“pH” means the expression of the intensity of the acid or alkaline condition of a solution, such as water, as indicated by the hydrogen ion concentration and expressed as a number on the scale of 0 to 14, with 0 being most acidic, 7 being neutral, and 14 being most basic.

Source. (See Revision Note #2 at chapter heading for Env-Wq 1100) #10577, eff 5-1-14; ss by #13198, eff 5-1-21 (formerly Env-Wq 1102.38) (see Revision Note #3 at chapter heading for Env-Wq 1100); ss by #13198, eff 5-1-21 (formerly Env-Wq 1102.38) (see Revision Note #3 at chapter heading for Env-Wq 1100)