Salt level rising in Michigan groundwaters, endangering crops, homes

A worrisome environmental issue is bubbling up from deep below Michigan’s ground with little public awareness, experts say.

The salinity of the state’s groundwater is on the rise, raising concerns about killed crops and corroded pipes.

The problem is increasingly severe and requires action, but Michigan residents and lawmakers struggle to recognize it, said Alan Steinman, a Grand Valley State University water researcher and board member of the Alliance for the Great Lakes.

“It’s hard for people to imagine that we have a water problem in Michigan when their view is the Great Lakes,” he said. “Because we’re surrounded by so much water, they can’t imagine that we’re having an issue with the supply.”

To understand why it’s happening, go back to Michigan’s prehistoric roots, Steinman said.

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Before glaciers shaped the state, Michigan sat on an ancient seabed, he said. Today, that salty water sits thousands of feet below ground in deep aquifers.

Above them are potable “surface aquifers” with non-saline water from the glaciers. Over time, people depleted them and started drilling deeper and deeper wells, often punching into the salty water below, Steinman said.

The problem is worse along the shorelines, where the bowl-shaped deep aquifers are closest to the surface. Agricultural areas in Southwest Michigan and the Thumb are already facing problems, Steinman said.

In Ottawa County, troubles became evident almost 20 years ago.

In 2006, a farmer called the county for help after he woke up to a field of crops “burned to a crisp” by saline water he was pumping from a deep well, said Paul Sachs, the county’s director of strategic impact.

The county secured state funding to study the situation, he said. It found that an aquifer of salty water sat high underground in the central parts of the county. Tests found that the water could be nine times saltier than the ocean.

In the years since, the county has used state funding to closely monitor its water supply and attempts to drill wells in the right places, hopefully avoiding the wrong aquifers, Sachs said.

The long-term solution, however, will involve a shift in how the public thinks about water, with a new emphasis on conservation, he said.

Sachs said he suspects that will be tricky, because Michigan residents don’t think about water as limited.

“We’re the Great Lakes state – we seem to have water everywhere,” Sachs said. “So, up to this point, it hasn’t been necessary to think about practical water reuse and conservation like you see in the more arid parts of the country.”

Ottawa County is also unique in being heavily studied and understood. The geology and water salinity of the rest of the state is largely a mystery, said Steinman, the researcher.

“We don’t know how problematic this will be across the state,” he said. “We talk about water being the identity of Michigan, and yet we don’t know much about what we use.”

Michigan’s Water Use Advisory Council recommended the state invest in data collection and mapping of wells and aquifers in its 2022 report. The proposed cost would be $3 million a year.

That’s costly, Stenman said, but necessary.

“It would be very expensive,” he said. “But think about the cost of surface aquifers going dry and agriculture having water conflicts with residential users. Those potential costs could be enormous.”

Some other human activities directly increase the salinity of groundwater.

Popular water filters create saline backwash that’s often drained right into the water supply, said Eric Chatterson, a geology specialist in the Department of Environment, Great Lakes and Energy’s Water Resources Division.

The sodium and chloride the filters produce can’t be removed by most wastewater treatment plants, he said.

Michigan once had strict limits on the amount of sodium and chloride that could be discharged, Chatterson said.

But, a 2013 law greatly raised those limits after lobbying by the restaurant industry, which argued that the filtration systems are necessary to make clear ice cubes.

Environmental advocates unsuccessfully opposed that change.

“We were trying to clamp down and making people clean up a bit,” Chatterson said. “Then the restaurant association called the Legislature, and they passed a bill that raised the limits.”