OWML: QA/QC

Quality Assurance/Quality Control Manual: Ohio Water Microbiology Laboratory

GENERAL LABORATORY QUALITY ASSURANCE/QUALITY- CONTROL PRACTICES

Analytical Methods
The methods used by the OWML can be categorized into four groups: compliance, official, provisional, and experimental.  The United States Environmental Protection Agency (USEPA) and others in the research community are continuously developing new methods for detecting and quantifying microbiological pathogens and indica­tors in water; therefore, several types of methods for target organisms may be currently in use at the OWML.

Compliance methods are those published by USEPA in the Federal Register and are used to determine compliance with standards for protection of public health in swimmable or drinkable waters. Analytical methods for fecal-indicator bacteria are often in this group because they are straightforward, quantitative, and routinely used.

Official methods are those noncompliance methods published by water-analysis authorities such as American Public Health Association, the U.S. Environmental Protection Agency, or the USGS. Official methods should be well established, have known levels of bias and variability, and be relatively easy to apply in field opera­tions or have holding times long enough to allow shipping to a central laboratory for analysis.

Provisional methods are published methods that are still being validated by the method developer, usually the USEPA.  For these methods, the method developer establishes precision and accuracy and ensures the methods are adequately tested.  Because methods for detection of protozoa are complex, qualitative to semiquantitative, expensive, and very time consuming, these methods are often provisional.

Experimental methods are unpublished methods that are currently being testing to establish QA/QC practices and determine applicability to ambient monitoring programs.