Project #4584

Evaluation of Flushing to Reduce Lead Levels

Principal Investigator
Research Manager
Mr. Jonathan Cuppett
Cornwell Engineering Group


The project evaluated the impact of high-velocity flushing on the removal of particulate lead from service lines and premise plumbing, and the subsequent impact on "at the tap" lead concentrations. The goals of the project were not only to see if high-velocity flushing can successfully reduce lead levels at the tap, but also to see how frequently the flushing may need to be repeated in order to maintain any observed lead reduction. The research includes guidance to utilities on how to perform in-home tap flushing following a service line disturbance (partial or full replacement). The guidance addresses flushing duration, frequency, and different options depending on the type of lead being released (dissolved or particulate). Tailored collaboration partner: DC Water. Published in 2018.