The City of Newark, NJ conducted a study of the PUR filters in Newark between August and September 2019. The study showed that 97.5% of the filters, when properly installed and maintained, reduced lead to 10 parts-per-billion (ppb) or below. When the faucet was flushed for 5 minutes prior to filtering, 99.5% of the filters reduced lead to 10 ppb or below.
The full filter study report and a filter program guide are available here.