How to Flush Your Plumbing to Reduce Lead Exposure

Lead enters water primarily when water sits in contact with lead-containing materials. This process is known as stagnation. The longer water remains stagnant, the more opportunity lead has to leach into the water. Flushing removes stagnant water and replaces it with fresh water from the main supply.

When Flushing Is Most Important

Homes with lead service lines or older plumbing benefit most from consistent flushing practices.

• First thing in the morning
• After returning from travel
• After plumbing repairs
• After periods of low water us

How to Flush Properly

Flushing time varies based on pipe length and household plumbing configuration.

• Running cold water taps
• Allowing water to flow until it reaches a consistent cold temperature
• Using flushed water for non-consumptive purposes such as cleaning or watering plants

Limitations of Flushing

While flushing reduces lead levels temporarily, it does not eliminate the source of lead. Lead levels may rise again after water sits unused. For this reason, flushing is most effective when combined with other mitigation strategies such as filtration and routine testing.

Confirming Effectiveness with Testing:

Testing before and after flushing can demonstrate how stagnation affects lead levels in a specific home. Screening tests provide a practical way to assess whether flushing practices are reducing detectable lead.

Flushing is a simple, science-backed method to reduce lead exposure from drinking water. When performed consistently and combined with other protective measures, it can significantly reduce risk.

By A. Anagnos, Biomedical Engineering Specialist