SOUTH PORTLAND, Maine — Events in South Portland on Monday ensured the Nov. 5 ballot will be contentious and costly.

On Monday morning, members of Concerned Citizens for South Portland submitted nearly 3,800 petition signatures to City Clerk Sue Mooney for a referendum question designed to block the flow of Canadian tar sands oil into the city.

By Wednesday morning, Mooney had validated the 939 signatures needed to forward the petition to city councilors. Councilors can accept the ordinance or put it on the ballot, after conducting a public hearing.

On Monday night, with Councilor Melissa Linscott absent, councilors unanimously supported placing a $14 million bond question on the ballot to construct a new “community services” facility on Highland Avenue. The total cost of principal and interest will be $20 million, according to city Finance Director Greg L’Heureux.

At a 30-minute news conference in front of City Hall to announce the results of the 11-day petition drive, Mayor Tom Blake expressed support for banning the loading of tar sands tankers in South Portland, expansion of Portland Pipe Line facilities, and the construction of any towers needed for burning off additives to the tar sands.

Blake and his wife, Dee Dee, were the last people to sign the petitions.

Blake, who also said he hasn’t decided if will seek another three-year term on the City Council in November, said importing tar sands oil through the 237-mile system of pipelines owned by Portland Pipe Line is incompatible with healthy economic and environmental growth for the city.

“I firmly believe that the extraction transportation and use of tar sands are not only bad for the globe, but most definitely bad for South Portland,” he said.

On March 11, Blake and other councilors hosted a five-hour workshop regarding the dangers and benefits of importing the oil that would be exported to international markets.

Blake also visited Mayflower, Ark., earlier this spring after the town endured a spill of tar sands oil. He said conversations with residents there reinforced his belief that tar sands oil should not be a part of the city’s future.

Chris Gillis of Portland Pipe Line attended the City Council meeting Monday night and said “obviously we are disappointed with the contents” of the proposed ordinance.

Company spokesman Ted O’ Meara said officials are still reviewing the proposed changes. He asked residents to put their trust in the company.

“We are not currently proposing to construct facilities at our marine terminal, but should we desire to develop our facilities further we have every confidence that the city of South Portland and other agencies would treat us fairly and consistently as they have in the past,” O’ Meara said in a June 7 press release.

Concerned Citizens members rejoiced Monday in the results of the 11-day petition drive. Sign bearers of all ages lined the City Hall porch as Carol Masterson praised 125 volunteers who collected signatures.

“We have been blown away by the support we have received across the city,” Masterson said, before asking Preble Street resident Roberta Zuckerman to speak.

Zuckerman said the prospect of viewing two 70-foot smokestacks near Bug Light Park was a motivating factor for residents.

“We do have ‘life as it should be.’ We can’t let that be threatened by two unsightly 70-foot smokestacks at Bug Light, emitting toxins in the air,” she said.

In 2009, the company was granted a permit from the Planning Board to build “vapor combustion towers” needed to capture emissions from burning off additives in tar sands oil. At the time, the company expected to reverse the flow in one of the pipelines in about two years. The permit has since expired.

The petitions submitted to Mooney reflect the wishes of about 20 percent of city voters.

The 6-0 vote amending the bond ordinance to ask voters to approve $14 million in principal for community services reflects a long-time desire of veteran councilors Blake and Patti Smith and a goal for Councilor Linda Cohen.

Using city land off Highland Avenue in the vicinity of the Wainwright Recreation Complex, the Public Works, Transportation and Parks and Recreation departments would be housed in one facility and the existing transfer station would be rebuilt nearby.

Plans outline about 10,000 square feet of office space, 23,600 square feet of vehicle maintenance bays, and 23,500 square feet of indoor storage for city vehicles, including plow trucks and buses.

The ordinance amendment increased the bond principal from $10 million to $14 million. Councilors had considered costlier plans in workshops through the winter and spring, but a reduction in storage space helped reduce the cost from an estimated $17 million, before interest.

If approved in November, bonding would still be delayed a year to 2017 to allow some current city debt to be retired, L’Heureux noted. His estimated cost of $20 million to pay off the bonds is based on 4 percent interest and a 20-year bond term.

“I am thrilled I am still here and can fight for this building,” Smith said.

Cohen said the move is long overdue.

“I’ve made no secret I support it,” she said. “…The (O’Neil Street) neighborhood has never wanted it there.”

The bond and construction plans drew sharp criticism form Colchester Road resident Albert DiMillo Jr. He estimated rebuilding at O’Neil Street would cost $3 million to $5 million and doubted the need to consolidate the departments at one site.

He also said L’Heureux and city staff were underestimating the cost fo the project.

“This is a $25 million mistake,” DiMillo said.