GRAND RAPIDS, Mich. -- An estimated 45 million Americans wear contact lenses, but despite what some of them may think, it's actually not a good idea to flush them down the toilet or sink.
According to a recent study, about 20 percent of people admit to flushing their lenses when they're done. Grand Rapids officials tell FOX 17 that some lenses won't ever be removed, and instead will be put right into the Grand River.
Water at the Grand Rapids Water Resource Recovery facility is somewhat clean, ready to make its way to the Grand River and eventually into Lake Michigan. But beneath the surface could be what's left of contact lenses that end up in sewers.
"Contact lenses should never go down the toilet, they should never wind up here," said Utilities Director Michael Lunn. "This plant is not made to treat contact lenses or any other kind of trash."
Lunn has 40 years of experience in water treatment and says contact lenses are just part of the problem.
"Your toilet is not a trash can," he said. "You should not put anything but paper, pee and poop in it because that's what this facility treats."
A study at Arizona State University found that roughly one in five contact wearers admit to flushing their lenses, with roughly 20 metric tons of contact lenses ending up in waste water every year. Whatever ends up in a sewer starts at the bar screens, which pulls out larger objects.
"We have quarter-inch bar screens that initially take the big objects out that we don't want to get into our pumps and pipes downstream," Lunn said.
From there it goes to the grid chamber, where lighter objects like soap and grease float to the top and heavier objects like rocks and sand fall to the bottom. This might catch some of the contacts, but not all of them.
"They’re likely going to end up in this tank and they’ll either wind up in the solids of the tank if they’re glass or heavier ones. The ones that’ll float will float to the top and come off the scum or if they’re some place in the middle and have buoyancy the same as water they’ll just float through the whole process back out to the river," Lunn said.
Lunn says contacts, like much of the waste that ends up here, seems small, but they add up fast. This facility sends nearly 15 yards of waste to a landfill each week.
"For the most part they just don't know," Lunn said. "They're used to the toilet being magic; you throw stuff in there and it goes away, right? They don't know what happens here and they're all invited for a tour here to find out what happens."
The Water Resource Recovery facility serves the city of Grand Rapids as well as 11 surrounding communities, including businesses, and about 270,000 people. Lunn says they spend up to $500,000 extra per year just removing things like flushable wipes, feminine products and things like contact lenses, from their pipes and pumps.