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

(1) "µmhos/cm" means micromhos per centimeter (1 µmhos/cm = 1 S/cm).

(2) "µg/L" means micrograms per liter (1 µg/L = 1 ppb).

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

(4) "Bioaccumulative" means a chemical that can accumulate in the body when regular exposure occurs through drinking water.

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

(6) "CFU" means colony-forming unit.

(7) "Chronic" means posing a risk to human health only when exposure occurs over many years to a contaminant above a state or federal health standard.

(8) "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.

(9) "Confirmation" means to demonstrate that the results of a sample accurately represents the original sample result by analyzing another sample from the same location within a reasonable given period of time. This confirmation analysis is in addition to any analytical method confirmation requirements.

(10) "Contaminant" means a substance present in drinking water that may adversely affect the health of the consumer or the aesthetic quality of the water. It is measured using an analytical method for compliance purposes under chapters 246-290 and 246-291 WAC.

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

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

(13) "CU" means color unit.

(14) "Department" means the Washington state department of health or health officer as identified in a joint plan of responsibility under WAC 246-290-030(1).

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

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

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

(18) "GWR" means groundwater rule.

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

(20) "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.

(21) "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 95 percent probability.

(22) "Minimum detection level (MDL)" means the minimum measured concentration of a substance that can be reported with 99 percent confidence that the measured concentration is distinguishable from the method blank results.

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

(24) "MFL" means microfibers per liter.

(25) "mg/L" means milligrams per liter (1 mg/L = 1 ppm).

(26) "MPN" means most probable number.

(27) "ng/L" means nanograms per liter (1 ng/L = 1 ppt).

(28) "NTU" means nephelometric turbidity units.

(29) "pCi/L" means picocuries per liter.

(30) "ppb" means parts per billion (1 ppb = 1 µg/L).

(31) "ppm" means parts per million (1 ppm = 1 mg/L).

(32) "ppt" means parts per trillion (1 ppt = 1 ng/L).

(33) "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.

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

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

(36) "State action level (SAL)" means the concentration of a contaminant or group of contaminants, without an MCL, established to protect public health in accordance with WAC 246-290-315 and which, if exceeded, triggers actions a purveyor takes in accordance with WAC 246-290-320.

(37) "State detection reporting limit (SDRL)" means the minimum reportable detection of a contaminant as established in Tables 3 through 7 of this chapter.

(38) "Tentatively identified compound (TIC)" means compounds detected in samples that are not target compounds, internal standards, system monitoring compounds or surrogates.