The definitions, abbreviations, and acronyms in this section apply throughout this chapter, unless the context clearly indicates otherwise.

(1) "Acute" means posing an immediate risk to human health.

(2) "Analyte" means the constituent or property of a sample measured using an analytical method for compliance purposes under chapters 246-290 and 246-291 WAC.

(3) "C.F.R." means the Code of Federal Regulations.

(4) "Chronic" means human exposure over many years to a contaminant at levels above the MCL.

(5) "Close of business" means the latest time during a business day when a lab is no longer in routine operation for accepting or performing drinking water sample analysis.

(6) "Confirmation" means an additional sample is analyzed from the same location where a detection has occurred to confirm the detection. The original sample and the confirmation sample are collected and analyzed within a reasonable period of time, generally not to exceed two weeks. Confirmation occurs when the confirmation sample analysis result falls within plus or minus thirty percent of the original sample result. This confirmation analysis is in addition to any analytical method confirmation requirements.

(7) "Contracted lab" means a certified lab that receives a drinking water sample from another certified lab for analysis.

(8) "Contracting lab" means a certified lab that sends a drinking water sample to another certified lab to be analyzed.

(9) "Department" means the Washington state department of health.

(10) "Ecology" means the Washington state department of ecology.

(11) "EPA" means the United States Environmental Protection Agency.

(12) "Estimated concentration" means the level of the analyte reported to the department is above a lab's MDL, but below the lab's MRL.

(13) "GWR" means groundwater rule.

(14) "Lab" or "certified lab" means an environmental lab accredited under chapter 173-50 WAC for one or more drinking water analytes and meets the requirements of this chapter.

(15) "Maximum contaminant level (MCL)" means the maximum permissible level of a contaminant in water that a public water system delivers to consumers. MCLs are established in chapters 246-290 and 246-291 WAC.

(16) "Minimum detectable activity (MDA)" means the smallest activity or concentration of radioactive material in a sample that will yield a net count (above sample background) that can be detected with ninety-five percent probability.

(17) "Minimum detection level (MDL)" means the minimum measured concentration of a substance that can be reported with ninety-nine percent confidence that the measured concentration is distinguishable from the method blank results.

(18) "Method reporting limit (MRL)" means the lowest concentration of a standard used for calibration.

(19) "Proficiency testing (PT)" means the evaluation of sample analysis results, the true values of which are known to the supplier of the samples, but unknown to the lab conducting the analysis. PT samples are provided by a source external to the certified lab.

(20) "Public water system" is defined and referenced under WAC 246-290-020 and 246-291-010.

(21) "Quality control (QC)" means a set of measures used during an analytical method to ensure that the process is within specified control parameters.

(22) "State detection reporting limit (SDRL)" means the minimum reportable detection of an analyte as established in Tables 1 through 4 of this chapter.