Any plumbing/metal plumbing fixtures that were installed prior to 1978 (that have not been renovated) are very likely to have lead…and it’s not just water fixtures, but also corrosion from lead service pipes leading into buildings that are still an issue. Maryland is a very old state, so there has been a lot of work to do. Since Maryland has been strict with lead testing and removing lead fixtures starting in the early 1990’s, the lead exposure rates have gone down drastically, but there’s still a lot of work to do.

And yes, the mandate specified water had to be tested after sitting in the pipes between 8-18 hours. A worst case scenario is still important to test…the kid who gets dropped off to school first every day and immediately needs a drink of water still matters.