EPA Releases Engineering Evaluation & Cost Analysis for Colorado Site

Nov. 30, 2016
Public comment period now open

The U.S. Environmental Protection Agency (EPA) released an Engineering Evaluation and Cost Analysis (EE/CA) that evaluates continuing operations of the Gold King Mine Interim Water Treatment Plant (IWTP) at Gladstone, Colo., beyond the end of this year. The IWTP has treated discharge from the Gold King Mine since October 2015. The EE/CA and supporting documents are available for public review and comment during the public comment period Nov. 14 to Dec. 14, 2016.

EPA’s recommended action is to continue operations of the IWTP, as currently configured, while it evaluates longer-term options to address water quality issues as part of the Bonita Peak Mining District Superfund site remedial action. However, before making a final decision regarding continued operations of the IWTP, EPA will consider all comments received during the public comment period.

The EE/CA also analyzes the effectiveness, ability to implement and cost of continuing to operate the IWTP, as presently configured. If EPA decides after reviewing comments on the EE/CA that continued operation of the IWTP is warranted, EPA will prepare and sign a Non-Time Critical Removal Action (NTCRA) Action Memo that will transition the IWTP operation from an emergency removal action to a NTCRA.

As EPA continues its remedial investigation, the remedial program will provide a comprehensive evaluation, not just of the IWTP, but of the various sources of mine-impacted water in the Cement Creek drainage. As EPA understands more about the hydrology of the area and how various sources of contamination are affecting water quality, the it will consider any number of options, including potential expansion of the IWTP, to address the contamination.

The results of the EE/CA and EPA’s response decision will be summarized in an Action Memorandum. EPA will address all significant public comments in a responsiveness summary appended to the Action Memorandum.

The EE/CA and supporting documents can be viewed in the following administrative record collection: Bonita Peak Mining District, Gladstone Interim Water Treatment Plant, NTCRA Action Memo.

Source: U.S. Environmental Protection Agency