Each day, the Madison Metropolitan Sewerage District’s Nine Springs Wastewater Treatment plant receives more salt than this pile dissolved in wastewater coming to the plant. The treatment plant isn't designed to remove dissolved salt, so it passes through the treatment plant into freshwater streams. At high enough levels, the chloride from salt can threaten freshwater plants and animals, which can't tolerate salt water.
In Wisconsin, researchers have determined that long-term exposure to a chloride concentration of 395 milligrams per liter or higher can be harmful to freshwater life — a concentration equal to about half of a tablespoon of salt in five gallons of water. At times, the concentration of chloride that reaches the treatment plant is higher than 395, reflecting chloride contributions from sources such as water softening systems, industrial sources and winter ice control.
It all adds up
It's easy to add salt to water, but costly and energy-intensive to remove it. While it only costs 20 cents to add a pound of salt to water, it would cost five dollars to remove it. To build treatment technology to reduce chloride at the treatment plant, it would cost over $400 million -- meaning higher sewer bills. Fortunately, there is another way. Rather than adding costly treatment to continue protecting our freshwater life, we can reduce chloride at the source. Together, we can take steps to reduce the amount of salt put into water.
Chloride FAQ - Learn More.
More than 100,000 water softeners are tributary to MMSD’s Nine Springs Wastewater Treatment Plant, delivering about 60% of the chloride going to our fresh water.
- Large buildings like apartments, hotels, schools, factories and other commercial/industrial facilities can use a significant amount of salt, particularly for systems like laundry, heating/cooling and industrial processes. Updating your soft water system will not only reduce the amount of salt that flows to MMSD’s plant, but it could additionally save you money on your operations.
- Commercial & Industrial Grant programs for large water softeners
- Case Studies
- Schedule a free salt assessment with a pollution prevention specialist: PP@Madsewer.org
- Learn more...
- With an efficient softener, most homes will use a bag of salt per month, or less.
- Old softeners can use more salt than is needed. Upgrading them with a new high-efficiency is recommended.
- If you're in the market for a new softener, consider replacing with these Best Practices
- Check the settings on your softener, or have a professional hep you optimize it - even new softeners may be set up inefficiently
- Evaluate your water softener now !
Be WI Salt Wise! - Adopt Water and Winter- Friendly Procedures
Chlorides are an issue for all local waters, including groundwater, drinking water, lakes and rivers. The health of our waters needs to be considered along with Wisconsin residents’ desire to have dry roads, dry parking lots and dry sidewalks immediately after winter storm events.
Let's work to protect our water resources by employing effective winter maintenance methods to avoid the over-use of road salt products. Remember to "Shovel, Scatter, Switch", or in otherwords, remove the snow first, use the correct tools, prevent compaction, understand the size of the area you’re working with and most importantly, use the correct amount of salt (cups are available). For more information on how you can help Wisconsin’s waters, visit WiSaltWise.com: