Section 096-200-5-24 - Closure and Post-Closure Maintenance StandardsA.Closure Maintenance Criteria(1) Performance Standards (a) The Applicant shall design the closure of the mine to minimize the need for maintenance, and to control the release of mine waste and constituents into the air and the groundwater and surface water, and to ensure protection of public health and safety, and the environment. Closure activities must: (i) Restore the mine site to approximate pre-mining baseline hydrologic and geologic conditions and ensure that mining wastes will not contaminate ground and surface water;(ii) Meet performance requirements;(iii) Comply with design, monitoring, and operating criteria approved in the closure plan for the mine, and each mine waste unit; and(iv) Comply with the general technical requirements below.(b) The Permittee shall undertake the following activities: (i) Provide certification by a qualified professional(s) that each mine waste unit, given its location, composition, and construction, is designed to meet current standards of practice for geotechnical engineering;(ii) Institute or maintain a run-on/runoff control system that meets the requirements of this Chapter; and(iii) Implement and maintain monitoring systems as approved in the closure plan.(c) For leachate management systems, ore leaching facilities including associated solution ponds, and collection systems including trenches, piping, leachate collection systems, and equipment, which contain leach solutions, the Permittee shall ensure the following: (i) Water that is not to be recycled for processing shall be treated and disposed of in a manner that ensures compliance with the performance requirements and shall in any event comply with the terms and conditions of the permit; and(ii) Leachate collection and management systems must continue until leachate no longer contains constituents in concentrations above those described in the performance requirements for the period of time specified in the permit or otherwise provided by the Department.(2) Closure Plan (a) A closure plan must be submitted at the time of application for a permit. At a minimum, the plan must include the following information for each mine waste unit: (i) The methods, designs, procedures, and processes necessary to satisfy the closure performance standards for each mine waste unit;(ii) An estimate of the maximum capacity and maximum volume of mine waste that can be managed in the unit at any time during the life of the mine waste unit;(iii) A description of activities required to close leaching operations, including compliance with the standards at the time of closure;(iv) A schedule of closure activities; and(v) A detailed cost estimate of closure activities.(b) Closure plans must be amended to reflect applicable changes in unit design, operations, or mine waste management technology, and applicable legal requirements, at intervals not to exceed 5 years.(c) The closure plan for each mine waste unit must minimize the onsite and offsite use or contact with mine waste if such use or contact would pose a significant risk to the environment or public health and safety.(d) A copy of the closure plan must be kept at the site or at an alternate location approved by the Department until the post-closure maintenance period has ended.(3) Closure Design Requirements (a) Closure design must be based on the following factors:(i) The geology and geologic setting of the unit;(ii) The character of the waste, including waste treatment;(iii) The potential for and degree of contamination of the environment at or in the vicinity of the mining operation, if applicable;(iv) Corrective action(s) in place or planned, if applicable;(v) The operating practices at the waste unit;(vi) The geographic location of the unit; and(vii) Any other factors which are necessary for an informed determination of an appropriate design.(b) The closure design must minimize maintenance and control the release of contaminants to ensure that performance requirements are met.(c) Final closure requirements for mine waste units including, but not limited to, dry stack tailings management structures are as follows:(i) Final cover for a mine waste unit must have a permeability less than or equal to the permeability of the primary liner system;(ii) The cover must be designed and constructed to function with the minimum maintenance possible;(iii) Closed mine waste units must be graded and maintained to prevent ponding and to divert surface drainage from covered wastes;(iv) Areas with slopes greater than 10%, surface drainage courses, and areas subject to erosion by water and wind must be protected to prevent such erosion; and(v) No discharge to surface or groundwater may be allowed except as licensed by the Department.(d) A protected, permanent benchmark must be established on each closed mine waste unit. This benchmark shall be shown on all recorded drawings.(4) Closure Trigger (a) Closure must begin, if for the preceding 12 months, the mine waste unit has not received for disposal more than 10% of the average annual volume of waste received during the mine life to date as measured from the arrival of a substantial quantity of waste at that mine unit and not including time elapsed during any suspension of mining, unless the Permittee has applied for the extension described in this section.(b) The Department may grant an extension to the initiation of closure if the Permittee demonstrates that: (i) The mine waste unit is planned to be used within the next 7 years;(ii) The mine waste unit is in compliance with performance, design, and operating requirements; and(iii) The mine waste unit will continue to comply with performance, design, and operating requirements during the extension.(c) The Department may grant a 12-month extension, up to a maximum of 7 extensions.(5) Certification of Closure (a) Within the 90-day period following closure of the mine waste unit, the Permittee must submit certification to the Department verifying that closure has been completed in accordance with an approved closure plan.(b) Certification shall be based on a review of the mine waste facility by a qualified professional approved by the Department, a responsible officer of the Permittee and an inspection of the facility by the Department.B.Post-Closure Maintenance Criteria(1) Applicability. Following certification of the closure, the Permittee shall commence postclosure maintenance for the closed mine waste unit.(2) Performance Standards (a) The Permittee shall conduct post-closure maintenance activities to ensure the continued protection of public health and safety, and the environment, and to ensure the performance requirements continue to be met.(b) Site access during the post-closure maintenance period must be controlled as necessary to prevent the removal of mine waste and ensure continued effectiveness of closure and post-closure maintenance activities.(c) Post-closure land uses shall not impair the integrity of containment structures.(3) Requirements (a) The Department may require the Permittee to conduct, at a minimum, any or all of the following activities during post-closure maintenance:(i) Periodic sampling of the mine waste as necessary to characterize the mobilization or conversion of mine wastes or parameters;(ii) Inspection and maintenance activities necessary to maintain the structural and chemical stability of the mine waste unit;(iii) Continued operation and maintenance of run-on/run-off control systems and leachate management systems, if any;(iv) Continued operation and maintenance of groundwater and surface water monitoring stations and other monitoring locations; and(v) Any other measure necessary to prevent a violation of a performance standard or other legal requirement and otherwise to protect public health and the environment.(b) All post-closure monitoring activities shall continue until such time as the Department provides written approval for their cessation. In addition, the Department may alter postclosure requirements in response to monitoring information or other assessments.(c) Mine waste units that have been closed may be reactivated or re-utilized only under a new or amended permit. The Permittee shall ensure that:(i) Operations conform to the performance requirements, design operating criteria, and monitoring requirements of this Chapter; and(ii) If mining wastes remain in the mine waste unit following the removal of materials for additional beneficiation, or at the completion of additional storage or disposal activities, the mine waste unit is closed in compliance with the requirements of this section.(d) If any performance requirement is not met, the Permittee shall develop and implement a corrective action plan pursuant to section 30(A) of this Chapter.(4) Post-Closure Maintenance Plan (a) The Applicant shall prepare and submit a detailed post-closure maintenance plan as part of the application. At a minimum, the plan must include the following information: (i) A description of activities and frequency of activities necessary to satisfy the performance standards;(ii) A detailed estimate of post-closure maintenance costs;(iii) A description of the planned use of the property to satisfy the post-closure maintenance performance standards, including the following information: (A) Prevention of exposure of mine waste or constituents to the environment, unless such exposure would pose no significant risk to health or environment and is within licensed limits; and(B) Continued maintenance of the structural and operational components of closure and post-closure; and(iv) The name, address, and telephone number of the Permittee's contact during the postclosure maintenance period.(b) A copy of the post-closure maintenance plan shall be kept at the mine waste unit or alternate location as approved by the Department throughout the post-closure maintenance period.(5) Length of the Post-Closure Care Period. The collection, treatment, and disposal methods must be designed to ensure that discharges to affected areas must meet water quality standards without requiring active treatment as soon as practicable, but in no case greater than 10 years post-closure. The post-closure care period for Group A and Group B wastes must end 30 years from the time of closure certification, provided the Department determines the mine waste unit has been closed in compliance with the performance requirements of this Chapter and the post-closure performance standards of this section, and that the site will continue to remain in compliance with such standards. The post-closure care period for Group C waste must be 5 years from the time of closure certification.(6) Deed Notation(a) During the first year following closure certification the Permittee shall record a notation on the deed to property, or other instrument normally examined during a title search, if any mine waste or constituent remain at the site.(b) The deed notation must state that the land has been used for the management of mine waste, that mine waste or constituents remain at the mine waste unit and, if applicable, that land use is restricted.(7) Post-Closure Certification(a) After completion of post-closure maintenance for the mine waste unit, the Permittee shall submit certification to the Department verifying completion of post-closure maintenance. All inspection records and reports pertaining to certification shall be submitted to the Department.(b) The certification must be based on a review of the mine waste unit by a qualified professional approved by the Department and executed by a responsible officer of the Permittee and an inspection of the facility by the Department.(c) Approval of certification of the completion of postclosure maintenance of a waste unit by the Department does not release the Permittee from any subsequent corrective action requirements or other legal responsibility including the requirement for any monitoring determined to be necessary by the Department.06-096 C.M.R. ch. 200, § 5-24