Jack Lessenberry for Thursday, May 25th, 2017.

I want to warn you that today, I’m going to be talking about poop. Specifically, more than 3.3 billion gallons of it a year, all of it produced in Michigan by what are euphemistically called “Concentrated Animal Feeding Operations,” or CAFOs.

Many of us call them “Factory Farms” instead. They are places where animals are crowded in what are anything but humane conditions to be fattened as quickly as possible for slaughter, or if they are cows, drained of their milk.

But beyond animal cruelty, what I’m concerned about is our drinking water. Three years ago, toxic algal blooms in Lake Erie left the water unsafe to drink for a few days.

That hasn’t happened again. But we now have new evidence that suggests strongly that, as Pam Taylor put it in a report she sent me yesterday, “unless efforts are targeted, it’s just a matter of time before another toxic mass floats into another municipal water intake somewhere in the Great Lakes."

"Where," she asked, "will it happen next?”

Taylor is a former teacher whose family has been farming in southern Michigan’s Lenawee County since Michigan became a state. Some years ago, she became concerned about what our farming practices are doing to the environment, especially our water.

So she joined the Environmentally Concerned Citizens of South Central Michigan, and has been studying specifically how much manure Michigan’s factory farms produce and how it is treated. This week, her group released a new report called A Watershed Moment, which I read last night. I don’t recommend it as bedtime reading.

Factory farms or CAFOs, by the way, are operations that have at least 2,500 animals. There are 272 of these in Michigan, which all told house nearly 21 million animals.

And they produce billions of gallons of manure – 80% of it from dairy cattle. This is not chemically treated like human sewage; it tends to be stored in vast cesspools bizarrely called “lagoons.” Later, it is mixed with groundwater and spread as fertilizer, where way too much of it gets into Lake Erie.

The manure contains phosphorus, which actually feeds cyanobacteria, which produces a toxin. The federal government has been spending millions to try and keep phosphorous from entering the Great Lakes, but at the same gives millions to factory farms to keep on doing what they are doing.

Taylor looked hard at the River Raisin in Monroe County, which flows into Lake Erie, and found that “while the level of total phosphorous has declined greatly over the years, the amount of dissolved phosphorus,” the stuff that actually feeds the algae and cyanobacteria, has almost doubled since the 1990s.

By the way, the most dangerous place may be the Saginaw Bay-Lake Huron area, where there are a huge number of these farms in a small area – which together have racked up hundreds of environmental enforcement citations from the state.

What we need to do is clear. Outlaw putting fertilizer on frozen ground, where it can run off more readily; make requirements tougher and stop giving money that could be used to save the earth as subsidies for polluting CAFOs. Those are all no-brainers.

The Watershed Moment document quotes Gordon Lightfoot, but clichéd as it is, I would have preferred Joni Mitchell. Sometimes, you really don’t know what you’ve got 'til it’s gone.

Jack Lessenberry is Michigan Radio’s Senior Political Analyst. Views expressed in his essays are his own and do not necessarily reflect those of Michigan Radio, its management or the station licensee, The University of Michigan.