Accuracy is a measurement of how close an analytical result is to the true or known value. Accuracy data are generated by performing laboratory control samples and/or matrix spikes and calculating the [..]

The level of chemical which, if exceeded, triggers treatment or other requirements that a water system must follow.

Calibration standards are used to calibrate instrumentation and to ensure adequate instrument performance. Calibration procedures are as stated in the individual methods.

California Assessment Manual.

A group of related bacteria whose presence in drinking water may indicate contamination by disease-causing microorganisms.

A water system which supplies drinking water to 25 or more of the same people year-round in their residences.

US Environmental Protection Agency.

Water that has been treated and is ready to be delivered to customers.

Good Laboratory Practice Standards of the EPA (40 CFR Part 160)

Internal standards are added to the samples and their associated QC after extraction and prior to analysis. The same amount of internal standard is added to each standard, QC sample, and client sample [..]