MINNEAPOLIS (WCCO) — Most people are used to seeing mussels on a dinner plate, steamed in white wine and swimming in garlic.
But at Minneapolis Water Treatment and Distribution Services, 12 mussels are the muscle behind clean and safe water.
“They are filter feeders, so they are feeding off of the water that’s in there, pulling the nutrients down,” said George Kraynick of Minneapolis Water Works.
Snuggled up side by side, a dozen mollusks live in a tank with water continuously being cycled in from the Mississippi River. If the mollusks come across anything funky like gasoline or heavy metals, they’ll all clam up, setting off tiny sensors attached to their shells.
“Those wires are connected to a computer that we have and it will actually show a flat line telling us that they have closed,” said Kraynick.
Minneapolis is the only city in the country that uses mussels in what’s technically called a bio-monitoring system. With how far science has come, this is a slightly primitive way to be looking at water quality, but it really works.
“They live for up to 50 years, they are there 24/7 and they are happy in the tank, just feeding,” said Kraynick.
Since the mussels went on duty more than 10 years ago, the city hasn’t seen a major spill or contamination that has triggered the alert system. Once this particular group mussels outgrow the tank, they won’t end up on anyone’s dinner plate.
“Most likely, we will just set them free in the river. They’ve served their time,” said Kraynick. “They’re still young, they have a long life to lead.”
Right now, the city is in the process of upgrading their alert system. Before the end of the summer, officials will be able to get text messages and emails about the mussels’ activity and their response to the water quality.
By the way, the mussels do not have names.