1983-06-03_REVISION - M1977285 (2)

Home Browse Search

43.90(g) • • (g) Corrective Action Program. If the groundwater protection standards established under paragraph 43.90(f) are exceeded at a licensed site, • a corrective action program must be put into operation as soon as is practicable, and in no event later than 18 months after the Agency finds that the standards have been exceeded. The licensee shall submit the proposed corrective action program and supporting rationale for Agency approval prior to putting the program into operation, unless otherwise directed by the Agency. The licensee's proposed program must address removing or treating in place any hazardous constituents that exceed concentration limits in groundwater between the point of compliance and downgradient licensed site boundary. The licensee shall continue corrective action measures to the extent necessary to achieve and maintain compliance with the groundwater protection standard. The Agency will determine when the licensee may terminate corrective action measures based on data from the ground- water monitoring program and other information that provides reasonable assurance that the groundwater protection standard will not be exceeded. (h) In developing and conducting groundwater protection programs, appli- cants and licensees shall also consider the following: (1) Installation of bottom liners. Where synthetic liners are used, a leakage-detection system shall be installed immediately below the liner to ensure detection of any major failures. This is in addition to the groundwater monitoring program conducted as provided in 43.90(m)(2). Where clay liners are proposed or rela- • lively thin, in situ clay soils are to be relied upon for seepage control, tests shall be conducted with representative tailings solutions and clay materials to confirm that no significant deterioration of permeability or stability properties will occur with continuous exposure of clay to tailing solutions. Tests shall be run for a sufficient period of time to reveal any effects that may occur. (2) Mill process designs which provide the maximum practicable recycle of solutions and conservation of water to reduce the net input of liquid to the tailings impoundment. (3) Dewatering of tailings by process devices and/or in situ drainage systems. At new sites, tailings shall be dewatered by a drainage system installed at the bottom of the impoundment to lower the phreatic surface and reduce the driving head of seepage, unless tests show tailings are not amenable to such a system. Where in situ dewatering is to be conducted, the impoundment bottom shall be graded to assure that the drains are at a low point. The drains shall be protected by suitable filter materials to assure that drains remain free-running. The drainage system shall also be adequately sized to assure good drainage. (4) Neutralization to promote immobilization of hazardous constit- uents. • 43 - 21 (April 1990)