Lead
Lead in tap water comes from the pipes and fixtures inside your house.
Treated water leaves the plant essentially lead-free, then picks up lead from pre-1986 solder and pre-2014 brass fixtures inside the home, most when water sits overnight. No peer-reviewed study has found a safe threshold. The optimal level is zero, and a certified point-of-use filter at the kitchen tap addresses it directly.
Science and Health line for lead in water
No safe level
Lead enters at your plumbing, not the utility. The science recognizes no threshold below which it is harmless.
Lead: what is it, and where does it come from?
Lead is a heavy metal with no biological role in the body and no pathway that fully clears it once absorbed.
In drinking water it almost always enters inside the home, where water sits against lead-bearing brass fittings, valves, or the lead-based solder used on copper joints before 1986. For most homes on a compliant US utility, the water leaving the treatment plant carries little detectable lead. The source is usually inside the house.
The major exception is older systems that still have lead service lines feeding the property, common in parts of the Midwest and Northeast, which is why federal rules now mandate their replacement. Any home built before 2014 likely still contains lead-bearing components somewhere in its plumbing chain.
Lead: why does it matter?
Lead deposits in bone for decades, then re-enters the bloodstream during pregnancy and lactation, and through ordinary bone turnover with age. In the developing brain it interferes with the wiring of synapses and with dopamine signaling, producing cognitive deficits that persist.
In adults it accelerates vascular calcification, raises blood pressure, and strains the kidneys. The dose-response curve is steepest at the lowest measured exposures, so the harm of moving from very low to low exposure is larger per unit than moving from high to very high.
In the pooled childhood data, blood lead climbing through the low single digits tracked with a measurable drop in IQ, and the steepest losses sat at the bottom of the range. That is why the operational rule is simple: any detection is worth acting on.
In a pooled international study of children, no threshold for harm was found. IQ declined across the full range, and the loss was steepest at the lowest blood lead levels, where the first few micrograms accounted for the largest per-unit drop.
Lanphear et al., 2005 (Environ Health Perspect; international pooled analysis of children's IQ)
In a cohort of over 14,000 US adults followed for nearly two decades, lead rising from the 10th to the 90th percentile tracked with markedly higher all-cause, cardiovascular, and ischemic heart disease mortality, with no clear lower bound.
Lanphear et al., 2018 (Lancet Public Health; low-level lead and mortality in US adults)
EPA holds the health goal for lead in water at zero and states plainly that there is no safe level of lead exposure, while CDC states that no safe blood lead level in children exists and even low levels cause harm.
US EPA, Lead and Copper Rule Improvements (final rule, 2024)
Lead: what do we grade it against?
Our Science and Health line for lead is no safe level: any detection is flagged, because no amount of lead is known to be safe. The table below sets every published level for lead, including the legal limit, beside the source that set it.
Science and Health line
No safe level
Any detection is flagged, because no amount of lead is known to be safe
Lead, water
Health-based level 0 no safe level; optimal is zeroAction level 15 ppb EPA action level (drops to 10 by Nov 2027)No safe levelSource: US EPA MCLG (0) and Lead and Copper Rule Improvements
Lead, bottled water
Health-based level 0 no safe levelLegal limit 5 ppb FDA bottled water standardNo safe levelBlood lead, children
Health-based level 0 no safe blood lead level existsReference value 3.5 µg/dL CDC reference value (97.5th percentile, not a safety line)Reference value, not a safety line
The levels for lead, as a table
| Contaminant | Health-based level | Legal limit | Source (health-based) |
|---|---|---|---|
| Lead, water (ppb) | 0 no safe level; optimal is zero | 15 EPA action level (drops to 10 by Nov 2027) | US EPA MCLG (0) and Lead and Copper Rule Improvements |
| Lead, bottled water (ppb) | 0 no safe level | 5 FDA bottled water standard | US EPA MCLG (health) vs FDA bottled standard |
| Blood lead, children (µg/dL) | 0 no safe blood lead level exists | 3.5 CDC reference value (97.5th percentile, not a safety line) | US CDC Blood Lead Reference Value, 2021 |
The Science and Health line is where we flag. We set it from the health research, and it is never looser than any legal limit. Legal limits are enforceable compromises that also weigh what treatment costs. Your report grades to the Science and Health line.
What helps against Lead?
The approaches below are the ones people use for Lead at home. Each entry says what it does and what it cannot do, and not every one helps.
Direct fixes
Point-of-use filter certified to NSF/ANSI 53 (lead) at the kitchen tap
Certified to remove at least 99% of dissolved lead from the test water used to rate it. Placed where drinking water is poured, it addresses the relevant exposure point at low cost.
Performance depends on changing the cartridge on schedule. A basic carbon-only cartridge handles lead dissolved in the water but not the flakes of lead that break loose from brass fittings upstream.
Bigger retrofits
Point-of-use reverse osmosis certified to NSF/ANSI 58
Very high confidence on lead, and it also reduces arsenic, nitrate, and total dissolved solids. A sediment pre-stage handles particulate lead better than carbon alone.
Covers water at that tap only, not water used elsewhere in the home; higher upfront cost, under-sink space, a brine line, and more water waste per gallon.
Replace pre-2014 brass faucets, valves, and supply stops with NSF/ANSI 372 (0.25% lead-free) components
Addresses the fixture source permanently with no consumable. The right move where lead is detected and replacing two to four fixtures resolves the main exposure points.
Does not address lead-soldered copper joints in pre-1986 homes; that source needs diagnostic testing and, if dominant, a repipe.
Free and behavioral
Flush before drinking; never cook or mix formula with first-draw water
Morning first-draw water sat against brass and solder overnight and carries the day's highest lead. Running the tap before filling a glass or pot lowers exposure at no cost.
A behavioral stopgap, not a fix; it relies on memory and does not address the source. Use it alongside a certified filter, not instead of one.
See how well each fix works
The numbers you will see quoted, 5, 10, and 15 ppb, are action levels, not safety lines.
They are policy compromises between health protection and what is operationally feasible for water systems and bottlers. The peer-reviewed science recognizes no safe level, and EPA's own health goal for lead is zero. A test of your own tap gives you a reading to compare with the evidence, and a certified filter can reduce lead.
Common questions about Lead
If my city's water tests fine, can my tap still have lead?
Yes. Utilities test the water leaving the plant and the distribution system, where lead is typically near zero. Lead in a home usually enters at the last stretch, from pre-1986 solder and pre-2014 brass fixtures inside the house, and shows up most after water sits overnight. Your tap is the only place that captures that.
Is there a level of lead that is actually safe to drink?
No. No peer-reviewed study has found a threshold below which lead is harmless, and the harm per unit is largest at the lowest exposures. EPA sets its health goal at zero and states there is no safe level, which is why any detection is worth acting on.
My home was built after 1986, so I'm fine, right?
Lower risk, but not zero. The 1986 ban covered lead solder on copper joints. Brass fixtures sold as lead-free could still legally contain up to 8% lead in wetted surfaces until January 4, 2014. A home built or refitted before 2014 may still carry lead-bearing fixtures, and other legacy components can remain in the plumbing chain.
What is the single most effective fix?
A point-of-use filter certified to NSF/ANSI 53 for lead, or a reverse-osmosis system certified to NSF/ANSI 58, installed at the kitchen tap where drinking water is poured. That puts the treatment at the exposure point at modest cost. If a test localizes the source to specific fixtures, replacing those with 0.25% lead-free parts fixes it permanently.
Should I just run the tap before drinking?
Flushing helps and costs nothing, since first-draw water carries the most lead after overnight stagnation. But it depends on remembering every time and does not remove the source. Treat it as a stopgap alongside a certified filter, not a replacement for one. Never use unflushed first-draw water for formula or cooking.
How do I test if I have lead in my water?
Lead has to be measured at your own tap, because it enters the water after the utility's report ends, from the service line, the solder and the brass fixtures inside your house. A certified lab reading a first-draw sample is the method, and first-draw means water that sat in the pipes 8 or more hours overnight. Compare the result to the health goal, not the enforcement line: EPA's health goal is zero, against a 15 ppb action level that drops to 10 in November 2027.
Sources cited for Lead
Every number on this Lead page traces to one of the 7 sources below: 2 peer-reviewed, 2 government or regulatory.
Peer-reviewed
Government & regulatory
Institutional & standards
- NSF/ANSI 53: Drinking Water Treatment Units, Health Effects (lead)
- NSF/ANSI 58: Reverse Osmosis Drinking Water Treatment Systems
- NSF/ANSI 372: Drinking Water System Components, Lead Content (0.25% wetted-surface)