As a chemist, I found the Press Herald articles regarding Alberta tar sands informative (“Maine pipeline has good safety record,” June 17, and “Maine may be central as oil flow shifts east,” June 18). However, both stories described the tar-like substance being “diluted with natural gas compounds.” While accurate, it is not the whole story. The dilution compounds are proprietary, a trade secret, unknown even to first responders.

In 2010, 843,000 gallons of diluted bitumen spilled into tributaries of the Kalamazoo River. The volatile hydrocarbons in the dilution compound evaporated into a toxic plume, while heavy bitumen sank in the affected rivers, coating nearly 200 acres of river bottom.

After two years and nearly $1 billion in cleanup costs, 30 miles of the affected rivers remain closed. The cleanup continues with no end in sight. This first large spill of diluted bitumen has shown that cleanup efforts are vastly different and more expensive than conventional cleanup operations.

A spill in Portland Harbor, near Sebago Lake, the drinking water supply for 15 percent of Maine citizens or where the pipeline crosses the Crooked River, the Presumpscot River, the Pleasant River or the Androscoggin River in Gilead could harm life in and around these rivers and water bodies.

The Kalamazoo spill likewise highlighted technical difficulties that pipeline operators experience identifying in remote control rooms when a disruption, even a large disruption, has occurred. Operators of the Enbridge pipeline in a span of 17 hours tried to restart the flow twice the day of the rupture, unaware that a major spill was occurring.

A profitable but destructive myth is held in Canada and the U.S. that oil can be extracted from tar sand deposits in Alberta equaling the land area of France with acceptable environmental consequences. Processing is energy and resource intensive, environmentally destructive, obviating a need to develop alternative energy systems with Manhattan Project focus and urgency.

Stephen Demetriou

Portland

We should applaud the petroleum tank cars crossing Maine and the predictions of the reversal of the Portland-Montreal Pipe Line to handle Canadian oil from an important perspective — achieving petroleum independence and saving lives.

With an abundance of natural gas and tight oil released by technology, our nation’s energy paradigm has changed dramatically.

Yes, environmentalists have reason to be concerned, but much less so than if these energy resources were traversing open seas. Technology can detect and help prevent spills; pipelines can be quickly shut down; and as with the Maine Responder, commercial interests involved could be required to establish a rapid response team to deal with such issues.

North American petroleum independence is realistic. With electric- and/or natural gas-powered commercial and private vehicles, energy-efficient, cost-effective alternative energies, and natural gas-powered electricity generating plants, North America could become close to energy self-sufficient.

We and Canada are now exporting petroleum products, and whereas liquefied natural gas import terminals were planned a few years ago, the talk now concerns LNG-exporting terminals!

Our military excursions in the Middle East arise from a variety of realities, but our appetite for oil is a most influential factor. Energy independence could substantially reduce the loss of military lives and the tragic maiming of our soldiers’ bodies and minds.

I suggest the families of loved ones lost in our Middle East military exercises would have liked the Portland pipeline reversed long ago if it could mean that their lost family members could be with them today.

Double-lined pipe can be mandated, petroleum spills on land and in rivers and lakes can be contained and damaged waters and land can be remediated and reclaimed. The lost lives of our young military personnel and their wounded bodies and minds can’t be replaced at any cost. Let’s get our priorities right!

Samuel C. Townsend

Cape Elizabeth

Lobstermen fall victim to modern manufacturing

Remember how, long ago, we made stuff right here in the good old U.S. of A.? And sometimes there were even two places that made something, so if you couldn’t get what you needed from the first place, you could go to the second place. Remember?

Well, of course, times have changed. So now the only place you could get tags for lobster traps can’t deliver, and there’s no other place you can get tags for lobster traps, and there’s no other way you can tag lobster traps except the one way (“Tag maker delay puts freeze on lobstering,” June 21). And, of course, you just can’t trust guys that catch crawly bottom feeders. The rules are the rules, after all.

Sometime, when the lobster tag maker gets around to fixing the one machine in the world that makes tags for lobster traps, the guys who catch crawly, bottom-feeding lobsters can go back to work, if they haven’t gone broke from lack of income.

It is comforting to know that the rules will not change, and that there’s no need for an alternate method or supplier for tagging those lobster traps. It’s an object lesson in the new paradigm of American manufacturing: If you need something made now, made right and at a price you can afford, then whoops! See you offshore, folks.

William Hobbs

Portland

Man charged with assault had personal space violated

With regard to the article “Bridgton man charged with assault of reporter” (June 16):

Whose assault? David Houston, private citizen, versus Steve Roldan and witness, cameraman Dave Hill.

Roldan violated Houston’s personal space by rudely and aggressively shoving a microphone (assault weapon) into Houston’s face. Any reasonable man would grab the microphone (offending weapon) to move it back.

Don’t encourage rude paparazzi tactics, especially stalking and trespassing.

Interviews are not news. Just report the facts. Back off First Amendment, free-speech rights. Let people enjoy their right to privacy — no computer equals no email, no online, no cells, no Webs, not hits, no .coms, no Tweets, no Facebooks, no blogs.

For personal privacy, utilize the national “do not call” option.

Norman J. Harrison

Limington