What type of samples does the Lead and Copper Rule require?

The Lead and Copper Rule requires first-draw or first-flush samples to assess lead and copper levels in drinking water. This sampling technique is crucial because it targets contaminants that may leach into water from plumbing materials, particularly after water has stagnated in pipes. When a tap is opened after a period of non-use, the water that comes out first has had the most contact with lead or copper sources, providing a clearer indication of the potential risk to consumers. This approach ensures that the samples reflect the worst-case scenario for exposure, which is important for regulatory compliance and public health monitoring. Other sampling methods, such as composite samples or grab samples, may not capture the highest levels of contaminants as effectively in the context of these specific metals.