Municipal Waste Landfills

General Description

A Municipal Solid Waste Landfill (MSWLF) is a disposal facility in a contiguous geographical space, where household waste is placed in or on land.

Summary of Federal Requirements

The regulations for MSWLFs are extensive and detailed. They address location, design, operation construction, monitoring, documentation, and closure.

Location and Design

Location restrictions primarily are for proximity to airports, wetlands, floodplains, and seismic impact zones.

Design criteria is concerned primarily with leachate and run-off. The MSWLF must be designed so that leachate is prevented from reaching the uppermost aquifer in excessive concentrations. The run-on control system must prevent flow onto the active portion of the landfill during the peak discharge from a 25-yr storm. The runoff control system from the active portion of the landfill must collect and control at least the water volume resulting from a 24-h, 25-yr storm. Public access to the MSWLF must be controlled and unauthorized vehicular traffic and illegal dumping of wastes prevented through the use of artificial barriers, natural barriers, or both.

Operating Requirements

Hazardous waste must NOT be disposed of in MSWLFs.

The solid waste must be covered with 6 in. of earthen material, or another approved material at an alternative thickness, at the end of each operating day or more frequently, if necessary, in order to control disease vectors, fires, odors, blowing litter, and scavenging.

The concentration of methane gas generated by the MSWLF must not exceed 25 percent of the lower explosive limit (LEL) for methane in facility structures (excluding gas control or recovery system components).

The concentration of methane gas at the MSWLF property boundary must not exceed the LEL for methane.

There can be no open burning of solid waste, except for the infrequent burning of agricultural wastes, silvicultural wastes, landclearing debris, diseased trees, or debris from emergency cleanup.

Certain PCB bulk product waste may be disposed of in a facility permitted, licensed, or registered by a state as a municipal or nonmunicipal nonhazardous waste landfill:

  • plastics (such as plastic insulation from wire or cable; radio, television, and computer casings; vehicle parts; or furniture laminates); preformed or molded rubber parts and components; applied dried paints, varnishes, waxes or other similar coatings or sealants; caulking; Galbestos; nonliquid building demolition debris; or nonliquid PCB bulk product waste from the shredding of automobiles or household appliances from which PCB small capacitors have been removed (shredder fluff)
  • other sampled PCB bulk product waste that leaches PCBs at <10 g/L of water measured with a procedure used to simulate leachate generation.)

MSWLF with a design capacity =/> 2.5 million Mg by mass or 2.5 million m3 by volume are required to perform the extra task of calculating NMOC emissions and reporting them. Based on the results of the calculations, additional monitoring equipment may be required.

MSWLFs are required to monitor groundwater, run-on and run-off, and air emissions as well as any additional monitoring requirements in permits.


The final cover must be designed to minimize infiltration and erosion according to the following criteria:

  • it has a permeability less than or equal to the permeability of any bottom liner system or natural subsoils present, or a permeability no greater then 1 x 10 -4 cm/s, whichever is less
  • it minimizes infiltrations through the closed MSWLF by use of an infiltration layer that contains a minimum 18 in. of earthen material
  • it minimizes erosion of the final cover by the use of an erosion layer that contains a minimum 6 in. of earthen material that is capable of sustaining native plant growth.

MSWLFs are required to have a written closure plan in place and follow the plan in case of closure.

The State must be notified of the intent to close the MSWLF.

Closure activities must begin no later than 30 days after the date the MSWLF receives the final receipt of waste, or no later than 1 yr after the most recent receipt of waste if the unit has remaining capacity. Closure activities of each MSWLF unit must be completed within 180 days following the beginning of closure.

Summary of State Requirements

A State may be more restrictive about where a MSWLF may be located. It is not uncommon for the State to require additional monitoring as well as operation training and certification not addressed in the Federal regulations. Additionally, in states with primacy for the program, the state can approve the use of alternative technologies or processes.

Laws and Statutes

The Clean Air Act
The Clean Water Act
Resource Conservation and Recovery Act, Subtitle D
Toxic Substances Control Act

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