(1)Above grade tailings disposal systems must be constructed to include a secondary dam or dike capable of, and designed to, contain the maximum quantity of tailings which could be released in the case of primary containment failure. Where a multiple dam or dike system is used, secondary dams or dikes must be provided to retain any tailings released in the failure of any section of the primary containment.
(2)Following abandonment and sufficient drying time to permit satisfactory reclamation, tailings must be covered by sufficient capping material and/or overburden, not less than three meters in thickness, to ensure that radon flux from the surface of the disposal area does not exceed two picocuries per square meter per second above background.
(3)External gamma radiation levels above background must not be statistically significant.
(4)The site must be covered with riprap and must be revegetated with plant life compatible with projected site uses.
(5)Following reclamation, the site certificate holder shall develop and maintain an environmental surveillance program, approved by the Council, to verify the adequacy of reclamation and revegetation methods in complying with requirements of this rule. The certificate holder shall continue to implement the surveillance program until the state or federal government has accepted title to the property and until the certificate holder has completed its financial obligations as required by OAR 345-095-0150 (Financial Assurance).
(6)All tailings disposal sites must be lined with natural materials selected for their impermeability.
Rule 345-095-0120 — Tailings Disposal,