What you're getting at is really that we need to test the water at the tap to ensure that especially babies being bottle fed are not ingesting high amounts of lead. The tap is connected to pipes within maybe an old house from the 1930s, as you said. Just because you took the lead line out doesn't mean that all of the lead potential is gone. That's a good point.
On February 23rd, 2017. See this statement in context.