Compliance Status Report
Description of Delineation of
Soil Contamination 391-3-19-.06(3)(b)2.
This portion of a CSR details soil properties, methods used to assess the soil, and a description of any soil contamination. Soil should be assessed with an appropriate number of data points (samples) at appropriate locations in and surrounding all of the source areas at the site. Contamination at the site should be delineated to background concentrations in all directions. The following descriptions should be included in the soil assessment:
- Delineation to background concentrations including a general description of how each source area was assessed for potential soil contamination.
- Analytical parameters selected and reason for selection.
- Sampling/analysis procedures: Sampling should be in accordance with EPA Region 4 soil sampling guidance available at the Region 4 web site (http://www.epa.gov/region4/sesd/fbqstp/index.html). This should include the following descriptions:
- All sampling equipment.
- Field analytical or measurement techniques including make and model of the testing equipment and calibration schedule. PID/FID/OVA readings should be listed on the boring logs (sample log)
- Sample handling and preservation.
- Equipment decontamination procedures.
- Chain-of-Custody procedures
- Laboratory analytical techniques (methods & QA/QC)
- Laboratory certification including the name of the laboratory, name of the accreditor, accreditation ID number, scope of accreditation, and effective/expiration dates of accreditation. See Chapter 391-3-26 for more information.
- Statistics supporting data used to determine a release. All calculations must be shown, and enough information to duplicate the information must be provided.
- Background determination procedures
- For VOCs, SVOCs and other constituents that are not naturally occurring, the background level is typically considered to be the detection limit. Exceptions to this include certain herbicides or pesticides that are widely distributed over large areas, or if an up-gradient unregulated source is contaminating the site.
- Constituents, such as metals, that do naturally occur in soil should be assessed using statistical methods. Care should be taken to eliminate any outliers in the statistical set (outlier test). A common way to calculate background is the equation: Background = Mean + 2(Standard Deviation).
- A good reference for calculating background is Guidance for Comparing Background and Chemical Concentrations in Soil for CERCLA Sites (http://www.epa.gov/oswer/riskassessment/pdf/background.pdf) and Role of Background in the CERCLA Cleanup Program (http://www.epa.gov/oswer/riskassessment/pdf/bkgpol_jan01.pdf)
- A summary of all pertinent field data and laboratory results to conclude horizontal and vertical delineation to background concentrations.
List of Figures to Include
- A site map showing the locations of all soil samples collected at the site. The map should have a scale of 1” = 200’ or less.
- A map for each constituent detected in the soil showing the sample locations, listing the depth of the sample below grade, dates samples were collected, and concentrations at each sample location. All detections below the detection limit or practical quantitation limit should list concentration values as “<(insert limit)” rather than “BB”, “<DL” or “<PQL”. Units of concentrations should also be noted on this figure.
- Boring logs for each soil boring detailing site-specific geology (hyperlink to example of boring log) (example of boring log)
List of Tables to Include
- A table of analytical data for all soil samples collected at the site. The table should list:
- Each sample number or other designator
- Depth of sample
- Sample collection date
- Concentrations of each regulated substances detected with units specified
- Risk reduction standards calculated for each regulated substance
Other Items to Include
- Copy of the Chain-of-Custody for all samples collected.
- Copy of the laboratory analytical report.
- Incorrect sampling:
- Not using Encore® or the syringe method for VOC sampling
- Not homogenizing soil samples for SVOCs, pesticides/herbicides, PCBs, and metals
- Failure to include a thorough written description of the soil sampling equipment, sampling method, sampling location and reason for sampling that location, any sample homogenization needed, sample containers, any preservation techniques, chain of custody record, and decontamination of sample equipment.
- Failure to properly calculate background concentrations for metals:
- Not including an outlier test
- Not having enough samples (minimum of 5 samples from each soil horizon)
- Not providing detailed calculations if background statistical analysis was performed (all calculations must be shown)
- Delineating to risk reduction standards instead of delineating to background concentrations.
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