Passive Gas System Design PRESENTED BY BRYAN WELDON P.E. Passive - - PowerPoint PPT Presentation

Passive Gas System Design

PRESENTED BY BRYAN WELDON P.E.

Passive System Overview 01 Passive Components 02 Integrating and Upgrading 03 Questions 04

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Passive System Overview

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Passive Gas System

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Passive Gas System

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• Usually not Installed until

Final Cap Construction

• Should be Designed with

New Cell Construction

• If Landfill Expands in Future,

May Require Active System

Vent GAS COLLECTION LAYER WASTE

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Passive Components

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Passive Components

G A S C O N V E YA N C E P I P E W O R K

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• Installed Under the Cap
• Almost Entirely Perforated/Slotted

Pipework

• Pipework Buries in Drainage

Aggregate Pipework

• Similar to Active System, Best

Practice to Maintain Grade

• Pipe Sizes and Vents Designed

to Handle Gas Generation Rates

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Passive Components

S O L A R F L A R E S

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• Install in Gas Vents
• Localized Gas Flaring
• Operate with Low Flows
• Operate at Ambient Pressure or

Low Vacuum

• Difficult to Operate in Cold

Weather Climates

• Heat Pads, Insulation and

Running Power

Source: solar-spark.com

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Integrating and Upgrading

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Integration and Upgrading

I N T E R M E D I AT E G A S V E N T I N G

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• Caisson Wells
• Extended up as waste is filled

around it

• Self draining if tied into leachate

drainage layer

• Can connect to passive gas vents

to allow deep gas extraction and migration control

• Horizontal Wells
• Used for intermediate venting

before final cover

• Can be connected to final vents

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Integrating and Upgrading

C O N N E C T I N G B L O W E R T O L E A C H AT E O R PA S S I V E V E N T S

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• Not a Preferred Method of Gas

Extraction

• Need to Design Isolation Valves

and Blank Flanges to Limit Air Infiltration

• Consider Condensate Drainage

Sumps

• Use Wellhead to Regulate Flow

Through Leachate Pipework

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Questions

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