Typical Kitchen Faucet–Use Flow Rates: Implications for Lead Concentration Sampling

Previous researchers have documented that the concentration of lead obtained in a water sample from piping systems is significantly influenced by the sample rate of flow, with higher flow rates yielding higher lead concentrations. This has implications for both regulatory monitoring and lead release research. However, data on instantaneous flow rates for typical use are not readily available, so a survey was conducted to address this gap. Respondents were asked to measure flow from the faucet into a wide-mouth container using a flow approximating normal use. The survey collected responses from 21 homes and 43 testers, with 257 individual flow tests. The median value of reported flow measurements was 1.4 gpm, with quartile values of 1.25 and 1.88 gpm, and an average of 1.54 gpm. It is recommended that lead concentration sampling should attempt to use sample flow rates that generally approximate these flow rates.