What action should be taken if a water sample shows the presence of lead above permitted levels?

When a water sample indicates the presence of lead above permitted levels, notifying the local health department is essential. This action is crucial because the health department is equipped to assess the situation, implement necessary public health measures, and provide guidance and resources to mitigate exposure to lead.

Lead in drinking water poses significant health risks, particularly to vulnerable populations like pregnant women and children. Therefore, timely communication with health authorities ensures that further testing can be conducted, the source of contamination can be identified, and appropriate actions can be taken to safeguard public health.

The other choices do not adequately address the health risks associated with lead contamination. Ignoring the results disregards the potential danger that lead poses. Issuing a boil water advisory is typically relevant for microbial contaminants and does not effectively address lead issues. Increasing chemical dosing may not resolve the lead problem and could potentially worsen water quality without addressing the root cause. Thus, notifying the local health department is the most responsible and effective course of action.