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Proprietary and Confidential
Using the DQO Process to Improve
Field Sampling
February 13, 2013
Rowdy Bindert
Account Executive
2
Agenda
• Background on Planning Process
– DQO Process
– Field Sampling Plan
• Critical Considerations for Data Quality
– Chains of Custody
– Bottles
– Holding times
– Preservatives
3
Background on Planning
Process
• Environmental data collection requires systematic planning and
forethought
• Data Quality Objective Process (DQO’s) http://www.epa.gov/QUALITY/qs-docs/g4-final.pdf
– Intended for projects under US EPA oversight, but can be used
for any projects that require environmental chemical data
collection
May need an extensive project team for large projects or
a single well informed individual for smaller projects
– DQO process, even on a reduced scale, will facilitate logical
thinking and provide a systematic and organized project plan
4
Background on Planning
Process
Goal is to collect relevant and valid data
• Planning, implementation and
assessment phases
• Planning is the most critical phase of
the data collection process
– TestAmerica can participate in
the DQO development process
• TestAmerica would like to be able to
review and comment on
– Sampling & Analysis Plan (SAP)
– Quality Assurance Project Plan
(QAPjP)
Assessment Task 7: Data Quality Assessment
Task 6: Data Evaluation
Implementation Task 5: Field and Lab QA/QC
Task 4: Lab Analysis Task 3: Sampling and Field Data Collection
Planning Task 2: Sampling and Analysis Plan
Task 1: Data Quality Objectives
Planning phase for Environmental Data Collection
Assessment Task 7: Data Quality Assessment
Task 6: Data Evaluation
Implementation Task 5: Field and Lab QA/QC
Task 4: Lab Analysis Task 3: Sampling and Field Data Collection
Planning Task 2: Sampling and Analysis Plan
Task 1: Data Quality Objectives
5
Sampling Plan
Components of a Sampling
Plan
• Analytes of Interest
• Sampling Location
• Collection Methods
• Frequency of testing
Planning phase for Environmental Data Collection
Assessment Task 7: Data Quality Assessment
Task 6: Data Evaluation
Implementation Task 5: Field and Lab QA/QC
Task 4: Lab Analysis Task 3: Sampling and Field Data Collection
Planning Task 2: Sampling and Analysis Plan
Task 1: Data Quality Objectives
6
Analytes of interest
Why is this important?
Proper sample containers and
preservatives are critical.
Why are you collecting the
samples? Permit, disposal,
etc?
Planning phase for Environmental Data Collection
7
Method Selection
• Method selection should be completed as part of the
DQO process by the project team.
– Consensus Methods - ASTM
– Compliance (NPDES) Methods - 40 CFR Part 136
– Drinking Water Methods
– Solid & Hazardous Waste - US EPA SW 846
– Contract Laboratory Program (CLP)
• CLP SOM01.2
• CLP ILM05.4
Method Selection is another Presentation!
Assessment Task 7: Data Quality Assessment
Task 6: Data Evaluation
Implementation Task 5: Field and Lab QA/QC
Task 4: Lab Analysis Task 3: Sampling and Field Data Collection
Planning Task 2: Sampling and Analysis Plan
Task 1: Data Quality Objectives
8
Sampling Location
Wastewater outfall
Does the outfall represent an
accurate portrayal of the the
overall waste stream.
Solid Waste
Is the sub sample you are
collecting an accurate
representation of the waste.
Planning phase for Environmental Data Collection
Assessment Task 7: Data Quality Assessment
Task 6: Data Evaluation
Implementation Task 5: Field and Lab QA/QC
Task 4: Lab Analysis Task 3: Sampling and Field Data Collection
Planning Task 2: Sampling and Analysis Plan
Task 1: Data Quality Objectives
9
Collection Methods
Grab Sample
A sample which is taken from a
waste stream on a one-time basis
without consideration of the flow
rate of the waste stream and
without consideration of time.
Composite Sample
Sample composed of two or more
discrete samples. The aggregate
sample will reflect the average
water quality covering the
compositing or sample period.
Planning phase for Environmental Data Collection
Assessment Task 7: Data Quality Assessment
Task 6: Data Evaluation
Implementation Task 5: Field and Lab QA/QC
Task 4: Lab Analysis Task 3: Sampling and Field Data Collection
Planning Task 2: Sampling and Analysis Plan
Task 1: Data Quality Objectives
10
Frequency
• Weekly, monthly, daily, etc.
Planning phase for Environmental Data Collection
11
Our Goal
• Overall goal of the project is to generate
relevant and valid chemical data
• Although errors do occur in the lab,
“analytical” errors are often associated
with field sample collection
• Lab and the field team working together
can minimize any potential errors
– Bottle, preservatives & field QC
samples
– Ultimately it is the field team who
has to collect the representative
sample for the lab
The data provided by the laboratory is only
as good as the field sample provided.
12
Critical Considerations For
Data Quality
• Once the sampling and analytical strategies are complete – it’s time to go into the field.
• Critical considerations that will impact the overall project outcome are:
– Chains of Custody: must be “cradle-to-grave”
– Bottles: must be clean and conform to method requirements, and volume must be sufficient
– Holding Times: must be considered, so samples arrive at lab in time for “in-hold” analyses
– Preservatives: must be appropriate for the method
– Coolers: must be packed to ensure sample integrity and labeled to conform with DOT requirements
13
Chains of Custody (CoC)
Environmental samples can become legal evidence. Possession must be traceable • Chains of Custody provide the ability to
guarantee the identity and integrity of samples from collection through the reporting of the results.
• Samples are in custody if:
– in sampler’s possession
– in sampler’s view after being in possession
– In sampler’s possession and then locked so tampering cannot occur
– in a secure area with access restricted to authorized personnel
• Documenting transfer of sample from one person to another is critical
14
Custody Process
• Field samplers initiate the COC when samples are being collected
Sample bottles are placed in cooler, packed and ready for shipping
Field sampler signs COC to transfer custody to Courier or Express Carrier
• Once samples are received in the laboratory
Sample receiving personnel sign as the receiving party
Custody protocols are maintained while samples are in the lab through internal sample custody tracking.
• All signatures, dates and times must be legible and in permanent ink
15
More on COCs
• EPA offers an online course on Chain of Custody Procedures ( Air Pollution Training Institute of EPA)
http://www.epa.gov/apti/coc/
16
Bottles
• Lab will send new, Certified Clean Bottles – or have a lab blank program to verify cleanliness
– Note: EPA has published “Specifications and Guidance for Contaminant-Free Sample Containers” Publication 9240.0-05A, EPA/540/R-93/051 December 1992
• Bottles used must not compromise physical and chemical properties of samples
• Bottles must conform to method requirements, and be sized to ensure sufficient volume for test/reanalysis/QC (if required)
• Bottles are generally: – Amber and/or Clear Glass – High Density Polyethylene (HDPE) Plastic – EnCore/TerraCore
• If bottles have been taken to the field, they cannot be returned to the laboratory for use again.
18
Holding Times
• Holding time is the length of time a sample can be stored after collection and prior to analysis without affecting the results
• Holding times vary based on
– Analyte
– Sample matrix
– Analytical method
• Maximum holding times have been established in each analytical method
• Preservations help to extend holding times by reducing biodegradation, volatilization, oxidation, sorption, precipitation, and other chemical and physical processes
19
Preservatives
A preservation technique must be effective for the analyte in question, must be compatible with the analytical technique/ instrument, and must be safe and compatible with sample disposal requirements.
Common Preservation Techniques
• Refrigeration – slows microbial activity, slows chemical reactions, maximizes solubility of gasses/volatiles, minimizes volatilization
• Nitric acid – solubilizes metals
• Hydrochloric acid – minimizes microbial activity
• Sulfuric acid – minimizes microbial activity
• Sodium hydroxide – raises pH to maintain solubility of cyanides & sulfides
• Zero headspace – minimizes volatilization
• For Soil VOCs – Methanol, Sodium Bisulfate & Water for use w/TerraCores
Laboratory will supply the correct preservatives for requested analyses.
20
Next Phase
Samples arrive at the lab
Chains of Custody are reviewed,
anomalies are resolved and/or
noted, samples are logged, and
lab proceeds with analysis.
Assessment Task 7: Data Quality Assessment
Task 6: Data Evaluation
Implementation Task 5: Field and Lab QA/QC
Task 4: Lab Analysis Task 3: Sampling and Field Data Collection
Planning
Task 2: Sampling and Analysis Plan Task 1: Data Quality Objectives
Planning phase for Environmental Data Collection