There are only about 500 year-round residents on Mackinac Island, but the popular tourist destination sees more than a million visitors every year.
The City of Mackinac Island is expanding and renovating its wastewater plant, with a $77 million dollar project that accounts for projected population and tourist growth.
Allen Burt, the island's director of public works, said the upgrades are long overdue and will increase the plant's capacity to handle sewage by 44%.
"The plant is designed to to be expandable to the full growth of the island, but for right now, we are covering our existing capacity needs and a few decades into the future in terms of more volume and loading capacity," Burt said.
The state recently pitched in nearly $40 million in funding to support the project. Burt said the city is taking advantage of federal infrastructure funding, which he considers a "once-in-a-lifetime" opportunity.
"(I don't think) we'll ever see infrastructure money like this in our lifetimes," Burt said. "So this is a very good opportunity to do a lot of much needed work, catch up, take advantage of it and then continue to plan into the future."
Infrastructure projects on the island are automatically more difficult and limit what the city can do, according to Burt.
For example, the public works department considered treatment options like an oxidation ditch, but the volume of concrete that would need to be hauled to the island is "well beyond the cost of what we could do."
"The vehicle restrictions and the complications with boats and time and weather and housing — it's all added to the complexity and the cost," Burt said.
Burt said the upgrades will result in a 5% rate increase for residences and 25% rate increase for commerical purposes, with the rates for a thousand gallons set respectively at $11.13 and $13.25.
The new system is scheduled to begin running in 2026, but Burt said the old one will not be abandoned immediately.
