Download - Landfill Gas Battelle 2014 - UPPAL 1
Emergency Response for Landfill Gas
Mitigation and Full-Scale Remedy Design
Authors: Omer J. Uppal, Neil Rivers, Stewart H. Abrams, Sachin Sharma,
and Matthew Ambrusch
Presentation Outline
Site Conceptual Model
Rapid Emergency Response
Pilot Testing
Temporary Mitigation System
Full-Scale Design
Conclusions
LANDFILL
VILLAGE
Site Layout
Formerly closed sanitary landfill
Site Conceptual Model
Former passive gas collection system
Ineffective vapor capture due to water in pipes
Passive SSDS’s in nearby residences
High Methane Detections
Colorless/Odorless
5.00% by volume CH4 = 100% LEL
1.25% by volume CH4 = 25% LEL
Historic Results 2004-2008
Rapid Response – April 2011
Baseline methane survey – April 2011
Temporary activation of existing venting system – April 2011
Pilot testing – May 2011
Pilot Test Results May 2011
Pilot Testing – May 2011
Temporary Mitigation System – April 2011 through Current System extracts landfill gas from the shallow trenches and two deep SVE wells.
Within 6 weeks, methane concentrations in the shallow monitoring points declined from 74% methane by volume to ND
Consistent decrease in methane gas concentration in blower discharge
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
Feb-11 Sep-11 Apr-12 Oct-12 May-13 Nov-13 Jun-14
Met
han
e C
on
cen
trat
ion
(%
by
Vo
lum
e)
Time
Full-Scale Design Objectives
Prevent landfill gas migration from landfill towards residential
properties through both the shallow and deep pathways
Utilize as much of existing system as possible
Utilize passive and active soil gas venting and treatment systems to
increase effectiveness
Create well network for proper monitoring
Design Basis
Shallow Fine-Medium Sands
Deep Fine Sands
Fill
LG Migration Pathways Site Lithology
Pneumatic Modeling
Why Modeling?
Simulate air flow field in subsurface
Determine design parameters
Approach - MDFIT
Outputs
Ki, ROI, FD , PV exchanges
Benefits
More cost-effective design
Valuable tool for SVE, VI Mitigation & Air Sparging design
Full-Scale Design
Active LG Venting Component
Existing LF gas venting trench
Thermal flare for off-gas treatment (optional)
10 Passive venting wells
Barrier SVE Component (contingency)
8 Paired SVE well locations
3 Deep vapor points
FULL-SCALE SYSTEM DESIGN
Proposed Methane
Mitigation System
Active LG Venting Barrier
SVE
VILLAGE
LANDFILL
SHOPPING CENTER / LANDFILL
Passive Vent Points
Existing Vapor Collection Trench (Active LG Venting) System Shed
PROPOSED METHANE MITIGATION SYSTEM
N
Legend: PASSIVE VENT PTS SYSTEM SHED EXISTING SYSTEM
FULL-SCALE SYSTEM DESIGN
Proposed Methane
Mitigation System
Active LG Venting Barrier
SVE
VILLAGE
LANDFILL
SHOPPING CENTER / LANDFILL
Passive Vent Points
Existing Vapor Collection Trench (Active LG Venting)
Barrier SVE Wells SVE 1 & 2 (Existing)
System Shed
Deep VPs
PROPOSED METHANE MITIGATION SYSTEM
N
Legend: PASSIVE VENT PTS SYSTEM SHED EXISTING SYSTEM SVE WELLS DEEP VPs
Beats the Alternative
Cost-Effective Alternative to a Barrier Trench
Substantial Cost Savings: ~ $3 Million
Elimination of slope stability and trench construction issues
Conclusions
RAPID ACTION (in less than one week)
Mobilized, installed, and activated temporary gas collection
system
Protected dozens of private homes
System continues to effectively operate
Innovative Design Strategy Benefits
Questions?