By SCWS Team
Published February 17, 2026 · 11 min read
Here's something most well owners don't realize: if your water contains lead, it's probably not coming from your well—it's coming from your house. Lead in groundwater is rare, but lead from household plumbing is common, especially in older homes.
Understanding where lead actually comes from helps you take the right steps to protect your family. This guide explains lead sources, health risks, testing approaches, and treatment options for private well owners.
No Safe Level of Lead
The EPA, CDC, and WHO agree: there is no safe level of lead exposure, especially for children. Even low levels can cause irreversible developmental harm. The 15 ppb "action level" is a regulatory threshold, not a safety standard.
Where Lead Actually Comes From
Not Usually the Well
Lead is relatively rare in natural groundwater. Unlike arsenic or uranium, lead doesn't dissolve readily from most geological formations. When lead is found in well water, the source is almost always:
- Household plumbing: Lead pipes, lead solder, brass fittings
- Service lines: In some older properties, the pipe from well to house
- Well components: Older brass well fittings or pump components
- Historical contamination: Rare—mining or industrial sources
Lead in Home Plumbing
Most lead contamination in drinking water comes from within the home:
Common Lead Sources in Homes
- Lead pipes: Common in homes built before 1930; possible through 1986
- Lead solder: Used to join copper pipes until banned in 1986
- Brass fixtures: Faucets, valves, and fittings can contain up to 8% lead (pre-2014)
- Galvanized steel pipes: Can accumulate lead scale over time
Key insight: Lead leaches into water when it sits in contact with lead-containing materials. This is why "first-draw" water (water sitting in pipes overnight) typically has the highest lead levels.
Factors That Increase Lead Leaching
- Corrosive water: Low pH (acidic) water dissolves lead more readily
- Soft water: Low mineral content increases corrosivity
- Hot water: Leaches lead faster than cold water
- Standing time: Longer contact time means more lead
- New plumbing: Paradoxically, new brass fixtures may leach more initially
Health Effects of Lead Exposure
Effects on Children
Children are extremely vulnerable to lead because their developing brains and bodies absorb it more readily:
- Developmental delays: Cognitive and physical development
- Learning difficulties: Reduced IQ, attention problems
- Behavioral issues: Hyperactivity, impulsivity
- Hearing damage: Even at low exposure levels
- Slowed growth: Physical development impacted
These effects can be permanent. There is no way to reverse lead-related brain damage.
Effects on Adults
- Cardiovascular effects: High blood pressure, increased heart disease risk
- Kidney damage: Long-term exposure affects kidney function
- Reproductive effects: Reduced fertility, pregnancy complications
- Nervous system: Memory problems, mood changes
Pregnancy Concerns
Lead stored in bones can be released during pregnancy, exposing the developing fetus. Effects include premature birth, low birth weight, and developmental problems. Women planning pregnancy should be especially careful about lead exposure.
Testing for Lead
First-Draw Testing
For lead, how you collect the sample matters enormously:
- Let water sit: Don't use water for at least 6 hours (overnight is ideal)
- First draw: Collect the very first water from the tap—don't let it run
- Sample from regular tap: Use a tap you actually drink from
- Use clean container: Lab-provided bottles recommended
This "first-draw" sample captures the highest lead concentration, representing worst-case exposure from your plumbing.
Flushed Sample Testing
Some experts recommend testing both first-draw and flushed samples:
- Flushed sample: Run water for 3-5 minutes, then collect
- Comparison: High first-draw, low flushed = plumbing source
- Both elevated: May indicate source water issue or service line
Treatment Options
Best Solution: Remove the Source
The most effective approach is eliminating lead sources:
- Replace lead pipes with copper or PEX
- Replace fixtures with "lead-free" certified products
- Replace lead solder joints (may require repiping)
Point-of-Use Treatment
If source removal isn't immediately feasible:
- Reverse osmosis: 95-99% lead removal; NSF 58 certified
- Carbon block filters: NSF 53 certified for lead; 93-99% removal
- Distillation: 99%+ removal
Look for Certification: Not all filters remove lead. Look for NSF 53 (carbon filters) or NSF 58 (reverse osmosis) certification specifically for lead reduction. Standard pitcher filters may not be effective.
Immediate Protective Steps
While arranging testing or treatment:
- Flush before drinking: Run cold water 30 seconds to 2 minutes before use
- Use cold water: Never use hot tap water for drinking, cooking, or baby formula
- Consider bottled water: Especially for infant formula and young children
- Clean aerators: Lead particles can accumulate in faucet screens
Frequently Asked Questions
Does well water contain lead?
Groundwater itself rarely contains lead—lead is uncommon in natural geological formations. However, well water can pick up lead as it travels through your home's plumbing system. The most common sources are lead pipes, lead solder, brass fixtures, and lead components in well pump systems.
What is a safe level of lead in drinking water?
There is NO safe level of lead—any lead exposure carries some risk, especially for children. The EPA's Action Level is 15 parts per billion (ppb), which triggers treatment requirements for public water systems. However, this isn't a "safe" threshold—it's a regulatory trigger. Many experts recommend treatment if lead exceeds 5 ppb, especially with children in the home.
What are the health effects of lead in water?
Lead is a potent neurotoxin with no safe exposure level. In children, lead causes developmental delays, learning difficulties, lower IQ, behavioral problems, hearing damage, and slowed growth. In adults, lead causes high blood pressure, kidney damage, reproductive problems, and nervous system effects.
How do I test my well water for lead?
For lead testing, sample collection method matters significantly. Use "first-draw" sampling: collect water first thing in the morning from a tap you regularly drink from. This captures lead that has leached from pipes while water sat stagnant. Testing costs $20-40 through certified labs.
Concerned About Lead in Your Water?
Southern California Well Service can help coordinate water testing and provide guidance on protecting your family's water supply.
Call (760) 463-0493