Chloride in well water: road salt, taste and what to do
Chloride isn't a health risk at the levels found in wells. Above 250 mg/L (EPA and Ontario) water tastes salty and can corrode pipes and fixtures. A rising chloride level often points to road salt, a water softener or a septic system reaching the well.
- US (EPA)
- 250 mg/L cosmetic guideline.
- Ontario
- 250 mg/L aesthetic objective.
What it is
Chloride is the salt part of sodium chloride and other salts. Some groundwater is naturally salty, but in many areas the chloride in wells comes from road salt, salt storage piles, water softener discharge or septic systems.
What your number means
- Within limitsBelow 250 mg/L
No taste effect expected. If it was much lower on an earlier test, keep an eye on the trend.
- Worth a look250 to 500 mg/L
Water can taste salty, and chloride can speed up corrosion of pipes, water heaters and fixtures.
- Worth a lookAbove 500 mg/L
Strongly salty. Look for a salt source near the well, and check your sodium result too.
What to do
- Check your sodium result. High sodium and chloride together usually point to road salt or a water softener.
- Look for salt sources near the well: a salted road or driveway, a salt pile, or softener backwash draining nearby.
- If chloride is high and your pH is low, test for lead and copper at the kitchen tap, because salty, acidic water corrodes plumbing faster.
- For drinking water, reverse osmosis or distillation removes chloride. A water softener doesn't, and its backwash can add more.
How often to test
With a full panel every 3 to 5 years. Test every year if your well is near a salted road, and sooner if the water starts to taste salty.
Common questions
Is chloride in well water dangerous?
Not at the levels found in wells. The 250 mg/L limit is about taste and corrosion, not health. If your sodium is also high, share it with anyone on a low sodium diet.
Why did my chloride go up?
The most common reasons are road salt, a salt storage pile, water softener discharge or a nearby septic system. Rising chloride can be an early sign that surface water is reaching the well, so it's worth finding the source.
Sources: EPA secondary standards; Ontario: testing and treating private wells. Limits checked November 2026.