What is the MCL for Arsenic?

The Maximum Contaminant Level (MCL) for arsenic in drinking water is set at 10 µg/L (micrograms per liter), which is equivalent to 0.010 mg/L. The reason why the 10 µg/L standard is significant is due to arsenic's toxic effects on human health, including its association with various cancers and other serious health conditions when consumed above safe limits over prolonged periods. This regulatory standard is established by the Environmental Protection Agency (EPA) to protect public health, ensuring that water systems take necessary actions to reduce arsenic levels.

When considering the available answers, it is important to note that one of the correct options for MCL aligns with regulatory standards, thus emphasizing the importance of compliance regarding arsenic levels in drinking water. Although some choices indicate lower limits which might seem appropriate, they do not represent the established MCL criteria used in water treatment and testing regulations. Accurate knowledge of these levels is crucial for water operators in maintaining water safety and public health.