The hazardous waste owner and operator must monitor the aquifer to determine if the leak exceeds the GWPS. Where in the aquifer should monitoring occur?

The hazardous waste owner and operator must monitor the aquifer to determine if the leak exceeds the GWPS. Where in the aquifer should monitoring occur?

• A. Midpoint
• B. Uppermost
• C. At several location in the aquifer
• D. Lowermost

Answer: (B)

The key idea is that monitoring for a hazardous waste release is aimed at the aquifer that most directly affects drinking water and is the first layer to be impacted by any leak. Groundwater protection standards are defined for the uppermost aquifer, so placing monitoring wells in that layer allows early detection of any contaminants before they can degrade the water supply. If monitoring were focused deeper, in the lowermost part, a leak might go unnoticed in the upper layers where regulatory standards apply, delaying response and potentially allowing a plume to spread. While multiple wells across the aquifer are often used to delineate a plume, the essential location for GWPS monitoring is the uppermost aquifer.

The key idea is that monitoring for a hazardous waste release is aimed at the aquifer that most directly affects drinking water and is the first layer to be impacted by any leak. Groundwater protection standards are defined for the uppermost aquifer, so placing monitoring wells in that layer allows early detection of any contaminants before they can degrade the water supply. If monitoring were focused deeper, in the lowermost part, a leak might go unnoticed in the upper layers where regulatory standards apply, delaying response and potentially allowing a plume to spread. While multiple wells across the aquifer are often used to delineate a plume, the essential location for GWPS monitoring is the uppermost aquifer.