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Temporal and spatial pore water pressure distribution surrounding a vertical landfill leachate recirculation well.

Kadambala R, Townsend TG, Jain P, Singh K - Int J Environ Res Public Health (2011)

Bottom Line: While the impact of vertical well leachate recirculation on landfill pore water pressures has been mathematically modeled, measurements of these systems in operating landfills have not been reported.After liquid addition stopped, measured pore pressures did not immediately drop, but slowly decreased with time.The spatial variation of the pressures recorded in this study suggests that waste permeability is anisotropic and decreases with depth.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Engineering Sciences, University of Florida, PO BOX 116450, Gainesville, FL 32611, USA. kadambalar@cdm.com

ABSTRACT
Addition of liquids into landfilled waste can result in an increase in pore water pressure, and this in turn may increase concerns with respect to geotechnical stability of the landfilled waste mass. While the impact of vertical well leachate recirculation on landfill pore water pressures has been mathematically modeled, measurements of these systems in operating landfills have not been reported. Pressure readings from vibrating wire piezometers placed in the waste surrounding a liquids addition well at a full-scale operating landfill in Florida were recorded over a 2-year period. Prior to the addition of liquids, measured pore pressures were found to increase with landfill depth, an indication of gas pressure increase and decreasing waste permeability with depth. When liquid addition commenced, piezometers located closer to either the leachate injection well or the landfill surface responded more rapidly to leachate addition relative to those far from the well and those at deeper locations. After liquid addition stopped, measured pore pressures did not immediately drop, but slowly decreased with time. Despite the large pressures present at the bottom of the liquid addition well, much smaller pressures were measured in the surrounding waste. The spatial variation of the pressures recorded in this study suggests that waste permeability is anisotropic and decreases with depth.

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The temporal impact of leachate injection on the pore pressures of surrounding waste in the radial direction and at various depths. (a) Piezometers at a depth of 5.8 m from the surface of the landfill; (b) Piezometers at a depth of 8.8 m from the surface of the landfill; (c) Piezometers at a depth of 11.9 m from the surface of the landfill; (d) Piezometers at a depth of 14.9 m from the surface of the landfill; (e) Piezometers at a depth of 18 m from the surface of the landfill.
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f6-ijerph-08-01692: The temporal impact of leachate injection on the pore pressures of surrounding waste in the radial direction and at various depths. (a) Piezometers at a depth of 5.8 m from the surface of the landfill; (b) Piezometers at a depth of 8.8 m from the surface of the landfill; (c) Piezometers at a depth of 11.9 m from the surface of the landfill; (d) Piezometers at a depth of 14.9 m from the surface of the landfill; (e) Piezometers at a depth of 18 m from the surface of the landfill.

Mentions: Ten piezometers were chosen to illustrate the temporal impact of liquid recirculation into the buried vertical well on the pore water pressure in the surrounding waste. Five piezometers were located at a radial distance of 2.2 m from the buried vertical well and at a depth of 5.8, 8.8, 11.9, 14.9 and 18 m from the surface of the landfill. The remaining five piezometers were located at a radial distance of 6.3 m from the buried vertical well and at a depth of 5.8, 8.8, 11.9, 14.9 and 18 m from the surface of the landfill. Figure 6 shows the change in pore pressure of the piezometers and the leachate injection pressure over time.


Temporal and spatial pore water pressure distribution surrounding a vertical landfill leachate recirculation well.

Kadambala R, Townsend TG, Jain P, Singh K - Int J Environ Res Public Health (2011)

The temporal impact of leachate injection on the pore pressures of surrounding waste in the radial direction and at various depths. (a) Piezometers at a depth of 5.8 m from the surface of the landfill; (b) Piezometers at a depth of 8.8 m from the surface of the landfill; (c) Piezometers at a depth of 11.9 m from the surface of the landfill; (d) Piezometers at a depth of 14.9 m from the surface of the landfill; (e) Piezometers at a depth of 18 m from the surface of the landfill.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3108135&req=5

f6-ijerph-08-01692: The temporal impact of leachate injection on the pore pressures of surrounding waste in the radial direction and at various depths. (a) Piezometers at a depth of 5.8 m from the surface of the landfill; (b) Piezometers at a depth of 8.8 m from the surface of the landfill; (c) Piezometers at a depth of 11.9 m from the surface of the landfill; (d) Piezometers at a depth of 14.9 m from the surface of the landfill; (e) Piezometers at a depth of 18 m from the surface of the landfill.
Mentions: Ten piezometers were chosen to illustrate the temporal impact of liquid recirculation into the buried vertical well on the pore water pressure in the surrounding waste. Five piezometers were located at a radial distance of 2.2 m from the buried vertical well and at a depth of 5.8, 8.8, 11.9, 14.9 and 18 m from the surface of the landfill. The remaining five piezometers were located at a radial distance of 6.3 m from the buried vertical well and at a depth of 5.8, 8.8, 11.9, 14.9 and 18 m from the surface of the landfill. Figure 6 shows the change in pore pressure of the piezometers and the leachate injection pressure over time.

Bottom Line: While the impact of vertical well leachate recirculation on landfill pore water pressures has been mathematically modeled, measurements of these systems in operating landfills have not been reported.After liquid addition stopped, measured pore pressures did not immediately drop, but slowly decreased with time.The spatial variation of the pressures recorded in this study suggests that waste permeability is anisotropic and decreases with depth.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Engineering Sciences, University of Florida, PO BOX 116450, Gainesville, FL 32611, USA. kadambalar@cdm.com

ABSTRACT
Addition of liquids into landfilled waste can result in an increase in pore water pressure, and this in turn may increase concerns with respect to geotechnical stability of the landfilled waste mass. While the impact of vertical well leachate recirculation on landfill pore water pressures has been mathematically modeled, measurements of these systems in operating landfills have not been reported. Pressure readings from vibrating wire piezometers placed in the waste surrounding a liquids addition well at a full-scale operating landfill in Florida were recorded over a 2-year period. Prior to the addition of liquids, measured pore pressures were found to increase with landfill depth, an indication of gas pressure increase and decreasing waste permeability with depth. When liquid addition commenced, piezometers located closer to either the leachate injection well or the landfill surface responded more rapidly to leachate addition relative to those far from the well and those at deeper locations. After liquid addition stopped, measured pore pressures did not immediately drop, but slowly decreased with time. Despite the large pressures present at the bottom of the liquid addition well, much smaller pressures were measured in the surrounding waste. The spatial variation of the pressures recorded in this study suggests that waste permeability is anisotropic and decreases with depth.

Show MeSH