US researchers say that at least one underground site is operating on American soil, and they predict that a public operation will open despite the potential consequences.

“That is the way that drug policy issues have moved forward in this country [over the] last 25 years,” said Alex Kral, an epidemiologist at the think tank RTI International, who has studied supervised drug consumption. Cities enduring the deaths, disease, crime and cost of drug epidemics have taken the lead in handing out free needles and distributing the overdose antidote naloxone – sometimes after legal battles.

San Francisco plans to add supervised injection services to an existing community health facility. Those could start as soon as July 1.

“We just have to do what’s best for the client, and we hope the federal government will understand,” said Barbara Garcia, director of health for the city and county of San Francisco. “I’m not looking to change federal law. I’m looking to save lives.”

Canada’s plans do not stop at supervised injection. Some sites now test users’ drugs for fentanyl, and some are aiming to provide prescription opioids from vending machines.

The most far-reaching intervention is just two blocks from the pop-up site, where the Providence Crosstown Clinic provides 130 of the city’s most hard-core drug users with pharmaceutical-grade heroin and other narcotics. Users come to inject themselves as often as three times a day, and some also swallow a morphine tablet to carry them through the night.

Freed of the need to steal, beg and trade sex for drug money, some now have apartments and jobs. The clinic, run by a medical centre, hopes to add 50 more clients soon.

“The ability to say ‘I’m receiving treatment, I’m not a dirty user’ does so much for their self-esteem,” said Jennifer Mackenzie, the clinical nurse leader. “It opens so many doors for them. They’re getting medical treatment, and they look at themselves differently.”

Research shows that the approach, like supervised drug consumption, saves lives, cuts criminal justice and health care costs, limits the spread of diseases such as HIV and helps reduce used needles and other debris in its immediate neighbourhood. A similar facility recently opened in Ottawa, and Canada has loosened requirements to encourage still others.

But British Columbia’s programmes have not blunted its opioid crisis. Overdose deaths have skyrocketed from fewer than 400 in 2014, when fentanyl became widely available on the street, to more than 1,400 in 2017. Eighty-one per cent of last year’s deaths involved fentanyl.

Critics said that statistic speaks to the futility of harm reduction. “To say the best we can do is to revive people who are victims and are going to be victims again … is reprehensible,” said John Walters, drug tsar under President George W. Bush and now chief operating officer of the Hudson Institute, a conservative think-tank in Washington.

Walters favours a dramatic expansion of drug treatment in the United States, which recorded 42,000 opioid deaths in 2016, coupled with a much more concerted effort to keep drugs such as fentanyl out of the country. He questions the rigour of the academic studies that support harm reduction. And he believes that normalisation and tolerance of drug use are reasons that addicts crowd the streets of this city’s small Downtown Eastside district.

“Look at Vancouver, it’s tried every bad policy you can try,” Walters said. “This is another step in that whole policy that has made Vancouver a nightmare.”

Drug smokers like Coleman are still restricted to the Overdose Prevention Society’s outdoor tents because the new building, a former grocery, has no ventilation system. It is home mostly to injection drug users. A long, narrow main room is nearly bare except for 13 stainless-steel tables and some posters on the walls. Red partitions divide the rest of the floor, making space for a couple of desks, a cot where workers can calm down after resuscitating an overdose victim, and supplies piled high in boxes.

The most critical are oxygen and naloxone, the antidote that has saved countless lives. In the 30 years that supervised sites have been open in Europe, and the 15 years that they have existed in Canada, no site has suffered an overdose death, Kral said.

Users enter here through a guarded door off a back alley that used to be the scene of widespread drug use, dealing and prostitution. A small street shrine to a dead woman sits just outside the entrance.

From a small table of supplies they pick up what they need: syringes, matches, elastic strips to tie off veins, water to dilute drugs, small squares of foil, tiny tins for cooking heroin. Also available are condoms and lube.

Some of the volunteers who greet them are current or former users themselves. They usher clients to the tables. On a clipboard, one staff member logs names (usually aliases), gender, the drugs being used and the time a person comes in. Between the indoor and outdoor sections, 300 to 700 people show up daily. The largest crowds are on days when welfare payments arrive.

The pop-up was born of necessity in late 2016, when fentanyl was overwhelming the neighbourhood and a 15-year-old supervised-use programme. Overdoses on the street would send panicked bystanders to a nearby open-air market to find naloxone or call an ambulance.

“If there was an overdose, they would come running to the market and we would have Narcan ready,” Blyth said, using the antidote’s brand name. “Then it became so frequent that it was happening all the time. We had no choice really.” A GoFundMe campaign started the tent facility. Aid from the government followed.

The organisers acknowledge that their main goal is just to keep people alive, though they have seen a few clients get into treatment and off drugs.

“If these services didn’t exist, trust me, it would have been a catastrophe, especially in the past year and a half, when the fentanyl crisis spiked,” said RonnieGrigg, a large, soft-spoken man with a chest-length beard who helps manage the site. In the past three years, Grigg said, 100 people he knew have died of overdoses.

At the Providence Crosstown Clinic a short walk along West Hastings Street, some users measure their addictions in decades.

Nothing else has worked for these men and women, who clinically are in the grip of “severe opioid disorder.” Methadone has proven ineffective, as have therapeutic approaches such as 12-step programmes. Most of them no longer feel any pleasure from the drugs; they take them simply to function and prevent severe withdrawal symptoms.

“It makes me feel normal,” explained a 52-year-old woman named Lori, who did not want her last name used.

Other than more than a decade on drugs, Lori leads a fairly unremarkable life. She has two grown children who don’t know about her twice-a-day clinic visits. She is married and holds a part-time job in a call centre, taking customer service complaints. She is clearheaded and contemplative.

Over time, the cost of her habit reached US$200 a day. In 2011, she heard about a research study at the clinic and began getting her drugs there.

“Thank God, because I would be on the street,” she said. “Everything would be finished. My marriage would be over. I don’t think I’d be here.”