Possible Signs
- Black staining
- Gray staining
- Dark particles
- Black residue in toilets and fixtures
Rhode Island Context
URI and RIDOH launched a statewide manganese-management project in 2026. Manganese treatment can be sensitive to pH, concentration, oxidation state and other water chemistry.
Treatment
Do not select equipment from stain color alone. Test the water and design treatment around the measured chemistry and required flow.