Guidance for Residents Addressing Copper Problems in Drinking Water: Opportunities and Challenges.

Residents and their pets may experience aesthetic or health concerns resulting from elevated copper in their drinking water. The United States Environmental Protection Agency Lead and Copper Rule focuses on addressing systemwide corrosion issues, but gaps in the rule leave some municipal water consumers and residents with private well water vulnerable to high cuprosolvency. We developed guidance to aid residents in understanding, detecting, and addressing cuprosolvency issues in their drinking water. Three types of at-home test kits for copper and one for pH were determined to be accurate enough ( R 2 > 0.9 (lab, based on average values from n = 5 replicates each) and >0.7 (field)) to detect concerns related to high cuprosolvency and inform selection of intervention options. Case study results indicate that, although water treatments such as increasing pH on-site may be effective, long-term treatment (>36 weeks or permanently) may be needed to maintain reductions in cuprosolvency. A decision tree is provided to help residents and citizen scientists navigate these concerns for both public water systems and private wells.