EPA legal limit
15 ppb
Maximum Contaminant Level
EWG health guideline
0 ppb
Science-based, stricter target
IARC classification
Group 2A
Cancer research classification
Health effects
Lead causes irreversible neurological damage, particularly in children and developing fetuses. Effects include reduced IQ, learning disabilities, behavioral problems, and slowed growth. In adults, elevated lead exposure is associated with hypertension, kidney disease, and reproductive harm. There is no safe level of lead exposure.
Where it comes from
The primary source of lead in drinking water is not the utility — it is household plumbing. Lead service lines connecting homes to the water main, lead solder used in pipes before 1986, and lead-containing brass fixtures all leach lead into water, particularly when water sits in pipes overnight. The treatment plant result may show no lead while tap water is still elevated.
How it's regulated
Regulated under the Lead and Copper Rule (LCR), revised in 2021 (LCRR). The action level is 15 ppb at the 90th percentile of tap samples. Utilities must begin replacing lead service lines if >10% of samples exceed 15 ppb. The EPA action level is not a health-based MCL — there is no safe level.
The EPA vs EWG gap
The legal limit (15 ppb) is Infinity× higher than the EWG health guideline (0 ppb). Water can be legally compliant while still exceeding the science-based threshold.
How to filter lead
Not all filters address lead. Look for independently certified filters — NSF International certification means the removal claim has been independently verified.
Frequently asked questions
What is lead?
A toxic heavy metal with no safe level in drinking water. The EPA's 15 ppb action level (not an MCL) is a threshold for requiring utility action — it is not a health-based limit. The EWG health guideline is zero.
What are the health effects of lead?
Lead causes irreversible neurological damage, particularly in children and developing fetuses. Effects include reduced IQ, learning disabilities, behavioral problems, and slowed growth. In adults, elevated lead exposure is associated with hypertension, kidney disease, and reproductive harm. There is no safe level of lead exposure.
Is lead regulated in drinking water?
Regulated under the Lead and Copper Rule (LCR), revised in 2021 (LCRR). The action level is 15 ppb at the 90th percentile of tap samples. Utilities must begin replacing lead service lines if >10% of samples exceed 15 ppb. The EPA action level is not a health-based MCL — there is no safe level.
Where does lead come from?
The primary source of lead in drinking water is not the utility — it is household plumbing. Lead service lines connecting homes to the water main, lead solder used in pipes before 1986, and lead-containing brass fixtures all leach lead into water, particularly when water sits in pipes overnight. The treatment plant result may show no lead while tap water is still elevated.
How do I remove lead from tap water?
The most effective methods for removing lead are: Reverse osmosis (RO), NSF 53 certified filter, NSF 58 certified RO system, Activated carbon block filter. Look for NSF-certified systems — independent certification confirms removal claims have been verified.
Is lead in your water?
Enter your ZIP code to see the measured level in your specific utility.