Iron, manganese, and hard water in wells

Most everyday complaints about well water come down to minerals from the rock and soil around the well. They stain fixtures, clog pipes, and taste odd, but mostly they aren't health hazards. EPA covers them with secondary standards, which are guidelines for taste, odor, color, and staining rather than enforceable health limits.

Iron

Iron is common in groundwater. EPA's secondary standard is 0.3 mg/L. Above that you may see orange or reddish-brown stains in sinks, toilets, and laundry, taste something metallic, or find water that comes out clear but turns rusty after standing. Iron can also feed iron bacteria, which leave slimy orange deposits in toilet tanks and can cause odors.

Iron at these levels isn't considered a health risk, but it's a nuisance and can shorten the life of water heaters and fixtures.

Manganese

Manganese often travels with iron. EPA's secondary standard is 0.05 mg/L. Above that you may see black or brownish-black stains and notice a bitter, metallic taste. Unlike iron, manganese also has a health angle. EPA has a lifetime health advisory for adults of 0.3 mg/L, with lower guidance for infants. If your well is over 0.3 mg/L, treat manganese as a health issue, not just a staining problem. Our test reader flags both levels.

Hardness

Hard water carries dissolved calcium and magnesium. It's not a health concern, but it leaves scale on fixtures and in water heaters, makes soap lather poorly, and leaves spots on dishes. There's no federal standard. The USGS uses these classes, measured as mg/L of calcium carbonate:

• 0 to 60 mg/L: soft
• 61 to 120 mg/L: moderately hard
• 121 to 180 mg/L: hard
• more than 180 mg/L: very hard

Some labs and softener sellers use grains per gallon. Multiply grains per gallon by 17.1 to get mg/L.

Other secondary standards

EPA also sets secondary levels for pH (6.5 to 8.5), total dissolved solids (500 mg/L), chloride (250 mg/L), and sulfate (250 mg/L), among others. Low pH deserves attention. Acidic water can dissolve lead and copper from plumbing, which turns a nuisance into a health issue. If your pH is low, test for lead and copper too.

Treatment basics

The right treatment depends on the combination of minerals, pH, and whether bacteria are present, so start with a full lab test. Common options:

• Water softeners (ion exchange) remove hardness and can handle low levels of dissolved iron.
• Oxidizing filters (for example, greensand or air-injection systems) turn dissolved iron and manganese into particles and filter them out.
• Neutralizing filters raise the pH of acidic water.
• Shock chlorination can knock back iron bacteria. See shock chlorinating a well.

On a septic system, ask whether a softener's backwash brine is suitable for your system. Some installers and health departments recommend routing it elsewhere. After installing any treatment, test the treated water to confirm it's working.