How often must sampling be conducted if volatile organic compounds (VOCs) are detected?

Sampling for volatile organic compounds (VOCs) is conducted quarterly when they are detected in water systems. This frequency is critical for monitoring the safety of drinking water and ensuring that levels of VOCs remain within permissible limits set by regulatory agencies. Quarterly sampling allows for timely detection of any increases in VOC concentrations, which can pose health risks to consumers. Regular monitoring ensures that any necessary corrective actions can be implemented swiftly to protect public health, comply with regulations, and maintain the integrity of the water supply system.

Other options suggest less frequent monitoring intervals, which would not provide adequate oversight for potential contaminants like VOCs that can vary in concentration and pose significant health concerns. Thus, the quarterly schedule strikes a balance between ensuring safety and maintaining practical oversight of water quality.