Where does lead come from in well water?
Unlike most well water contaminants, lead rarely enters from the aquifer itself. Instead, it leaches from plumbing materials — particularly in homes built before 1986, when lead solder was legally used in plumbing. Key sources:
- Lead-soldered copper pipe joints (pre-1986 homes)
- Brass faucets and fixtures (can contain up to 8% lead under pre-2014 standards)
- Lead service lines (primarily a municipal issue, but some older private connections exist)
- Galvanized steel pipes corroded by water that previously flowed through lead pipes
Acidic water (low pH) and soft water with low alkalinity dissolve lead much more aggressively. If your water is corrosive, even newer fixtures can contribute lead.
Who is at highest risk?
Lead contamination is most prevalent in Michigan, Illinois, Ohio, Pennsylvania, and New Jersey — states with older housing stock and pre-1986 plumbing. But risk is driven by your home's age and plumbing, not geography alone. Any home built before 1986 warrants lead testing.
Health effects
- Neurological development impairment in children — No safe blood lead level has been established in children. Even low exposures cause reduced IQ, learning disabilities, and behavioral problems. Infants consuming formula made with lead-contaminated water face concentrated exposure.
- Cardiovascular disease in adults — Chronic lead exposure in adults is linked to hypertension and increased cardiovascular mortality.
The EPA limit: action level 15 µg/L, MCLG = 0
The Lead and Copper Rule uses an action level (AL) of 15 µg/L, not a traditional MCL. When more than 10% of first-draw samples from high-risk homes exceed 15 µg/L, a utility must take action. Critically, the MCLG is 0 — EPA acknowledges no safe level. The 15 µg/L action level is a regulatory trigger, not a health-based safe threshold.
Testing your well
Lead testing requires first-draw sampling: collect the sample from the kitchen cold tap after water has stood in pipes for at least 6 hours (overnight). This captures lead that has leached into standing water. Do not flush before sampling. Use ICP-MS analysis at a certified lab.
A negative result after flushing may miss lead from internal plumbing. Always follow first-draw protocol.
Find a certified lab and learn first-draw sampling protocol
Treatment
- Reverse osmosis (RO) — point-of-use, removes >95% of lead. Most practical immediate solution.
- NSF/ANSI 53-certified carbon block filters — verified to reduce lead; look specifically for NSF/ANSI Standard 53 certification for lead reduction (not all carbon filters qualify).
- pH correction — raising water pH to 7.5–8.5 reduces lead leaching; treat the cause, not just the symptom.
- Pipe and fixture replacement — the permanent solution; replace lead solder joints and pre-2014 brass fixtures with lead-free materials.