Porter Airlines has submitted a second proposal to further reduce noise as public consultations begin on its request to extend the runway at Toronto’s downtown island airport and allow it to operate Bombardier CSeries jets.

The original plan, submitted in April when Porter placed a conditional order for up to 30 107-seat CS100s, is to extend the runway by 168 meters at each end. The new proposal would increase that to 200 meters at each end to allow a reduced-thrust departure to lower noise.

Porter argues the CSeries will have a noise level comparable to the Bombardier Q400 turboprops it now flies from Billy Bishop Toronto City Airport, but it requires both a runway extension and the lifting of a 30-year-old ban on operating jets at the airport.

The new plan “does not replace our proposal to extend the runway 168 meters at each end. That is still valid, still a good solution, and we still support it,” CEO Robert Deluce tells Aviation Week. The proposal was based on not causing “material movement” of buoys marking the western shipping channel.

“We subsequently used some outside consultants to validate our proposal, and they suggested we could extend the runway further without affecting the buoys,” he says, adding “there are couple of real benefits” to an even longer runway.

In addition to allowing quieter, reduced-power departures, he says, the longer extension of the runway’s western end would act as a breakwater and reduce exposure to the waves from the open lake for water traffic using the western channel.

“We do not have a preference,” says Deluce, who adds that both extension proposals include 150-meter runway-end safety areas, which the airport currently lacks. Transport Canada has proposed a rulemaking requiring safety areas, “so we are being proactive,” he says.

Toronto city council has begun public consultations on the Porter plan, with the first workshop taking place Sept. 4. A further workshop is planned for Sept. 9 and an open town hall meeting for Sept. 12, Deluce says.

Staffers will report to the council’s executive committee on Sept. 24. Another executive meeting is planned for Dec. 5 and a full council meeting for Dec. 16, when a vote is expected. “We are keeping on track for a January 2016 delivery” of the first CSeries, he says.

In addition to approval for the runway extension, a 1983 tripartite agreement banning jets at Bill Bishop will have to be amended by its signatories: the city council, Toronto Port Authority and federal government.

Deluce says he is encouraged by public support for opening the downtown airport to jets able to fly longer routes, citing an online poll today by CBC that showed around 60% were in favor the plan, which would allow Porter to serve Vancouver, Florida and the Caribbean from Toronto.

Bombardier, meanwhile, is poised to begin high-speed taxi tests of the CSeries, the last major step before first flight. Medium-speed taxi tests began Sept. 1 after the first flight-test aircraft, FTV1 (a CS100), emerged from the paint shop at Mirabel, near Montreal.

[Editor’s note: This article has been updated to correct the three signatories for the 1983 tripartite agreement.]