N.Y. Comp. Codes R. & Regs. Tit. 6 §§ 363-4.3

Current through Register Vol. 46, No. 45, November 2, 2024

Section 363-4.3 - Engineering report

The engineering report must contain, at a minimum:

(a) A site description and analysis of the proposed facility including the following:

(1) A brief description of the type and amount of waste, in tons, accepted by the facility, specifying the anticipated maximum amount of wastes to be accepted on a daily and annual basis, including those wastes anticipated to be accepted for use as alternative operating cover, the anticipated maximum in-place density of waste to be placed in the landfill, and the proposed maximum amount of waste and alternative operating cover that will be placed in the landfill.

(2) A description of the number, types and specifications of all machinery and equipment needed to effectively operate the facility at the proposed rate of waste acceptance, and all proposed structures and areas designated for unloading, processing, sorting, storage, and loading.

(3) A description of the materials and construction methods that demonstrate compliance with the requirements in Subpart 363-6 of this Part and are used for the placement of:

(i) each monitoring well pursuant to the requirements of section 363-4.4(k) of this Part;

(ii) the landfill gas management system;

(iii) the leachate conveyance, storage, treatment and disposal system;

(iv) the cover system; and

(v) the liner and leachate collection and removal system. The description must also include the precautions that will be taken to prevent frost action upon the composite liner system in areas where waste will not be placed within one year of department approval of construction certification;

(4) A description of post-construction care measures to be taken to ensure that the construction materials noted in paragraph (3) of this subdivision meet the specifications and comply with the requirements of Subpart 363-6 of this Part from the time of construction completion to the beginning of landfill operation.

(5) A comprehensive and detailed description of each of the following features of the operation of the landfill gas management system:

(i) a year-by-year estimate of the quantities of landfill gas that will be generated during the active life and post-closure care period, including a year-by-year estimate of greenhouse gas emissions;

(ii) how landfill gas will be managed;

(iii) how any landfill gas condensate generation will be minimized, disposed, and/or recirculated into the landfill waste mass;

(iv) all machinery, equipment, and construction materials to be used at the facility, including the equipment design capacity;

(v) how the landfill gas management system will be designed, constructed and maintained so as not to interfere with the integrity of the proposed or existing landfill final cover system; and

(vi) a description of how the landfill gas management system will effectively control landfill decomposition gas-related odors.

(b) A landfill liner subbase settlement analysis that:

(1) predicts the total and differential settlement of the landfill subbase, liner, leachate collection and removal system, and other critical containment structure components of the landfill demonstrating that the liner system and leachate collection and removal system will maintain their integrity and performance at the maximum predicted settlements. The calculated settlement should account for secondary consolidation for a period of 30 years after the estimated closure date of the facility;

(2) includes plan and cross-sectional views depicting the predicted maximum critical landfill subbase settlement elevations and the landfill liner and leachate collection and removal system elevations when the subbase settlement analysis predicts settlement exceeding one foot. In all cases, the slope must not be less than one percent for pipe valley areas and two percent for liner subbase areas; and

(3) includes a landfill settlement monitoring plan when the landfill subbase settlements are predicted to exceed one foot. The landfill settlement monitoring plan must be designed to demonstrate that the leachate collection and removal system is functioning as designed and to verify acceptable integrity of key leachate collection and removal system and conveyance appurtenances within the system.

(c) A structural integrity and overall slope stability analysis.

The analysis must demonstrate the structural integrity and overall stability of the landfill site, the subgrade, each component of the liner, leachate collection and removal system, and final cover system, and must include:

(1) An evaluation of the following failure modes:

(i) overall global stability of the waste mass and foundation soils;

(ii) local and deep stability along critical interfaces of the liner and final cover system, including veneer stability of the leachate drainage and protective cover soil layers above liners and along drainage soil layers and geosynthetic interfaces within the landfill final cover system for anticipated field conditions. The analysis must identify the shear strength properties necessary to meet the requirements of paragraph (3) of this subdivision; and

(iii) local and global stability of access routes, leachate storage tanks, landfill access ramps, retaining walls, and other applicable facility components critical to operation, closure and monitoring of the facility.

(2) An evaluation of site geometries, impacts of pore pressures and loading conditions:

(i) during construction of the liner and final cover system;

(ii) during filling or excavating of waste in the landfill, including the typical stockpiling of materials, overfilling and other interim conditions;

(iii) at full load conditions represented by attaining the landfill's maximum design capacity; and

(iv) associated with leachate recirculation, if proposed.

(3) a demonstration that the design considers an appropriate selection of shear strengths based on the variability of materials the potential for mobilization of post-peak displacement shear strengths. The potential pore pressure regimes caused by liquid buildup, seepage forces, and landfill gas pressures should also be considered and the system should achieve the following factors of safety under static stability conditions:

(i) a minimum factor of safety of 2.00 for the subgrade soil-bearing capacity of any loaded structures or appurtenances (e.g., tanks, manholes, retaining walls, etc.) associated with the landfill at full load conditions.

(a) If the factor of safety for the soil-bearing capacity is less than 3.00, it must be demonstrated that the structures or appurtenances can accommodate the anticipated settlements over the life of the facility;

(ii) a minimum factor of safety of 1.25 for the design of the facility liner and leachate collection and removal system components for short-term conditions considering the maximum anticipated construction and early landfill operational transient loads;

(iii) a minimum factor of safety of 1.50 for interim and final elevation of waste slopes that occur during operation and upon closure of a landfill cell; and

(iv) a minimum factor of safety of 1.50 for the final cover system considering seepage patterns that will typically develop assuming the saturated hydraulic conductivity of the barrier protection and topsoil layers during the wettest months of the year.

(d) a seismic stability analysis. Any facility located in a seismic impact zone, as defined in section 360.2, must include a seismic stability analysis. The seismic stability analysis must address the serviceable life of the landfill, its internal components and its related appurtenances and must demonstrate that:

(1) all long-term containment structures, including liners, the leachate collection and removal system, and the surface water control system but excluding the cover system, are stable by utilizing either:

(i) a pseudo-dynamic analysis, requiring both the static and pseudo-static analyses to be based on large-displacement shear strengths (3 inch) along the critical surface, that demonstrates all long-term containment structures are designed to retain a minimum factor of safety of 1.0 using a seismic coefficient (expressed as a fraction of the acceleration of gravity) equal to 0.75 of the free field peak ground acceleration at the site for the design earthquake (i.e., the earthquake that has a 10 percent or greater probability in 250 years or two percent or greater probability in 50 years in the lithified earth from the latest USGS seismic hazard map or site specific seismic hazard study); or

(ii) a displacement analysis that limits the calculated permanent seismic deformations to less than six inches using a decoupled seismic response/deformation analysis, to resist the maximum horizontal acceleration for the site. If the computed displacement is greater than 0.4 inch then large-displacement shear strengths (3 inch) must be used for both the static and the dynamic analysis.

(2) the landfill's long-term containment structures and any related appurtenances are not susceptible to damage from liquefaction when subjected to the maximum horizontal acceleration in lithified earth.

(e) A description and analysis of the leachate collection and removal system that includes:

(1) An evaluation of leachate generation data, including:

(i) an estimate of the leachate generation quantities for the landfill, based on the maximum hydraulic infiltration rate using a 24-hour 25-year storm, assuming little or no waste in place in the landfill;

(ii) an evaluation of impacts on the portion of the landfill's leachate collection and removal system, that does not have intermediate or final cover material placed, which would result from a 500-year storm and provide discussion of mitigating procedures to any impacts; and

(iii) for landfill expansions or landfills undergoing subsequent development, an analysis of the anticipated increase above the existing landfill's actual leachate generation as a result of the expansion and/or subsequent development.

(2) A description of how the components of the landfill liner and leachate collection and removal system will:

(i) withstand dynamic and static loading stresses anticipated during the construction, operation, closure, post-closure period of the facility, including subsequent permit modifications that involve changes in waste types and vertical expansion designs;

(ii) allow for effective monitoring of leachate flow and liner system performance in accordance with paragraph (3) of this subdivision; and

(iii) allow for effective access for routine maintenance.

(3) An estimate of the maximum daily volume of leachate generated, and a demonstration that the leachate head on the primary liner system will not exceed 12 inches per the provisions of paragraph 363-6.6(a)(3), and that the maximum daily volume of leachate that may infiltrate through the primary liner will not exceed the allowable primary liner leakage rate of 20 gallons per acre per day in accordance with provisions of paragraph 363-7.1(f)(7).

(f) Design information for a stormwater/run-off conveyance system. This information must demonstrate that the stormwater detention/retention basin system is designed to manage a 100-year, 24hour design storm from the landfill site without sustaining damage. This must include an evaluation of impacts on the stormwater/run-off conveyance system which would be anticipated as from a 500-year storm to inform a contingency plan for such an event.

(g) a mined use plan.

(1) If the facility plans to use material excavated on-site as operating cover for the landfill, and construction of that landfill will not take place in the area from which the operating cover material is to be removed, the facility must submit a mined land use plan with information that demonstrates compliance with the applicable requirements of Part 422 of this Title.

(2) A mined land use plan is not required if the facility plans to perform on-site excavation of material to be used as operating cover for the landfill and the landfill footprint will be situated upon the area from which the operating cover material is to be removed.

(3) Material excavated on-site may not be used off-site unless the applicant has first obtained a mining permit pursuant to Part 421 of this Title;

(h) Facility closure and post-closure design plan. The facility's closure and post-closure design plan must include at a minimum:

(1) closure design;

(2) post-closure water quality monitoring program;

(3) an operation and closure plan for the leachate collection, treatment, and storage facilities;

(4) an operation and closure plan for the landfill gas management system; and

(5) any proposed and alternative end uses for the site.

N.Y. Comp. Codes R. & Regs. Tit. 6 §§ 363-4.3

Adopted New York State Register September 20, 2017/Volume XXXIX, Issue 38, eff. 11/4/2017

Amended New York State Register June 7, 2023/Volume XLV, Issue 23, eff. 7/22/2023

Amended New York State Register June 21, 2023/Volume XLV, Issue 25, eff. 7/23/2023