WAC 246-290-72004   Report contents -- Definitions.  (1) Each report must include the following definitions:

     (a) Maximum contaminant level goal or MCLG: The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.

     (b) Maximum contaminant level or MCL: The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.

     (2) A report for a community water system operating under a variance or an exemption issued under WAC 246-290-060 must include the following definition: Variances and exemptions: State or EPA permission not to meet an MCL or a treatment technique under certain conditions.

     (3) A report that contains data on contaminants that the Environmental Protection Agency regulates using any of the following terms must include the applicable definitions:

     (a) Treatment technique: A required process intended to reduce the level of a contaminant in drinking water.

     (b) Action level: The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow.

     (c) Maximum residual disinfectant level goal or MRDLG: The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

     (d) Maximum residual disinfectant level or MRDL: The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.



[Statutory Authority: RCW 43.20.050. 00-15-080, § 246-290-72004, filed 7/19/00, effective 8/19/00.]