Landfill sites

Systematic-judgmental sampling scheme for monitoring the leaching of pollutants from a landfill. Sites where samples are collected are represented by the solid dots. 

Landfilling Methods and Operations To use the available area at a landfill site effectively, a plan of operation for the placement of solid wastes must be prepared. Various operational methods have been developed primarily on the basis of field experience. The principal methods used for landfilling dry areas may be classified as (1) area, and (2) depression. 

TABLE 25-71 Important Factors in Preliminary Selection of Landfill Sites... 

Landfills in wet areas. Because of the problems associated with contamination of local groundwaters, the development of odors, and structural stabihty, landfills must be avoided in wetlands. If wet areas such as ponds, pits, or quarries must be used as landfill sites, special provisions must be made to contain or ehminate the movement of leachate and gases from completed cells. Usually this is accomplished by first draining the site and then lining the bottom with a clay liner or other appropriate sealants. If a clay uner is used, it is important to continue operation of the drainage facility until the site is filled to avoid the creation of uplift pressures that could cause the liner to rupture from heaving. 

Landfill-operation plan. The layout of the site and the development of a workable operating schedule are the main features of a landfill-operation plan. In planning the layout of a landfill site, the location of the following must be determined (1) access roads (2) equipment shelters (3) scales, if used (4) storage sites for special wastes (5) topsoil-stockpile sites (6) landfill areas and (7) plantings. 

Many but not all hazardous wastes can be disposed of on land in properly designed landfills. To minimize potentially adverse environmental effects from wastes deposited at hazardous-waste landfill sites, the U.S. Environmental Protection Agency (EPA) has developed specific regulations regarding the characteristics of wastes suitable for landfilling. These regulations (40 CFR 265) include a prohibition on the placement of ... 

LANDFILL Disposal of wastc in the ground. This method is eommonly used for both domestie waste and more hazardous ehemieal waste. Landfill sites used for diffieult and potentially-dangerous wastes are now engineered, managed and monitored to prevent poisons leaking out. 

Bunding of storage areas, segregation of waste storage areas, security of landfill sites, etc. 

At the Lipari Landfill site in New Jersey, the gas venting system installed in 1983 consisted of two underground 4-inch (10-cm) perforated PVC pipes and five vent risers. Two parallel PVC pipes were installed 200 feet apart prior to cap emplacement during the period of wall construction and were placed about 3 feet beneath the finished grade. The vent risers were connected to the buried manifold pipes and consisted of open pipe installed perpendicular to the underground pipes and the ground surface. Filters were not attached to the riser exit points (U.S. EPA, 1987). 

McAneny, C. and A. Hathaway. Design and Construction of Covers for Uncontrolled Landfill Sites. In Management of Uncontrolled Hazardous Waste Sites Proceedings, Washington, D.C., 1985, p.331. 

Case 2 - The Hyde Park Landfill site, located in an industrial complex in the extreme northwest corner of Niagara, New York, was used from 1953 to 1975 as a disposal site for an estimated 80,000 tons of chemical waste, including chlorinated hydrocarbons. A compacted clay cover was installed in 1978 over the landfill and a tile leachate collection system was installed in 1979. Hazardous compounds such as ortho-, meta- and para-chlorobenzoic acid toluene ortho- and meta-chlorotoluene 3,4-dichlorotoluene and 2,6-dichlorotoluene were detected in the leachate (Irvine et al., 1984). Since 1979, the existing leachate treatment system has used activated carbon as the technology for removing organic carbon. Although... 

It also specifies data requirements, assumptions, limitations, eventual type of critical review, and the report requirements. For example, a study could be done to select between one of two materials when developing a dust transport container for a baghouse filter. The intended audience may be the designers, the results being used to indicate which one of the two materials provides the lowest environmental impact. The system function may be to transport dust from the baghouse filter to a landfill site, and the functional unit may be one metric ton or m of dust. The system boundaries may be described by considering which processes are included and which are outside the system limits. 

Discharge with the EPA and Agreements with the water companies. Discharges to controlled landfill sites are by agreement with the local waste disposal authority. In all cases the Consents and Agreements will impose conditions on the quantity, rate of discharge and chemical composition of the trade effluents acceptable for discharge. 

Disposal of industrial effluents to controlled landfill sites is generally confined to slurries and sludge. The quantity and composition of the wastes acceptable for disposal is controlled by licenses issued by the waste disposal authority. 

The cost of depositing waste on controlled landfill sites is relatively cheap. However, the expense of road transport to suitable sites generally limits this disposal route to relatively low-volume applications. 

HM Mines and Quarries Inspectorate All mines, quarries and landfill sites ... 

Thermal recycling of plastics is becoming a more popular option in Japan, largely because of a lack of landfill sites, and also because of the materials potential as an untapped source of energy. The article supplies brief details of the advantages of thermal recycling. 

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.

According to EPA (1974), pesticides such as endosulfan should be destroyed at high temperature in an approved incinerator with a hydrochloric acid scrubber, if available. Any sludges or solid residues generated from this process are to be disposed of in a manner approved by all applicable federal, state, and local pollution control requirements. EPA strongly recommends that if incineration of excess pesticides is not possible, organic pesticides should be buried in a designated landfill site. 

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. 

PCBs have been implicated in the decline of certain populations of fish-eating birds, for example, in the Great Lakes of North America. Although their use is now banned in most countries and very little is released into the environment as a consequence of human activity, considerable quantities remain in sinks (e.g., contaminated sediments and landfill sites), from which they are slowly redistributed to other compartments of the environment. There continues to be evidence that PCB residues are still having environmental effects, for example, on birds and fish. 

This process is an extension of the anaerobic treatment of waste diseussed in Chapter 2, and is also similar to the natural process operating in landfill sites, which evolves methane. By treatment of biomass with bacteria in the absence of air a gas rich in methane can be produced a typical digester may produce over 300 m of gas containing over 50% methane per tonne of dry biomass. The economics of biogas generation for use as a fuel are currently unfavourable. The plants that do exist have been built because of the need to treat waste such as sewage sludge. 

In Japan the amount of waste poly(vinyl chloride) (PVC) has been sharply increasing since disposal of building materials such as pipe and roof liners with long service life has been started recently. It was estimated to be approximately one million tons in FY 2000, and it is predicted to increase further to approximately 1.8 million tons in FY 2020. Since the landfill sites run short and the incineration to reduce its volume produces dioxins and corrodes boiler tube by hydrogen chloride, development of a safe and inexpensive technology for the recycling of waste PVC is one of the most urgent issues. 

Authors have proposed a novel process not to dispose to landfill sites both waste PVC and waste glass but to utilize them to produce fuel and neutralize each other at the same moment. It has been successfully demonstrated that hydrogen chloride produced during flash pyrolysis of PVC was completely neutralized by the fixed glass bed and thus chlorine-lree fuel was produced [1-2]. To carry forward our proposed process we need to know the kinetics of the neutralization process. Also we have to solve the problem of formation of metal chlorides in the product char during pyrolysis of PVC, which is a critical issue for its thermal utilization. Consequently, in the present study the evaluations of neutralization kinetics of glass cullets and the decomposition of CaCl2 in char by steam were conducted. 

Some elevated outdoor air levels of triehloroethylene reported are associated with waste disposal sites. Average trichloroethylene levels of 0.08-2.43 ppb were detected in ambient air at six landfill sites in New Jersey the maximum concentration was 12.3 ppb (Harkov et al. 1985). Levels between 3.0 and 3.2 pg/m (0.56 ppb and 0.60 ppb) were found at a distance of 0.5-1.5 meters above the surface of a landfill known to contain halogenated volatile organic compounds in Germany (Koenig et al. 1987). 

Landfill gas is produced as a result of organic wastes decomposing in landfill sites. It can be recovered at an inexpensive cost of for direct use as a boiler fuel, converted into electricity with a microturbine or upgraded to a higher value fuel gas. This is a very effective mitigation technology since methane is 21 times as powerful as carbon dioxide as a greenhouse gas. 

In some case, experts may debate the reuse of nonhazardous materials, which, they insist, should still be dumped to general landfill sites where nonhazardous materials belong, like municipal solid waste. It is also insisted that there is no documented regulation requiring the reuse of nonhazardous materials. Therefore, to defend the beneficial reuse program of foundry solid waste, regulations should specifically permit their marketing. 

In engineering terms, a sanitary landfill is also sometimes identified as a bioreactor due to the presence of anaerobic activities in the wastes. As such, landfilling sites need the incoming waste stream top be monitored, as well as placement and compaction of the waste, and installation of landfill environmental monitoring and control facilities. Gas vent and leachate collection pipes are important features of a modem landfill. 

It is expected that leachate characteristics will vary by country. This is because the soil under a landfill site, the composition of disposed waste, the climate, sampling and landfill management vary among countries.7-8... 

Leachate can also be degraded biologically in situ at the landfill site. Conditions within the landfill are controlled to encourage microbial activity, and leachate is recirculated through the... 

Robinson, H.D. and Luo, M.M.H., Characterization and treatment of leachates from Hong Kong landfill sites, J. Inst. Water Environ. Manage., 5, 326-334, 1991. 

Idris, A., Hassan, M.N., and Chong, T.L., Overview of Municipal Solid Wastes Landfill Sites in Malaysia, Proceeding of 2nd Workshop on Material Cycles and Waste Management in Asia, NIES Tsukuba, Japan, December 2-3, 2003. 

The ET cover cannot be tested at every landfill site so it is necessary to extrapolate the results from sites of known performance to specific landfill sites. The factors that affect the hydrologic design of ET covers encompass several scientific disciplines and there are numerous interactions between factors. As a consequence, a comprehensive computer model is needed to evaluate the ET cover for a site.48 The model should effectively incorporate soil, plant, and climate variables, and include their interactions and the resultant effect on hydrology and water balance. An important function of the model is to simulate the variability of performance in response to climate variability and to evaluate cover response to extreme events. Because the expected life of the cover is decades, possibly centuries, the model should be capable of estimating long-term performance. In addition to a complete water balance, the model should be capable of estimating long-term plant biomass production, need for fertilizer, wind and water erosion, and possible loss of primary plant nutrients from the ecosystem. 

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