What is a form of a grit chamber intended to retain the heavy debris in storm water? Should be cleaned periodically; if neglected, odor and mosquito problems may occur.

• A. Catch Basin
• B. Grit Chamber
• C. Inlet Box
• D. Sediment Trap

Answer: (A)

The concept here is how stormwater structures trap heavy solids and keep them from moving downstream. A catch basin fits best because it sits at street level with a grated inlet and a bottom sump that collects surface runoff and the heavier debris it carries. That sump acts like a grit/debris trap, so it must be cleaned on a regular schedule. If it’s neglected, the trapped material can decay and create odors, and the standing water in the basin can become a mosquito breeding site. The other options don’t are not designed to perform this specific debris-trapping function in stormwater: an inlet box is simply a conduit entry point, a sediment trap is a separate device for coarse sediment, and a grit chamber is typically used for removing grit in wastewater treatment rather than as a stormwater debris catcher.