“Diatomaceous filter” means a pressure or vacuum-type filter that uses a white powder derived from fossilized organisms called diatoms as a filtering medium.

Source. (See Revision Note #1 at chapter heading for Env-Wq 1100) #8468, eff 11-1-05; ss by #10577, eff 5-1-14 (See Revision Note #2 at chapter heading for Env-Wq 1100); ss by #13198, eff 5-1-21 (formerly Env-Wq 1102.19) (see Revision Note #3 at chapter heading for Env-Wq 1100)