Transcript Mod13-A QA/QC for Environmental Measurement

QA/QC FOR
ENVIRONMENTAL
MEASUREMENT
Unit 4: Module 13, Lecture 1
QA/QC for environmental measurement
http:/water.usgs.gov/
 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
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QA/QC for environmental measurement
 Quality control refers to
routine technical activities
– the purpose of which is
to control error
http://oceanexplorer.noaa.gov/explorations/02hud
son/logs/aug29/aug29.html
 QC can be considered the
“HOW” of the QA process
 applicable to field, lab and
office procedures
http://www.jmg.gov.my/Client_s_Charter/client_s_
charter.html
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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?
http://www.darcnw.noaa.gov/bbpix.htm
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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
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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
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Where is QA applicable?
 Non-research areas utilize environmental QA
measures also
 business and industry
 lobbying groups and special interests
 legislators
 lawyers
 others
http://www.lanl.gov/orgs/pa/News/060297.html
http://gov.state.nv.us/S
pecialSessio
n072902.asp
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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Quality assurance vs. quality control
 Quality Assurance
(QA)
 broad program plan
 establishes the need
for QC
Developed by: Zwiebel, Filbin
 Quality Controls (QC)
 individual checks
and balances
 the “HOW” of QA
Updated: June 14, 2005
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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
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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
http://climchange.cr.usgs.gov/info/lacs/wate
rsampling.htm
sechi readings
Developed by: Zwiebel, Filbin
field filtration
Updated: June 14, 2005
http://www.fe.doe.gov/techline/tl_
hydrates_oregon.shtml
logging sea cores
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QC in the field
 Standardized field
method programs
 US Army Corps of
Engineers
 ASTM methods
 USGS classification
 APHA
 AIHA
 NIST
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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QC in the laboratory
 Laboratory data analysis, measurement and
acquisition:
 Chain of custody forms
 Equipment calibration
 Storage practices
 Analytical methods
 Holding times
 MDLs
www.odc.gov/noeh/dls
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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QC in the laboratory
 Standardized
laboratory method
programs
 EPA Methods
 State Modified
Methods
 APHA Methods
 ASTM
 AIHA
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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
http://www.va.gov/optometry/page.cfm?pg=4
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
www.cr.nps.gov/aad/collections/ mgt_pr.htm
Photo from MN DNR
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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
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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”
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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Quality control (QC): Internal
http://www.ars.usda.gov/is/np/fnrb/fnrb1001.htm
 Internal Quality Control:
 Equipment calibration
 Proper training and
certification of participants
 Proper sampling and
containment techniques
 Proper data documentation
http://il.water.usgs.gov/adcp/photos/class_apr99.html
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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Quality control (QC): External
http://www.ars.usda.gov/is/np/fnrb/fnrb1001.htm
 External quality
control:
 Performance audits
 Split sample analysis
 Replicate (duplicate)
sample analysis
http://www.tfhrc.gov/pubrds/novdec98/seven.htm
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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
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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
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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
http://www.d.umn.edu/faculty/ UMD med school
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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Key concepts of QA/QC: Accuracy
 accuracy = (average
value) – (true value)
 precision represents
repeatability
 bias 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
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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??

http://pubs.usgs.gov/fs/fs-0058-99
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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 ??
Developed by: Zwiebel, Filbin

Updated: June 14, 2005
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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 ?? 
http://www.nssl.noaa.gov/publicaffairs/bac
kgrounders/backgrounder_ww.html
http://www.nrcs.usda.gov/programs/cta/ctasummary.html
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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Review: QA vs. QC
 Quality Assurance
(QA)
 broad program plan
 establishes the need
for QC
Developed by: Zwiebel, Filbin
 Quality Controls (QC)
 standardized tests
and methods
 the “HOW” of QA
Updated: June 14, 2005
U5-m13a-s28
Review: Quality Assurance Project Plans
 The QAPP is a
project-specific QA
document.
 The QAPP outlines
the QC measures to
be taken for the
project.
Developed by: Zwiebel, Filbin
 QAPP guides:
 the selection of
parameters and
procedures
 data management
and analysis
 steps taken to
determine the
validity of specific
sampling or analysis
procedures
Updated: June 14, 2005
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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)
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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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/qappexe
c.htm
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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•http://waterontheweb.org/index.html
Developed by: Zwiebel, Filbin
Updated: June 14, 2005
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