40.18.070 Remediation Standards

Any voluntary or involuntary remedial action conducted by an owner, operator or responsible party or by the TM-TRP, shall:

(a) Be protective of human health, safety and the environment. A remedy shall be considered to be protective of human health if it reduces risk to human receptors of acute and chronic toxic exposures to contaminants to levels that do not pose a significant risk to human health. A remedy shall be considered to be protective of the environment if it adequately reduces risk of significant adverse impacts to ecological receptors for which habitats have been identified on or near the site. Remedies may meet this requirement through a combination of removal, treatment, monitored natural attenuation, engineering or Tribal institutional controls. Any site where a remedy is proposed that includes leaving contamination above background or risk based levels in place utilizing engineering or Tribal institutional controls must also be approved by the Tribal Council pursuant to this Act;

(b) Attain Standards Established by the Tribe. A remedy shall attain standards established under this section for air, soil, water and ground water affected by the release, unless the Tribal EPA Director sets an alternate standard. No standard set under this section for a contaminant shall be set at a level or concentration lower than the background level or concentration for that contaminant. A remedy must attain standards or alternate standards by the end of the remediation period set forth in the Remediation Agreement. A remedy shall be considered to attain Tribal standards for air, soil water and ground water if it:

(1) Meets any applicable media standards established under Tribal or federal Act, law or rule or regulation; or

(2) Meets site-specific, risk-based standards developed for the eligible site;

(c) Meet Site-Specific, Risk-Based Standards. The exposure factors to be used by the Tribal EPA Director to establish site-specific, risk-based standards under this section for hazardous substances, pollutants or contaminants in groundwater shall assume that groundwater may be used as a drinking water source, provided that no standard set under this section for a contaminant shall be set at a level or concentration lower than the background level or concentration for that contaminant. For substances that may adversely impact water quality, the exposure factors to be used by the Tribal EPA Director shall assume uses consistent with the class of use prior to contamination of the groundwater;

(d) Maintain Source Control. The remedy shall control any sources of releases so as to reduce or eliminate, to the extent technically practicable, further releases as required to protect human health and the environment. A remedy shall be considered to control sources of releases if it controls the release of contaminants from sources to any media in concentrations that:

(1) exceed applicable standards set by the Tribal EPA Director under this section, or the soil standards under this section; and

(2) complies with any applicable federal, state or Tribal standard for management of wastes generated as a consequence of the remedy; and

(e) Comply with this Act. A remedy shall be considered to comply with applicable standards for management of wastes if all wastes generated as a consequence of implementation of the remedy are treated, stored or disposed of in compliance with the requirements of this Act and any applicable state or federal requirements.