As a retired CMP environmental engineer, I want to comment on proposed legislation requiring CMP to evaluate Portland Pipe Line as an underground conduit for CMP’s proposed transmission connection to Hydro-Quebec.

For starters, an 80-year old pipeline likely has contamination issues. Maine should be wary of any initiative that could expose the state or utility customers to financial liability for a complex, multi-jurisdictional environmental cleanup. The owners may be all too willing to hand over the corridor if they can shed financial liability for cleanup.

There are also issues of feasibility. The pipeline consists of three individual pipes, only one of which is decommissioned, and that of insufficient size to accommodate the electric cables. Utilizing one of the larger pipes would require Portland Pipe Line to abandon much of its pumping capability. Also, heavy conductor cannot handle sharp bends, and the curvature of the pipe may in places require its relocation. Finally, the pipeline doesn’t align with either proposed transmission interconnection point, requiring additional transmission line and substation construction.

Pipeline co-location will have substantial construction and environmental impacts. Friction and tensile strength of the conductor limits the distance cables can be pulled to about one-half mile. Approximately 500 construction sites would therefore be required for concrete splice vaults to pull and splice the cables.

The pipeline alternative would also trigger a new permit request to ISO New England, setting the project back by two years or more, potentially impacting project viability.

Permitting would also be required with New Hampshire and Vermont, with unknown delays and costs.

CMP’s proposed overhead transmission route through northern Maine will have minimal environmental impacts. The majority of the route is not pristine but working forest crisscrossed with logging activities. It represents the best solution for New England’s access to clean hydropower.

Roy Koster


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