Lead in Drinking Water: A Scientist's Guide For Your Home

Eric Roy, PhD | Chief Scientist

I have spent much of my career working on lead in drinking water. My first water filter company (Hydroviv) launched in direct response to the Flint water crisis. In 2019, I testified before the U.S. House Committee on Science, Space, and Technology about the gaps in federal research and infrastructure surrounding lead contamination. Since then, my teams have built and shipped hundreds of thousands of certified lead-removal filters for homes across the country.

The difficult truth is that we built our cities using a material that should never contact drinking water. Lead is chemically incompatible with the water standards and health protections we expect today.

How Lead Enters Drinking Water

Lead behaves differently from most other contaminants because it does not come from the water source. It comes from the distribution system and your home’s plumbing. This means the contamination occurs downstream of the treatment plant and must be removed at the tap.

The Lead Plumbing Problem The largest single contributor to lead in water is the Lead Service Line, which is the pipe connecting the water main in the street to the home. An estimated 9.2 million American homes still use these pipes.

Homes built before 1986 carry additional risk. Your plumbing ecosystem may contain lead in:

• The service line.
• Lead-based solder used with copper pipes.
• Brass fixtures and faucet components.

Even homes that appear modern can have lead-containing components behind walls, inside valves, or attached to older plumbing.

What is the Safe Level of Lead In Drinking Water?

Toxicologists and public health agencies agree: There is no safe level of lead exposure.

In Children: Lead interferes with brain development during critical growth periods. Even low levels of exposure are associated with:

• Lower IQ
• Learning and attention difficulties
• Behavioral issues
• Hearing and speech delays

In Adults: Long-term lead exposure is linked to:

• Cardiovascular disease
• High blood pressure
• Kidney dysfunction
• Reproductive issues

Lead also accumulates in bone and can be released into the bloodstream during pregnancy or periods of calcium loss, creating additional risk.

How Lead Is Regulated?

Most people assume their water is safe because their city reports compliance with federal regulations. The reality is more complicated.

Lead in public water systems is regulated under the EPA Lead and Copper Rule. Unlike other contaminants, there is no "Maximum Contaminant Level" (MCL). Instead, there is an "Action Level" of 15 parts per billion (ppb). A system is considered compliant if 90 percent of tested samples are below that level.

The Safety Gap (1 ppb vs. 15 ppb) A critical detail is that the EPA’s 15 ppb action level is not a health-based threshold. Regulators set it to balance cost and feasibility, not because it is safe. Medical experts take a much stricter position:

• The American Academy of Pediatrics recommends keeping lead in drinking water below 1 ppb to protect children.
• Toxicologists emphasize that the only truly safe level is as close to zero as possible.

This means a city can meet federal rules while still delivering water to individual homes at levels that exceed what health professionals consider acceptable.

How To Filtering Lead From Your Home’s Water

Look for NSF/ANSI Standard 53 Certification Marketing claims like “purified,” “advanced filtration,” or “nursery water” are not meaningful. The only way to know a product is proven to remove lead is through NSF/ANSI Standard 53 certification for Lead Reduction.

This certification requires independent laboratory testing that verifies:

1. The filter reliably reduces lead to very low levels.
2. The performance holds across the entire service life.
3. The system works under standardized test conditions.

Certification may be issued by NSF, WQA, or IAPMO. If a product cannot show this certification, assume it has not been proven effective.

Install Where You Drink Install the filter directly where you consume water:

• Under-sink system
• Countertop system
• Dedicated filtered tap

Replace Filters on Schedule Certified filters are tested based on a defined service life. When they expire, removal efficiency drops quickly. Replacing filters on time is essential.

What Does Not Work

• Boiling water: This concentrates the lead as water evaporates.
• Standard Pitcher Filters: Unless specifically certified for lead, most only remove chlorine taste.

Frequently Asked Questions

How do I know if I have lead pipes? You can perform a "Scratch Test" on the pipe entering your home (usually in the basement).

• Lead: Soft, easily scratched, and shiny silver underneath.
• Copper: The color of a penny.
• Galvanized Steel: Hard and gray/magnetic.

How do I know if I have lead in my brass plumbing components?

This isn't a perefect solution, but brass plumbing componets (valves, shutoffs) should have a logo on them that shows LF for lead free or has a checkmark on them.

Should I test my water? If you have a lead service line, testing is useful but can be tricky. Lead release is "sporadic"—a particle might break off today but not tomorrow. If you have known risk factors (pre-1986 plumbing), the safest route is simply to install a certified filter.

What To Do Next

1. Inspect: Check your basement service line material.
2. Check Data: Look at your city's Water Quality Report for lead violations.
3. Filter: Install a Point-of-Use filter certified to NSF/ANSI Standard 53 for Lead.

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