SOUTH PORTLAND — City Councilors prepared Wednesday to pass a six-month moratorium on any project that would bring so-called tar sands crude oil into South Portland.

The highly charged discussion came a day after the Waterfront Protection Ordinance failed by a narrow margin at the ballot box. The moratorium would function in some ways as a “cooling off” period while the city assesses how to move forward.

“The point of a moratorium is to give breathing room to examine the issue,” said Sally Daggett, South Portland’s attorney, who drafted the moratorium. “You all may not know where you want to end up until the study is complete.”

What many in the city would like to see, however, is a council-generated ordinance to permanently bar the substance from passing through the city after a public process that involved more stakeholders.

Wednesday provided a first look at the measure for the council. Before it could come to a vote, two public hearings are required. If a preliminary schedule holds true, the moratorium could be passed as early as Dec. 16. It would extend until May 6, or 180 days from Wednesday’s meeting, and halt the approval of any project to pump unrefined oil sands through South Portland and onto tankers.

Once passed into law, the moratorium would allow for a committee of stakeholders to study the potential risks and impacts if tar sands were to flow through the city’s port. Eventually, that committee could help the council craft a city ordinance similar in purpose to the failed Waterfront Protection Ordinance.

The composition of that committee will be determined at a future meeting, but will likely include representatives from the petroleum industry, citizens who supported the failed ordinance and harbor officials.

While there is no guarantee that a committee process will generate an ordinance to bar so-called tar sands, some councilors expressed hope that it would at least mend the broken trust among residents.

Effects of the divisive campaign lingered among the audience. A few dozen people spoke before the councilors took up the draft moratorium, including former campaign interests on both sides, as well as residents disappointed at the tenor of the campaign.

“In my 50 years in South Portland, I have never seen the type of animosity that has taken place during this campaign,” said Dan Mooers, 70.

At the heart of the issue is whether Portland Pipeline Corp. should be allowed to reverse the flow of its underground connection with Montreal, where the company has pumped crude for refinement since the 1940s. Larry Wilson, the company’s President and CEO, said he’s seen similar moratorium language in other places, and said he is concerned about inaccuracies it contains. Yet, he thanked the community for a “seat at the table.”

“We look forward to being there for that discussion and that collaboration,” Wilson said. “We all need more time, we all need for this discussion to take place.”

South Portland has long been an oil-handling port, not only for crude piped to Canada, but for shipments of home heating oil, gasoline, jet fuel and other petroleum products stored in massive tank farms.

The specter of Canadian oil sands was first raised in 2009, when Portland Pipe Line Corp. received state and local permits to reverse the flow of one of its pipes to bring oil sands crude from Alberta into South Portland for loading onto tankers that would ferry it to refineries overseas, although it later abandoned the project.

Tar sands oil has become a target of environmentalists, who say its development will accelerate global climate change and pose other environmental risks. The petroleum industry has said it poses no greater risk than other types of oil.

In its raw form, the crude is a mixture of sticky petroleum, water and sand that at room temperature has the consistency of cold molasses. It is mixed with potent chemicals that dilute its consistency, so that it can be handled efficiently and pumped through piping. The product is referred to as diluted bitumen.

The failed zoning ordinance would have redefined the allowable uses in the city’s shipyard zone and other parts of the waterfront, strictly defining the unloading of petroleum as an allowed use and limiting any expansion or alteration of petroleum facilities that would change their function or capacity.

It also generated deep divisions in the city, sometimes pitting neighbor against neighbor, and sparked campaigns that spent countless hours and hundreds of thousands of dollars attempting to discredit the other.

Staff Writer Matt Byrne can be reached at 791-6303, or: mbyrne@pressherald.com