A TSDF would like to modify an existing permit application to incorporate design of groundwater monitoring wells; this can be accomplished using:

• A. Class I modification
• B. Class II modification
• C. Class III modification
• D. Class IV modification

Answer: (B)

The main idea is that permit modifications are grouped by how much the change affects compliance and the permit’s conditions. Adding or revising the design of groundwater monitoring wells changes how the facility must monitor and demonstrate compliance with environmental protections, so it’s more than a simple administrative edit. It isn’t a full, major rewrite of the permit (which would be a larger, more disruptive change) and it isn’t an emergency or temporary adjustment, so it doesn’t fit the most extreme category. For these reasons, this type of change is treated as a moderate modification that typically requires review and public notice, fitting a Class II modification.