M&A predicts impacts to water resources in the Grand Canyon region under four possible mining alternatives.
Client: SWCA / BLM- Time frame: 2009–2011
- Location: Coconino County, Arizona
M&A was part of an expedited effort to evaluate environmental impacts related to a proposed withdrawal of BLM and Forest Service lands from new mining claims. This proposal by Secretary of the Interior Ken Salazar was a response to an increased interest in high-grade uranium deposits near the Grand Canyon and concerns over potential impacts to the Canyon’s watershed. Based on input from BLM, the 15 cooperating agencies, and more than 80,000 public comments received during the scoping process, water resources issues were identified as the highest concern overall for the EIS.
In part because of our on our prior experience in the region, M&A was hired to assess impacts to the water and soil resources under four proposed alternatives:
- Alternative A: No action
- Alternative B: Proposed action
- Alternatives C & D: Partial withdrawal
Alternative B was selected, resulting in the withdrawal of about 1 million acres from operation of the Mining Law of 1872 for a 20-year period.
M&A used available reports and data to prepare a detailed characterization of hydrogeologic conditions within the various watersheds and groundwater basins. To facilitate characterization, determine baseline conditions, and provide a basis for projected impacts, we compiled and/or developed regional datasets and databases for wells, water quality, springs, surface water features, breccia pipes, geology, hydrology, and soils.
M&A identified potential environmental impacts — direct, indirect, and cumulative — to water and soil resources from reasonably foreseeable mining development for the 20-year period of the proposed withdrawal. We developed new methods of projecting impacts where necessary and helped develop the “partial-withdrawal” alternatives.
Through an iterative review process, we prepared several drafts of the EIS sections, responded to each phase of comments from the cooperating agencies, and defended our conclusions. M&A also responded to public comments on water and soil resources in the Draft EIS and attended public meetings. Finally, we prepared sections of the Final EIS, conducting additional work in response to the public comments.
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