INTERPRETING YOUR LAB DATA

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INTERPRETING YOUR LAB DATA
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TYPES OF LABORATORY REPORTS

• ANALYTICAL
• WHOLE EFFLUENT TOXICITY

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INFORMATION COMMON TO ALL REPORTS

• Title
• Laboratory Name
• Address, Phone, Contact
• Unique Identifier (Laboratory Control No.)
• Number of Pages
• Client Name
• Date of Receipt

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SAMPLE SPECIFIC INFORMATION

• Unique Sample Identifier
• Sample ID
• Sample Collection Date and Time

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ANALYTICAL DATA - SAMPLE

• Parameter
• Analytical Method
• Data
• Units
• Reporting Limit RL, MDL, PQL
• Date of Analysis
• Workgroup / Batch
• Analyst

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QUALITY CONTROL DATA

• Laboratory Control Sample
• Matrix Spike Sample
• Sample Duplicate
• Surrogates
• Laboratory Blank

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LABORATORY CONTROL SAMPLE

• A sample matrix, free from the analytes of
  interest, spiked with verified known amounts of
  analytes or a material containing known and
  verified amounts of analyte. It is generally,
  used to establish intra-laboratory or analyst
  specific precision and bias or to assess the
  performance of all or a portion of the
  measurement system.

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• Frequency Minimum 1/batch
• Individual LCS is compared to the acceptance
  criteria as published in the mandated test method
  or based upon three standard deviations around
  the mean
• A LCS that is determined to be within the
  criteria effectively establishes that the
  analytical system is in control and validates
  system performance for the samples in the
  associated batch.

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• If a large number of analytes are in the LCS, it
  becomes statistically likely that a few will be
  outside the control limits. This may or may not
  indicate that the system is out of control.
• Many laboratories have established Marginal
  Exceedances (ME) Limits. ME limits are between
  three or four standard deviations around the mean.

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• The number of marginal exceedances allowable is
  dependent upon the number of analytes in the LCS.
• gt90 analytes, 5 ME
• 71-90 analytes, 4 ME
• 51-70 analytes, 3 ME
• 31-50 analytes, 2 ME
• 11-30 analytes, 1 ME
• lt11 analytes, 0 ME allowed

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MATRIX SPIKE

• A sample prepared by adding a known amount of
  target analyte to a specified amount of matrix
  sample.
• Matrix spikes are used to determine the effect of
  the matrix on recovery efficiency.

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• Theoretically, matrix spike control limits are
  typically equal to or greater than laboratory
  control sample limits.
• If the matrix spike amount is less than four (4)
  times the result in the unspiked sample, the
  MS/MSD data may not represent the matrix effect.

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SAMPLE DUPLICATE

• Replicate aliquots of the same sample taken
  through the entire analytical procedure.
• The results from the analysis indicate the
  precision of the results for the specific sample
  using the method selected and are expressed as
  relative percent difference (RPD).
• Typically, RPD limits for sample duplicates gt RPD
  limits established from LSC/MS duplicates.

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SURROGATES

• Surrogates are used most often in organic
  chromatographic test methods and are chosen to
  reflect the chemistries of the targeted
  components of the method.
• Added prior to sample preparation /extraction,
  they provide a measure of recovery for every
  sample matrix.

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METHOD BLANK

• A sample of a matrix similar to the batch of
  associated samples that is free from the analytes
  of interest and is processed simultaneously with
  and under the same conditions as samples through
  all steps of the analytical procedure, and in
  which no target analytes or interferences are
  present at concentrations that impact the
  analytical results for sample analyses.

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• Goal is to have no detectable contaminants.
• Common method blank contaminates are acetone,
  methylene chloride, copper, iron, and zinc.

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GENERAL GUIDANCE - BLANKS

• If the sample contains the contaminant at levels
  of at least 10 times that in the blank, then the
  likely contribution to the sample from the
  contaminant in the laboratory environment is at
  most 10. The possible contamination is
  negligible

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• If the sample contains the contaminant at levels
  of at least 5 times but less than 10 times the
  blank result, the compound is probably present in
  the sample, but the numerical result should be
  considered an upper limit of the true
  concentration.

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• If the sample contains the contaminant at levels
  below 5 times the level in the blank, there is no
  adequate means by which to judge whether or not
  the sample result is attributable to laboratory
  contamination. The results for that compound in
  the sample then becomes unacceptable for
  compliance monitoring.

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• Parameter Relationships
• CODgtBODgtTOC
• BODgt CBOD
• Total Solids TSS TDS
• TKNgtNH3N
• Total Nitrogen TKN NO3N NO2N
• Total Organic Nitrogen TKN NH3N
• OG gt TPH
• Total Analytegt Dissolved Analyte
• Cr Cr3 Cr6

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SUPPLEMENT REPORT INFORMATION

• Sample Receipt Documentation
• Case Narrative
• Data Qualifiers

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SAMPLE RECEIPT DOCUMENTATION

• Upon receipt, samples are inspected to determine
  if they meet regulatory compliance. If a sample
  fails to meet the requirements, the client should
  be contacted for instructions. If the decision
  is to proceed with the analysis, any sample
  failing to meet requirements must be
  appropriately flagged on the final report.

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• Temperature
• Preservation
• Holding Time
• Container Information
• Documentation (COC)

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CASE NARRATIVE

• Provides a correlation between field sample and
  laboratory sample numbers
• Identifies any issues with sample receipt
• Identifies extractions or analyses that are
  performed out of holding times

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• Deviations from the method
• Identification of any QC failures and associated
  corrective actions taken by the laboratory
• Any other factors that could affect the sample
  results (e.g., air bubbles in VOC sample vials,
  excess headspace, multi-phasic samples, container
  type or volume)

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DATA QUALIFIERS

• Data Qualifers are added by the laboratory during
  the review process
• Data Qualifers are applied when measurement
  quality objects are not met and corrective action
  is not successful or when corrective action is
  not performed
• They may also be applied to provided additional
  information concerning the reported data

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• B Analytes are detected in the blank above the
  reporting limit
• J The analyte was positive the associated
  numerical value is the approximate concentration
  of the analyte in the sample
• Q Data requires usability review due to the
  exceedance of method-specific holding time,
  calibration, or batch QC data associated with the
  sample does not meet measurement quality
  objectives
• H Holding time was exceeded
• W Data is presented on an as-received-basis

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WHOLE EFFLUENT TOXICITY
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INTRODUCTION

• Permit Number
• Toxicity Testing Requirement of Permit
• Plant Location
• Name of Receiving water body
• Contract Laboratory
• Objective of Test

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PLANT OPERATONS

• Products
• Raw Materials
• Operating Schedule
• Description of waste treatment
• Schematic of waste treatment
• Retention time (if applicable)
• Volume of waste flow
• Design flow of treatment facility at time of
  sampling

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Source of Effluent, Receiving Water and Dilution
Water

• Effluent Samples
• Sampling Point
• Collection dates and times
• Sample Collection method
• Physical and chemical data
• Mean daily discharge on sample collection date
• Lapsed time from sample collection to delivery
• Sample temperature when received at laboratory

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• Receiving Water Samples
• Sampling point
• Collection date and time
• Sample collection method
• Physical and chemical data
• Streamflow
• Sample temperature when received at lab
• Lapsed time from sample collection to delivery

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• Dilution Water Samples
• Source
• Collection dates and times
• Pretreatment
• Physical and chemical characteristics

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TEST METHOD

• Toxicity test method used
• Endpoints of test
• Deviation from reference method
• Date and time test started
• Date and time test terminated
• Type and volume of test chambers

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• Number of organisms per test
• Number of replicate test chambers per treatment
• Acclimation of test organisms
• Test temperature
• Specify if aeration was needed
• Feeding Frequency, and amount and type of food
• Specify if pH control measures were implemented

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TEST ORGANISMS

• Scientific name
• Age
• Life stage
• Source

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QUALITY CONTROL

• Reference toxicant used routinely
• Date and time of most recent reference toxicant
  test, test results, and current control chart
• Dilution water used in reference toxicant test
• Results (NOEC or where applicable, LOEC, LC50,
  EC50, IC25 and/or IC50)
• Report Percent Minimum Significant Difference
  (PMSD) calculated for sublethal endpoints
  determined by hypothesis testing in reference
  toxicant test
• Physical and chemical methods used.

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RESULTS

• Provide raw toxicity data in tabular form,
  including daily records of affected organisms in
  each concentration (including controls) and
  replicate, and in graphical form (plots of
  toxicity data)
• Provide table of LC50s, NOECs, IC25, IC50, etc
  (as required in applicable NPDES permit)
• Indicate statistical methods used to calculate
  endpoints

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• Provide summary table of physical and chemical
  data
• Tabulate QA data
• Provide percent minimum significant differences
  (PMSD) calculated for sublethal endpoints.
• Relationship between test endpoints and permit
  limits
• Actions to be taken (if any)

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GLOSSARY

• Effect Concentration (EC) is a point estimate of
  the toxicant concentration that would cause an
  observable adverse effect in a given percent of
  the test organisms. EC25 is a point estimate of
  the toxicant concentration that would cause an
  observable adverse effect in 25 percent of the
  test organism

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• Inhibition Concentration (IC) is a point estimate
  of the toxicant concentration that causes a
  percent reduction in a non-lethal biological
  measurement (reproduction and growth), calculated
  from a continuous model. IC25 is a point
  estimate of the toxicant that would cause a 25
  reduction in a non-lethal biological measurement.
• LC50 (lethal concentration, 50) is the toxicant
  or effluent concentration that would cause death
  in 50 percent of organisms.

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• Lowest Observed Effect Concentration (LOEC) is
  the lowest concentration of an effluent or
  toxicant that results in adverse effects on the
  test organisms.
• No Observed Effect Concentration (NOEC) is the
  highest test concentration of an effluent or
  toxicant that causes no observable adverse effect
  on the organism
• Percent Minimum Significant Difference (PMSD)
  allows comparison of different tests and
  represents the smallest significant difference
  from the control as a percentage of the control
  mean that can be measured.

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GUIDANCE FOR REVIEWING BIOMONITORING REPORTS
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• Were all samples chilled to 4oC during and/or
  immediately after collection and maintained at
  just above freezing.
• When reviewing the holding times the maximum
  holding time of effluents is 36 hours and samples
  should not be used for renewals if older than 72
  hours.

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• Was the dilution series used in the test as
  specified in the permit?
• Does the laboratory have your latest permit?
• Fathead Minnows tests use to be a series of 10
  minnows /4 concentrations. New permits now have
  8 minnows / 5 concentrations.
• Was the DO acceptable for the test gt4 but lt9?

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• Was chlorine present in the receiving water ?
• Was the sample brought to the correct temperature
  prior to starting the analysis?
• Was the control and sample handled in exactly the
  same manner. (Example Treated for the same
  interferences (UV / antibiotic)?
• Was the critical dilution reported the same as
  that listed in the permit?

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• Was the Coefficient of Variation (CV) in the
  control and the critical dilution lt40.
• Fathead Survival in control must be at least
  80. The average dry weight per surviving control
  larvae at the end of the test must equal or
  exceed of 0.25 mg.
• Ceriodaphnia dubia Test result acceptable, at
  least 80 of all control organisms must survive,
  and 60 of surviving control females must produce
  at least three broods, with an average of 15 or
  more young per surviving female.

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VARIABILITY CRITERIA FOR SUBLETHAL HYPOTHESIS
(Upper and Lower PMSD)

• Fathead Minnow 12-30
• Ceriodaphnia dubia 13-47

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CONTROL (CV) RANGECOEFFICIENTS OF VARIATION

• Fathead 3.5 to 20 Minnow (0.035-0.2)
• Ceriodaphnia 8.9 to 42
• dubia (0.089 to 0.42)