Loading crude oil onto ships would be prohibited on South Portland’s waterfront, if the City Council enacts ordinance changes recommended by a committee formed to find a way to prevent tar sands oil from coming into the city.

The Draft Ordinance Committee will present its proposal to the City Council at a workshop Wednesday.

The recommendations have a narrower scope than the voter-rejected Waterfront Protection Ordinance, a citizen’s initiative that was also designed to prevent Portland Pipe Line Corp. from bringing tar sands oil into the city from Canada in the underground pipeline that now carries crude from South Portland to Montreal.

While the defeated ordinance would have blocked tar sands oil, it would have accomplished that goal by prohibiting expansion of all petroleum-related facilities on the waterfront, which many argued would have had an adverse effect on many other waterfront businesses.

Residents rejected that proposal by fewer than 200 votes in November. But the narrow margin, despite an opposition campaign backed by the oil industry, indicated to the council that the community’s disapproval of tar sands oil was strong.

Environmental groups say tar sands oil is more dangerous to ship through pipelines and more difficult to clean up if spilled. Oil companies, including Portland Pipe Line, dispute those claims.

After the vote in November, the council enacted a moratorium on tar-sands-related development and created a committee to address the issue through ordinance amendments. That committee has met 19 times since February for about 60 hours total, said facilitator Jeff Edelstein.

The recommendations prohibit loading crude oil in bulk onto marine tank vessels and building or expanding facilities for that purpose.

The committee found that loading crude oil onto an empty ship creates more possibility for harmful air pollution than unloading it onto shore because hazardous vapors get displaced in the process. Also, the vapor combustion tanks needed to mitigate that pollution would have a negative visual impact on the city’s waterfront, the committee said in its report.

Jim Merrill, spokesman for Portland Pipe Line, wouldn’t say whether the company would fight the new proposal, but only that it “is closely monitoring the proceedings” of the committee and the city.

Members of Protect South Portland, the group that supported the Waterfront Protection Ordinance, have followed the work of the committee and are hoping the City Council will enact its recommendations “without delay,” said spokeswoman Mary-Jane Ferrier.

She said the “simple, straightforward” proposal would protect the city and poses no threat to existing businesses. “I see no way it can be construed that way,” she said.

The public can comment on the proposed changes at the workshop Wednesday, which starts at 7 p.m. at Mahoney Middle School.

City Manager Jim Gailey said the council is scheduled to take an initial vote on the proposal July 7. That would be followed by a Planning Board review July 15, then a final vote by the council on July 21.