Final answer:
An EC MCL violation refers to a situation where contaminants exceed the safe drinking water thresholds established by regulations, implying a risk to public health and necessitating immediate corrective action.
Step-by-step explanation:
An EC MCL violation occurs when there is any combination of contaminants that exceed Maximum Contaminant Levels (MCL) established by regulatory agencies for safe drinking water. The term 'EC' most likely refers to 'Exceedance of Contaminant,' and an MCL violation implies that particular contaminants in the water supply have surpassed the legal threshold considered safe for human consumption. Such a violation would prompt corrective actions by the water system operator and notification of consumers to protect public health and safety.
MCLs are tailored to protect against both immediate and long-term health effects and are calculated considering a margin of safety. The occurrence of an EC MCL violation indicates that there is a potential risk to consumers and that immediate action is required to return contaminant levels to an acceptable range.