Managing Leachate Seeps Below Final Cover Managing... · Below Final Cover Ali Khatami, Ph.D., P.E....
Transcript of Managing Leachate Seeps Below Final Cover Managing... · Below Final Cover Ali Khatami, Ph.D., P.E....
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S C S E N G I N E E R S
Managing Leachate SeepsBelow Final Cover
Ali Khatami, Ph.D., P.E.SCS Engineers
S C S E N G I N E E R S
Leachate Seeps
• Many reasons for leachate seeps
• Operator manages leachate seeps while slope unclosed
• Various means and methods for management of leachate seeps
• Full closure and leachate seeps
• Partial closure and leachate seep
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S C S E N G I N E E R S
Leachate Seeps Below Geomembrane
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Leachate Toe Drain System
(LTDS)
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Location of LTDS
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Leachate at Toe of Slope
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Leachate Pool at Perimeter Berm
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Removing Leachate by Vac Truck
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Vac Truck
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Exposing Anchor Trench
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Excavating Overfill
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Excavating Overfill
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Grading Slope
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Graded Slope
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Graded Slope
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Graded Slope
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LTDS Geocomposite Deployment
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LTDS Geocomposite
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LTDS Geocomposite
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Anchor Trench Excavation
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Anchor Trench for LTDS Geocomposite
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Bottom of LTDS Geocomposite
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Extension of LTDS Geocomposite
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Extended LTDS Geocomposite on Slope
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Anchor at High End of Seep
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Connection Points to Cleanouts
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Connection Point to Sump Riser
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Connection Point to Sump Riser
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Deployment of LTDS Geotextile
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LTDS Pipe Placement
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Vertical Pipe
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LTDS Pipe Placement
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Vertical Pipe
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LTDS Pipe Connection to Cleanout Pipe
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Connection of LTDS Pipe to Sump Riser
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Connection of LTDS Pipe to Sump Riser
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Connection of LTDS Pipe to Sump Riser
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LTDS Gravel Placement
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Forming Gravel around LTDS Pipe
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LTDS Gravel Placement
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LTDS Gravel Placement
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Gravel at End of LTDS Pipe
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Closing LTDS Burrito
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Placement of Soil Above LTDS Burrito
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Soil Above LTDS Burrito
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LTDS at Completion
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LTDS Pipe at Cell Construction Time
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LTDS Drain Pipes
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LTDS Drain Pipe into Leachate Sump
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LTDS Drain Pipe into Leachate Sump
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LTDS Drain Pipe into Leachate Sump
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Sump and LTDS Drain Pipe
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LTDS Drain Pipe at Leachate Sump
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LTDS Drain Pipe into Leachate Corridor
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Closed Burrito
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Cover Geomembrane Welded toBottom Geomembrane
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Cover Geomembrane Welded toBottom Geomembrane
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Granular Bentonite Over Extrusion Weld
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Granular Bentonite Over Extrusion Weld
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GCL Strip Over Granular Bentonite
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GCL Strip Over Granular Bentonite
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GCL Strip Over Granular Bentonite
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GCL Strip Over Granular Bentonite
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Cover Soil Placement
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Slope Final Condition
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Slope Final Condition
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Benefits of LTDS
• Collects and removes leachate below final cover geomembrane
• Eliminates ponding of leachate below final cover geomembrane at toe of slope
• Provides gas collection at toe of slope
• Connects to leachate collection sump, sump riser, or cleanouts
• Addresses aggressive leachate seeps on slope
S C S E N G I N E E R S
Construction Recommendations
• Construct LTDS and drain pipes at time of cell development
• Set LTDS pipe invert below top of berm
• Leave no sand between LTDS geocomposite and LTDS geotextile
• Construct vertical pipes for future connection to gas system
• Do not use sacrificial geomembrane over LTDS, use geotextile to allow infiltration