EGLE grant helps supporters combat salt in Rouge River

Don’t let mild February temperatures in much of the state fool you: Winter in Michigan isn’t over yet. There will be more snow, more ice, more rain, and – yes – more road salt. And some of that salt, or chloride, will end up in Michigan’s surface waters.

With help from an EGLE grant, Friends of the Rouge is taking multiple water samples from January to May at some 40 sites along the Rouge River to test for chloride. 

In Southeast Michigan, with support from the Michigan Department of Environment, Great Lakes, and Energy (EGLE), the nonprofit Friends of the Rouge is doing its part to protect its namesake river by researching the amount of chloride found in the waterway and the best ways to test for it.

The salt problem

Even small quantities of salt can have a big impact on the environment. According to EGLE water quality values, chloride concentrations of 150 parts per million (ppm) and above cause long-term, chronic effects to aquatic life, while levels of 320 ppm and above cause acute or toxic effects to aquatic life.

Chloride has been detected in many lakes and streams around Michigan, sometimes at high levels. And because there’s no easy way to remove it from water, efforts focus on keeping it out in the first place while ensuring motorist safety.

“We’ve been reducing salt usage and developing best practices for salt application for more than 20 years,” said Jocelyn Garza, communications specialist with the Michigan Department of Transportation (MDOT).

Brine (liquid salt solution), sand, and other materials are used in certain locations and conditions to keep roads safe for travel. Other practices include prewetting rock salt and lowering the speed of salt trucks to reduce scattering off the roadway. An MDOT pilot project is currently reviewing brine treatments during winter events in three locations across Michigan.

Sampling the Rouge

Part of understanding the environmental impact of salt is learning how much is out there, and where.

The Rouge River winds for 127 miles through Oakland, Washtenaw, and Wayne counties, draining more than 400 square miles before emptying into the Detroit River.

With help from an approximately $40,000 Watershed Council Support Grant from EGLE’s Nonpoint Source Program, Friends of the Rouge staff and interns are taking multiple samples from January-May at around 40 sites all along the river. EGLE staff have helped with feedback on collection sites and the logistics of sampling.

“One of our favorite aspects of this project was the collaboration between the nonprofit group and the department to the mutual benefit of both,” said EGLE Environmental Quality Analyst Jack Cotrone. “Friends of the Rouge builds capacity in its monitoring program, gathers useful water quality data to inform its work, and gets opportunities for public education on chloride pollution. EGLE also gets useful data on elevated chloride levels and methods for assessing them.”

Cotrone said the effort also could become a model for partnerships to monitor other watersheds.

Friends of the Rouge has monitored salt levels in the river since 2020, said Monitoring Manager Lauren Eaton. The group uses salt testing strips obtained free of charge from the national conservation nonprofit Izaak Walton League of America (IWLA).

Salinity data is collected at the group’s bug hunts and stonefly searches – macroinvertebrate surveys to gauge the river’s health. For example, the 2022 Fall Bug Hunt Report found seven test sites had toxic levels of chloride.

The new project uses four testing methods: the test strips, two different sensor readings, and collecting a sample bottle of water for analysis at a laboratory.

Eaton said the goal is to compare the methods and also to provide data to EGLE.

If inexpensive test strips and/or quick sensors are found to be as reliable as lab analysis, watershed groups might be able to assess more waterways for chloride more often.

The project began in September 2023 and will wrap up in December.

About Friends of the Rouge

Founded in 1986 to raise awareness about Rouge River cleanup needs, the nonprofit has a full-time staff of about 20 whose mission is to restore, protect, and enhance the river watershed through stewardship, education, and collaboration. Its bug hunts and other activities drew 7,691 volunteers in 2023, including hundreds of area schoolchildren.

Using salt responsibly

If you use salt to clear walkways or driveways around your house, you can help limit the impact on the environment by remembering four words: shovel, scatter, sweep, switch:

• Shovel snow first, before applying salt.
• Scatter salt so there is space between the grains and no clumps.
• Sweep up excess salt.
• Switch methods for temperatures below about 15 degrees, when salt will not melt ice effectively.

Visit the IWLA’s website to take the Salt Watch Pledge and order a free testing kit to see if road salt pollution is a problem in your local stream.