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

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1 Environmental Effects of Underground & Overhead Transmission Line Construction & Maintenance in the United States Ryan A. Brockbank Halifax, Nova Scotia September 20 23, 2015 Environmental Concerns on ROW Management 11 th International Symposium

2 Electric Power Research Institute (EPRI) John Goodrich-Mahoney, EPRI Project Manager Ryan Brockbank Kevin McLoughlin ECI Principal Investigators Lynn Askew Heather Harder Wendy Hosman Power Engineers Principal Investigators

3 The Demand For Safe & Reliable Electricity

4 IOUs Invest $92.9 Billion on Transmission Projected Transmission Capital Expenditures By Activity Type 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 11% 11% 10% 10% 4% 3% 2% 2% 22% 28% 26% 25% 15% 15% 16% 17% 48% 43% 46% 46% Security Measures/Other Advanced Technologies System Improvement Line Replacement Transmission Expansion & New Build Source: EEI Updated November 2014

5 Overhead vs. Underground Transmission Overhead (OH) Lower Cost Higher Outage Frequency Shorter Outage Duration Faster Repair Time Underground (UG) Higher Cost Lower Outage Frequency Longer Outage Duration Slower Repair Time

6 Overhead Transmission Construction BPA McNary-John Day 500 kv Overhead Transmission Project

7 Overhead Transmission Construction BPA McNary-John Day 500 kv Overhead Transmission Project

8 Underground Transmission Construction PG&E s Jefferson-Martin 230 kv Underground Transmission Project Northeast Energy Link Proposed 230 Mile Underground DC Cable

9 Potentially Affected Resources Land Use Biological Soil & Geological Water Cultural Visual The project does not address health issues (EMFs) or air resource impacts.

10 Land Use Types Agricultural Forests & Wilderness Parks, Recreation & Preservation Areas Transportation & Access Developed Lands Residential Commercial Public Facilities Industrial

11 Effects on Land Use

12 Trenchless Construction HDD Frac-Out Event

13 Underground HDD Frac-Out Event

14 Effects on Land Use - Wildfire

15 Effects on Land Use - Wildfire

16 Effects on Land Use - Wildfire

17 Effects on Biological Resources Vegetation Effects Disruption of existing vegetation Change in habitat type or vegetation composition Habitat fragmentation Disruption of rare, threatened, and endangered species Introduction of invasive plant species

18 Effects on Biological Resources - Vegetation ROW corridors can enhance plant diversity Positive effect on some individual species, however Habitat generalists can thrive Replacing rare plants with common ones Invasive plant impacts on native plant species

19 Effects on Biological Resources Wildlife Effects Habitat and population fragmentation Habitat loss and reduced species abundance Wildlife displacement and disturbance Disruption of rare, threatened, and endangered species

20 Effects on Biological Resources - Wildlife Displacement vs. Mortality

21 Effects on Biological Resources - Wildlife

22 Native Pollinator Karner Blue Butterfly Early successional habitat Blue lupine is vital to the butterfly s survival Federally endangered Karner Blue Butterfly thriving on WI ROW

23 Effects on Soils and Geological Resources Soil erosion Soil compaction Soil profile disruption Reclamation constraints

24 Effects on Soils and Geological Resources

25 Effects on Soils and Geological Resources

26 Effects on Water Resources Water resource availability, accessibility, and quality Surface water Wetlands Floodplains Groundwater

27 Effects on Water Resources 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.

28 Effects on Water Resources

29 Effects on Cultural Resources Prehistoric and Historic Archaeological Resources Architectural Resources Traditional Cultural Properties 106 National Historic Preservation Act

30 Effects on Cultural Resources

31 Effects on Visual Resources New York City 1887 Vancouver, BC 1914

32 Effects on Visual Resources

33 Summary Both OH and UG transmission can have beneficial and detrimental effects on the environment UG transmission can actually have greater detrimental effects

34 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 categories UG 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

35 Thank You! Questions... Ryan A. Brockbank