Techniques and Methods 5–B6
Book 5, Laboratory Analysis
Section B, Methods of the National Water Quality Laboratory
Chapter 6
McCurdy, D.E., Garbarino, J.R., and Mullin, A.H., 2008, Interpreting and reporting radiological water-quality data: U.S. Geological Survey Techniques and Methods, book 5, chap. B6, 33 p.
Abstract
Introduction
1. Analytical Information Reported by the Contract Laboratory
2. Definitions of Important Analytical Parameters
2.1 Combined Standard Uncertainty
2.2 Sample-Specific Critical Level (ssLC)
2.3 Minimum Detectable Concentration
2.3.1 a priori Minimum Detectable Concentration (a priori MDC)
2.3.2 Sample-Specific Minimum Detectable Concentration (ssMDC)
2.4 Comparison of Radiological, Inorganic, and Organic Detection Levels
3. National Water Quality Laboratory Evaluations of Contract Laboratory Results
3.1 Initial Evaluation Criteria
3.2 Rounding Results
3.3 Review of Negative Results
3.4 Assigning Remark and Value-Qualifier Codes
3.5 Information Sent to the National Water Information System (NWIS) Database
3.6 Information in Detailed Data Packages
4. Water Science Center Reviews of National Water Information System (NWIS) Database Results
5. Publishing Results
5.1 Technical Reports
5.2 Nontechnical Reports
6. Interpretation and Reporting of Results from an Aggregated Dataset
Acknowledgments
References Cited
Glossary
Appendix: Typical Equations for Calculating Radiological Parameters
A1. Calculating the Concentration
A2. Calculating the Combined Standard Uncertainty
A3. Calculating the Critical Level
A3.1 General Principles
A3.2 Calculating the Sample-Specific Critical Level (ssLC)
A3.3 Practical Approach for Verifying the Reported Sample-Specific Critical Level
A4. Calculating the Minimum Detectable Concentration
A4.1 General Principles
A4.2 Calculating the Sample-Specific Minimum Detectable Concentration (ssMDC)
A4.3 Practical Approach for Verifying the Reported Sample-Specific Minimum Detectable Concentration
A4.4 The Effect of Sample Size and Counting Time on the Reported Sample-Specific Minimum Detectable Concentration (ssMDC)
A4.5 The Relation between the Combined Standard Uncertainty and the Calculated Activity in a Sample for Two Radioanalytical Measurement Techniques