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TAG Proposal“Forest vegetation as an indicator of
natural gas leaks”
Don Davis (PI)Lynda Farrell, Consultant
TAG Proposal“Forest vegetation as an indicator of
natural gas leaks”
Don Davis (PI)Lynda Farrell, Consultant
GAS WELL DRILLING:POTENTIAL ADVERSE FOREST EFFECTS
GAS WELL DRILLING:POTENTIAL ADVERSE FOREST EFFECTS
Gas Wells
60% Forested
GAS WELL DRILLING:POTENTIAL ADVERSE FOREST EFFECTS
1. Pad Site Logging & Construction
GAS WELL DRILLING:POTENTIAL ADVERSE FOREST EFFECTS
1. Pad Site Logging & Construction
Removal and Sale of Trees
Logging Wounds on Residual Trees at EdgeLogging Wounds on Residual Trees at Edge
1. Direct Effects2. Secondary Effects
2. Excavating & Grading
1. “Edge Effects” 2. Surface Water Flow Changes
“Edge Effects” (Tree Mortality Along Edge)
1. Mortality not necc from salt, etc.2. May continue for years
3. Leaks & Spills of Brine (+ Frac’n Chemicals?)
Leaks from Lined Pits
Deer Attracted to Salt
Salt DamageSalt Damage
4. Precursors to Ozone Formation(i.e., NOx Emissions from
Compressor Stations)
4. Precursors to Ozone Formation(i.e., NOx Emissions from
Compressor Stations)
Tons/Yr
Source: PA DEP (2010)
Tons/Yr
Ozone-Sensitive PlantsOzone-Sensitive Plants
Black Cherry
Chinese Tallowtree
Vegetation Associated with PipelinesVegetation Associated with Pipelines
Clearing
Excavation
GradingGrading Seeding
Establishment ofGrasses, clover, etc.
Common Perennial Plants on PA Pipeline Corridors
Common Perennial Plants on PA Pipeline Corridors
Grass
Clover
Vetch
Trefoil
Grass
So, what happens if there is a leak in a natural gas pipeline?
So, what happens if there is a leak in a natural gas pipeline?
Root Death • Soil atmosphere • Soil oxygen depleted • Methanobacter
(+ Size of leak, Pressure, etc. etc.)
Gas migratesupward in aninverted cone
**OLD** Pipelines
Aerial View Pattern Influenced By • Soil Texture • Soil Disturbance
Within Trench • Soil Moisture • Depth of Freezing
Underground Leak
**OLD** Pipelines
Woody Shrubs Over Old PipelinesWoody Shrubs Over Old Pipelines
SUMMARY: Early Detection of LeaksUsing Dead, Dying, or Discolored Vegetation
Above Leaking Natural Gas Pipeline
SUMMARY: Early Detection of LeaksUsing Dead, Dying, or Discolored Vegetation
Above Leaking Natural Gas Pipeline
TAG Proposal“Forest vegetation as an indicator of
natural gas leaks”
TAG Proposal“Forest vegetation as an indicator of
natural gas leaks”
• 1. Outreach ActivitiesPresentations at meetingsPrep of publications, brochures, etc.
• 2. Aerial surveys above old pipelines to locate patterns of discolored or injured vegetation • Follow-up with ground-truth surveys
• 1. Outreach ActivitiesPresentations at meetingsPrep of publications, brochures, etc.
• 2. Aerial surveys above old pipelines to locate patterns of discolored or injured vegetation • Follow-up with ground-truth surveys
