A March 3 Maine Voices column by Jamie Py would have us believe that crude oil from tar sands is no riskier than conventional crude.

It is true that dilbit (diluted bitumen) is not tarlike and has not been shown to be any more corrosive to pipelines than any other oil. It does not contain sand and is not gritty.

However, that does not mean it is safe to transport. The problems begin when a spill occurs, and we have seen that spills do occur. Dilbit contains volatile additives that evaporate when the oil is released from the pipeline. These chemicals can cause headaches, vomiting and sickness. Once these diluting agents evaporate, the remaining oil is dense and sinks in water. This makes it hard to clean up.

Cleanup of the 2010 dilbit spill in Michigan is still going on. A story last month from Michigan Public Radio states that the cleanup has already cost Enbridge more than $1 billion, and they are not done.

The spill left 180,000 gallons of crude oil on the river bottom. This has now turned to tiny particles of weathered material mixed with the sediment. Enbridge plans to dredge up and dispose of 135,000 cubic yards of contaminated sediment.

Imagine if we had a spill like this in the Crooked River, which is crossed several times by the pipeline. Would there even be the resources to do an adequate cleanup, and how long would the leak persist before being discovered?

If dilbit were to be transported from Montreal to South Portland, we’d need a lot of assurances and transparency regarding pipeline inspections, cleanup plans and who’d pay for a spill.

Must we take this risk, or should we just do the prudent thing and say “no” to the prospect of the transport of dilbit through our watershed?

Harold McWilliams