Hydraulic and earth engineering – Subterranean waste disposal – containment – or treatment – Waste barrier – containment – or monitoring
Reexamination Certificate
2000-05-12
2003-07-29
Will, Thomas B. (Department: 3671)
Hydraulic and earth engineering
Subterranean waste disposal, containment, or treatment
Waste barrier, containment, or monitoring
C405S129570, C210S170050
Reexamination Certificate
active
06599058
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to a landfill, and more specifically to an apparatus for the collection of leachate from a landfill site, and specifically to a bottom liner and collection well apparatus for the containment and collection of leachate flowing from a landfill.
The protection of ground water is a primary concern in the design of a landfill. Many designs of containment and collection systems are known for preventing the leachate flowing from a landfill from contaminating the underlying substrate and underlying ground water sources. Such systems generally involve a liner or barrier layer of waterproof or low permeability material separating the landfill from the subjacent strata. The leachate is collected above the liner and directed to a series of conduits for drainage to a storage or treatment facility. It is known to provide a layer of granular material, such as sand or gravel, above the liner to function as a collection and drainage layer for the leachate. Because the hydraulic permeability of granular material is somewhat limited, typically between 0.01 and 0.00001 cm/sec, a series of lateral collection pipes are provided to collect the leachate from the granular layer and to direct it to a common collection header directed toward a storage or transport facility. The underlying strata and liner are typically sloped to allow the leachate to flow through the granular material to the lateral collection and header pipes. The lateral collection pipes and headers are perforated along their lengths to allow the leachate to flow out of the granular material and into the pipes. The lateral collection pipes are sloped toward the collection header, which is in turn sloped toward a collection sump. The collection pipe functions to direct the leachate flow from the plurality of lateral collection pipes to a common collection and discharge point.
It is also known to provide a second leakage collection and containment system operable to intercept any leachate escaping from a primary leachate collection apparatus. Such a secondary system may have lateral collection and header pipes similar to the leachate collection system. In a properly functioning leachate collection system, there would be very little flow in the secondary leakage collection apparatus. However, in the event of a failure of the primary leachate collection apparatus, the leakage collection apparatus will function to further protect the underlying strata by directing the leachate leakage to a proper disposal location. Monitoring for flow through the secondary leakage collection system provides an indication of the proper functioning or malfunctioning of the primary leachate collection system.
U.S. Pat. No. 5,092,709 issued on Mar. 3, 1992, to Davis, incorporated by reference herein, describes a typical prior art landfill leachate collection system. A liner impedes the passage of liquids between the landfill and a subjacent stratum. Appertured conduits embedded within a drainage material disposed above the liner convey the leachate to a gallery extending along the side of the landfill site. A secondary collection system is constructed below the primary liner. To support the functioning of the lateral conduits and the gallery, the floor of the site is graded to be saddle-shaped to encourage the leachate flow into the conduits, toward the galleries within the conduits, and within the galleries to low points where sumps are located. The cost of construction of such a landfill leachate collection apparatus is increased by the need for a complicated grading pattern and construction methods, and the need for a plurality of lateral collection conduits disposed across the width of the landfill.
BRIEF SUMMARY OF THE INVENTION
Thus, there is a particular need for a landfill leachate collection apparatus that is less expensive to construct than prior art systems. There is also a need for a leachate collection system that is easy to install and that has a minimum number of potential leak locations.
Accordingly, a leachate collection apparatus for a landfill disposed over a subjacent stratumis described herein as having: a lower liner disposed over the subjacent stratum; a leakage collection layer of geonet disposed over the lower liner; an upper liner disposed over the leakage collection layer of geonet; a leachate collection layer of geonet disposed over the upper liner; a layer of geotextile filter fabric disposed over the leachate collection layer of geonet; a leachate collection compartment having an upwardly facing inlet opening defined by a leachate collection compartment upper surface; a leakage collection compartment having an upwardly facing inlet opening defined by a leakage collection compartment upper surface; wherein the leachate collection compartment inlet opening is disposed below an opening formed in the upper liner and is in fluid communication with the leachate collection layer of geonet; and wherein the leakage collection compartment inlet opening is disposed below an opening formed in the lower liner and is in fluid communication with the leakage collection layer of geonet.
REFERENCES:
patent: 4350461 (1982-09-01), Valiga et al.
patent: 4388357 (1983-06-01), Luebke
patent: 4451173 (1984-05-01), Watson et al.
patent: 4543013 (1984-06-01), Wagner et al.
patent: 4697954 (1987-10-01), Grund
patent: 4810131 (1989-03-01), Turner
patent: 4846604 (1989-07-01), Holtmann
patent: 5000618 (1991-03-01), Greenley
patent: 5056960 (1991-10-01), Marienfeld
patent: 5092709 (1992-03-01), Davis
patent: 5137393 (1992-08-01), Fuhr et al.
patent: 5320454 (1994-06-01), Walling
patent: 5401552 (1995-03-01), Bohrer et al.
patent: RE35272 (1996-06-01), Mathieson et al.
patent: 5544976 (1996-08-01), Marchbanks
patent: 5582310 (1996-12-01), Del Zotto
patent: 5667869 (1997-09-01), Beretta
patent: 5728424 (1998-03-01), Walling
patent: 5846024 (1998-12-01), Mao et al.
patent: 5851089 (1998-12-01), Beretta
Das, Braja M. Principles of Geotechnical Engineering, 1994, PWS Publishing Company, Third Edition, pp. 587, 592, 595-599.
Beusse Brownlee Bowdoin & Wolter, P.
Mayo Tara L.
Wolter, Es Robert L.
LandOfFree
Landfill leachate collection apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Landfill leachate collection apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Landfill leachate collection apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3039764