Which statement about washing, agitation, and decantation is true?

• A. Decant the wash water before any agitation.
• B. Continue the washing, agitation and decantation until the wash water is clear.
• C. Stop washing after a single rinse regardless of water clarity.
• D. Use only mechanical agitation without washing.

Answer: (B)

The goal here is to remove contaminants from the material by washing, and that requires repeating the cycle of agitation and decantation until the wash water runs clear. Agitation keeps particles in suspension and helps contaminants detach from the material, so each wash step more effectively cleans. Decantation then removes the dirty water so you can apply fresh water and repeat the process. You continue these steps until the wash water is clear, which signals that most of the fines and contaminants have been washed away. A single rinse won’t guarantee cleanliness, and trying to clean without proper washing or decanting before agitation won’t remove the contaminants effectively. Therefore, continuing the wash-agitate-decanate cycle until the water is clear is the correct approach.