In most areas of Wisconsin, chloride in groundwater is naturally less than 10 ppm. Some higher concentrations in limestone and sandstone aquifers in eastern Wisconsin also may be natural.  Higher concentrations usually indicate contamination by septic systems, road salt, fertilizers, animal waste or other wastes.  High chloride may speed up corrosion in plumbing.

Acceptable results: Chloride has no health standard.  Levels less than 10 ppm are desirable.  Levels more than 250 ppm may cause a salty taste.

Sources:  Septic systems, road salt, fertilizer, animal waste, landfill or other wastes

Recommended testing: Annually