Hazardous Pollutants in Class II Landfills

Wood, John A.; Porter, M. L.

doi:10.1080/08940630.1987.10466250

Cited by 25 publications

(25 citation statements)

References 2 publications

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“…Even municipal landfills accepting only nonhazardous material have been found to contain toxic VOC at concentrations high enough to cause concern. In a study by Wood and Porter (1987), vinyl chloride and benzene were detected in gas drawn from the refuse zone in 85 percent' of 20 municipal landfills investigated, often at concentrations exceeding 1 ppm. Several landfills closed for many years were among those with relatively high concentrations of these compounds.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of soil-gas transport of organic chemicals into residential buildings: Final report

Hodgson¹,

Garbesi²,

Sextro³

et al. 1988

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Section: Introductionmentioning

confidence: 99%

Evaluation of soil-gas transport of organic chemicals into residential buildings: Final report

Hodgson¹,

Garbesi²,

Sextro³

et al. 1988

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“…Besides contamination issues associated with volatile liquid contaminants, there has been a long-term concern over the subsurface migration of methane gas from municipal landfills. Subsurface methane transport through unsaturated soils can cause explosive hazards in buildings and can carry with it volatile hazardous compounds such as vinyl chloride (Wood and Porter 1987).…”

Section: Introductionmentioning

confidence: 99%

Buoyant Advection of Gases in Unsaturated Soil

Seely

Falta²

1994

J. Environ. Eng.

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In unsaturated soil, methane and volatile organic compounds can significantly alter the density of soil gas and induce buoyant gas flow. A series of laboratory experiments was conducted in a twodimensional, homogeneous sand pack with gas permeabilities ranging from 110 to 3,000 darcy. Pure methane gas was injected horizontally into the sand and steady-state methane profiles were measured. Experimental results are in close agreement with a numerical model that represents the advective and diffusive components of methane transport. Comparison of simulations with and without gravitational acceleration permits identification of conditions where buoyancy dominates methane transport. Significant buoyant flow requires a Rayleigh number greater than 10 and an injected gas velocity sufficient to overcome dilution by molecular diffusion near the source. These criteria allow the extension of laboratory results to idealized field conditions for methane as well as denser-than-air vapors produced by volatilizing nonaqueous phase liquids trapped in unsaturated soil.

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“…First, the results of this dissertation are directly applicable to the transport of other gas-phase soil contaminants into houses. Recent theoretical and experimental (Wood and Porter, 1987;Fischer et al, 1995) studies suggest that contaminated soil can be an important source of indoor volatile contaminants. Although little research has been done to determine the magnitude of this source, the understanding of the processes affecting radon entry into houses can be used as a basis for understanding the transport of volatile contaminants into houses and for estimating the associated health risk.…”

Section: Directions For Future Researchmentioning

confidence: 99%

“…. Advective soil-gas flow may also transport VOCs (volatile organic chemicals) from contaminated soils into buildings thereby contributing to indoor exposures to these contaminants (Wood and Porter, 1987;. Soil-gas entry into houses is commonly associated with small but sustained indoor-outdoor pressure differences of the order of several Pa created by temperature effects, wind interaction with the building shell, and the operation of heating, ventilation and air-conditioning (HVAC) systems ).…”

Section: Introductionmentioning

confidence: 99%

Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

Robinson

1996

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An improved understanding of the factors that control radon entry into buildings is needed in order to reduce the public health risks caused by exposure to indoor radon. This dissertation examines three issues associated with radon entry into buildings: 1) the influence of a subslab gravel layer and the size of the openings between the soil and the building interior on radon entry; 2) the effect of atmospheric pressure fluctuations on radon entry; and 3) the development and validation of mathematical models which simulate radon and soil-gas entry into houses.Experiments were conducted using two experimental basements to examine the influence of a subslab gravel layer on advective radon entry driven by steady indoor-outdoor pressure differences. These basement structures are identical except that in one the floor slab lies directly on native soil whereas in the other the slab lies on a high-permeability gravel layer. Our measurements indicate that a high permeability subslab gravel layer increases the advective radon entry rate into the structure by as much as a factor of 30. The magnitude of the enhancement caused by the subslab gravel layer depends on the area of the openings in the structure floor; the smaller the area of these openings the larger the enhancement in the radon entry rate caused by the subslab gravel layer. A three-dimensional, finite-difference model correctly predicts the effect of a .. 11 DISCLAIMERPortions of this document may be illegible in electronic image products. Images are produced from the best available original document.subslab gravel layer and open area configuration on advective radon entry driven by steady indoor-outdoor pressure differences; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5.Experiments were conducted in the structure with the subslab gravel layer to examine the importance of radon entry driven by atmospheric pressure fluctuations. Continuous measurements of soil-gas and radon entry driven by atmospheric pressure fluctuations were made for a range of steady indoor-outdoor pressure differences. In the absence of a steady indoor-outdoor pressure difference, atmospheric pressure fluctuations drive 1.5 times more radon entry into the experimental structure than diffusion. Pressurizing or depressurizing the interior of the structure diminishes the contribution of atmospheric pressure fluctuations to the long-term radon entry rate into the experimental structure.To explain the effect of atmospheric pressure fluctuations on radon entry into houses, we present a detailed analysis of soil-gas flow driven by these fluctuations. A theoretical framework is developed to predict transient soil-gas entry into houses. Utilizing this framework, we examine and compare the measurements of soil-gas flow and the predictions of an analytical and a numerical model in both the time and frequency domains. Two scaling parameters are identified from a dimensional analysis of the analytical model to characterize how changes in water tab...

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Hazardous Pollutants in Class II Landfills

Cited by 25 publications

References 2 publications

Evaluation of soil-gas transport of organic chemicals into residential buildings: Final report

Evaluation of soil-gas transport of organic chemicals into residential buildings: Final report

Buoyant Advection of Gases in Unsaturated Soil

Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

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