Industries discharging storm water under a General Storm Water Permit are required to sample what?

Sampling storm water from outside industrial activities under a General Storm Water Permit is essential for several reasons. Storm water is defined as water from precipitation events that flows over surfaces and can pick up pollutants before being discharged into nearby water bodies. By sampling storm water specifically from areas where industrial activities occur, facilities can assess the quality of the runoff to ensure compliance with regulatory standards and identify potential sources of contamination.

This practice is crucial for environmental protection, as it allows industries to monitor their impact on local water sources and take corrective actions if necessary. In contrast, other options such as sampling groundwater, settled sludge, or process influent do not directly address the contamination and management of storm water runoff, which is the primary concern of storm water permits. Sampling storm water provides critical data for maintaining compliance with water quality standards and helps in the overall management of storm water discharge.