For several years, a few Islanders have kept focused on one particular issue in the long-simmering debate over Glacier Northwest’s plans to mine sand and gravel on Maury Island: Over and over, they’ve asked about the arsenic-laced soil, now dormant and thus relatively benign, that would be disturbed in the process of unearthing tons of sand and gravel.

Now, that issue is coming to a head. According to Rep. Sharon Nelson, D-Maury Island, activists fighting Glacier have discovered that there’s a bit of a catch-22 for the company. The county’s environmental impact statement says arsenic-contaminated soil has to be placed in a landfill. At the same time, the county’s 2006 comprehensive plan says a landfill cannot be placed over an aquifer such as the one beneath Glacier’s site.

And this, in turn, means Glacier would likely have to truck countless tons of soil off the Island. Vashon’s own landfill closed years ago.

Is this a deal-breaker? Could this be the death knell Islanders have sought in their sometimes quixotic quest to stop Glacier? It’s hard to know at this point — Glacier has powerful friends in its corner who will no doubt work assiduously to find an escape clause.

Either way, the latest development speaks to the tenacity of several Islanders — some high-profile, some not — who continue to work tirelessly to protect Vashon and the region from what many consider an ecologically disasterous plan. Let’s be thankful for their doggedness as we await the outcome of yet another twist in this decade-long drama.