Quality Assessments and Performance Evaluation - Chesapeake Bay Program

<body> <H4>Quality Assessments and Performance Evaluation</H4><P>During the collection and analysis of environmental samples, scientists continually check for random and systematic errors by analyzing quality control samples. Blanks, duplicates and spiked samples are processed in the field and laboratory to monitor bias and imprecision in the data. <BR> <BR>In addition to these internal quality control checks, several external, independent assessments of data quality are performed:</P><UL><LI>Laboratories analyze quality control samples of unknown concentration such as reference samples, blind audit samples and split samples. Results of these samples are evaluated by quality assurance staff to assess laboratory performance. Poor performance results often require followup and corrective action. For more information, see the Chesapeake Bay Split Sample and Blind Sample Programs site. (new pg)<BR><BR></LI><LI>Chesapeake Bay Program staff conduct on-site audits of field, laboratory and data management procedures to ensure that staff are following their standard operating procedures. <BR><BR> </LI><LI>Reported data undergo a final check before they are released. An automated computer program called Quality Assurance Tool performs up to 150 checks on water quality data sets as a final check on accuracy. </LI></UL><H4>Documentation:</H4><UL><LI>Procedures for Collecting Mainstem Split Samples (pdf)</LI><LI>Procedures for Analyzing and Reporting Water Quality Split Samples (pdf)</LI><LI>Procedures for Counting and Reporting Plankton Split Samples (pdf)</LI><LI>Chesapeake Bay Program Blind Audit Nutrient Results - January and June 1998 (pdf)</LI><LI>USGS Nutrient Reference Sample Results (pdf)</LI></UL><H4>Publications (CBP):</H4><UL><LI>Recommended Guidelines for Sampling and Analyses in the Chesapeake Bay Monitoring Program, Chapter II (EPA-903-R-96-006)</LI><LI>Chesapeake Bay Program Mainstem Coordinated Split Sample Program Report,1994-1998 (EPA-903-R-99-024)</LI><LI><A HREF="http://cbl.umces.edu/nasl/documents/np.pdf" TARGET="_top">Nitrogen and Phosphorus Determinations in Estuarine Waters: A Comparison of Methods Used in Chesapeake Bay Monitoring</A> (CBP/TRS 7/87) <IMG SRC="../images/pdf.gif" WIDTH="17" HEIGHT="16" ALT="PDF File"> <BR></LI></UL><table border="1" cellpadding="4" cellspacing="0" bgcolor="#C6C68C" width="100%"> <tr valign="top"> <td><strong>Other Sites of Interest:</strong><ul><li><A HREF="http://www.epa.gov/quality1" TARGET="_top">The EPA Quality System</A> -</li><li><A HREF="http://www.epa.gov/quality1/qa_docs.html" TARGET="_top">U.S. EPA QA Plan Guidance</A> -</li><li><A HREF="http://bqs.usgs.gov/srs/FS_031_98.html">USGS Reference Sample Program</A> -</li><li><A HREF="http://www.epa.gov/region03/esc/library/index.htm" TARGET="_top">EPA Region 3 Library</A> -</li></ul></td></tr> </table><hr> <P ALIGN="CENTER"><a name="Ecosystem"></a><font face="Times New Roman" size="2">To bookmark this page, please use this URL: <a href="../qaperformance.htm" target="_top">http://www.chesapeakebay.net/qaperformance.htm</a></font></P><P ALIGN="CENTER"><font size="2">For more information, contact the Chesapeake Bay Program Office:<br> 410 Severn Avenue, Suite 109, Annapolis, MD 21403 / Tel: (800) YOUR-BAY / Fax: (410) 267-5777</font><font size="2">.</font></P><P ALIGN="CENTER"><font size="2"><a href="../termsofuse.htm" target="_top">Terms of Use</a> | <a href="../privacypolicy.htm" target="_top">Privacy Policy</a> | <a href="../comments.htm" target="_top">Contact Us<br> </a></font><font size="2"><a href="http://www.chesapeakebay.net/directions.htm" target="_top"> Directions to the Bay Program Office</a></font><br> <a href="http://www.chesapeakebay.net/cims" target="_top"><img src="../images/cims1.gif" height="19" width="51" border="0" align="left" vspace="10" alt="Chesapeake Information Management System (CIMS) "></a><a href="javascript:print()"><img src="../images/print.gif" width="31" height="38" border="0" alt="Print Current Page" align="right"></a><br> <font size="2">Last modified: 02/12/02</font></P></td><td align="left" valign="top" bgcolor="#E7E7D6">   </td></tr> <tr> <td align="left" valign="top" bgcolor="#E7E7D6"><img src="../images/endc3.gif" alt="endc3.gif (827 bytes)" WIDTH="8" HEIGHT="14"></td><td align="right" valign="top" bgcolor="#E7E7D6" colspan="2"><img src="../images/endd3.gif" alt="endd3.gif (827 bytes)" WIDTH="8" HEIGHT="14"></td></tr> </table></div>