Bristol Bay, EPA’s Risk assessment and the mine plan that isn’t yet a plan

Bristol Bay, Alaska is the location of the Pebble Deposit. Image source: NASA Goddard Space Flight Center

Last week (Jan 21, 2014), EPA released its risk assessment of the impact of large scale mining in the Bristol Bay watershed on the ecosystem of the watershed. The report evaluates potential mining of the Pebble deposit. The report is controversial, to say the least, with political implications. As pointed out by the Pebble Partnership in a press release, the report is not an assessment of the Pebble Project because no permit has been submitted by the proponents of the mine. This fact (that no permit has yet been submitted) is the most controversial aspect of this assessment. Usually, government agencies prepare impact assessments in response to a proposed action (a mine plan or development action/plan). In this case, the EPA has prepared a 945 page document based on a hypothetical!

The EPA is well within its right, drawn from the Clean Water Act, to prepare such a report. And in fact, the mine plan which is the basis of this report is part of a pre-feasibility study prepared for Northern Dynasty Minerals. Hence, the plan is conceivably a potential plan to exploit the Pebble deposit. Why the report is controversial is the fact that any mine planning exercise is iterative and evolves until a final plan is prepared. Hence, any plan prior to permit submission is just an alternative subject to change.

My intent in this post is to: (i) show the role of mine planning in permitting; and (ii) encourage discussion on how to accommodate impacts to sensitive habitats in mine plans, which is going to become increasingly important.

Mine plans are drawings, schedules, and other documents developed to promulgate a plan to exploit a geologic deposit. Mine plans are developed at various stages in the life cycle of a mine. Like all engineering design tasks, various alternatives are generated and the optimal alternative is selected as the plan. At different stages, different issues become highlighted leading to new alternative plans to address them. The issues that are addressed by revised plans are different for the different stages of a mine and the different time horizons of mine plans. The issues could be changes in production costs, commodity prices, or any number of issues.

In pre-feasibility studies like what is the basis of this EPA report, the emphasis tends to be on economic viability of the deposit. Mining companies, at this stage, are most concerned with making go/no-go decisions on the project. This emphasis changes during and immediately before mine permitting, when mine engineers become more focused on developing alternatives to address environmental impacts, community concerns, what is likely to get a permit etc. Sometimes, these alternatives make significant economic trade-offs. Admittedly, sometimes these issues are never fully addressed to the satisfaction of all stakeholders.

The Pebble Project is controversial primarily because of the location. Bristol Bay is a sensitive ecosystem with significant implications for Alaska’s salmon industry and natives who have built a lifestyle around it. As we run out of easily accessible deposits, our industry is going to have to deal increasingly with deposits like the Pebble deposit in sensitive ecosystems. This is going to demand that mine engineers design mines that accommodate stakeholder concerns in tangible ways. We can no longer expect society to just accept our designs as best practice (for instance, tailings impoundments and spillway designs are a key concern in the Pebble Project). Mine planning engineers need to get more creative and apply innovative engineering techniques to address these issues.

Most mine engineers never get the opportunity to design mines from scratch. For those who get the opportunity, we have a responsibility to put forth the best mine plan for the particular project. Soceity’s expectations are only going to get higher. I hope you are up to the task.