EXAMINATION OF MODERN SANITARY LANDFILLS
W. Gregory VogtChair, Sanitary Landfill Working Group, ISWA
Vice President, SCS Engineers
Major Challenges
Acceptance and Approvals for:
– Facility Expansions
– Siting New Facilities
Operational Practices
Regulatory Enforcement
Expansions and New Facilities
Few New Sites Receive Approvals
Public is More Organized Against But Understands the Need
Large Expansions and Quarry Fills
Stabilization Concerns
Expansions and New FacilitiesClosure of Poorly Located Sites Large, New Regional Facilities,
Larger Equipment, Rail AccessLeachate Recirculation Combined
with Better CompactionNew Landfills Atop Old LandfillsNew Structures Atop Old Landfills
Biogas Migration Protection
Robust Foundation Designs
California Office Park
Operating Practices
Control of Moisture (Liquids)Promoting Run-offWork AreasCover ApplicationWeather IssuesProblem WastesEnvironmental Controls (Birds, Dust,
Litter, Vectors, Odor)Landfill Biogas
Moisture Control
Keep Liquid Wastes OutGood CompactionReach Final Elevation QuicklyApply Effective Intermediate and
Final Cover
Waste In Trench Landfill
Trench landfills not approved in most countries
Ponding
. . . Infiltrates the waste mass
Ponding Causes Leachate
Promote Run-Off
Eliminate Ponding (Depressions)
Divert Water From Wastes
Control Run-On
Run-on/Run-off Controls
Run-on/Run-off Controls
Run-off Control
. . . By Grade Breaks
Stormwater Interception
. . . Direct Run-off
Flooded Cell
. . . Requires Pumping
Don’t Forget Road Drainage
Run-Off to Sediment Basin
Basin With Run-off
Slope Erosion
. . . Collected
Basin Collects Sediment
Erosion Control — Silt Fence
. . . Impacting Working Face and Compaction
Erosion Control — Rip-rap Ditch
Erosion Control — Jute Matting
Management of Work Areas
Controlled Working Face
Compaction
Cell Construction
Uncontrolled Working Face
Poor Compactor Practice
Small Working Face
Compaction
Generally Work Up The Slope
Keep Layers To 1 Meter - Loose
Maintain Proper Slope
– 3:1 (Horiz: Vert) Maximum
Efficiency: 3 - 5 Passes
Compaction Efficiency - Depth
Thickness of Layer
Compaction Efficiency With Number Of Passes
Number of Passes
Cell Construction
Layer Thickness
Cell Construction
Working Face Cover
Cell Construction
Layer Thickness
Landfill Cover
Daily
Alternative Daily Covers
Intermediate
Final
Daily Cover
Sanitary Landfill Requires
– Control Litter, Odors and Vermin
– Fire Protection
Generally 15 cm Compacted Soil
Forget the Daily Cover?
Daily Soil Cover
Stockpile . . . Even in the Winter
Alternate Daily Cover (ADC)
FoamsSlurriesBlankets/TarpsShredded Waste (e.g., Tires)Ash and ResiduesContaminated Soils Compost
ADC — Foam Daily Cover
Tarp — On Roller
. . . Note Assistant
Tarp Roller
Attachment to Compactor
Intermediate Cover
The Same As Daily Cover Plus:
– At Least 0.3 meters (Soil)
– Reduce Infiltration
– Control Gas Migration
– Provide “Operating” Surface
Final Cover
As Specified In Permit
Final Control of Infiltration and Gas
Support Vegetative Growth
Biogas Sampling Well
Gas Monitoring Well
Methane and Biogas Meter
Methane Sample Instrument
Biogas Management Options
Venting to Atmosphere
Flare Burning
Incineration (Controlled Process)
Recovery as an Energy Source
Active Biogas Control
Gas Well Connected to Collection Pipe
Active Collection System
Biogas Extraction Well
Active Biogas Systems
Collection Pipe With Supports
. . . Water is Maintenance Item
Active Biogas Systems
Blower for Vacuum
Active Biogas Extraction
Blowers and Controls
Passive Biogas Systems
Passive Biogas Systems
Open Pipe Vented to Atmosphere
Potential for Biogas Recovery
1,000,000 Tons of Waste Minimum
Site Closed Less Than 5 Years
12 meters Minimum Average Depth
Impermeable Cover
LFG Use Options
Sale of Generated Electricity
Sale as Natural Gas Alternative
Burn in Flare
Value of Carbon Credits
Electricity From Biogas
Large Equipment
Electric Power Units
. . . Or Portable Units
Burn in Flare
No Treatment
No Energy Recovery
Still Requires Water Removal
Enclosed Flare & Candle Flare
Regulatory Enforcement Documents
Permits
Approved Plans and Specifications
Variances
Compliance Agreements
Types of Plans
Design Plans - Design Engineer
Operating Plans - Landfill Manager
Summary
Gain Acceptance from the Public Through Use of Good Engineering Design and Regulatory Compliance
Design and Operations Must Address Control of All Landfill Issues (odors, contamination)
Regulators, Inspectors, and Landfill Operators Should Receive Training