What action should be taken if a system exceeds action levels for multiple contaminants?

When a system exceeds action levels for multiple contaminants, it is essential to implement corrective actions as prescribed. This choice reflects the necessity to address the contamination comprehensively to ensure the safety of the water supply and comply with regulatory standards. Corrective actions may include additional monitoring, treatment adjustments, or operational changes that mitigate the presence of contaminants.

Monitoring only the main contaminant would fail to address other potentially hazardous substances that might also exceed safe levels, compromising water quality and public health. Shutting down the facility immediately is often not a practical or necessary response, as it may lead to service interruptions without addressing the underlying issues; typically, systems work to rectify the problem while still operating safely. Reporting only to the federal government is insufficient as well; local authorities and potentially affected communities also need to be informed to take necessary precautions.

Therefore, implementing corrective actions is the appropriate response to ensure compliance with health standards and to safeguard water quality.