Road salts, such as sodium chloride and magnesium chloride, are commonly used to control the accumulation of ice on roadways in the winter. While they keep our winter roads safer, winter deicers can cause widespread pollution in surface and groundwater. In urban areas like Chicago, there has been a significant increase in chloride in shallow sand and gravel aquifers due to them. Figure 1 explains how road salt can enter a private well.
Figure 1. Chloride pathways to water bodies
(used with permission- image credit - Pu Xia, 2021)
High levels of chloride can affect a well by giving the water a salty taste and increasing corrosion in your plumbing system. Road salts are not the only contributor to chloride levels in water. Other sources include fertilizers, wastewater, water treatment byproducts, and natural ones like the ocean and some weathering rocks. Chloride is listed as a secondary contaminant by the USEPA because it can cause a bad taste and corrosion.
When should I test for chloride in my well water?
The USEPA recommends removing chloride if greater than 250 milligrams per liter (mg/l) as this is when it begins to taste salty. To ensure you are protecting your family’s health, we have developed a set of recommendations for testing that are provided in our article, "What do I need to know about sampling my well water?". When testing your well water you will very rarely be testing for only one thing — like chloride — and instead testing for a suite of constituents that are important to identify if in your drinking water.
What treatment should I use if there is chloride in my well water?
How do I remove chloride from my water?
Once you test and have decided to treat your water to remove chloride, the Minnesota Department of Health has developed a Home Water Treatment Guide that covers treatment for any common constituent in well water. The most important advice we can provide you is if you are going to add treatment to your home water system, be sure the treatment device has been certified to remove iron by an independent third-party certification organization.
Where can I get local help and information about iron in my well water?
Contact your local health department – They can help you interpret your sample results and may have information on the best treatment options for your situation. If they personally aren’t able to answer your questions, they will know who to contact who will be able to help you, likely at your state health department.
Contact a water treatment professional – We would recommend contacting a water treatment professional who has been certified through the Water Quality Association’s Professional Certification Program.
State or Federal Geologic or Water Resource Agency – They may have completed field studies of your area or collected samples from water wells to map and understand the water quality in your state. In addition, they may house water well logs, including yours, or be able to provide additional information about the aquifer your well is getting water from.
Consult your well driller or drilling contractor – The contractor that drilled your well, and other local contractors, may be aware of the water quality issues nearby including high chloride, and might have worked with other well owners in your area to solve this issue.
Research online – You should be inquisitive; it will help you significantly because there can be great information available online. Use search terms like “my state (CA, ME, IL, etc.) water well logs,” “my state groundwater quality,” or “my state well water quality.”
Contact us directly – If these other local sources don’t work out for you, we may be able to help. We may be able to provide direct assistance, and/or direct you to a technical assistance provider in your area who can help answer your questions (This is a free service funded by USEPA).
Additional Resources
Xia, Pu. Environmental Impacts of Chloride Contamination. 2021. Illinois State Water Survey.
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