Lead is rarely found in well water from the aquifer itself — it almost always comes from the plumbing inside your home. Here is what causes lead in well water, who is most at risk, and how to test and treat it.
The groundwater in most private wells does not contain lead. Lead enters drinking water at the tap through corrosion of lead-containing plumbing materials:
Lead exposure is most dangerous for children under 6 and pregnant women. In children, lead causes permanent neurological damage — there is no safe level of lead exposure for children. Adults are less vulnerable but face cardiovascular and kidney effects with chronic exposure.
| Lead Level | EPA Action Level | Recommended Action |
|---|---|---|
| 0 μg/L | Ideal | No action needed |
| 1–15 μg/L | Below action level | Investigate plumbing; use filter for children |
| 15+ μg/L | EPA action level | Immediate treatment required |
| Any level | Children present | Use certified lead-removing filter |
For meaningful results, use "first draw" sampling — collect water from the cold tap that has been sitting unused for at least 6 hours (overnight is best). This maximizes the time water has been in contact with plumbing, giving the most conservative result. Use a certified laboratory.
NSF/ANSI 58 certified RO systems remove 95–99% of lead from drinking water. Cost: $200–$500. Most practical solution for most households.
Some pitcher filters and faucet-mount filters are NSF/ANSI 53 certified for lead removal. Look for the NSF certification specifically for lead — not all carbon filters remove lead. Cost: $30–$150.
Treating the water is a stop-gap. The permanent solution is replacing lead plumbing and addressing acidic water. If your pH is below 7.0, install a calcite neutralizer — this reduces lead leaching at the source. Old lead pipes should be replaced by a licensed plumber.
Never use hot tap water for cooking, infant formula, or drinking. Hot water dissolves more lead from plumbing than cold water. Always use cold water and run it for 30–60 seconds before using if the tap has been unused for several hours.
Almost always from your home's plumbing, not the aquifer. Lead pipes (pre-1930 homes), lead solder (used until banned in 1986), and older brass fixtures (pre-2014, up to 8% lead) are the typical sources — groundwater itself rarely contains lead.
Use 'first draw' sampling — collect water from the cold tap after it has sat unused for at least 6 hours, ideally overnight. This maximizes contact time between the water and plumbing, giving the most meaningful lead reading.
The EPA action level is 15 μg/L or higher, which requires immediate treatment. But there is no safe level of lead for children — if children are present in the household, use a certified lead-removing filter regardless of the test result.
Yes. Acidic water with a pH below 7.0 accelerates corrosion of metal plumbing, which is the primary driver of lead leaching into tap water — even from plumbing that would otherwise leach very little lead.
Children under 6 and pregnant women face the greatest risk. In children, lead causes permanent neurological damage, and there is no safe exposure level. Adults are less vulnerable but can still experience cardiovascular and kidney effects with chronic exposure.
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