Extended Sentinel Sampling
The Extended Sampling Program is a continuation of the original Sentinel Sampling Program that uses a smaller pool of participants (170 or so). It also includes sampling only once a month.
The Extended Sentinel sampling program is focused on areas most likely to have high levels of lead and/or copper.
All the homes with known lead service lines were encouraged to continue participation.
The Extended Sentinel sites were selected based on homes with one or more of the following criteria:
- Lead service lines
- Service lines replaced under the "Fast Start" pilot service line replacement program
- High lead results for copper or galvanized lines during the original sentinel sampling
- Areas with predicted elevated blood lead levels
- Homes built between 1983-1988 when lead solder was use more frequently with copper interior plumbing