Environmental Effects of Underground & Overhead ......Environmental Effects of Underground & Overhead Transmission Line Construction & Maintenance in the United States Ryan A. Brockbank

Environmental Effects of Underground & Overhead Transmission Line Construction & Maintenance in the United States

Ryan A. BrockbankHalifax, Nova Scotia September 20 – 23, 2015

Environmental Concerns on ROW Management 11th International Symposium

Environmental Concerns in ROW Management 11th International SymposiumHalifax, Nova Scotia September 20 - 23, 2015

Electric Power Research Institute (EPRI)

John Goodrich-Mahoney, EPRI Project Manager

Ryan Brockbank Kevin McLoughlinECI Principal Investigators

Lynn Askew Heather Harder Wendy HosmanPower Engineers Principal Investigators


The Demand For Safe & Reliable Electricity


IOUs Invest $92.9 Billion on Transmission

48% 43% 46% 46%

15%15% 16% 17%

22% 28% 26% 25%

4% 3% 2% 2%11% 11% 10% 10%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2014 2015 2016 2017

Security Measures/Other

Advanced Technologies

System Improvement

Line Replacement

Transmission Expansion

Source: EEI Updated November 2014

& New Build

Projected Transmission Capital Expenditures By Activity Type


Overhead vs. Underground Transmission

Overhead (OH)Lower CostHigher Outage FrequencyShorter Outage Duration Faster Repair Time

Underground (UG)Higher Cost Lower Outage FrequencyLonger Outage DurationSlower Repair Time


Overhead Transmission Construction

BPA McNary-John Day 500 kV Overhead Transmission Project

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCMHs0LOx-scCFUyciAodtbAB1Q&url=http://www.youtube.com/watch?v%3DPyCWIFL30mU&psig=AFQjCNHpfAOzRO6xSwZBnwxb7ztZpB9Iww&ust=1442452369935404

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCMHs0LOx-scCFUyciAodtbAB1Q&url=http://www.youtube.com/watch?v%3DPyCWIFL30mU&psig=AFQjCNHpfAOzRO6xSwZBnwxb7ztZpB9Iww&ust=1442452369935404


Overhead Transmission Construction

BPA McNary-John Day 500 kV Overhead Transmission Project


Underground Transmission Construction

PG&E’s Jefferson-Martin 230 kV Underground Transmission Project

Northeast Energy Link – Proposed 230 Mile Underground DC Cable


Potentially Affected Resources

Land UseBiologicalSoil & GeologicalWaterCulturalVisual

The project does not address health issues (EMFs) or air resource impacts.


Land Use Types

AgriculturalForests & WildernessParks, Recreation & Preservation AreasTransportation & AccessDeveloped Lands

ResidentialCommercialPublic FacilitiesIndustrial


Effects on Land Use


Trenchless Construction HDD Frac-Out Event


Underground HDD Frac-Out Event


Effects on Land Use - Wildfire






Effects on Biological Resources

Vegetation EffectsDisruption of existing vegetationChange in habitat type or vegetation compositionHabitat fragmentationDisruption of rare, threatened, and endangered speciesIntroduction of invasive plant species


Effects on Biological Resources - Vegetation

ROW corridors can enhance plant diversityPositive effect on some individual species, however…Habitat generalists can thriveReplacing rare plants with common onesInvasive plant impacts on native plant species


Effects on Biological Resources

Wildlife EffectsHabitat and population fragmentationHabitat loss and reduced species abundanceWildlife displacement and disturbanceDisruption of rare, threatened, and endangered species


Effects on Biological Resources - Wildlife

Displacement vs. Mortality


Effects on Biological Resources - Wildlife


Native Pollinator – Karner Blue Butterfly

Early successional habitatBlue lupine is vital to the butterfly’s survivalFederally endangered Karner Blue Butterfly thriving on WI ROW


Effects on Soils and Geological Resources

Soil erosion Soil compactionSoil profile disruptionReclamation constraints






Effects on Water Resources

Water resource availability, accessibility, and qualitySurface waterWetlandsFloodplainsGroundwater



Research reported on long-term effects of an overhead transmission construction project in MA; discovered that cattail marsh and wooded wetland ecosystems completely recovered within a few years.




Effects on Cultural Resources

Prehistoric and Historic Archaeological ResourcesArchitectural ResourcesTraditional Cultural Properties§ 106 National Historic Preservation Act


Effects on Cultural Resources


New York City 1887 Vancouver, BC 1914

Effects on Visual Resources


Effects on Visual Resources


Summary

Both OH and UG transmission can have beneficial and detrimental effects on the environmentUG transmission can actually have greater detrimental effects


Summary

Out of 33 potential environmental impacts associated with OH vs UG transmission construction and maintenance:

UG can have greater detrimental effects in 33% of the impact categoriesUG can have lesser detrimental effects in 15% of the impact categories UG and OH have similar environmental impact potential in 52% of the categories

Site-specific evaluation and mitigation techniques determine actual relative impacts


Thank You! Questions...

Ryan A. [email protected]

Environmental Effects of Underground & Overhead ......Environmental Effects of Underground & Overhead Transmission Line Construction & Maintenance in the United States Ryan A. Brockbank

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