The Definitive Guide to “First Draw” Water Testing

For homeowners concerned about water quality, especially with lead, a “First Draw” test is a critical diagnostic tool. Unlike random or flushed samples, this test provides a snapshot of the water that has been sitting in your plumbing overnight, offering the most accurate assessment of contamination leaching from pipes and fixtures.

When to Perform a First Draw Test
Test when water has been stagnant in your home’s plumbing for at least 6-8 hours, typically first thing in the morning. This is essential before using any taps for drinking, cooking, or flushing toilets. Key moments to test include: moving into an older home (built before 1986), when a household member is pregnant or nursing, after plumbing work, or if you notice changes in water taste, odor, or appearance.

Which Contaminants to Screen For
The primary target of a First Draw test is lead, which can leach from lead pipes, solder, or brass fixtures. Copper is another common target. A comprehensive screen should also include:

• Metals: Lead, copper, iron, zinc.
• Corrosion Byproducts: Testing for pH and alkalinity helps assess your water’s corrosivity.
• Optional, but Recommended: Consider adding tests for common volatile organic compounds (VOCs) that can also accumulate in standing water.

How to Interpret the Lab Report
Your report will list contaminants in milligrams per liter (mg/L) or parts per billion (ppb). Focus on the Action Level (AL) or Maximum Contaminant Level Goal (MCLG).

• Lead: The EPA’s action level is 15 ppb. Any result above zero is a concern, as there is no safe level of lead exposure. Results even below 15 ppb indicate some leaching is occurring.
• Copper: The action level is 1.3 mg/L (or 1300 ppb). High levels can cause gastrointestinal distress and impart a metallic taste.
• Corrosivity: A low pH (below 7) suggests acidic, corrosive water that readily dissolves metals from pipes.

A First Draw test is your first line of defense. If results show elevated levels, immediately begin using flushed water (after running the tap for several minutes) for consumption and consult a water treatment professional about long-term solutions like filtration or pipe replacement. This simple, targeted test empowers you to protect your household from invisible threats in your water supply.