Snow crunches beneath Gerry Nellestijn's boots as he walks over a century old tailings pond.

A short drive from the community of Ymir, south of Nelson, the tailings were abandoned after two nearby mines stopped operating in the 1940s. But the land remains polluted 鈥� a 2009 report found arsenic, cadmium, lead and zinc in the soil.

Even though the site is in the middle of a forest, trees that surround the perimeter are thin and short. Steps away at Wildhorse Creek, Nellestijn points out erosion on the bank that shows visible tailings he says are contaminating the water.

鈥淭his is the reality of it, and it goes on and on, site after site.鈥�

Inactive tailings ponds are where mining companies dumped and left their waste. The Ministry for Mining and Critical Minerals says there are approximately 140 such sites that it knows about across B.C.

But a new initiative is reconsidering what might have been left behind in tailings ponds, if they have any future extraction value, and how they might be remediated.

Geoscience BC, a non-profit organization that researches critical mineral and water issues, has started a program that will create a visual inventory of every tailings pond in the province. The map will be publicly available to search for locations, site history, what minerals were extracted and which First Nations hold relevant land rights.

Once the map is completed, work will begin on assessing whether any critical minerals such as lithium or cobalt exist at the sites, how they could be extracted and the sites remediated.

Critical minerals are considered essential to the future of mining in B.C. and Canada. The federal government has identified 34 minerals and metals it is prioritizing for the production of consumer and military technologies as well as clean-energy initiatives to meet domestic and international demand.

In B.C., the mining sector contributes $7.5 billion to the gross domestic product. The provincial government is developing its own plan set to be launched in 2025 with a goal of expediting new critical mining projects. The Mining Association of British Columbia meanwhile says 16 critical mining sites are also being considered.

Brady Clift, manager for Geoscience BC, said 20th-century mining operations were typically focused on minerals such as silver and, without having a crystal ball available, discarded what society values today.

鈥淭hey may have only been looking at the copper. So there could be a big pile of molybdenum, there could be zinc, there could be lead, there could be all kinds of other minerals that are on the [federal critical minerals] list now that didn't mean anything to them.鈥�

Geoscience BC's project is informed by work previously done by Nellestijn, a co-founder of the Salmo Watershed Streamkeepers Society that formed in 1998 as a community initiative to restore local watersheds.

The group has experience remediating tailings ponds. For 10 years Nellestijn advocated for cleaning up the former Yankee Girl site, which sits on the edge of a creek next to Ymir.

鈥淥ftentimes what we find are these tails are right on the edge of the river or on the edge of a tributary, and are accessible to erosion during high-water events. So they're constantly being dumped into the river, or they are accessible to the river through the water table.

鈥淪o definitely, our approach here is about trying to make this place a healthier place, to upgrade our water quality and to upgrade the habitat for aquatic species.鈥�

It took two years and $6.5 million to remediate Yankee Girl. The work was completed in 2009, and now the area is a community park and disc golf course.

Nellestijn says the process of cleaning Yankee Girl was far too expensive, partly due to requirements from current legislation regarding remediation. Money, however, might motivate mining companies to do the work themselves.

In 2017, Nellestijn was approached by Tyler Rice with an idea. Cassiar Gold owns the Sheep Creek gold claim southeast of Salmo that has been inactive since 1951. Rice, who lives in the Nelson area and works as senior advisor of corporate affairs with Cassiar, wanted to know if the site's tailings pile might be a viable tungsten source.

鈥淔rom my personal opinion, it's not necessarily let's go find new critical mineral resources," said Rice. "It's how can we more efficiently extrapolate what's already available to us.鈥�

At the time, the sample they took didn't suggest it was worth reprocessing. But the data they gained from the test led to provincial permission to test other sample sites in 2018 and 2019.

Geoscience BC took notice of what the pair had done, and this year added Rice to its project advisory committee.

Techological advances have made extracting minerals from waste rock more efficient and feasible. Last year a Vancouver mining company  for potential extraction at three mines that operated at the turn of the 20th century at Mount Sicker, located on the south of Vancouver Island.

Clift says mining companies used to consider extracting copper only if the cutoff grade was better than eight per cent of what they dug up. Anything less would be tossed into a waste pile, which today is creating sulphuric acid.

鈥淣ow you could extract stuff that's 0.15 per cent, which could be your cutoff grade. So you could extract a huge amount of copper that could probably be enough to pay for cleaning up that site. Plus someone can also make some money on top of it.鈥�

One barrier however could be the cost of returning to old sites.

Ten years after a breach at the Mount Polley tailings dam led to 25 million cubic metres of toxic waste contaminating a nearby lake and stream, Rice said liability costs associated with site cleanup have led to a hesitancy within the mining industry to take on historic tailings ponds.

The rules make sense, he said, but are still a barrier to convincing companies that critical minerals left behind in those ponds are worth the investment. 

鈥淚n good conscience, it's a good rule to have because you don't want just everyone going out and digging up these tails to see what they have in them, because you could be uncovering a massive environmental liability just through that initiative.鈥�

Any mineral extraction that leads to remediation is worth it to Nellestijn.

Although he isn't directly involved in the Geoscience BC project, he's supportive of it. Mapping tailings ponds is a starting point to deciding which sites can support further extraction and be cleaned up, he says, rather than left to pollute the environment for decades.

鈥淲e need to develop these holistic approaches that lead to remediation and restoration of habitat, and we should do that in a prioritized, functional way.鈥�