A landfill is a disposal facility where waste is placed in or on the land and is considered to be the final disposal site. Waste disposal in Indiana must occur at a land disposal facility permitted to accept that waste. The purpose is to contain the waste and liquids contacting or passing through the waste (leachate) from leaving the landfill. Liquid waste must not be disposed in landfills. Landfills must be constructed and operated according to specified standards to prevent contaminants from being released to the environment, manage storm water, control erosion, and control dust and litter from blowing off site.
Depending on the type and age of a landfill, the landfill will have some type of liner or barrier to prevent leakage. Most landfills also have leachate collection systems and ground water monitoring wells which can detect if a landfill is leaking. Landfills may also have setback requirements, such as being a certain distance from residences, public water supply, wells, rivers, etc.
At the end of the operation, the landfills must close with soil and/or plastic cover, drainage, and vegetation on top. Closed landfills must monitor and maintain the cover, leachate collection, gas extraction, sedimentation and erosion controls, and monitor ground water for any contamination for at least 30 years after completing closure (called post-closure maintenance). All permittees are required to provide financial assurance to cover the cost of closure and post-closure maintenance.
Hazardous Waste Landfills
Hazardous waste from industrial and commercial operations are disposed of in hazardous waste landfills. Construction and operation requirements specific to these landfills are provided in federal rule 40 CFR 264. Indiana has adopted these rules by reference in 329 IAC 3.1. Certain waste that can leach contaminants are not allowed to be disposed in landfills before treating them further, which are called land disposal restrictions.
Hazardous waste landfills must also have a dual composite liner system, made of clay and plastic, with a leak detection system. Other Hazardous Waste Disposal Units include waste piles, surface impoundments, and land treatment units.
Solid Waste Landfills
A solid waste land disposal facility is defined in IC 13-11-2-206 and 329 IAC 10-2-176. Solid waste landfills are defined in IC 13-11-2-208. The requirements for solid waste landfills are in rule 329 IAC 10. The financial assurance requirements are in 329 IAC 10-39.
There are several types of solid waste land disposal facilities. Each type of landfill has different minimal design, setback, and operational requirements. The Landfill fact sheet (available on the IDEM Fact Sheets page) has additional information on solid waste landfills.
Municipal Solid Waste Landfills (MSWLFs)
Trash from homes and businesses, construction and demolition debris, and most non-hazardous industrial wastes are disposed of in MSWLFs. 329 IAC 10-9-2 provides waste criteria for solid waste that can and cannot be accepted at a MSWLF.
These landfills must not accept:
- Hazardous waste (except household hazardous waste and conditionally exempt small quantity waste)
- Certain polychlorinated biphenyl (PCB) waste
- Untreated infectious waste
- Vegetative matter, unless from homes or properly bagged
- Whole waste tires
- Lead acid batteries and mercury switches
- Regulated asbestos-containing material not managed in accordance with Air rules 326 IAC 14-10 and 329 IAC 10-8.2-4
- Appliances or motor vehicle air conditioner containing a refrigerant or other class I or Class II substance that has not been removed as required by 40 CFR 82.156
- Biosolids as defined in 327 IAC 6.1-2-7 that is not managed in accordance with 327 IAC 6.1-1-7
- Wastewater as defined in the 327 IAC 7.1-2-41 that is not managed in accordance with 327 IAC 7.1-7-1
MSWLFs must also have methane gas extraction/control system; and storm water pollution controls. Requirements specific to these landfills are provided in 329 IAC 10-15 through 329 IAC 23.
Non-municipal Solid Waste Landfills (Non-MSWLFs)
Non-MSWLFs may accept waste that is approved in the facility permit except certain waste like MSW, hazardous waste, PCB waste, infectious waste etc. Examples of acceptable waste include construction and demolition waste, industrial process waste, and pollution control wastes, such as wastewater treatment sludges, baghouse dust, scrubber sludges, chemical spill clean-up wastes, and environmental cleanup wastes.
Typically, non-MSWLFs are also required to have methane gas extraction. Construction, operation, closure and post-closure requirements specific to these landfills are provided in 329 IAC 10-24 through 329 IAC 31.
Construction and Demolition Landfills (C/D sites)
Construction and demolition waste is defined in 329 IAC 10-2-37. Construction demolition waste must not be further shredded, crushed, ground, pulverized, or otherwise processed after construction/demolition activity or before disposal to a form unrecognizable as construction/demolition waste. C/D landfills may only accept construction and demolition debris, such as scrap lumber, bricks, stone, glass, wallboard, roofing, plumbing fixtures, wiring, and non-asbestos insulation. Most C/D landfills do not have a leachate collection system or a ground water monitoring. Requirements specific to these landfills are provided in 329 IAC 10-32 through 329 IAC 38.
Restricted Waste Sites (RWSs) (RWS I, II and III Landfills)
Sometimes called a monofill, typically, a RWS is built and operated for the on-site disposal of non-hazardous industrial wastes generated by a single type of industrial activity. Restricted waste sites may only receive wastes which are similar in origin or chemical character and, additionally, are not subject to organic decomposition. For example, a foundry may dispose of foundry sand but not absorbents used to clean up oil spills in their restricted waste site.
IDEM issues three different types of Restricted Waste Site permits -- Types III (RWS III), II (RWS II), and I (RWS I) -- with progressively more stringent levels of monitoring and containment. The requirements for the design of the landfill depends on the chemical concentration of the materials disposed. A waste classification must be obtained before constructing a RWS landfill. Restricted waste criteria are specified in 329 IAC 10-9-4.
Construction and operation requirements specific to these landfills are provided in 329 IAC 10-24 through 329 IAC 38.
Coal Combustion Residual (CCR) Landfills
In Indiana, CCR waste from power plants, such as fly ash and bottom ash, is mostly disposed of in restricted waste sites regulated under 329 IAC 10. With the passage of federal rules, these landfills must also comply with the requirements in 40 CFR 257 subpart D.
Other Solid Waste Land Disposal Units
Surface impoundments, ponds, or lagoons are units where wastes like sludge are conveyed by water into ponds for treatment (dewatering). These units generally have a construction permit and National Pollutant Discharge Elimination System permit from IDEM’s Office of Water Quality for construction, treatment, and operating of wastewater discharge. After stopping NPDES discharge operation, waste placed in these units is subject to solid waste disposal regulations. If the waste remains in the unit, the unit must undergo closure similar to the closure of the landfill. If the waste is removed including all contaminated media, the unit may be able to demonstrate “clean closure”. For more information on closure of the impoundments, please contact the OLQ Solid Waste Permit Section.