All facilities shall meet the following standards:
(a) Commencement of closure: Approved closure activities shall commence no later than thirty (30) days after the date on which each unit receives the known final receipt of wastes and shall be completed within one hundred eighty (180) days following commencement of closure. The Administrator may approve: - (i) Delayed closure of a facility or unit if the facility or unit has additional remaining disposal capacity, and the owner demonstrates that there will be no threats to human health or the environment from the unclosed facility or unit, and
- (ii) Extensions of the closure period if needed to adequately complete closure activities and the owner demonstrates that there will be no threats to human health or the environment from the unclosed facility or unit.
(b) Notification and certification of facility and unit closure: Prior to the commencement of closure activities, the operator shall notify the Administrator in writing and place a notice of closure in the operating record. Following closure of each unit and facility, the operator shall submit a certification with supporting documentation signed by an engineer licensed to practice in Wyoming that closure has been completed in accordance with the approved closure plan and place a copy of the certification in the facility operating record. - (i) Notice on deed: At facility closure, an instrument which clearly gives notice of the restrictions that apply to future activities on the disposal facility property shall be filed for recording by the registrar of deeds (county clerk) in the county where the facility is located. Wording of such an instrument shall indicate that the property has been used as a solid waste disposal facility. This shall be recorded prior to any property transaction resulting in another use for the property. The owner/operator, or its successors, shall ensure that post-closure use of the property will be restricted to prevent any disturbance to the facility's containment system including caps and liners, or the functioning of the facility's monitoring system. The owner or operator may request permission from the Administrator to remove the notation from the deed if all wastes are removed from the facility.
(c) Closure permit applications: Closure permit applications shall include the information in this section. A copy of the pertinent materials from the approved permit application or approved renewal permit application, revised and updated as necessary, may be used to fulfill these requirements. - (i) Permit application form: Each closure permit application shall contain a permit application form signed in the manner described in Sections 2(b)(ii) and 2(b)(iii) of this chapter.
- (ii) General information:
- (A) General site information specified in Sections 3(a) through 3(e) and Section 3(m) of this chapter.
- (B) A detailed descriptive statement of the closure/post-closure stage of landfill development, including the following information:
- (I) A description of the land use anticipated after closure;
- (II) The wording of the deed notice;
- (C) A narrative describing the site operating history including the dates of operation, the disposal methods used and the types and amounts of waste accepted.
- (iii) Regional geology information: The application shall include the information required by Section 5.
- (iv) Site specific geology information: The application shall include the information required by Section 6.
- (v) Design and construction information: The application shall demonstrate compliance with the standards in this section.
- (A) Prevention of erosion or ponding problems: Facilities shall be engineered to inhibit future problems with erosion or ponding of surface water over filled areas. This may be done via site grading and revegetation, placement of rip rap or other appropriate means. The application shall describe the method and length of time that surface water will be diverted from the site and the methods by which surface erosion or water ponding problems will be corrected.
- (B) Revegetation: At facility closure, any portion of the facility that has been disturbed by solid waste disposal activities shall be revegetated to minimize wind and water erosion, consistent with the post-closure land use. Vegetation shall be a diverse mix selected to be compatible with the climatic conditions and require little maintenance.
- (C) Final cover shall be designed and constructed to:
- (I) Have a permeability less than or equal to the permeability of any bottom liner system or natural subsoils present or a permeability no greater than 1 X 10-5 cm/sec, whichever is less; and
- (II) Minimize infiltration through the MSWLF by the use of an infiltration layer that contains a minimum of 18 inches of earthen material, and
- (III) Minimize erosion of the final cover by the use of an erosion layer that contains a minimum of 6 inches of earthen material revegetated to sustain native plant growth or an erosion layer that provides equivalent protection from wind and water erosion as approved by the Administrator.
- (IV) The Administrator may approve an alternative final cover system design that includes an infiltration layer that achieves an equivalent reduction in infiltration as the layer specified in (C)(I) and (C)(II) above. The Administrator may require monitoring of alternative final cover designs to demonstrate the performance of the designs.
- (V) Compacted soil barrier layers forming a cap shall be overlain by a layer of soil which is of suitable thickness to protect the compacted soil barrier layer from frost penetration.
- (D) Surveyed corners: At facility closure, all facility boundary corners shall be surveyed and marked with permanent survey caps.
- (E) Access control: Facility fences, gates and any other access restrictions shall be maintained until the facility has been satisfactorily closed and revegetated, if post-closure land use requires establishment of vegetative cover
- (F) Waste containment systems, including but not limited to liners, leachate detection, collection, and management systems, and final cover systems, surface water structures, environmental monitoring systems, and corrective action systems shall be maintained throughout the closure and post-closure periods.
- (G) The frequency of planned inspections to discover problems such as surface erosion and water ponding during the post-closure period.
- (vi) Monitoring information: The application shall demonstrate compliance with Section 9 and describe the method by which any environmental monitoring systems and corrective action systems will be maintained, including the time period over which this will occur.
- (vii) Recordkeeping information: The application shall demonstrate compliance with the applicable requirements of Section 10.
- (viii) Reporting information: The application shall demonstrate compliance with the applicable requirements of Section 11.
- (ix) Financial assurance information: The application shall demonstrate compliance with Chapter 7.
- (x) Corrective action information: The application shall demonstrate compliance with Section 14 if applicable.
- (xi) Transfer, treatment and storage facility information: The application shall demonstrate compliance with applicable closure and post-closure standards of Chapter 6.
- (xii) Special waste information: The application shall demonstrate compliance with applicable closure and post-closure standards of Chapter 8.
- (xiii) Supporting documentation: The application shall include any supporting documentation listed in Section 18 of this chapter that is pertinent to the closure/post-closure phase, including but not limited to:
- (A) A general facility plot plan at a scale approved by the Administrator illustrating past areas of waste deposition, estimated dates of fill and any other pertinent features;
- (B) A map of the site area showing land ownership, land use and zoning within one (1) mile of the disposal site. The map or photograph shall be of sufficient scale to show all city boundaries, each occupied dwelling house, schools, hospitals, industrial buildings, water wells, water courses, roads and other applicable details and shall indicate the general topography;
- (C) A final contour map showing proposed final contours prepared with a scale and contour intervals approved by the Administrator.
(d) Post-closure land use: Each facility shall be returned to the post-closure land use specified in the permit, unless an alternative use is approved by the Administrator.
(e) Post-closure period: - (i) The post-closure period for MSWLFs which continued to receive wastes on or after October 9, 1997 shall extend for a period of not less than thirty (30) years after certification of all facility closure activities is approved by the Administrator. The minimum post-closure period may be terminated by the Administrator at an earlier date if the Administrator determines that the facility has been adequately stabilized and that the environmental monitoring or control systems have demonstrated that the facility closure is protective of public health and the environment consistent with the purposes of the act.
- (ii) The post-closure period for municipal solid waste landfills that ceased receipt of waste prior to October 9, 1997 shall extend for the period specified in rules in place May 28, 2013 and any closure permit issued for the facility.
(f) Post-closure period extension: Following the initial minimum post-closure period, the post-closure period shall be automatically extended until such time when the Administrator determines, upon petition by the operator accompanied by submission of relevant information, that the facility has been adequately stabilized in a manner protective of human health and the environment.
(g) Petitions to terminate post-closure care: Petitions to terminate the post-closure period shall include certification from a Wyoming registered professional engineer that post-closure care has been completed in compliance with the post-closure plan and in a manner protective of human health and the environment.
020-2 Wyo. Code R. § 2-12