qa/qc for environmental measurement

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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) - PowerPoint PPT Presentation

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  • QA/QC FOR ENVIRONMENTAL MEASUREMENTUnit 4: Module 13, Lecture 1

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    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)

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    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

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    QA for environmental measurement Why do we need quality assurance for environmental measurement?understand data reliabilityquantify areas of analytical uncertaintystandardize measurement to allow for repeatable and comparable data across time and placeQA ensures that data will meet defined standards of quality with a standard level of confidence

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    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?

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    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.

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

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

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Where is QA applicable?Non-research areas utilize environmental QA measures also business and industrylobbying groups and special interests legislatorslawyersothers

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Quality assurance vs. quality controlQuality Assurance (QA)broad program plan establishes the need for QC

    Quality Controls (QC) individual checks and balancesthe HOW of QA

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    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

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    QC in the fieldQC is particularly critical in filed data collectionoften the most costly aspect of a project data is never reproducible under the exact same condition or settingsechi readingsfield filtrationlogging sea cores

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    QC in the fieldStandardized field method programsUS Army Corps of Engineers ASTM methodsUSGS classificationAPHAAIHANIST

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    QC in the laboratoryLaboratory data analysis, measurement and acquisition:Chain of custody formsEquipment calibrationStorage practicesAnalytical methodsHolding timesMDLs

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    QC in the laboratoryStandardized laboratory method programsEPA MethodsState Modified MethodsAPHA Methods ASTMAIHA

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    QC in the officeIn office planning, data evaluation and summation of results:QAPP quality assuranceproject plan outlines allproject managementassessment and oversightdata validationwww.cr.nps.gov/aad/collections/ mgt_pr.htm Photo from MN DNR

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    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

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    QC: Internal vs. external measuresInternal quality controlcontrollable by those responsible for undertaking the project or directly involved in the program

    External quality controla set of measures established for and conducted by those people and organizations outside of the program

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Quality control (QC): Internal Internal Quality Control:Equipment calibrationProper training and certification of participantsProper sampling and containment techniques Proper data documentation

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Quality control (QC): ExternalExternal quality control:Performance auditsSplit sample analysisReplicate (duplicate) sample analysis

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    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.

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    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 proceduresguides data management and analysisprovides steps to determine the validity of specific sampling or analysis proceduresdesignates both internal and external QC measures

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    QA/QC: Data objective and key conceptsSuccessful data collection and analysis is dependant upon The PARCC Parameters: PrecisionAccuracyRepresentativenessCompletenessComparability

    The key concepts of QA/QC are the PARCC Parameters the WHY of the QAPP

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Key concepts of QA/QC: Precision -degree of agreement there is between repeated measurements of the same characteristiccan be biased meaning there is a consistent error in the resultsAccuracy - measures how close data results are to a true or expected value does not allow for bias

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Key concepts of QA/QC: Accuracyaccuracy = (average value) (true value)precision represents repeatabilitybias represents amount of error

    low bias and high precision = statistical accuracy

    http://www.epa.gov/owow/monitoring/volunteer/qappexec.html

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Key concept QA/QC: RepresentativenessRepresentativeness - 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??

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Key concepts of QA/QC: CompletenessCompleteness -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 ??

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    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 ??

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Review: QA vs. QC Quality Assurance (QA)broad program plan establishes the need for QC

    Quality Controls (QC) standardized tests and methodsthe HOW of QA

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Review: Quality Assurance Project PlansThe 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 proceduresdata management and analysissteps taken to determine the validity of specific sampling or analysis procedures

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Elements of a QAPPThe QAPP governs work conducted in the field, laboratory, and the office.

    QAPP can be broken out into four areas of the projectProject management (office)Measurement and data acquisition (field and lab)Assessment and oversight (field, lab, and office)Data validation and usability (field, lab, and office)

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    Review: QA/QC key conceptsThe PARCC Parameters are the WHY of QA/QC and assure successful data analysis: PrecisionAccuracyRepresentativenessCompletenessComparability The key concepts and WHY of QA/QC are the PARCC Parameters

    Developed by: Zwiebel, Filbin Updated: June 14, 2005 U5-m13a-s*

    ReferencesEPA 1996, Environmental Protection Agency Volunteer Monitors 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: