In 2011 and 2012, EPA Region 5 and the Chicago Department of Water Management conducted a study on field sampling protocols for lead in drinking water. The purpose of the study was to evaluate the method used by public water systems to monitor lead levels. EPA intends to consider the study’s findings while revising the Lead and Copper Rule.
Although the study was conducted in Chicago, its results may have implications for other cities with lead service lines. A lead service line is a pipe that is made of lead that brings drinking water into your home from the city’s water main. Lead service lines are the single largest source of lead in residential drinking water.
The study found that:
The existing sampling protocol under the Lead and Copper Rule underestimates lead corrosion and lead levels in drinking water at sites with lead service lines.
Sites with disturbed lead service lines had the highest lead levels.
Sites with disturbed lead service lines and low water use may have high lead levels for years.
The time required to flush water containing lead from taps is in many cases greater than the time recommended by EPA and other sources.
The findings of the study have been published in the journal Environmental Science & Technology.