactive mine waste must duly consider the detailed composition of the mine wastes and the environmental settings of the depository.
This is clearer and better informed guidance than that in ITRC and in integrating and synthesizing the guidance of MEND and GARD Guide it makes the bottom line of these resources clearer and more amendable to decision making as well to the creation of regulatory standards.
Lindsay Newland Bowker, CPCU, ARM, Environmental Risk Manager
Director, Bowker Associates Science & Research In The Public Interest
August 15, 2014
The province approved expansion of the Mount Polley mine despite concerns over the tailings pond and even before environment ministry staff had made a decision on allowing the company to release water into Hazeltine Creek.
“The government is directly implicated in this breach,” charged Bob Simpson, former MLA for Cariboo North. “The Ministry of Mines approved the mine expansion … failing to account for the increased effluent into an already suspect tailings pond.”
B.C. Commissioner On Information & Privacy Investigating whether public alert/notice laws followed on risk of breach
“The aim is to achieve maximum storage capacity with the least amount of embankment fill. Natural valleys and other topographical depressions are usually investigated first. As a rule of thumb, embankment heights are kept below 200 feet” ( EPA technical Report op cit p 18)
“We usually do a three- or four-metre raise on the impoundment just to increase the capacity for tailings,” Mr. Robertson said.He said the dam was “within its design parameters” when the breach occurred.”
“The tailings dam was about 35 metres high( 112 ‘) when it was breached.”
AMEC, formerly independent consultant to the B.C. Government on Mt. Polley, and following Knight Piesold as consulting engineer to Imperial on the Impoundment. was in the process of implementing its design for an expansion raising the height of the dam at the time of the breach.
Mt Polley is a centerline site, a hybrid of upstream (the least safe) and downstream ( the most safe but also the most costly)
INDSIDERS CLAIM IMPERIAL IGNORED AMECs RECCOMENDATION TO STRENGTHEN IMPOUNDMENT WALL WITH ROCK