TRAVERSE CITY — Cyanide in groundwater beneath the Hotel Indigo construction site poses a threat to the health of nearby Grand Traverse Bay, and has sparked an investigation into whether the toxin already is migrating into the picturesque body of water.
Local officials on Friday stressed that significantly high cyanide levels are not considered a threat to public health. They said swimmers or others who regularly use the bay for recreational purposes should not be concerned, even if the toxin is seeping into the bay through an underwater aquifer.
But documents obtained by the Record-Eagle through a state Freedom of Information Act request show cyanide levels found in groundwater pose a threat to the bay's ecosystem.
Measurements of cyanide in groundwater at the Indigo site along Grandview Parkway measured as high as 1,200 parts per billion on June 21. That figure is more than 100 times higher than acceptable levels of environmental cleanup standards for aquatic health set by Michigan for bodies of water like Grand Traverse Bay, said local environmental consultant Chris Grobbel.
“It’s significant,” said Grobbel. “We have rules and laws in place to prevent this type of thing because we care about the health of our waterways.”
Jean Derenzy, deputy director of Grand Traverse County's Planning & Development Department, said last week that Hotel Indigo's spring 2014 opening will be delayed because higher-than-expected levels of cyanide were discovered in groundwater at the site.
Cyanide of that concentration requires extensive pre-treatment of groundwater before it can be dispatched to a wastewater treatment plant. That necessity in turn translates into unexpected costs for the project’s developer, Jeff Schmitz.
Schmitz did not respond to a request for comment on this story.
Derenzy said the surprise cyanide levels spike prompted state Department of Environmental Quality officials to allocate more than $600,000 to the brownfield project to help with on-site water treatment. Cyanide-contaminated water is being treated with bleach on-site, Derenzy said, before it is sent to the treatment facility.