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QA/QC FOR ENVIRONMENTAL MEASUREMENT

QA/QC FOR ENVIRONMENTAL MEASUREMENT. Unit 4: Module 13, Lecture 1. http:/water.usgs.gov/. QA/QC for environmental measurement . What is quality assurance (QA)? a broad plan for maintaining quality in all aspects of a program - Keith et al. (1983)

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QA/QC FOR ENVIRONMENTAL MEASUREMENT

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  1. QA/QC FOR ENVIRONMENTAL MEASUREMENT Unit 4: Module 13, Lecture 1

  2. http:/water.usgs.gov/ QA/QC for environmental measurement • What is quality assurance (QA)? • a broad plan for maintaining quality in all aspects of a program - Keith et al. (1983) • establishes the need for quality control (QC)

  3. http://oceanexplorer.noaa.gov/explorations/02hudson/logs/aug29/aug29.htmlhttp://oceanexplorer.noaa.gov/explorations/02hudson/logs/aug29/aug29.html http://www.jmg.gov.my/Client_s_Charter/client_s_charter.html QA/QC for environmental measurement • Quality control refers to routine technical activities – the purpose of which is to control error • QC can be considered the “HOW” of the QA process • applicable to field, lab and office procedures

  4. QA for environmental measurement • Why do we need quality assurance for environmental measurement? • understand data reliability • quantify areas of analytical uncertainty • standardize measurement to allow for repeatable and comparable data across time and place QA ensures that data will meet defined standards of quality with a standard level of confidence

  5. http://www.darcnw.noaa.gov/bbpix.htm QA for environmental assessment • Need for consistency - monitoring a copper impacted stream • Is this problem getting worse or is being mitigated? • How can you tell? • Why is standardized measurement so important?

  6. Where is QA applicable? • Who in the environmental arena uses quality assurance measures and when is it necessary? • nearly all REGULATORY decisions about: issuing permits, monitoring human health and environmental quality, pollution investigations and the progress of site remediation are based on one thing -- the data gathered from the site.

  7. Where is QA applicable? • What other environmental arenas utilize quality assurance measures? • laboratories • universities and research organization

  8. http://www.lanl.gov/orgs/pa/News/060297.html http://gov.state.nv.us/SpecialSession072902.asp Where is QA applicable? • Non-research areas utilize environmental QA measures also • business and industry • lobbying groups and special interests • legislators • lawyers • others

  9. Quality Assurance (QA) broad program plan establishes the need for QC Quality Controls (QC) individual checks and balances the “HOW” of QA Quality assurance vs. quality control

  10. Where is QC applicable? • Quality control is applicable in all aspects of a project including: • Field data collection and sampling • Laboratory analysis and processing • Data evaluation and assessment • Reporting and project documentation QC provides steps that ensure data will meet defined standards of quality with a standard level of confidence

  11. http://climchange.cr.usgs.gov/info/lacs/watersampling.htm http://www.fe.doe.gov/techline/tl_hydrates_oregon.shtml QC in the field • QC is particularly critical in filed data collection • often the most costly aspect of a project • data is never reproducible under the exact same condition or setting sechi readings logging sea cores field filtration

  12. QC in the field • Standardized field method programs • US Army Corps of Engineers • ASTM methods • USGS classification • APHA • AIHA • NIST

  13. www.odc.gov/noeh/dls QC in the laboratory • Laboratory data analysis, measurement and acquisition: • Chain of custody forms • Equipment calibration • Storage practices • Analytical methods • Holding times • MDLs

  14. QC in the laboratory • Standardized laboratory method programs • EPA Methods • State Modified Methods • APHA Methods • ASTM • AIHA

  15. http://www.va.gov/optometry/page.cfm?pg=4 QC in the office • In office planning, data evaluation and summation of results: • QAPP – quality assurance project plan outlines all • project management • assessment and oversight • data validation www.cr.nps.gov/aad/collections/ mgt_pr.htm Photo from MN DNR

  16. QC for environmental measurement • Why do we need quality control? • To prevent errors from happening • To identify and correct errors that have taken place QC is used to PREVENT and CORRECT ERRORS

  17. QC: Internal vs. external measures • Internal quality control • “controllable” by those responsible for undertaking the project or directly “involved in the program” • External quality control • a “set of measures” established for and conducted by those people and organizations “outside of the program”

  18. http://www.ars.usda.gov/is/np/fnrb/fnrb1001.htm http://il.water.usgs.gov/adcp/photos/class_apr99.html Quality control (QC): Internal • Internal Quality Control: • Equipment calibration • Proper training and certification of participants • Proper sampling and containment techniques • Proper data documentation

  19. http://www.ars.usda.gov/is/np/fnrb/fnrb1001.htm http://www.tfhrc.gov/pubrds/novdec98/seven.htm Quality control (QC): External • External quality control: • Performance audits • Split sample analysis • Replicate (duplicate) sample analysis

  20. Quality Assurance Project Plans (QAPP) • A quality assurance project plan (QAPP) is a project-specific QA document. • The QAPP outlines the QC measures used in implementing the project.

  21. Quality Assurance Project Plans (QAPP) • The QAPP governs work conducted in the field, laboratory, and the office. • The QAPP: • guides the selection of project parameters and procedures • guides data management and analysis • provides steps to determine the validity of specific sampling or analysis procedures • designates both internal and external QC measures

  22. QA/QC: Data objective and key concepts • Successful data collection and analysis is dependant upon “The PARCC Parameters”: • Precision • Accuracy • Representativeness • Completeness • Comparability The key concepts of QA/QC are the “PARCC” Parameters – the WHY of the QAPP

  23. http://www.d.umn.edu/faculty/ UMD med school Key concepts of QA/QC: • Precision - • degree of agreement there is between repeated measurements of the same characteristic • can be biased – meaning there is a consistent error in the results • Accuracy - • measures how close data results are to a true or expected value – does not allow for bias

  24. accuracy = (average value) – (true value) precision represents repeatability bias represents amount of error low bias and high precision = statistical accuracy Key concepts of QA/QC: Accuracy http://www.epa.gov/owow/monitoring/volunteer/qappexec.html

  25. http://pubs.usgs.gov/fs/fs-0058-99 Key concept QA/QC: Representativeness • Representativeness - • extent to which measurements actually represent the true environmental condition or population at the time a sample was collected. • Representative data should result in repeatable data  Does this represent this?? 

  26. Key concepts of QA/QC: Completeness • Completeness - • comparison between the amount of data intended to be collected vs. actual amount of valid (usable) data collected. • In the design of the QAPP – will the goals of the plan meet assessment needs? • Will sufficient data be collected? Would this give usable data?? 

  27. http://www.nrcs.usda.gov/programs/cta/ctasummary.html http://www.nssl.noaa.gov/publicaffairs/backgrounders/backgrounder_ww.html Key concepts of QA/QC: Comparability • Comparability - • the extent to which data can be compared between sample locations or periods of time within a project, or between projects  Will similar data from these sites be Comparable ?? 

  28. Quality Assurance (QA) broad program plan establishes the need for QC Quality Controls (QC) standardized tests and methods the “HOW” of QA Review: QA vs. QC

  29. The QAPP is a project-specific QA document. The QAPP outlines the QC measures to be taken for the project. QAPP guides: the selection of parameters and procedures data management and analysis steps taken to determine the validity of specific sampling or analysis procedures Review: Quality Assurance Project Plans

  30. Elements of a QAPP • The QAPP governs work conducted in the field, laboratory, and the office. • QAPP can be broken out into four areas of the project • Project management (office) • Measurement and data acquisition (field and lab) • Assessment and oversight (field, lab, and office) • Data validation and usability (field, lab, and office)

  31. Review: QA/QC key concepts • “The PARCC Parameters” are the WHY of QA/QC and assure successful data analysis: • Precision • Accuracy • Representativeness • Completeness • Comparability The key concepts and WHY of QA/QC are the “PARCC” Parameters

  32. References • EPA 1996, Environmental Protection Agency Volunteer Monitor’s Guide to: Quality Assurance Project Plans. 1996. EPA 841-B-96-003, Sep 1996, U.S. EPA, Office of Wetlands, Washington, D.C. 20460, USA http://www.epa.gov/owowwtr1/monitoring/volunteer/qappexec.htm

  33. http://waterontheweb.org/index.html

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