Alliance for Responsible Infrastructure · MPUC Docket No. 2025-00276

Health and Safety

Three concerns we're tracking outside our formal case in this docket: electromagnetic fields, herbicide use in vegetation management, and wildfire risk in a changing climate.

Our case in this docket challenges CMP's claimed need, protects the integrity of our communities, and pushes for planning that actually works — not just for Portland, but for the towns this line runs through. That's where our filings, our data requests, and our expert testimony are focused, for all the reasons laid out elsewhere on this site.

Separately — as neighbors, parents, and community members, not as a legal argument in the docket — many of us are also genuinely concerned about what runs through the air above this corridor, what gets sprayed on the ground beneath it, and what happens when overhead lines meet a hotter, stormier Maine. We want to be direct about each concern, and direct about what the evidence does and doesn't show.

Electromagnetic fields

There's clear reason for concern.

Research and data are incomplete — but that reflects how hard this is to study, not that there's nothing to find. No ethics board would ever approve deliberately exposing people, let alone children, to high-voltage fields to see what happens, so scientists have to piece the answer together by observing populations after the fact — a slower, messier way to get to a clean answer. On top of that limit, no study has yet confirmed a biological mechanism, and because the health outcomes in question are rare, the number of cases available to study is small enough to make other explanations hard to rule out.

Even working within those limits, the pattern that has emerged is hard to wave away. Studies of childhood leukemia near high-voltage lines have found a real, repeated statistical association at higher exposure levels, enough that the International Agency for Research on Cancer classified this type of exposure as a possible carcinogen in 2002. The exposure levels most people near transmission lines actually experience are lower than what the strongest studies looked at — which is exactly why this remains a live, open question rather than one that's been closed in either direction.

A gap in the evidence isn't proof of safety — it's proof that the question hasn't been definitively answered.

The research on high-voltage lines and neurodegenerative disease, including Alzheimer's, is newer and thinner, but pointing in the same direction: a large 2026 Swiss cohort study of 3.5 million adults found a statistical association between residential proximity to power lines and Alzheimer's mortality. The researchers themselves are candid that this doesn't establish a mechanism — but it's one more data point suggesting this deserves real caution, not dismissal.

Other countries aren't waiting for certainty

Several European countries have already decided that this gap in the evidence is reason enough to keep new high-voltage lines away from homes and schools — without waiting for the research to be settled. That's the same judgment we're asking CMP and the Commission to make here: when there's a real, live question about safety, the responsible move is to route around people, not through them.

Italy and Switzerland's figures are binding regulatory limits. The Netherlands, France, and Sweden figures are precautionary guidance or self-applied practice, not law — we're citing them as evidence of how seriously other governments and grid operators take this question, not as claims that they're legally required.

What we're asking for

That wildfire and extreme-weather risk be part of how this project is evaluated — not an afterthought — with commitments in writing for the life of the line. Specifically:

• Which vegetation standard applies, how wide the cleared corridor will be, and whether hazard trees outside it are covered.
• How often poles and hardware will be inspected up close — not just from the ground or the air.
• Whether fire-season protection settings will be used, so the line shuts off faster and doesn't automatically re-energize after a fault.
• What pole design and wind rating are planned for a stormier Maine.
• Whether undergrounding was evaluated for the most sensitive, heavily wooded, residential stretches — and what it would cost.
• How the proposed design compares with more resilient options, including battery storage and local generation.

Herbicides and vegetation management

What actually happens under the lines

Keeping a transmission right-of-way clear isn't just mowing. CMP's own filed vegetation management plan for its transmission corridors uses herbicide spraying — low-pressure foliar spray and cut-stump treatment on brush over 8 feet — on a roughly four-to-five-year cycle, using products including Garlon, Arsenal, Milestone, Rodeo, and Stalker. A wider right-of-way for this project means that treatment zone extends further into land that's currently outside it — closer to homes, wells, children's play areas, schools, and the conserved land along this corridor.

This isn't hypothetical: in 2013, CMP sprayed herbicide along a public walking trail on the Messalonskee Stream in Oakland, Maine, without advance notice to the town, prompting resident complaints over runoff into the stream. On the separate NECEC corridor project, CMP committed in writing not to use herbicides on that new corridor at all — after public and regulatory pushback. That's the precedent we think should apply here too: CMP has shown it will change its herbicide practice when a community pushes for it.

What the science says — and where it's genuinely disputed

Glyphosate, one of the most commonly used ROW herbicides, was classified by the World Health Organization's cancer research arm (IARC) as "probably carcinogenic to humans" in 2015 — a stronger classification than the one used for electromagnetic fields above. The EPA disagrees, and maintains glyphosate is not likely to be carcinogenic under normal label use. That disagreement is not settled: in 2022, a federal appeals court vacated EPA's own human-health reasoning on glyphosate and sent it back for reconsideration, which EPA is still redoing.

Two other herbicides in CMP's plan carry their own flags: triclopyr can cause permanent eye damage on direct contact and is toxic to fish and aquatic life, and imazapyr is prone to leaching into groundwater and running off — a specific concern for anyone near a well. Whichever way the glyphosate cancer classification debate resolves, the drift, runoff, and groundwater concerns with these other chemicals hold on their own, and get more serious the closer spraying happens to homes and wells.

What we're asking for

At minimum: real advance notice to every household near the corridor before any spraying, buffer zones around homes, wells, schools, and conserved land that go beyond the state's minimums, and consideration of non-herbicide vegetation management in the areas closest to where people live. CMP has already agreed to something close to a full herbicide-free commitment on another corridor when asked — we don't think that's an unreasonable thing to ask for here too.

Wildfire and climate resilience

Climate change is raising the risk

Maine is getting hotter, and the state's own climate scientists project “an earlier fire season,” “longer periods of high-fire risk,” and “more than a doubling of fire probability in the state.” We're already seeing it: in 2025, Maine had roughly four times its usual number of late-summer and fall wildfires. The state's assessment also names the places it considers most vulnerable — the wooded neighborhoods where homes meet forest. That's exactly where this corridor runs.

Overhead lines are a fire risk

Above-ground transmission lines can start fires when hardware wears out, trees fall into the wires, or wind brings lines down. California's deadliest wildfire, the 2018 Camp Fire, was started by a worn hook on a 115 kV line — the same voltage CMP is proposing here. It destroyed the town of Paradise and killed 85 people. Nationally, fires started by power lines have grown roughly 13-fold since the early 1990s. In a hotter climate, that risk only grows, for as long as the line stands.

A new overhead line also makes fires harder to fight: firefighting aircraft and ground crews have to keep their distance from live high-voltage lines. And utilities increasingly cut power during fire weather to prevent ignitions — which would shut off the well pumps many homes along this route depend on for water.

Undergrounding is the safer alternative

Burying the line largely removes its ability to start a wildfire. It keeps the line out of the path of falling trees and storms, and it spares the mature tree canopy that shades, cools, and shelters our neighborhoods. It deserves a real evaluation for the wooded, residential stretches of this route, alongside battery storage and local generation.

What we're asking for

• A genuine evaluation of undergrounding for the most sensitive, wooded, residential stretches of the route.
• Fire-safety commitments in writing for the life of the line. The national tree-clearing standard for transmission lines doesn't automatically cover 115 kV lines, so CMP should commit to how it will manage trees along the corridor, including hazard trees just outside it; how often poles and hardware will be inspected up close; and fire-season settings that shut the line off faster after a fault.
• A clear comparison of how the overhead design and more resilient alternatives would hold up in the hotter, stormier Maine the state's scientists project.

Sources

• World Health Organization — Electromagnetic Fields
  WHO doesn't set a low general exposure limit, but its own guidance supports low-cost precautionary siting for new construction near power lines.
  who.int — WHO International EMF Project ↗
• International Agency for Research on Cancer
  Classified extremely-low-frequency magnetic fields as "possibly carcinogenic to humans" (Group 2B) in 2002, based on pooled childhood leukemia studies.
  cancer.gov — NCI fact sheet on EMF and cancer ↗
• 2026 Swiss National Cohort study
  Found a statistical association between residential power-line proximity and Alzheimer's mortality across 3.5 million adults tracked for 18 years; authors caution the mechanism isn't established.
  sciencedirect.com — Swiss National Cohort study ↗
• CMP's 2018 Foliar Herbicide Plan
  Filed with the Maine Board of Pesticides Control; names the specific products and application methods used on CMP's transmission corridors.
  maine.gov — CMP Foliar Herbicide Plan (2018) ↗
• IARC — Glyphosate classification
  Classified glyphosate as "probably carcinogenic to humans" (Group 2A) in 2015 — a stronger classification than the one used for EMF.
  iarc.who.int — Glyphosate classification ↗
• U.S. EPA — Glyphosate
  EPA's differing position, and the 2022 court decision sending its human-health review back for reconsideration.
  epa.gov — Glyphosate ↗
• CMP's NECEC herbicide pledge (2019)
  CMP committed not to use herbicides on its separate NECEC corridor after public and regulatory pressure — the precedent we're pointing to here.
  pressherald.com — CMP's 2019 herbicide pledge ↗
• Maine Climate Council — Scientific Assessment of Climate Change and Its Effects in Maine (2024)
  Projects an earlier fire season, “more than a doubling of fire probability,” a 2–4°F rise by 2050, and more intense winter storms; flags Maine's wildland-urban interface as a vulnerability.
  maine.gov — STACS 2024 executive summary ↗
• Bangor Daily News — Maine's 2025 wildfire season
  750 wildfires through September 2025; 251 in August, more than twice any August in over two decades.
  bangordailynews.com — Dry conditions drive busy 2025 wildfire season ↗
• Central Maine — “Maine's wildfire threat is quietly heating up” (Sept. 2026)
  Maine Forest Service figures: 420 wildfires in August–October 2025, about four times the 20-year average for those months.
  centralmaine.com ↗
• Butte County District Attorney — Camp Fire investigation report
  Identifies PG&E's Caribou-Palermo 115 kV transmission line as the cause of the 2018 Camp Fire.
  buttecounty.net — Camp Fire public report ↗
• Headwaters Economics — Lessons from 30 years of wildfire ignition data
  Analysis of U.S. Forest Service data (1992–2024): power-line ignitions up roughly 13-fold; the largest average fire size of any human cause.
  headwaterseconomics.org ↗
• NERC FAC-003-4 — Transmission Vegetation Management
  The national standard applies automatically to lines of 200 kV and above; lower-voltage lines only if designated critical.
  ferc.gov — FAC-003-4 ↗
• KQED — State probe of the Camp Fire line
  California regulators found a close-up inspection could have caught the worn hook that failed.
  kqed.org ↗
• California PUC — West of Devers Draft EIR, Wildland Fire section
  How energized transmission lines constrain aerial and ground firefighting.
  cpuc.ca.gov ↗

What you can do

• Share this page with your neighbors — the more people who've actually read the research, the harder it is for this concern to be waved away.
• Raise it directly with your town councilors and ask where they stand on siting high-voltage infrastructure and herbicide spraying near homes and schools.
• Contact your state representative or senator — a specific, personal concern from a constituent carries real weight.
• Bring it up in public comment and at town meetings, alongside the property-impact and procedural concerns already documented on this site.

We encourage you to reach your own conclusions and make your position — and your community's — clear to the people making this decision.

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