What is the orange slime in my toilet tank and well water?

Orange, reddish-brown, or yellowish slime in your toilet tank, pipes, and fixtures is almost always iron bacteria. These naturally occurring bacteria feed on dissolved iron in water, producing a rusty, slimy biofilm. While not typically dangerous to health, iron bacteria cause staining, clogged pipes, and unpleasant odors.

Is iron bacteria in well water harmful to drink?

Iron bacteria themselves are not known to cause disease and are not considered a health hazard. However, the slime they produce can harbor other bacteria that may be harmful. Additionally, iron bacteria indicate conditions that might allow harmful bacteria to enter the well. If you have iron bacteria, it's wise to test for coliform bacteria as well.

How did iron bacteria get in my well?

Iron bacteria are naturally present in soil and groundwater. They typically enter wells during drilling, pump repairs, or any time the well is opened. They can also enter through cracks in the casing or inadequate well seals. Once introduced, they establish colonies and multiply, especially in wells with higher iron content.

Can I get rid of iron bacteria permanently?

Completely eliminating iron bacteria is challenging because they're so common in groundwater. Shock chlorination can kill existing bacteria, but recontamination is common. For lasting control, ongoing treatment is usually needed—either continuous low-level chlorination, UV disinfection, or periodic shock treatments combined with maintaining good well integrity.

How much does iron bacteria treatment cost?

Treatment costs vary: DIY shock chlorination costs $50-$150 in supplies. Professional shock treatment runs $300-$600. Installing a continuous chlorination system costs $1,000-$2,500. UV disinfection systems cost $500-$1,500. Severely affected wells may need rehabilitation ($2,000-$5,000) to remove heavy buildup before treatment is effective.