It is apparent that there are many uses of recycled materials in highway construction and related applications. Table 1.19 provides a summary of these uses for reference.
1.6.1 Recycling Hazardous Wastes
Under Subtitle C of RCRA, EPA has the authority to regulate recyclable hazardous waste material. It is critical to determine the type of waste and the proposed method of recycling in determining whether it is regulated under Subtitle C. The definition of solid waste under Section 261.2 identifies four types of recycling activities for which recycled wastes may be subject to Subtitle C regulation: use constituting disposal, burning waste-derived fuels for energy recovery, reclamation, and speculative reclamation.
Use Constituting Disposal. Use constituting disposal is defined as placing or applying a solid waste or a material contained in a product that was a solid waste on the land in a manner constituting disposal. In this case, land disposal regulations under RCRA Parts 264 and 265 apply. Use constituting disposal may include the following uses involved in the construction of highways or maintenance of highway landscaping: fill material, cover material, fertilizer, soil conditioner, dust suppressor, asphalt additive, and foundation material.
Burning and Blending of Waste Fuels. Burning and blending would be the applicable method for recycling used oil for fuel in asphalt plants. Used oil is not currently considered a hazardous waste unless it has a characteristic of ignitability, corrosivity, reactivity, or extraction procedure toxicity (ICRE characteristic). If the used oil is mixed with a hazardous waste, it is regulated as a hazardous waste fuel under RCRA, Part 266, Subpart D. Specifications for nonhazardous used oil fuel are described in Table 1.20. Used oils that do
Asphalt: Crop waste and other cellulose material may be reduced to an oil suitable for asphalt extender. Asphalt paving aggregate: Incinerator ash.
Asphalt mineral filler: Sewage sludge ash, fly ash, baghouse fines, cement kiln dust, lime waste. Asphalt-rubber binder: Scrap tires.
Asphalt stress-absorbing membranes: Scrap tires.
Asphalt rubberized crack sealant: Scrap tires.
Asphalt aggregate: Mill tailings, phosphogypsum, slag.
Asphalt fine aggregate: Glass and ceramics.
Asphalt cement modifier: Plastic waste.
Asphalt plant fuel: Used motor oil.
Asphalt paving: Bottom ash, boiler slag, blast furnace slag, steelmaking slag, nonferrous slag, reclaimed asphalt pavement, foundry sand, roofing shingle waste, petroleum-contaminated soils (after thermal treatment).
Base course: Glass and ceramic waste, construction and demolition debris, nonferrous slags, reclaimed asphalt pavement, reclaimed concrete pavement, mill tailings.
Pipe bedding: Foundry sand, glass, and ceramic waste.
Borrow material: Quarry waste, construction and demolition material.
Slope stabilization and erosion control: Sawdust and wood waste.
Mulch: Wood waste, paper waste (especially slick, magazine-type paper), compost.
Fertilizer: Animal manure and farm waste.
Embankments: Lumber and wood waste, sawdust and wood chips, recycled sanitary landfill refuse, fly ash, bottom ash, construction and demolition waste, sulfate waste, waste rock, mill tailings, coal refuse.
Cement stabilized base: Incinerator ash, fly ash, bottom ash, advanced SO2 control by-products, cement kiln dust, reclaimed asphalt pavement, petroleum-contaminated waste (after thermal treatment), coal refuse, and rice husk ash may be used as supplementary cementing material. Concrete: Incinerator ash from sewage sludge cake as vitrified aggregate or palletized aggregate. Lightweight fill material: Wood waste, sawdust, chipped wood, scrap tires.
Geotextile: Plastic waste.
Sealant: Scrap tires.
Safety hardware, fencing, signposts: Plastic wastes.
Flowable fill and grout: Quarry waste, fly ash.
Soil stabilization: Fly ash, advanced SO2 control by-product, cement kiln dust, lime waste. Antiskid material: Bottom ash, steelmaking slag.
Blasting grit: Nonferrous slags.
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TABLE 1.20 Specification Levels for Used Oil Fuels
Source: Adapted from Travis Wagner, Complete Handbook of Hazardous Waste Regulation, Perry-Wagner Publishing, Brunswick, Maine, 1988, p. 46. |
not meet one or all of these specifications and are not mixed with hazardous waste may still be burned in industrial boilers, but they must have an EPA identification number for this activity and must meet a higher standard of reporting than used oil meeting the specifications. A burner of either specification or off-specification used oil fuel must notify EPA of its used-oil-fuel activities and state the location and a general description of the used-oil — management activities. Copies of invoices and waste analysis conducted on the used oil must be maintained for at least 3 years.
Reclamation. Reclamation is the recovery of materials with value from a waste material and involves regeneration of waste material from the reclamation activities. Recovering precious metals from a waste stream (such as silver from x-ray film) is an example of reclamation. When the lead plates from lead-acid batteries are recovered, the activity is regulated under RCRA as reclamation. Use of material as feed stocks or ingredients in the production of a new product is not considered reclamation.
Speculative Accumulation. Any hazardous secondary material is considered a solid waste if accumulated before recycling unless 75 percent of the stockpile is recycled during a calendar year.
