Section 516.06. Closure of landfill areas.

  In addition to the requirements of s. NR 516.04 (3) , all construction documentation reports for the closure of landfill areas shall contain the following minimum information:

(1)   Engineering plans. A set of 24 inch by 36 inch engineering plan sheets, unless an alternative size is approved by the department in writing, prepared in accordance with s. NR 500.05 and including:

(a) A plan sheet documenting the final refuse grades, including daily or intermediate cover. Documentation of grades shall include spot elevations taken on a maximum 100-foot grid after grading has been performed to establish uniform slopes. Documentation of grades for landfills which primarily accept papermill sludge or other low strength wastes may be performed at the surface of the support layer, accompanied with documentation of the thickness of the support layer on a 100-foot grid and the orientation of any geosynthetics and pipe used for reinforcement, separation, filtration or drainage. For areas less than 4 acres, a 50-foot grid shall be used.

(b) A plan view drawing for each one–foot thickness of clay or soil barrier layer placed showing the locations of the various soil testing completed and detailing the tests performed at each location. Multiple plan views may be presented on a single engineering plan sheet if legibility is not compromised.

(c) A plan view drawing showing the location of all geomembrane tests, geomembrane panel layout, geomembrane patches and seam repairs, and geomembrane destructive samples.

(d) A plan sheet documenting the constructed final cap grades prior to topsoil placement on a maximum 100-foot grid. Approved final cap grades shall be shown for the same area in a clear and legible manner. For areas less than 4 acres, a 50-foot grid shall be used.

(e) A plan sheet documenting the gas and condensate transfer piping layout, top of header pipe elevation at each gas extraction well, at all major changes in slope and at the driplegs and the condensate tank, and the location of the anti-seep collar around pipes exiting the waste.

(f) Cross-sections through the closed area which are constructed parallel and perpendicular to the base line of the landfill. A minimum of 4 cross sections shall be submitted, 2 of which shall be in each direction. Each of the cross-sections shall show all surficial and subsurface features encountered including gas extraction wells or vents, leachate lines, and other landfill structures and shall be tied into the grades of adjacent previously filled areas. At a minimum, each cross section shall show actual sub-base grades, base grades, final refuse grades, and final topsoil grades.

(g) Detail drawings, plan view and cross-section, of typical gas extraction wells or gas vents, bedding and assembly of the lateral and header pipes, header pipe joining details, header pipe exiting the site, valves, driplegs, manholes, lift stations, collection tanks, and blower building and flare.

(h) Cross section details shall be included to illustrate all important construction features of the final cover, drainage systems for gas condensate, and sediment control and storm water management structures.

(i) Detail drawings shall be included for gas header and gas condensate drain lines outside the limits of waste in critical areas of below-ground piping such as where several pipes cross or meet to illustrate sufficient pipe location and invert information.

(2)   Report preparation. A comprehensive report containing a detailed narrative describing the closure of the area in a logical fashion shall be prepared. Particular emphasis shall be placed on any deviations from the approved plans. This report shall also include the following information at a minimum:

(a) An analysis and discussion of all soil, geomembrane and other geosynthetic testing work performed. All density and moisture content testing results shall clearly indicate which Proctor curve or line of optimums is applicable to the soil being compacted. Any changes in the referenced Proctor curve or line of optimums shall be identified as to when they occurred and why the change was made. All raw data from the soil, geomembrane and other geosynthetic testing performed shall be included in an appendix to the closure documentation report unless other arrangements were previously approved by the department. The raw data shall be summarized using a tabulated format. Also included shall be the make, model, weight and foot length of each piece of equipment used to compact clay.

(b) A table containing thicknesses of each layer in the cover system on a 100-foot grid pattern. When determining soil thickness by using surveying information, the table shall contain elevations before and after soil layer placement on the 100-foot grid. For areas less than 4 acres, a 50-foot grid shall be used. As an alternative to the survey method, soil thickness shall be controlled using settlement plates and grade stakes, and clay thickness shall be established on a 100-foot grid using auger borings. Boreholes shall be backfilled with a soil-bentonite mix such that the in-place permeability of the backfilled material is equal to or less than the surrounding clay cap.

(c) When the auger method is used to determine soil layer thicknesses, a discussion of how the auger boreholes were backfilled and the materials used.

(d) A table showing gas extraction well construction information including: location, surface elevation, depth of the borehole, top of casing elevation, elevation and length of the solid and perforated piping, elevation and length of the gravel backfill, bentonite seal and other backfill materials.

(e) Daily summary reports shall be prepared for each day that installation of geomembrane or other geosynthetics is either attempted or accomplished for composite-capped landfills and shall contain the information required in s. NR 516.05 (2) (e) .

(f) The rates and types of fertilizer, seed and mulch applied. Liming requirements shall also be included along with the actual rate of application.

(g) A series of properly labeled 35 millimeter color prints which document all major aspects of facility closure. This shall include panoramic views of the closed area as well as close-up photos of the construction process and completed engineering structures such as gas extraction wells or vents, blower and flare stations, cleanout ports, manholes, gas condensate tanks and other pertinent structures.

History: Cr. Register, January, 1988, No. 385 , eff. 2-6-88; r. (1) (d), (2) (e) renum. (intro.), (1) (intro.), (a), (b), (d), (f), (2) (intro.), (a), (f), (g) from NR 516.07 (intro.), (1) (intro.), (a), (b), (c), (e), (2) (intro.), (a), (b), (c) and am. (intro.), (1) (a), (b), (f), (2) (intro.), (a), cr. (1) (c), (e), (g) to (i), (2) (b) to (e), Register, June, 1996, No. 486 , eff. 7-1-96; am. (2) (e), Register, August, 1997, No. 500 , eff. 9-1-97; CR 05-020 : am. (1) (b) and (2) (a) Register January 2006 No. 601 , eff. 2-1-06.