OTTAWA -- Security lines at Canadian airports could get worse without new funding, the agency in charge warns in its annual corporate plan.

CATSA, the Canadian Air Transport Security Authority, says the number of passengers keeps rising at the same time that the agency's staffing costs are growing. But the federal funding isn't keeping pace.

"Given its current reference [budget] levels and expected passenger growth and billing rate increases," the agency says in its report, its "Wait Time Impact Model is forecasting longer passenger wait times in 2017-18 reflecting CATSA's declining purchasing power starting."

CATSA aims to screen 85 per cent of passengers at major airports within 15 minutes, it says in a report first cited by Blacklock's Reporter.

That leaves about 10 million passengers waiting between 15 minutes and an hour for screening, says Daniel-Robert Gooch, president of the Canadian Airports Council, despite travellers in Canada paying to cover part of the security screening cost.

"Travellers are paying an air travellers' fee that is designed to cover the cost of their screening, but the money is not all going to fund the service that they're expecting," Gooch said in an interview with CTV News.

"It goes into general revenues and every year the government, the minister of finance as part of his budget, decides how much of that money is going to fund CATSA every year."

CATSA spokesperson Mathieu Larocque said the government collects the air travellers security charge and “the government decides the level of funding that CATSA receives.”

Larocque said CATSA’s costs are expected to rise, and the numbers of passengers are projected to increase, so wait times will go up without more funding. The primary cost is due to rising salaries based on the collective agreement CATSA's contractors reached with their staff (CATSA outsources the screening to private companies).

He pointed out that there is no government-mandated service level.

“If the funding that is projected for next year doesn’t increase,” he told CTV News, “then a lot less passengers will be screened within 15 minutes.”

Number of passengers increasing

The rates were set in 2010, according to Transport Canada's website, with passengers paying an air travellers security charge of $7.98 for a one-way domestic flight, up to $25.91 for an international trip.

Revenue and security expenses from 2010 to 2015 were expected to balance at about $3.3 million each.

But the number of travellers has increased significantly since 2010, according to the CATSA report. In 2010-11, the agency screened about 47.7 million passengers at Class 1 airports (Vancouver, Calgary, Edmonton, Winnipeg, Toronto, Ottawa, Montreal and Halifax).

Last year, that rose to 61.8 million passengers. By 2020-21, CATSA expects the number of passengers being screened to hit 69.5 million.

CATSA received one-year additional funding of $26.8 million in 2015-16, and $29 million in 2016-17, the report says.

"We understand that the air traveller security charge brought in about $110 million more last year than what was delivered to CATSA," Gooch said.

"It does go to other areas of aviation security as we understand, but the transparency on that could certainly be improved."

Gooch says Canada needs a funding model "that more nimbly responds" to growing traffic. He also wants to see any money raised through user fees spent on the service to which Canadians expect it to go.

"We need service level standards that provide predictability to the traveller and we need greater control over the passenger experience," he said.

Transport Minister Marc Garneau declined an on-camera interview request. His spokeswoman said in a statement that Transport Canada is working with CATSA to accelerate passenger and baggage screening.

"The government recognizes that a strong, integrated and modern transportation system is fundamental to Canada's continuing economic performance and competitiveness," Delphine Denis said in an email to CTV News.

This story has been updated to correct that the increased costs are due to salaries paid by the contractors CATSA employs to do airport screening, not due to CATSA staff salaries.

With a report by CTV's Kevin Gallagher