Policy for the Approval of U.S. Geological Survey (USGS) Water-Quality Analytical Methods To: " WRD Archive File, "
CC: Nana Snow , Iris Collies Subject: Re: OWQ Tech Memo 98.05--Policy for the Approval of (USGS) Water-Quality Analytical Methods In Reply Refer To: Mail Stop 412 September 14, 1998 OFFICE OF WATER QUALITY TECHNICAL MEMORANDUM 98.05 Subject: Policy for the Approval of U.S. Geological Survey (USGS) Water-Quality Analytical Methods I. Purpose of Memorandum This memorandum restates the Water Resources Division (WRD) policy for the approval of water-quality analytical methods contained in WRD Memoranda 82.28 and 92.37 and supersedes both memoranda. It also includes a description of the process and requirements for obtaining WRD approval of a water-quality analytical method by the Office of Water Quality (Attachment 1). II. Policy All water-quality analytical data that are collected by the WRD on a routine, production basis for release to the public in data reports, district annual data reports, and data bases must be produced using WRD approved methods by a laboratory that has been approved by WRD according to OWQ Memorandum 98.03. This policy has been established to ensure that USGS data are of known and documented quality, and that the analytical methods used to produce the data are thoroughly tested, documented, and available to the public. Data produced using new, unapproved methods or using research methods may not be published in data reports or in district annual data reports. In addition, the data may not be released to the public in publicly accessible data bases. Data provided to the public from unapproved methods or research methods must be accompanied by a method description that documents the method and the quality of the data reported. III. Sources of Approved Methods Any methods already accepted and published by the following sources will have automatic WRD approval: a. Methods published by the U.S. Environmental Protection Agency (USEPA) b. Methods published by ASTM c. Standard Methods (American Public Health Association, 1995) New methods or modifications of existing methods that are not published in the sources above must be published in one of the following USGS series publications: Techniques of Water-Resources Investigations (TWRI) series; Open-File Reports (OFR); or Fact Sheets. REFERENCES: American Public Health Association, American Water Works Association, and Water Environment Federation, 1995, Standard methods for the examination of water and wastewater (19th ed.): Washington, D.C., American Public Health Association, variously paged. Hansen, 1991, Suggestions to authors of the reports of the United States Geological Survey. (7th ed.): Washington, D.C., U.S. Geological Survey, 289p. U.S. Environmental Protection Agency, 1994, Guidelines establishing test procedures for the analysis of pollutants (App. B, Part 136, Definition and procedures for the determination of the method detection limit): U.S. Code of Federal Regulations, Title 40, revised as of July 1, 1994, p. 635-637.a users. CITED MEMORANDA Office of Water Quality Technical Memorandum No. 98.03 (Revised): Policy for the Evaluation and Approval of Production Analytical Laboratories. April 16, 1998. Water Resources Division Memorandum No. 82.28 (Superseded): Water Quality-Acceptability and Use of Water-Quality Analytical Methods. January 21, 1982. Water Resources Division Memorandum 92.37 (Superseded): Policy of the Water Resources Division on Laboratory Analytical Methodology. April 16, 1992. Janice R. Ward Acting Chief, Office of Water Quality This memorandum supersedes Water Resources Division Memoranda No. 82.28 and 92.37. Distribution: A, B, S, FO, PO District Water-Quality Specialists OWQ Staff Regional Water-Quality Specialists Key words: analytical method, data base, laboratory, water quality Attachment 1: Process for Obtaining Approval of New Water-Quality Analytical Methods Definitions: 1. "Water-quality analytical methods" are chemical, biological, or physical methods used to measure various properties of hydrologic systems for purposes of assessing water quality. 2. "Hydrologic systems" include precipitation, surface water, and ground water, along with associated atmospheric, biological, and geologic components. "Data" refer to the results of the measurements on a hydrologic system using the water-quality analytical method. Results are typically quantifiable numbers, such as analyte concentrations, biological species names and numbers, and grain size or turbidity. 3. "Approved data" are the results of an approved water-quality analytical method conducted by an approved laboratory under the quality-assurance (QA)/quality-control specifications of the method. These data may be published in District data reports and/or distributed to the public through data bases. 4. "Analyte" refers to a constituent, element, isotope, or compound being determined in a chemical analysis. 5. "Data quality" refers to the properties of the measurement, such as precision, bias, detection limit, and other relevant measures. 6. "Final draft report" is a WRD report which has completed full editorial and technical peer review according to normal USGS report standards (Hansen, 1991) and is ready to be submitted for USGS approval. Process for Obtaining Approval of New Methods: Any laboratory providing data to WRD can request approval of a new water-quality analytical method by submitting the following to the Chief, OWQ: 1. A cover memorandum to the Chief, OWQ, from the originating laboratory, through the appropriate WRD supervisory chain-of-command, asking for approval of the method and describing why the method should be approved by WRD. The originating laboratory must also be approved by WRD according to OWQ Technical Memorandum 98.03. 2. A final draft WRD report, describing the water-quality analytical method. The USGS standard manuscript-routing sheet (Hansen, 1991, p. 40), including all signatures, up to final WRD approval must be included, along with all technical peer-review comments and the author's responses to those comments. At least one of the peer reviewers must be a technical expert from outside the originating laboratory. 3. The originating laboratory's standard operating procedure (SOP) for the method in the form and content specified by the originating laboratory's QA manual. Submittals will be reviewed by the OWQ within 3 weeks. All supporting data and calculations related to the draft report shall be available for review upon request. Any required changes will be communicated back to the originator in writing. The manuscript routing sheet will be signed by the Chief, OWQ, and returned to the originating laboratory for final report approval. Upon acceptance of the water-quality analytical method, and contingent upon approval of the report draft by USGS, a memo from the OWQ will be written to document the method as approved by WRD. Approval of a new method requires documentation of method performance, which shall include three different matrices; two different concentrations, one high and one low; and seven replicates of each combination. All analytes shall be spiked into each matrix. For water methods, the three matrices should include a surface water, a ground water, and a reagent water matrix. In some instances, specific water-quality variables, such as conductivity or dissolved-organic carbon, may be known to have substantial effects on the performance of analytical methods. Specific consideration should be given to selecting water sources that span expected ranges of those key variables. For other media, the laboratory should choose three different representative matrices that are appropriate. The laboratory method blank shall be fully characterized. An initial method detection limit (MDL) shall be determined according to the USEPA (1994), and must include necessary iterations as specified therein. Data for the MDL determination shall include data collected over several days using different calibration curves. Reporting conventions for the analytical data will be specified and justified, including numbers of significant figures for different analyte concentration ranges. Values reported for non-detections of each analyte will also be specified and justified. Process for Obtaining Approval for Modifications to Existing Approved Methods: Changes to WRD-approved water-quality analytical methods must be tightly controlled. To maintain data quality, method changes expected to affect data quality must be documented as a new water-quality analytical method with full validation in a new USGS publication as described above. On occasion, it may be appropriate to add analytes to an existing approved water-quality analytical method. These changes require documentation through a USGS publication using the same procedures outlined for the original method approval. Changes to approved water-quality analytical methods that are not expected to affect data quality must be documented in changes to the laboratory's SOP for that method. These changes shall be recorded as SOP version number changes, with all supporting data archived with the method file as specified in the laboratory's QA manual. These files must be available to data users who may need to investigate unexpected data-quality changes. Data changes resulting from recalculation or reinterpretation of old analytical information must also be fully documented in the laboratory-method file and be available for data users. On a yearly basis, a copy of all updates to the method file shall be sent to the Chief, Branch of Quality Systems, for tracking and availability to the USGS and the public. -