A Canadian plan to build an underground nuclear waste dump less than a mile from Lake Huron is getting unfriendly attention from US lawmakers, who are trying to force the Obama administration to invoke a 106-year-old treaty against its northern neighbor.

Though a Canadian review panel declared that the proposed Deep Geologic Repository will have "no significant adverse effects on the Great Lakes," opponents wonder why a site so close to the world's largest freshwater system was chosen. One environmental group even warned that the project could give terrorists the opportunity to steal radioactive materials and blow up a "dirty bomb" in downtown Toronto.

The project would bury 7 million cubic feet worth of low and intermediate level nuclear waste — including contaminated mop heads, paper towels, floor sweepings, but also filters and reactor components — 2,230 feet underground. Ontario Power Generation, which operates two nuclear power plants in Canada's most populous province, has chosen a site just north of the lakefront town of Kincardine, after getting approval from the municipality.

The power company claims that the site is "ideal" for containing the waste, which will lay ensconced in limestone under a 660-foot layer of shale, a boundary they call "impermeable." The risk from earthquakes is low, they say, and the rock formations have been stable for millions of years.

Data from a government earthquake database reveal that over the past 10 years there have been about a half dozen earthquakes roughly 20 miles north of the site. At less than 2 on the Richter scale, all of those tremors were extremely weak. The most powerful quake in the region, which hit 4.3 on the scale, was about 50 miles away.

This March, a review panel recommended that the government approve the dump, claiming that the health risks to people living around the lakes are "virtually zero." It would take 10 million years for a water particle to move three feet from the site, the report's authors said. Even accounting for roof cave-ins and supposing near-ideal conditions for radiation leaks, their models show that "the maximum calculated dose rate" is 100,000 times lower than safe exposure levels for humans. The risks stemming from a range of "what-if" scenarios, like troublemakers breaking into the dump, was found to be within the "acceptable" range.

That report was sent to Canada's environment minister, who is expected to announce a decision in early December.

But many challenge the panel's impartiality, with the Sierra Club Canada saying it's stacked with ex-nuclear industry officials, and the Canadian Environmental Law Agency (CELA) calling its report biased, incomplete, and "fundamentally flawed."

"The members of the panel support nuclear power from the outset," the Sierra Club's program director, John Bennett, told VICE News. "They've never not approved a project."

CELA blasted the panel and the power company for only considering a "hypothetical" alternative to the DGR plan, without looking at a single other real-world site to bury the waste.

"The failure or refusal by OPG to conduct an appropriate site selection process leaves the [review panel] with insufficient information," the group wrote in a submission to the panel. "At a minimum, any future [environmental assessment] work must require OPG to conduct an actual investigation of at least one other site."

Environmentalists have found allies in a wide range of counties and municipalities around the Great Lakes. In July, the National Association of Counties issued a resolution calling on the president and the secretary of state to oppose the project. Now, both of Michigan's senators are trying to bring legislative pressure to bear on the administration.

Last week, Senators Debbie Stabenow and Gary Peters announced that they will introduce the Stop Nuclear Waste by Our Lakes Act. The law will call on the US State Department to invoke the 1909 Boundary Waters Treaty and demand a binational review of the project by the International Joint Commission, a body that mediates boundary disputes. Representative Dan Kildee of Michigan will introduce a similar bill in the House.

"Canada's plan to permanently store nuclear waste on the shores of Lake Huron is an unnecessary threat to both the US and Canada's shared water resources," Kildee said in a press release. "Invoking the Waters Treaty is the latest action to protect our Great Lakes and to ensure that a thorough review is done."

But the power company says that the project has already been studied to death.

"The study has been underway for about 14 years, and the senator is calling for more science," company spokesman Neal Kelly told VICE News. "Well the science is there, and it's all peer reviewed. This is the most comprehensive environmental assessment you can go through in this country."

The State Department seems to agree. A department representative told VICE News that, along with the US Environmental Protection Agency, they are participating in the Canadian review process, which they consider "the appropriate channel for providing US input on this proposal." They said they have no plans to call for the binational review the senators are demanding.

"Our agencies are reviewing the draft version of the conditions required for the Deep Geological Repository project. Any comments will be provided within the review period," the representative said. "We do not plan to refer the project to the International Joint Commission."

It would take a major bipartisan effort for Stabenow, Peters, and Kildee to force the State Department to reverse course. Even if they get their bill through the House and the Senate, the president would still have the option of simply vetoing the law in the absence of a two-thirds majority in both chambers.

According to some, the risks go beyond environmental and health concerns, touching on national security. With waste traveling from the Pickering and Darlington power plants, both hundreds of miles away from Kincardine, the Sierra Club worries about what could happen during transit. Bennett warns that terrorists could intercept radioactive materials and use them to build a so-called "dirty bomb," which would spread deadly radiation by blowing it up with conventional explosives.

"They're opening themselves up to mishaps on the road," he told VICE News. "There could be anything from traffic mishaps to serious terrorist activities. Terrorists carrying one of those giant cylinders of nuclear waste could be on Bay Street in downtown Toronto before anyone even knew it was missing."

That's hardly an imminent risk, however. According to Kelly, the DGR won't be built for another five to seven years, and would still need to secure an operating license before waste could start moving to the site. Presumably, that would give authorities ample time to devise plans to secure the shipments.