South Portland, as expected, voted by a 6-1 margin Monday night to support its Clear Skies Ordinance, which bans the loading of crude oil, including tar sands oil, onto tanker ships along its waterfront.

It is the first community to ban tar sands oil in the country, according to the Natural Resources Council of Maine, prohibiting the loading of tar sand oil onto tanker ships. In addition, loading tar sands oil would require new infrastructure, including twin 70- foot combustion smokestacks, previously permitted by the city and state for Portland Pipe Line Corporation’s 2009 proposal to load tar sands onto tankers at South Portland. This vote would prohibit them from being built.

The smokestacks would have emitted volatile organic compounds and hazardous air pollutants, such as benzene, linked to human leukemia, during the loading process.

The initial vote was taken last Tuesday, and was 6-1 in favor of the Clear Skies Ordinance. A large majority of residents who came to speak on the issue also supported the ordinance.

Without the potential of loading tar sands at the end of the pipeline, it seems unlikely that the Canadian company that wants to send tar sands through northern New England would continue with the push to reverse the flow of this pipeline.

Tar sands, a form of heavy, sludgy crude oil, comes from Alberta, Canada. The material is much more corrosive than the light, sweet crude the Montreal-Portland pipeline has been carrying for many years. In recent years, pipelines ferrying tar sand oil have ruptured and spilled in the Kalamazoo River in Michigan, the Yellowstone River in Montana, and most recently, a subdivision near a wetland region and Lake Conway, near Mayflower, Ark. One of the things that residents and visitors remark on is the sour smell of the land and water that’s been affected, even though the companies claim that the water is safe and that there are no health hazards from using the land.

The proposed Keystone XL pipeline project would carry tar sands oil over the Ogallala Aquifer, the irrigation and drinking water supply for the majority of the nation’s breadbasket; an earlier pipeline carrying the same type of tar sands oil, the brand-new Keystone I pipeline, traveling under North and South Dakota, Nebraska, Kansas, Missouri, Illinois and Oklahoma, has already suffered 14 separate leaks since 2009.

Back in Maine, the Montreal-Portland pipeline crosses the Crooked River six times. The Crooked River provides 40 percent of the fresh water in Lake Sebago, which is the sole drinking water source for 15 percent of the population of Maine, including the city of Portland.

The pipeline also runs along the Androscoggin River for 13 miles, the largest water feature in Brunswick and Topsham, and a feeder to Merrymeeting Bay, which opens out into several local rivers, including the Kennebec, the Cathance, the Eastern, the Abagadasset, and the Muddy, and drains into the Kennebec Estuary and the Gulf of Maine and their prime fishing grounds. Bordering towns and cities include Bath, Brunswick, Topsham, Bowdoinham, Richmond, Dresden and Woolwich.

The amount of water and the number of people who would be catastrophically affected by a tar sands oil spill in Maine is beyond breathtaking.

Enbridge, the company that deals with the Canadian side of the pipeline, and Exxon, which handles the American side, operated the Kalamazoo River pipeline and the pipeline that ruptured under Mayflower, Ark., respectively.

Neither company has a fantastic track record, to put it mildly.

We are already on track to find an alternative for our thirst for oil, but we are unlikely — ever — to find an alternative for our need for water.

So we applaud South Portland’s decision. It’s rare that a single town or city can take an action that has the potential to avert disaster to a good percentage of the entire state, and New Hampshire and Vermont as well. It was the right decision, and one that the rest of southern and coastal Maine appreciates.