Scientists respond to EPA risk assessments
November 30th, 2012 | Carey Restino
This is a the third in a four-part series looking at responses to the Environmental Protection Agency's Draft Watershed Assessment of the Bristol Bay Region. In 2011, the EPA began an assessment of the Bristol Bay Region's watershed, in part in response to requests from stakeholders in the region, who were concerned about the potential impacts of the proposed Pebble Mine. The Pebble Prospect, which is not yet in the permitting phase, is controversial in the region. Touted as potentially one of the largest deposits of copper, gold and molybdenum in the world, those concerned about the mine say it could destroy the rich salmon runs, the mainstay of many in the region. Other communities near the mine, however, say they welcome the mine and the possibility of jobs in the economically struggling rural villages.
The EPA's assessment has been controversial from day one, with mine supporters and others expressing concern about the precedent such a federal regulation intrusion might set on other development in the area and the state. In addition, mine developers and others contended the assessment was premature, as the mine had yet to file any formal permit applications. The EPA, as well as supporters of the federal agency's action, said, however, that the extraordinary resource of Bristol Bays fishery warranted the agency involvement.
In October, following the release last summer of the draft assessment, comments from a panel of independent scientists were released. The following is a summary of some of the scientists responses to questions No. 5 through 9 of the 14 questions posed to the panel.
6) Does the assessment appropriately characterize risks to salmonid fish due to a potential failure of water and leachate collection and treatment from the mine site? If not, what suggestions do you have for improving this part of the assessment? Are significant literature, reports, or data not referenced that would be useful to characterize these risks, and if so what are they?
Most of the scientists commented that the characterization of water treatment failures was inadequate, given that it took up less than a page, but was, in some opinions, more likely to occur than a tailings facility failure, which received some 20 pages of analysis.
"Less than a page is devoted to the failure of water and leachate collection and treatment," wrote Steve Buckley, a geologist at WHPacific in Anchorage with a background in watershed analysis and earth science. "This seems inadequate given it would be one of the main systems that could impact fish at the potential mine site. In contrast, 20 pages are devoted to tailings dam failure."
Scientists had many questions about the potential volumes of leachates that might be collected and treated, and the qualities of those waters.
"Is copper the only constituent of concern to aquatic animals," asked Dennis Dauble, an adjunct professor at Washington State University with a background in fish biology. "Are there processing chemicals that could also be toxic."
Others expressed concern about other species that might be impacted beyond the sockeye salmon, such as the zooplankton which provide a food source for the sockeye.
Charles Slaughter, an adjunct professor of natural resources and engineering with the Center for Eco-Hydraulics Research at the University of Idaho in Boise, characterized the assumptions in this section of the report as "very generalized and optimistic," while Dirk van Zyl, professor and chair of mining and the environment at the Norman B. Keevil Institute of Mining Engineering at the University of British Columbia, states that the EPA assessment "does not identify or appropriately characterize the risks to salmonids fish due to a potential failure of water and leachate collection and treatment from the mine site. It only estimates the likelihoods of occurrence and the consequences."
7) Does the assessment appropriately characterize risks to salmonid fish due to culvert failures along the transportation corridor? If not, what suggestions do you have for improving this part of the assessment? Are significant literature, reports, or data not referenced that would be useful to characterize these risks, and if so what are they?
Some of the scientists noted that the material cited in the section on culverts came from areas outside of Bristol Bay, such as some studies coming from the Pacific Northwest where streams and culverts are heavily influenced by large woody debris loading.
"It is recommended that further evaluations be done of similar roads at mines constructed between mines and port facilities to update this section," wrote Zyl.
Others noted that the Alaska Department of Fish and Game's regulations are some of the most protective laws for fish and fish habitat in the Untied States, and would minimize the risk to salmonids fish due to culvert failures.
One scientist, however, requested more information about the risk of a road corridor being a source for the spread of invasive nonnative species to the area.
8) Does the assessment appropriately characterize risks to salmonid fish due to pipeline failures? If not, what suggestions do you have for improving this part of the assessment? Are significant literature, reports, or data not referenced that would be useful to characterize these risks, and if so what are they?
Scientists participating in the panel were by-and-large more comfortable with the data provided on pipeline failures, though some had concerns about the assertion made in the EPA's assessment that less than two spills were likely to occur over 78 years of the operation and that a spill would last only two minutes. Others questioned the use of an 80-year-old mine in Sweden as a model for the Bristol Bay assessment. Other questions, such as how workers would access a pipeline failure when it was covered in ice and snow, were asked. As in other sections of the report, the absence of a mine plan was brought into question.
"This section of the document focuses on the effects of pipeline failures; however, without a viable mine plan, descriptions of pipelines and estimates of possible effects are speculative," wrote Phyllis Scannell, an environmental consultant who worked as a senior biologist for the Alaska Department of Fish and Game. "Given that there currently is no information on road alignments or locations of future pipelines, it is not possible to estimate the number of stream crossings or an exact length of potentially affected waterways. The risks from pipeline failures outlined in the draft document should be revised when more specific information on the mine plan of operations becomes available."
9) Does the assessment appropriately characterize risks to salmonid fish due to a potential tailings dam failure? If not, what suggestions do you have for improving this part of the assessment? Are significant literature, reports, or data not referenced that would be useful to characterize these risks, and if so what are they?
The EPA's draft assessment describes in some detail the potential impacts of a catastrophic tailings dam failure, and several scientists stated they were comfortable with the report's assessment.
"There is no question that a tailings dam failure would be catastrophic for the fishery and the project and although low probability, is the single largest risk to the fishery," wrote David Atkins, principal hydrologist and owner of Watershed Environmental, with a background in mine hydrology. "A tailings dam failure could harm a very large area of the watershed for a very long period of time and could require a massive and expensive remediation effort."
Several scientists questioned the use of an analogy used in the report to the Mt. St. Helens volcanic eruption as a means of determining the long-term impacts and response of aquatic ecosystems to such major disturbances.
"The Mount St. Helens analogy is inappropriate for a variety of reasons and such comparisons should be removed from the assessment," stated John Stednick.
Zyl, as in other areas of the assessment, stated that significant improvements in mine management, including tailings management practice, have been made in recent years, and would almost certainly be incorporated into a mine plan at Pebble.
"It is expected that this likelihood will be much lower than those used in the evaluations of the scenario in the EPA Assessment," Zyl wrote.
Editor's note: In the fourth in the series looking at the scientists responses to the EPA's watershed assessment, scientists respond to the assessment's final five questions, including the characterization of risks to wildlife and human cultures due to risks to fish, as well as mitigation measures to reduce or minimize impacts of a potential mine.