Efficacy of Pitcher Filters for Drinking Water Lead Reduction: A Challenge and Demonstration Study in Denver, CO

The effectiveness of pitcher filters for removing lead and other metals (copper, iron, manganese, and zinc) without removing fluoride in drinking water was evaluated in laboratory and field environments in Denver Water. Effluent from corrosion control pipe racks (control at pH 7.8 adjusted to 8.8 and 1 mg/L as PO4 of orthophosphate) at two water treatment plants was used as challenge water to examine lead removal in five different NSF/ANSI-42 and 53 certified filters. The lead concentration in the challenge water from the control racks ranged between 31 and 97 ppb, and all filters had >94% removal efficiency. Based on the filter challenge study and the manufacturer reported longevity, pitcher Filter B was selected as the most appropriate for Denver's water quality. Field demonstration study samples were collected from at least 50 different sites twice a year. All distributed filters reduced lead levels under the Action Level of 15 ppb, except one sample where the filter concentration was 40.8 ppb and the unfiltered concentration was 1.4 ppb. Overall, filters are generally reliable, but water quality can impact the removal efficacy.