tag proposal “forest vegetation as an indicator of natural gas leaks” don davis (pi) lynda...

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