Well water test results, explained

Pick the result on your report. Each guide covers the limit, what your number means and what to do. Or decode your whole report at once.

• Total coliformTotal coliform bacteria aren't usually harmful on their own, but finding them means something from the surface or soil can reach your well.
• E. coliE.
• NitrateThe limit is 10 mg/L of nitrate as nitrogen.
• ArsenicThe limit is 0.010 mg/L, the same as 10 µg/L or 10 ppb.
• LeadLead in well water almost always comes from plumbing, not the aquifer.
• ManganeseAbove 0.05 mg/L, manganese causes black or brown stains and a bitter taste.
• IronIron isn't a health risk at well water levels.
• UraniumThe EPA limit is 30 µg/L and Ontario's is 20 µg/L.
• HardnessHardness isn't a health concern.
• pHThe recommended range is 6.5 to 8.5.
• SodiumSodium isn't a concern for most people.
• FluorideAbove 2 mg/L, fluoride can cause white spots on children's teeth.
• CopperCopper usually comes from copper pipes when water is acidic.
• SulfateSulfate isn't a serious health risk.

How to read and interpret your well water test results: units, detection limits, and the lines you can ignore.