With less than month left to go until recreational marijuana becomes legal in Canada, CTV News travelled south of the border in an effort to answer the questions that remain about what legalization might look like in British Columbia.

Voters in Washington state passed Initiative 502 in 2012, making the state one of the first two in the country to legalize marijuana.

The initiative made possession of up to an ounce, or 28 grams, of pot legal among adults over the age of 21. The first recreational marijuana stores in the state opened their doors in July 2014.

Fears have not materialized

Since then, state officials in Olympia, Washington's capital, say many of the initial fears around legalization, such as increased pot use among minors, have not materialized.

"We thought…legalization (would) make it more available and youth would use it," said Rick Garza, director of the Washington State Liquor and Cannabis Board.

In fact, the opposite has happened.

A statewide survey suggests that in 2010, two years before legalization, 20 per cent of Grade 10 students reported using marijuana in the month before being surveyed.

By 2016, four years after recreational use of the drug was legalized, that number had dropped to 17 per cent.

"We were surprised to see the number remained stable—that it hadn't increased," Garza said.

What did climb was the revenue flowing into state coffers in the form of tax dollars.

In 2015, the state was able to make more than $65 million on legalized pot. That number almost tripled the next year to nearly US$190 million. Last year, the state pulled in a staggering $319 million in sales taxes—far higher than anyone had predicted.

That kind of money has allowed Washington's government to invest in services for residents, including Medicaid.

"Half of the revenue, 50 per cent, goes to fund the basic health care plan in Washington," Garza said.

Another positive byproduct of legalization has been its effect on shrinking the marijuana black market.

"I suspect at least 50 per cent of the marketplace is now legal," Garza said.

But with state regulators collecting a hefty 37-per-cent excise tax on recreational pot, the industry has not been an easy one to stay afloat in for some retailers.

"You've really got to watch your sales and a lot of people didn't do that so in the first year, they started noticing the problem and they started falling off rather quickly," said Eric Sanchez, who works at a dispensary. "If Canada wants the businessmen to succeed, they should watch the taxes."

DUIs, poisoning calls trending upwards

Police officers in Washington, however, aren't as thrilled about the effects of legalization.

"We have been making more DUI drug-related arrests," said Lt. Rob Sharpe of the Washington State Patrol.

Data suggest the number of drivers involved in fatal crashes in the state who tested positive for marijuana was on its way down before commercial sales began in 2014, but started rising again when the drug became for widely available.

Sharpe encouraged Canadian law enforcement "stay the course on training officers to determine impairment."

As for the health impacts, calls to the Washington Poison Center have doubled since legalization. Last year, the center received 400 calls related to cannabis exposure.

Still, top bureaucrats say these apparent drawbacks of legalization are having a relatively small impact in an initiative they call a big win for Washington.

"If you go to the consumers or the citizens of the state, they thought it was going to have a more negative impact that it has," Garza said.

On Oct. 17, Canada will become the second country in the world to legalize recreational marijuana. Starting that day, British Columbians aged 19 or over will be allowed to possess up to 30 grams of dried cannabis in public.

Adults will also be allowed to cultivate up to four pot plants per household and prepare cannabis products such as edibles, as long as they are for personal consumption only.

Pot products will be sold in government stores that will operate both online and in brick-and-mortar locations as well as by private, licensed businesses.

The decision to allow the sale of non-medical marijuana has been left up to individual municipalities in B.C., some of which, including West Vancouver, Richmond, North Vancouver and Delta, have decided to prohibit the production and retail sale of cannabis altogether.

Only time will tell if and how British Columbia's experience might resemble Washington's, but Garza said if the state has learned anything, it's the importance of not rushing into legalization.

"I think the lesson learned was take your time in putting your regulations together," he said.

With files from CTV Vancouver's Scott Roberts