A well report's lead number depends on when the water was drawn
Lead on a well report is judged against 5 ug/L when the sample is flushed, as the New Jersey sale test requires. Fifteen is an action level for first-draw water, stood six hours or more, a sample the sale test skips.
Compiled from the sources listed at the end. Sources checked .
So a house can sound fine at one number and worrying at another, with nobody wrong. NJDEP's reporting form spells out the difference, though that copy is an older one.
Three lead numbers
Number
Applies to
Sample
5 ug/L
Private well sale test, state groundwater standard
Flushed at least two minutes
15 ug/L
Action level
First draw, stood six hours or more
10 ug/L
Public systems, compliance from late 2027
Not a private well rule
NJDEP reporting form; EPA Lead and Copper Improvements page
What does each sample tell me?
The flushed sample speaks mostly for the water as it comes from the well. A first draw also picks up what has dissolved from the house's own plumbing while it sat. Over 15 on a first draw, the form says, points to a lead source in the home plumbing. It offers three responses: treat the water so it is less corrosive, track down the source and take it out, or run the water each morning.
Low pH raises the stakes. Lead "risks can increase when pH is low (<6.5)," the state health department says, and low pH is common here, as our story on acid water shows. If your report is low on pH, a flushed lead result does not tell the whole story, so consider asking the lab for a first draw too.
What about the new federal 10?
That number is for public water systems. EPA's final rule lowers their action level from 15 to 10, with compliance starting in late 2027 by EPA's statement. It is not a law on your well, though it may help you weigh a result.
What can I do today?
EPA's advice is simple. Draw water for drinking, cooking and baby formula from the cold tap alone. Run the tap after water has sat. Do not rely on boiling, which does not remove lead. Then see the report story for how lead fits with the other lines.