PORTLAND — On July 25, 2010, more than 1 million gallons of oil spilled into the Kalamazoo River in Michigan. On July 25, 2013, much of this oil remained, polluting the riverbed and surrounding communities. It is the worst oil pipeline spill in U.S. history, with costs from the ongoing cleanup expected to soon top $1 billion.

On March 29, 2013, more than 200,000 gallons of oil spilled into a residential area and contaminated the popular Lake Conway in Mayflower, Ark.

These pipelines were carrying very heavy, unconventional crude oil derived from Canadian tar sands deposits.

There have been actions to bring such a tar sands pipeline through the state of Maine.

Unlike other sources of crude oil, tar sands is thick, gritty and sinks in water. It is processed with other chemicals until it is liquid enough to transport. The resulting mixture is called diluted bitumen, or “dilbit.”

Dilbit is more acidic, abrasive and sour (sulfur-containing) than conventional blends of crude oil. Early studies have shown that pipelines carrying dilbit spill more frequently than those carrying conventional crude oil.

Despite the risk, rapid and destructive expansion of tar sands oil fields in Alberta has led to a dramatic increase in the amount of oil transported throughout Canada and the United States.

Already, experience has shown that spills of dilbit are a new monster, vastly difficult to clean up. Dilbit spills lead to deterioration of air quality, bioaccumulation of heavy metals like arsenic, and sunken oil that can last and contribute to pollution for an indefinite number of years.

Portland Pipe Line Corp. and Montreal Pipe Line Limited have jointly operated the 236-mile-long Portland-Montreal Pipe Line for more than 70 years. Since World War II, this system has pumped imported crude oil from Portland Harbor to refineries in Montreal.

Portland Pipe Line Corp. does not have a spotless record, but it has been free of sizable pipeline incidents for 10 years. ExxonMobil, majority owner of Montreal Pipe Line Limited and Portland Pipe Line Corp., cannot say the same.

The 2013 spill in Arkansas was from the Pegasus pipeline, owned and operated by ExxonMobil. This traditional pipeline, like the one through Maine, is more than 60 years old, and it had been repurposed to carry dilbit.

Many steps have been taken by the operators of the Portland-Montreal Pipe Line toward a reversal project. This would repurpose the 63-year-old pipeline to carry dilbit.

This dilbit would cross the Androscoggin River, the Crooked River six times, and more than 40 miles of the Sebago Lake watershed — including passing through a cove of the lake itself at Panther Run — before ending in South Portland on Casco Bay. That’s not to mention the other streams, rivers, ponds, lakes and communities that this pipeline passes through or near.

So what exactly happens when these pipelines rupture? Released from the heightened temperature and pressure of the pipeline, the dilbit is free to separate. Immediately, lighter chemicals begin to evaporate into the air we breathe. These chemicals include benzene, a confirmed human carcinogen, and other toxics.

Unfortunately, the chemical mixtures are deemed trade secrets by the oil giants and have not been released to the public. We do know that they are dangerous.

According to a Michigan Department of Community Health report, the majority of residents near the Kalamazoo spill experienced respiratory, gastrointestinal and neurological problems attributable to the spill.

We cannot allow a tragedy of this scale to happen in our beautiful state. Maine has too much at stake, from our pristine waterways to our independent communities to our historic coastline. The risk of tar sands is very real and is not right for the state of Maine. Let’s learn from past disasters and take a stand to keep tar sands out of Maine.

 

Alexander Smith, a University of Pennsylvania student who grew up in Auburn, is a summer associate at Environment Maine in Portland.