Section 750. Quality assurance

A. General. The laboratory shall have quality control procedures for monitoring the validity of environmental tests undertaken. The resulting data shall be recorded in such a way that trends are detectable and, where practicable, statistical techniques shall be applied to the reviewing of the results. This monitoring shall be planned and reviewed and may include, but not be limited to, the following:

1. Regular use of certified reference materials or internal quality control using secondary reference materials or both.

2. Participation in interlaboratory comparison or proficiency testing program.

3. Replicate tests using the same or different methods.

4. Retesting of retained samples.

5. Correlation of results for different characteristics of a sample (e.g., total phosphate should be greater than or equal to orthophosphate).

B. Essential quality control procedures. The general quality control principles in subsection C of this section shall apply, where applicable, to all environmental laboratories. The manner in which they are implemented is dependent on the types of tests performed by the laboratory. 1VAC30-45-770 through 1VAC30-45-775, 1VAC30-45-790 through 1VAC30-45-798, and 1VAC30-45-810 through 1VAC30-45-818 specify quality control requirements for chemical testing, microbiological testing, and air testing, respectively. Noncommercial environmental laboratories that analyze environmental samples using other types of testing such as toxicity, radiochemical, or asbestos testing shall meet the quality control standards for the specific method and the specific type of testing in the 2009 TNI Standards for Environmental Laboratories. The standards for any given test type shall assure that the applicable principles are addressed.

C. All laboratories shall have detailed written protocols in place to monitor the following quality controls:

1. Positive and negative controls to monitor tests such as blanks, spikes, reference toxicants.

2. Tests to define the variability or repeatability of the laboratory results or both such as replicates.

3. Measures to assure the accuracy of the test method including calibration or continuing calibrations or both, use of certified reference materials, proficiency test samples, or other measures.

4. Measures to evaluate test method capability, such as method detection limits and quantitation limits or range of applicability such as linearity.

5. Selection of appropriate formulae to reduce raw data to final results such as regression analysis, comparison to internal and external standard calculations, and statistical analyses.

6. Selection and use of reagents and standards of appropriate quality.

7. Measures to assure the selectivity of the test for its intended purpose.

8. Measures to assure constant and consistent test conditions (both instrumental and environmental) where required by the test method such as temperature, humidity, light, or specific instrument conditions.

Historical Notes

Derived from Volume 25, Issue 07, eff. January 1, 2009; amended, Virginia Register Volume 32, Issue 22, eff. September 1, 2016.

Statutory Authority

§ 2.2-1105 of the Code of Virginia.