At which locations should lead and copper samples be collected?

Collecting lead and copper samples from high-risk locations is essential because these areas have a greater likelihood of containing lead and copper contaminants, particularly in the plumbing systems of older buildings. High-risk locations may include homes with lead service lines, those built before 1986, or locations known to have plumbing fixtures containing lead. This targeted testing ensures that the most vulnerable populations are accurately assessed, allowing for appropriate public health responses and water quality improvements.

Sampling from every household would not be practical or necessary, as it could overwhelm resources and may not yield additional valuable information beyond what targeted high-risk locations provide. Testing from main distribution lines does not adequately reflect the water quality that reaches consumers, as contaminants could leach from household plumbing systems after the main line. Similarly, industrial facilities, while they may be sources of various contaminants, are not typically the focus for lead and copper sampling in residential water supplies, given the specific health concerns surrounding these metals in domestic settings.