TORONTO (miningweekly.com) – The US Environmental Protection Agency (EPA) has started a process under the Clean Water Act to investigate potential impacts on the aquatic habitat and fisheries associated with mine development in south-west Alaska.

Canadian junior Northern Dynasty Minerals, the proponent of one of the world’s largest undeveloped deposits in the area, the controversial Pebble copper/gold/molybdenum project, which had been the subject of several environmentalist objections, said that the EPA process, which is a continuation of the Bristol Bay Assessment study started in 2011, would include consultation with the US Army Corps of Engineers and company subsidiary, the Pebble Limited Partnership.

In a news release on Friday, the US federal agency reported that “based on input the EPA receives during any one of these steps, the agency could decide that further review under Section 404c [of the Clean Water Act] is not necessary”.

"For a wide range of reasons, we remain confident that final decisions about Pebble will be made by federal and state regulators working within the rigorous National Environmental Policy Act (NEPA) permitting process, and not unilaterally and pre-emptively by the EPA," Northern Dynasty Minerals president and CEO Ron Thiessen said.

He added, however, that the company would participate fully in the EPA's process to consider necessary safeguards to ensure that responsible mineral development can co-exist with clean water and healthy fisheries in Bristol Bay. “We will continue our efforts to prepare for the NEPA permitting process to come,” he said.

Thiessen held that both the EPA and the peer reviewers they contracted to review the Bristol Bay Assessment have acknowledged that their study was insufficient as a foundation for regulatory decision-making regarding the Pebble project.

In response to peer review comments on the Bristol Bay Assessment, the EPA said that the assessment was not intended to duplicate or replace a regulatory process.

"We agree that a more detailed assessment of direct and indirect impacts of mining … will have to be done as part of the NEPA and permitting processes."

Thiessen also noted that Northern Dynasty had submitted hundreds of pages of documentation to the EPA Inspector General (IG), an independent office within the federal agency, calling for an investigation into the Bristol Bay assessment.

Based on Freedom of Information Act requests undertaken by the Pebble Partnership, the State of Alaska and others, Northern Dynasty's submission to the EPA IG raised serious issues of bias, political motivation and collusion with environmental nongovernmental organisations in the federal agency's preparation of the Bristol Bay Assessment.

"The US and Alaska have among the most stringent environmental laws for the protection of fish and water in the world, and the environmental impact statement (EIS) process under NEPA is the gold standard for ensuring that major project developments receive comprehensive, transparent and science-based assessment," Thiessen said.

"Given that, along with the global significance of the Pebble deposit and the inherent, well-documented limitations of the Bristol Bay Assessment study, including those acknowledged by the EPA itself, we continue to have every confidence that final decisions about Pebble will be made in the future following a comprehensive NEPA/EIS permitting process."