The primary source of lead in drinking water is customer-owned service lines. These are the pipes (pictured below) that deliver water from the main line in the street to the plumbing in a home. Since the homebuilder installs these pipes, San Juan does not have information on the type of material used.

State Water Resources Control Board regulation required the identification of the type of pipes used in the service lines throughout the district. A survey of past and current employees along with site specific inspections, which included digging up 5,148 service lines throughout the district, was concluded on July 8, 2024. This survey resulted in no lead service lines found throughout the district.