Michigan regulates livestock manure runoff

By Andi Anderson

A recent ruling by the Michigan Supreme Court has granted the state’s Department of Environment, Great Lakes, and Energy (EGLE) full authority to enforce stronger regulations on manure runoff from industrial animal agriculture.

This decision is expected to have significant implications for water quality across Michigan, which is home to nearly 300 concentrated animal feeding operations (CAFOs). These CAFOs produce the majority of the 4 billion gallons of untreated urine and feces generated annually by cows, hogs, chickens, and turkeys in the state.

Manure discharge from CAFOs often contains high levels of nitrates, phosphorus, and E.coli bacteria, which can leach into surface and groundwater. This runoff contributes to phosphorus pollution in Michigan's waterways, leading to toxic algal blooms in Lake Erie.

Until now, the agricultural industry, supported by the Michigan Farm Bureau, has resisted stronger regulations, arguing that they would make it more difficult for farmers to operate in the state.

With the new ruling, EGLE now has the power to take a range of actions to address the issue. Potential measures include requiring CAFOs to treat manure in wastewater facilities before spreading it on fields, or installing sensing and monitoring systems to detect leaks in manure storage tanks and lagoons.

The agency could impose limits on the levels of phosphorus, bacteria, and other pollutants in state waters and potentially restrict the number of animals housed in a CAFO.

While EGLE has not yet announced specific next steps, this ruling is being hailed as a significant victory for environmental advocates who have long pushed for stronger protections against manure pollution.

The decision marks a turning point in the state’s approach to managing the environmental impacts of large-scale livestock operations.

Regardless of the actions EGLE decides to take, the ruling represents a major step forward in protecting Michigan's water quality from the harmful effects of CAFO runoff.