Holden Mine Site Cleanup Remedial Action Objectives

 

Remedial Action Objectives (RAOs)

CERCLA provides for the establishment of Remedial Action Objectives (RAOs) that specify “contaminants and media of concern, potential exposure pathways and remediation goals,” 40 CFR § 300.430(e)(2)(i).  The remediation goals (and thus the RAOs) are to be modified as more information becomes available; final remedial goals are determined when the ROD is issued.

The Agencies presented RAOs in the SFS.  The Agencies subsequently revised the RAOs in the ASFS as provided in 40 CFR § 300.430(e)(2)(i), as shown below.

  1. Reduce surface water concentrations of hazardous substances to levels that are protective of aquatic life and comply with applicable, or relevant and appropriate requirements (ARARs) in Railroad Creek and other surface waters.
  2. Eliminate the adverse effect of ferricrete to aquatic life in Railroad Creek and monitor sediment quality to determine whether any further action is needed to protect aquatic life and comply with ARARs.
  3. Prevent migration of hazardous substances that exceed cleanup levels in groundwater (including the Main Portal discharge) from on-site waste management areas (WMAs) to protect aquatic life and comply with ARARs.
  4. Reduce exposure to hazardous substances in soil (including tailings and other wastes) to protect terrestrial organisms and comply with ARARs.  Prevent future releases of tailings and other wastes into surface water to protect aquatic receptors from hazardous substances.
  5. Protect human health and comply with ARARs by reducing human exposure to hazardous substances in soil and other wastes, and in groundwater as a drinking water resource.
  6. Implement the remedial action in a manner that complies with ARARs and protects human health, welfare, and the environment, including the Holden Village residential community during and after construction.

The Agencies understand that Holden Village, Inc. has concerns for the viability of its operations in the event that remedial construction results in substantial curtailment of the Village’s normal activities for more than two consecutive years, or a second curtailment within five years of the first construction period.  Intalco will propose a construction schedule, subject to Agency approval, that will evaluate the feasibility and timing of conducting the work sequentially or concurrently.  Intalco has already indicated a willingness to accomplish some work ahead of, or following, the period of major construction, and the Agencies believe this approach will mitigate impacts on Holden Village.  While the Agencies do not expect that it will be necessary for Holden Village to suspend operations during remedial construction, the Agencies understand a large construction project does not lend itself to the usual expected Holden Village experience.  Through review, input, and approval of remedial design, the Agencies are prepared to assist Holden Village to mitigate impacts of construction to the extent possible.  The Agencies will also take into account Holden Village’s request for a five-year gap between the conclusion of the first phase of construction and the initiation of any second phase, as is reflected in the ROD. 

  Impacted Railroad Creek