Which term is not considered a "discharge" under U.S. pollution regulations?

In the context of U.S. pollution regulations, the term that is not considered a "discharge" is related to the activity of sampling a harmful substance. Discharge typically refers to the release of pollutants or contaminants into the environment, whether intentionally or accidentally.

When an action involves taking a sample of a substance, the intention is to analyze it rather than to release it into the environment. Sampling is a controlled, necessary process aimed at monitoring or assessing the presence of pollutants without contributing to environmental contamination.

On the other hand, runoff from rain, accidental spills, and operational discharges involve actual releases of substances that can potentially harm the environment and are classified as discharges under regulations because they directly lead to the introduction of pollutants into natural water bodies or soil. This distinction helps clarify regulatory compliance and environmental protection measures.