What action must be taken if high levels of lead are detected in the first draw water sample?

If high levels of lead are detected in the first draw water sample, replacing piping from the second main service line is essential because it addresses a potential source of lead contamination directly associated with plumbing materials. Lead can leach into drinking water from lead pipes, solder, or fixtures, especially if the water is stagnant for a period of time, which is why the first draw sample is particularly telling.

Taking action to replace the piping helps to eliminate the lead source, thus reducing exposure risk for individuals consuming the water. It is a proactive measure aimed at ensuring the safety of the drinking water long-term and preventing any health risks associated with lead exposure.

In contexts like this, merely calling a water testing laboratory would not resolve the contamination already detected—it would delay the necessary remediation. Immediate replacement of faucets or doing nothing would not address the underlying issue of lead presence in the water supply and would still expose individuals to unsafe conditions.