Landfill disposal of waste

LANDFILL Disposal of waste in the ground. This method is commonly used for both domestic waste and more hazardous chemical waste. Landfill sites used for difficult and potentially-dangerous wastes are now engineered, managed and monitored to prevent poisons leaking out. 

A major attraction of landfill disposal of wastes has been its low cost. However, the increasingly stringent regulatory requirements have... 

Exposure at waste sites is most likely to occur from the landfill disposal of waste by-products originating from chlorinated hydrocarbon manufacture. 

Landfill disposal of certain categories of solid waste may result in gas generation, mainly methane, and a highly polluted leachate. The methane may be drawn off, to avoid a flammable hazard on- or off-site. The leachate is pumped off for treatment. 

Figures are given for annual waste production in the Paris area and its composition is outlined. Many of the Paris area cities joined with Paris to create a solid wastes metropolitan authority for domestic waste treatment (SYCTOM). Three incineration plants bum 75% of the SYCTOM area solid wastes and the energy produced provides 43% of the energy consumed by the Paris urban heating network. Landfill is now expensive. There has been a reduction in the number of sites and French legislation prohibits landfill disposal of untreated solid wastes after 2002. A sorting unit at the landfill site was due to open in 1993 and another unit was planned for one of the incineration plants.

Although the major concern about the fate of organic pollntants in soil has been about pesticides in agricultural soils, other scenarios are also important. The disposal of wastes on land (e.g., at landfill sites) has raised questions about movement of pollutants contained in them into the air or neighboring rivers or water conrses. The presence of polychlorinated biphenyls (PCBs) or PAHs in snch wastes can be a significant source of pollution. Likewise, the disposal of some industrial wastes in landfill sites (e.g., by the chemical industry) raises questions about movement into air or water and needs to be carefully controlled and monitored. 

When viewing effluent treatment methods, it is clear that the basic problem of disposing safely of waste material is, in many cases, not so much solved but moved from one place to another. If a method of treatment can be used that allows material to be recycled, then the waste problem is truly solved. However, if the treatment simply concentrates the waste as concentrated liquid, slurry or solid in a form, which cannot be recycled, then it will still need to be disposed of. Landfill disposal of such waste is increasingly unacceptable and thermal oxidation causes pollution through products of combustion and liquors from scrubbing systems. The best method for dealing with effluent problems is to solve the problem at source by waste minimization, as will be discussed in Chapter 28. 

Endrin and endrin aldehyde are listed as hazardous wastes and disposal of wastes is controlled by a number of federal regulations. Past disposal methods have included landfills (EPA 1987c). Chemical treatment (reductive dechlorination) and incineration are possible disposal methods (HSDB 1995 IRPTC 1985). Existing information on disposal appears adequate. No information was found on disposal of endrin ketone however, because endrin is no longer used in the United States, current levels of endrin ketone in wastes should be minimal and additional information on disposal is not needed. 

Hexachlorobutadiene may be released to soil by disposal of wastes in landfill operations. In 1982, only 0.2% of the 27 million pounds of hexachlorobutadiene waste produced as a by-product of chlorinated hydrocarbon-synthesis was disposed of in landfill operations (EPA 1982b). These data indicate that the release to soil was approximately 54,000 pounds. According to TRI90 (1992), no hexachlorobutadiene was discharged to the soil from manufacturing and processing facilities in the United States in 1990 (see Table 5-1). The TRI data should be used with caution since only certain types of facilities are required to report. This is not an exhaustive list. 

Use of the risk index in classifying waste is illustrated in Figure 6.2. Classification of waste essentially is a two-step process. The first step involves a determination of whether a waste can be classified as exempt, based on an assumed negligible risk and an exposure scenario for inadvertent intruders appropriate to disposal of waste in a municipal/industrial landfill for nonhazardous waste. If the waste is not exempt, the second step involves a determination of whether a waste can be classified as low-hazard, based on an assumed acceptable (barely tolerable) risk and an exposure scenario for inadvertent intruders appropriate to disposal in a dedicated nearsurface facility for hazardous wastes. 

Disposing of waste tires is becoming more expensive. Over the past 20 years the average tipping fees for disposing of tires have continually increased. This trend is likely to continue as landfill space becomes more scarce. 

The availability of the analytes for uptake by plants, for transport through the soil, and for dissolution into water can be estimated from a well-studied speciation scheme. Risk assessment for disposal of wastes in landfills or for land disposal of dredge spoils or sewage sludges requires knowledge not only of the total metal content but also of the content in each separate fraction to begin to understand how the metals will act in the environment. Table 5.7 summarizes the methods available for speciation of metals in samples. 

The costs of cleaning up hazardous waste, petroleum, and other contamination can be significant. Superfund sites commonly cost more than 30 million to remediate. The State of New York estimates that it would cost approximately 15— 20 million to excavate and dispose of wastes at a small industrial landfill, or approximately 3 million for the lower-cost alternative of capping [New York Department of Environmental Conservation (NYDEC) 2007]. Although costs are highly variable, it is clear that environmental cleanup is very expensive, and that like site assessments, cleanup will not happen without significant financial support. 

No information was found on the ambient concentrations of 1,1-dichloroethane in soil, or on the current disposal of waste products containing the compound in landfills. The compound has more commonly been detected in ambient air and groundwater samples taken at hazardous waste sites, and it is expected that the lack of available soil monitoring data is at least in part due to rapid partitioning of 1,1-dichloroethane released to soils to these other media. 

Unauthorized landfill disposal of uranium processing wastes (e.g., Shpack Landfill in Norton, Massachusetts, and the Middlesex Municipal Landfill in Middlesex, New Jersey) has resulted in soil contamination (Bechtel National 1984 Cottrell et al. 1981). Also, elevated uranium concentrations have been measured in soil samples collected at 30 of 51 hazardous waste sites and in sediment samples at 16 of 51 hazardous waste sites (HazDat 1998). The HazDat data includes both Superfund and NPL sites. Elevated concentrations of uranium have been detected in soil, in surface water, in groundwater, or in all three of these environmental media from these sites. In several cases, the uranium concentrations in soils were significantly elevated. For example, uranium concentrations from the Shpack/ALI site were found to be 16,460 pCi/g (24,000 pg/g). At the United States Radium Corporation site (New Jersey), uranium concentrahons ranged from 90 to 12,000 pCi/g (130-18,000 pg/g) for the Monticello site (Utah), uranium levels were reported to range from 1 to 24,000 pCi/g (1.5-36,000 pg/g) (HazDat 1998). 

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