VANCOUVER - A tentative contract reached by civic workers in suburban Richmond may have opened the door a tiny crack to solving the full-scale municipal strike in Vancouver.

Vancouver Mayor Sam Sullivan noted Wednesday that the deal in Richmond runs for five years and said he'd be willing to consider such a contract if the city's union leaders were amenable.

A source told The Canadian Press the tentative Richmond deal will give civic workers an 18.5 per cent pay increase over five years, as well as improved benefits and working conditions.

One of the key obstacles to reaching an agreement in Vancouver has been the length of a contract, with the city demanding labour peace through the 2010 Olympics.

Sullivan said the union has only proposed two and four-year deals - terms the city finds unacceptable because they would end either too close to an Olympics or too close to a civic election.

"I am open-minded about a five-year contract because it addresses my concerns about three-and four-year contracts," the mayor said in a news release.

"If . . . they are now open to a five year deal - and are prepared to come back with an affordable position - we will be prepared to consider it."

Barry O'Neill, the B.C. president of the Canadian Union of Public Employees, denied the city has ever before floated a five-year deal.

He said movement on the length of the contract is "a positive step forward."

"But there is a lot more to a collective agreement than wage and term," he said.

He urged the city to return to the bargaining table, where the union has said it has been waiting for talks for days.

"It is reasonable for us to expect that in return for security through the Olympics, for instance, job security for Vancouver's civic workers needs also to be addressed," said O'Neill.

Vancouver entered a full-scale strike this week as garbage pickup was halted and swimming pools, community centres and even some libraries were closed.

Business organizations in the city are worried a prolonged strike will impact tourism as garbage piles up and stews in the hot summer sun.

They're also worried about the impact on the construction and development industries as the city permit office remains closed and water and sewer hookups are on hold.

The first competition in the city's annual fireworks festival was going ahead Wednesday night. The event draws a crowd of hundreds of thousands of people.

As well, the gay pride festival begins this weekend.

Both events generate huge amounts of garbage, but people are being urged to take their trash home with them.

Officials at the Vancouver Aquarium issued a news release warning that garbage left along the beach where the fireworks are best viewed could cause a serious hazard to marine animals.

Cigarette butts, balloons, bags, food wrappers, beverage containers, straws, utensils and cups can be mistaken for food and once ingested, can lead to suffocation or starvation, the release said.

"It's really important that people take their litter home with them after the fireworks," said Jason Boyce, the aquarium's manager of conservation programs.

"It's not just an eyesore or an issue of odour. It's a major health concern for our oceans and the animals that live in or around the water."

Sealife affected can include harbour seals, porpoises and rockfish, as well as killer whales, sea lions and leatherback turtles if the litter drifts out to the open ocean, Boyce said.

Meanwhile, city councillors approved a motion to give any money saved during the strike back to homeowners in the form of property tax cuts in 2008.

Sullivan has been quoted as saying it's an "urban myth" that a strike saves the city money.

But Vision Vancouver, the opposition political party in the city, said according to a staff report, in 2000 a seven-week strike involving more than 4,000 workers resulted in a net savings of $1.3 million to the city.

Vancouver residents have been warned the strike could last up to two months .