On Sept. 19, 2000, the US Environmental Protection Agency, AWWA, and other stakeholders, such as state, environmental and public health organizations, signed an Agreement in Principle that describes how the Stage 2 Disinfection/Disinfectant Byproducts Rule (D/DBP Rule) monitoring locations are to be selected and how compliance will be determined. The stakeholders agreed to split the Stage 2 Rule into two parts: Stage 2a, in which the trihalomethane (THM) and haloacetic acid (HAA) maximum contaminant levels (MCL) will be temporarily increased to 120 ug/L and 100 ug/L respectively; and, Stage 2b in which the MCLs will return to 80 ug/L for THMs and 60 ug/L for HAA5.