Lead at the Tap: Sources and Control

TLDR

In early 1988, a survey of 94 water companies and districts assessed tap lead levels and the factors influencing them. The survey found lead‑based solder to be the primary source of tap lead, with brass faucets also contributing, while pH and plumbing age were the only significant water quality and site factors, respectively, and neither water quality nor site characteristics alone could predict lead levels.

Abstract

A survey of 94 water companies and districts was conducted in early 1988 to determine lead levels at customer taps and to evaluate the factors that influence these levels. The results of the survey indicate that lead‐based solder is the most significant source of lead at the tap. In addition, brass faucets were found to contribute substantially to the lead in the first‐draw samples. Although water quality and site characteristics cannot be used to predict lead levels, certain factors are associated with higher lead concentrations. Other than the presence of corrosion inhibitors, pH was the only water quality factor that appeared to influence lead levels at the tap. Site factors were also important, with plumbing age being the most significant.