• Dirty Jars And Other Bad Things… Part 2

  • This month’s blog continues our discussion of some of the problems that consultants can inadvertently create with our sample submissions for laboratory testing. Thanks again to my go-to lab folks at ALS Canada for their input. Now that we know what can go wrong, let’s all work to improve our habits and achieve better quality results and reports.

    Field Filtering
    Ground water samples for metals analyses are usually field-filtered during sample collection before placing the sample in the bottle with the necessary preservative. This is done to remove any sediment before the sample is preserved. The lab can sometimes run into issues when it’s not specified if the required analysis is for Total or Dissolved metals; or it’s not specified whether the samples were field filtered, un-filtered, or require lab filtering. This can cause delays or issues to confirm with the consultant while the samples have to remain on hold. There are notations on both the sample labels and the Chain-of-Custody (COC) forms to easily indicate the filtration methods and requirements, as well as whether analyses of Total or Dissolved metals is needed. Be clear on your testing requirements and instructions to the lab.

    Improper Labelling and Sample Submission
    Mistakes in labelling can occur in the field especially if staff are rushed (usually) or working in adverse weather or site conditions (often); and/or when there are a large number of samples to manage (also quite often). Be careful, consistent and diligent in note taking and labelling your samples, test-hole logs, sample jars and Chain-of-Custody. My lab colleagues have reported receiving multiple submissions with no COC and nothing written on the sample bottles. There should always be Client name and Sample ID as a bare minimum. Most labs are moving to smaller size coolers due to weight, which is great for everyone, but some consultants will still overload them with samples and ice. If you’re not sure how to properly pack your sample cooler for safety and sample integrity, please ask your lab for a demonstration or video.

    Specific Analytical Requests
    One of the analytical groups for disposal characterization is a TCLP analysis, or Toxicity Characteristic Leaching Procedure. There are multiple parameters for this analysis, and different disposal/receiving facilities often have their own specific TCLP requirements. Make sure you confirm the exact tests required as there are several and they can be expensive; simply writing TCLP on your sample and COC is not sufficient. Consultants should also be aware of the differences between Particle Size Analysis (PSA) and Grain Size Analysis. PSA is a quick (cheaper) grain size test to determine coarse vs. fine soil fractions; while the more expensive, in-depth Grain Size Analysis involves a full sieve and hydrometer analysis to plot a full grain size distribution curve, including per cent gravel, sand, silt and clay. There is a difference in the price and the data generated so be sure to specify which test is required.

    Chain of Custody
    Lastly, a properly filled out chain of custody is vital, not only as part of your report and as a legal document; but it serves as the main communication to the lab of the tests required. When documents are not filled out completely with data missing or analyses not specified, it causes many issues for the lab; and for your report as well. The administrative headaches can be minor compared to the potential for consultant error and legal liability. The labs are happy to guide clients through the process and ensure the chain of custody is completed properly.

    Bill Leedham, P. Geo., CESA

    Bill is the Head Instructor and Course Developer for the Associated Environmental Site Assessors of Canada (www.aesac.ca); and the founder and President of Down 2 Earth Environmental Services Inc. You can contact Bill at info@down2earthenvironmental.ca