Chloride Monitoring in Crow Wing County Minnesota

Chloride or salt is a naturally occurring element and a permanent pollutant. One teaspoon of chloride pollutes five gallons of water.

The current Minnesota Pollution Control Agency (MPCA) Standards are as follows: a stream, lake or wetland is impaired by chloride if two or more samples exceed 230 mg/L within a three-year period; or one sample exceeds 860 mg/L . As of 2022, 54 Minnesota waterbodies are impaired, with chloride being identified as the primary pollutant or stressor. Common chloride or salt sources include: Road Salt Water Softeners Fertilizers Manure Dust Suppressants

Sources:  Statewide Chloride Management Plan  and  Minnesota’s Impaired Waters List 

Drinking Water: Salt has contaminated groundwater in some areas of the state, and 75% of Minnesotans rely on groundwater for drinking water. Excess salt can affect the taste and healthfulness of drinking water. 

Fish and Aquatic Bugs: High amounts of chloride are toxic to fish, aquatic bugs, and amphibians. Chloride can negatively affect the fish and insect community structure, diversity, and productivity, even at lower levels.

Plants: Road salt splash can kill plants and trees along the roadside, and plants that take up salty water through their roots can also suffer. Chloride in streams, lakes, and wetlands harms aquatic vegetation and can change the plant community structure.

Soil: Salt-laden soil can lose its ability to retain water and store nutrients and be more prone to erosion and sediment runoff (which also harms water quality).

Pets: Salt can sicken pets who consume it, lick it off their paws, or drink salty snow melt/runoff. It can also irritate their paw pads.

Wildlife: Some birds, like finches and house sparrows, can die from ingesting deicing salt. Some salt-sensitive species are particularly at risk.

Infrastructure: Chloride corrodes road surfaces and bridges and damages reinforcing rods, increasing maintenance and repair costs.

Source: MPCA

Road salt is the number one source of chloride use in Minnesota.

An estimated 403,600 tons of road salt is applied in Minnesota annually (based off of 2016 data).

A University of Minnesota study found about 78% of salt applied in the Twin Cities for winter maintenance is either transported to groundwater or remains in the local lakes and wetlands (based off of 2008 data).

Most of the chloride research is conducted in the metro area of Minnesota. Crow Wing Soil and Water Conservation District (SWCD) and the Crow Wing County Highway Department (Highway Department) collaborated to change that.

Sources:  Chloride Contributions from Water Softeners and Other Domestic, Commercial, Industrial, and Agricultural Sources to Minnesota Waters ,  Chloride ion transport and mass balance in a metropolitan area using road salt , and  Minnesota's Chloride Conditions 

The purpose is to monitor chloride levels to ensure winter snow and ice removal efforts are not rapidly contributing to chloride levels in area lakes.

In 2019, ten lakes were selected to conduct chloride monitoring. Lakes were selected by their proximity to major highways. These lakes will be sampled spring, summer, and fall at the surface and near the lake bottom.

1. Big Trout
2. Crosslake
3. Gilbert
4. Lake Edward
5. Nokay
6. Pelican
7. Rabbit
8. Rock
9. Ross
10. Upper South Long

Browse the map below to view selected lakes and monitoring locations.

Crow Wing County chloride samples indicate low levels of chloride. The lowest reading obtained on Ross Lake in Ross Lake Township was 1.22 mg/L. The highest reading obtained on Gilbert Lake in Baxter was 15.9 mg/L. This is far below the MPCA's 230 mg/L standard.

Annually, the Highway Department offers Smart Salting Level 1 Roads training to their road salt applicators. It covers high and low speed snowplow operation best management practices. This training is hosted by the MCPA.

The Highway Department is Level 2 certified, which means that they have assessed their salt use using the Smart Salting Assessment Tool and took steps to minimize their impacts.

They have created a Snow and Ice Operations Methodology. This explains how they prioritize and perform winter maintenance on roads in Crow Wing County.

They have created a webpage that tracks their salt, sand, and brine use for each snowfall event. They have an interactive map that allows residents to track 16 county snowplows.

Sources:  Snow and Ice Operations Methodology ,  Snow Plowing Priority ,  Snow Plow Events,  and  Where's my snowplow? 

Smart Salting Classes Hosted in Crow Wing County

Property Management

Certification for management-level property managers or local government decision-makers to learn how to save money and protect water resources by using less salt while maintaining safe paved surfaces

Valid for 3 years

Level 1 Training

Roads: High and low speed snowplow operation

Parking Lots & Sidewalks: Maintaining private/public walkways and/or parking lots and service roads

Valid for 5 years

Level 2 Training

Certification for public and private organizations to help assess salt use and take steps to minimize it

Valid for 2 years 

 Smart Salting Training Calendar 

The Izaak Walton League of America Encourages citizens in Minnesota to monitor chloride levels in their streams, lakes and wetlands to help advocate for smarter salt use in their communities.

Free salt watch test kit includes 4 chloride test strips and instructional card.

Sign up  here  to get a kit delivered to your house.

If you have any questions about chloride monitoring in Crow Wing County, contact Bethany at 218-828-6197 or bethany@cwswcd.org.