Lead is not naturally occurring in the City of Sonoma’s source water, from Sonoma County Water Agency, and does not come from the city’s water distribution system piping. However, in some older homes, lead may be present in the pipe connecting the home to the water system – known as a service line – or within the home’s plumbing. Lead in service pipes, plumbing or fixtures can dissolve, and/or particles can be absorbed into water and end up in tap water. The most common sources of lead in drinking water are brass and bronze faucets and fixtures installed before 2003, or lead pipes installed before 1986.