62-701.600. Landfill Final Closure

(1) Applicability.

(a) Landfills or solid waste disposal units that were closed in a manner approved by the Department prior to January 6, 2010, or that have received final cover before July 1, 1985, are exempt from the requirements of this section, although they remain subject to the rules that were in effect at the time of closing.

(b) Owners or operators of landfills or solid waste disposal units that were no longer receiving wastes on January 6, 2010, that have not been closed in accordance with an approved closure plan or closure permit, and that do have an approved closure plan or closure permit are exempt from the requirements of this section as long as the closure plan or closure permit is complied with.

(c) Landfills or solid waste disposal units that receive wastes after January 6, 2010, shall comply with the requirements of this section.

(2) Closure permit requirements. Prior to initiating closure of a solid waste disposal unit, or part of a solid waste disposal unit, the owner or operator must receive authorization from the Department in one of the following manners. The owner or operator may submit an application to the Department for a closure permit on Form 62-701.900(1), which application shall include a closure plan. If the landfill is operating under a Department permit, the owner or operator may request a modification of the permit to address substantive changes in the closure plan, or the owner or operator may demonstrate that the closure plan in the existing operation permit includes sufficient detail to provide reasonable assurance of compliance with the provisions of this section. The application or request for modification shall include an updated closure plan which is made up of the following:

(a) A closure design plan;

(b) A closure operation plan;

(c) A plan for long-term care; and

(d) A demonstration that proof of financial assurance for long-term care will be provided.

(3) Closure design plan. The closure design plan shall consist of engineering plans and a report on closing procedures that apply to the final closing of solid waste disposal units during the operation of the landfill, the final closing of the landfill, and the monitoring and maintenance during the long-term care period. The closure design plan shall include the following information:

(a) A plan sheet showing phases of site closing.

(b) Drawings showing existing topography and proposed final grades.

(c) Provisions to close solid waste disposal units within the landfill as soon as they reach approved design dimensions and elevations and to finally close the landfill in accordance with the requirements of this rule. Landfills that are designed to be constructed in phases or sections shall include provisions for temporary closure of solid waste disposal units if subsequent, planned filling on top of them will not occur for six months or longer.

(d) Final elevations before settlement, based upon the capability of the foundation to support the total weight of the landfills, including water loading.

(e) Final side slope design. Side slopes of aboveground disposal units shall not be steeper than three feet horizontal to one foot vertical rise to control erosion of the final cover material. Such units shall be designed to control the flow of stormwater, such as building reverse sloping benches or terraces into the side slopes of the landfill, and shall contain down slope drainage ways with water flow energy dissipaters. Access for maintenance equipment shall be provided. Such designs shall address the susceptibility for erosion of the earthen material that is proposed for final cover relative to historical rainfall patterns for the area, the period between the patterns for the area, the period between the application of the final cover and establishment of vegetation, and maintenance procedures.

(f) Final cover installation plans showing the sequence of applying final cover.

1. The final cover shall be installed and tested in accordance with a construction quality assurance plan which meets the requirements of subsections 62-701.400(7) and (8), F.A.C.

2. Final cover shall be placed over the entire surface of each completed solid waste disposal unit or units within 180 days after the final waste deposit, or within the time frame set forth in the approved closure plan. The final cover shall be vegetated to control erosion and provide a moisture infiltration seal, with species that are drought resistant and have roots that will not penetrate the final cover.

3. Top gradients of final cover on landfill areas shall be graded to maximize runoff and minimize erosion, considering total fill height and expected subsidence caused by decomposing waste, and shall be designed to prevent ponding or low spots.

4. The closure design plan shall describe provisions for cover material for the long-term care erosion control, filling areas of subsidence or other depressions, maintaining berms, and general maintenance of the facility, and specify the anticipated source and amount of material necessary for proper closure of the landfill.

(g) Final cover design.

1. Landfills shall have a final cover designed to minimize infiltration and erosion, which shall include a barrier layer consisting of a soil layer, a geomembrane, or a combination of a geomembrane with a low permeability material. All geosynthetic and soil components used in the final cover shall meet the standards and specifications contained in subparagraphs 62-701.400(3)(d)1. and 2., (3)(d)5.-11., paragraph (e), and (f), F.A.C. For lined Class I and Class III landfills, the barrier layer shall have a permeability that is substantially equivalent to, or less than, the permeability of the bottom liner system. If the landfill uses a geomembrane in the bottom liner system, the barrier layer shall also incorporate a geomembrane. For unlined Class I landfills, the barrier layer shall have a permeability of 1 x 10-7 cm/sec or less. For unlined Class III landfills, the barrier layer shall have a permeability of 1 x 10-5 cm/sec or less. For unlined Class III landfills which accepted only yard trash, no barrier layer is required; instead, final cover shall consist of a 24-inch thick soil layer, or a 30-inch thick layer consisting of approximately 50 percent soil and 50 percent ground or chipped yard trash by volume, the upper six inches of which shall be capable of supporting vegetative growth.

2. If the barrier layer consists only of soil, it shall be at least 18 inches thick, installed in 6-inch thick lifts, and shall have a final, 18-inch thick layer of soil, or a 24-inch thick layer consisting of approximately 50 percent soil and 50 percent ground or chipped yard trash by volume, that will sustain vegetation to control erosion placed on top of the barrier layer.

3. If the barrier layer consists only of a GCL, a protective soil layer at least 24 inches thick shall be placed on top of the GCL with the upper six inches being able to sustain vegetative growth. In the alternative, the GCL may be covered with a 12-inch thick layer of soil that is then covered with a 15-inch thick layer consisting of approximately 50 percent soil and 50 percent ground or chipped yard trash by volume, with the upper six inches being able to sustain vegetative growth. The GCL shall be placed on a protective soil layer at least six inches thick. Material specifications and installation methods, which may include a drainage layer between the GCL and the protective soil layer over the GCL, shall be adequate to protect the barrier layer from root penetration, resist erosion, and remain stable on the final design slopes of the landfill.

4. If a geomembrane is used in the barrier layer, it shall be either HDPE or LLDPE with a minimum average thickness of 40 mils or PVC with a minimum average thickness of 30 mils, shall have chemical and physical resistance to materials it may come in contact with, and shall withstand exposure to the natural environmental stresses and forces throughout the installation, seaming process, and settlement of the waste during the closure and long-term care period. A protective soil layer at least 24 inches thick shall be put on top of the geomembrane. In the alternative, the geomembrane may be covered with a 12-inch thick layer of soil that is then covered with a 15-inch thick layer consisting of approximately 50 percent soil and 50 percent ground or chipped yard trash by volume, with the upper six inches being able to sustain vegetative growth. Material specifications, installation methods, and compaction specifications, which may include a drainage layer between the geomembrane and the protective soil layer, shall be adequate to protect the barrier layer from root penetration, resist erosion, and remain stable on the final design slopes of the landfill. This layer shall include topsoil or soils that will sustain vegetative growth.

5. The final cover design shall include an evaluation of the stability of the cover system and the disposed waste and shall be designed to meet the factor of safety criteria in subsection 62-701.400(2), F.A.C. This evaluation shall include an analysis of the potential for slides along the weakest interface of the final cover system and of the potential for deep seated rotational or translational failures through the waste and the final cover.

6. An applicant may use an alternate design for the barrier layer or parts of the barrier layer, or for the protective soil layer, upon a demonstration that the alternate design will result in a substantially equivalent rate of storm water infiltration through the final cover. Any alternate design shall be reviewed by the Department as part of its review of the closure design plan.

7. Nothing herein shall preclude the Department from requiring more stringent final or temporary cover designs in a permit or consent order if necessary to protect the public health or the environment because of the nature of wastes received or site specific geological or hydrogeological conditions, or if the landfill has not been adequately constructed, operated, maintained, or closed.

(h) Proposed method of stormwater control. The closure design plan shall demonstrate how the stormwater management systems shall be operated and maintained as necessary to meet the requirements of subsection 62-701.400(9), F.A.C.

(i) Proposed method of access control. The closure design plan shall show how access to the closed landfill shall be restricted to prevent any future waste dumping or use of the facility by unauthorized persons.

(j) A description of the proposed or existing gas management system that complies with Rule 62-701.530, F.A.C.

(4) Closure operation plan. The closure operation plan shall:

(a) Describe the actions that will be taken to close the landfill, such as placement of cover, grading, construction of berms, ditches, roads, retention-detention ponds, installation or closure of wells and boreholes, installation of fencing, seeding of vegetation, and protection of on-site utilities and easements;

(b) Provide a time schedule for completion of the closing and long-term care;

(c) Contain appropriate references to the closure design and other supporting documents;

(d) Describe the proposed method of demonstrating financial assurance for long-term care;

(e) Provide for operation of the water quality monitoring plan required in Rule 62-701.510, F.A.C.; and

(f) Provide for the development and implementation of the gas management system required in Rule 62-701.530, F.A.C.

(5) The owner or operator shall close the facility only in accordance with the closure design plan submitted with the permit application. The owner or operator shall at all times comply with the closure operation plan submitted with the permit application.

(6) Certification of closure construction completion. After closure construction has been completed, the engineer of record shall certify to the Department on Form 62-701.900(2) that the closure is complete and that it was done in accordance with the plans submitted to the Department except where minor deviation was necessary. All deviations shall be described in detail and the reasons therefore enumerated. The final report required by subsection 62-701.400(7), F.A.C. shall be submitted with the certification. If the certification is for the final closure of a landfill, it shall include a certification that one of the following has been done:

(a) For landfills with a final elevation of less than 20 feet above the natural land surface, concrete monuments shall be installed to mark the boundaries of the landfill property and other permanent markers shall be installed to outline the general waste filled areas. These markers shall be tied to one or more of the boundary markers by a survey performed by an engineer or a Florida Licensed Professional Surveyor and Mapper. The location and elevation of all markers shall be shown on a site plan filed with the “Declaration to the Public” described in subsection (7) of this section.

(b) For landfills with a final elevation of 20 feet or higher above the natural land surface, a final survey shall be performed after closure is complete by an engineer or a Florida Licensed Professional Surveyor and Mapper to verify that final contours and elevations of the facility are in accordance with the plans as approved in the permit. Aerial mapping techniques which provide equivalent survey accuracy may be substituted for the survey. Contours shall be shown at no greater than five-foot intervals. A copy of the survey shall be included with the certification of closure construction completion.

(7) Declaration to the public. Once closure construction has been completed, the landfill owner or operator shall file a declaration to the public in the deed records in the office of the county clerk of the county in which the landfill is located. The declaration shall include a legal description of the property on which the landfill is located and a site plan specifying the area actually filled with solid waste. The declaration shall also include a notice that any future owner or user of the site should consult with the Department prior to planning or initiating any activity involving the disturbance of the landfill cover, monitoring system or other control structures. A certified copy of the declaration shall be filed with the Department.

(8) Official date of closing. The Department shall evaluate the documents required in subsections (6) and (7) of this section, and within 30 days of its determination that such documents comply with the closure plan and the requirements of this section shall acknowledge by letter to the facility operator that closing of the facility has been completed. If the entire landfill has been closed, the date of this letter shall be the official date of landfill closing for purposes of determining the long-term care period. If only a portion of the landfill has been closed, the long-term care period will begin upon the closing of the entire landfill, unless:

(a) The portion that has been closed can be monitored and maintained separately from the rest of the landfill; or,

(b) The portion that has been closed can be maintained separately from the rest of the landfill and monitored within a facility-wide water quality monitoring network.

(9) Temporary closure.

(a) Placement of final cover over a solid waste disposal unit may be delayed for a period of time specified in an approved closure plan for the following reasons:

1. For the purpose of promoting biological degradation of waste;

2. If additional solid waste will be deposited on the solid waste disposal unit; or

3. If excavation of the waste is planned.

(b) Placement of final cover may be delayed only if the solid waste disposal unit is temporarily closed in accordance with an approved closure plan. Conditions of temporary closure shall include:

1. The solid waste disposal unit was constructed in compliance with its permit conditions, and has a liner and leachate control system;

2. A schedule for closure is shown in the closure plan application;

3. Final cover is installed on side slopes of each completed disposal unit that will not receive additional waste or that will not be excavated, except that if a landfill owner or operator can demonstrate in individual cases that a different process will be adequate to control erosion and odors, and will be expected to result in compliance with applicable stormwater and leachate management requirements, it can be approved as part of the closure plan;

4. Odors and vectors are controlled;

5. An intermediate cover is installed on the solid waste disposal unit;

6. The financial assurance requirements of Rule 62-701.630, F.A.C., are met, and the closure cost estimate takes into account the costs of temporary closure as well as the costs of the final closure; and

7. The landfill owner or operator demonstrates that delaying placement of final cover will not cause or contribute to any significant increase in leachate escaping from the solid waste disposal unit into the environment.

(c) In addition, a solid waste disposal unit that will be excavated in the future shall have a temporary final cover installed.

Rulemaking Authority 403.061, 403.704 FS. Law Implemented 403.702, 403.704, 403.707 FS. History–New 1-6-93, Amended 1-2-94, 5-19-94, Formerly 17-701.600, Amended 5-27-01, 1-6-10, 8-12-12, 2-15-15.