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.