• Dirty Jars And Other Bad Things… Part 1

  • In keeping with the recent theme about making life easier for the drafting department, this month’s blog addresses some of the problems that consultants can create when we submit samples for laboratory testing. When conducting environmental assessment and remediation, we collect and submit all types of samples for analyses including soil, sediment, ground and surface water, building materials, mould, air vapour and soil gases. A lot is riding on the proper collection and analysis of the samples and interpretation of the results. Sometimes multi-million dollar decisions and liabilities are dependent on the information obtained. It is imperative that consultants do everything possible to maintain strict quality control and obtain the most accurate and representative data. Thanks to my contacts Ed, Emily and Mary-Lynn at ALS Canada for their suggestions on things that consultants un-knowingly do that make the lab’s work harder.

    Dirty Jars
    When the sample jars are submitted caked with mud, it can affect the pre-determined tare weight of the sample container, thus affecting the results. Cleaning jars by lab staff is necessary to remove the excess crud to achieve accurate tare weight, requiring extra time and introducing potential for sample bias. Excess mud or sediment on the lid or top of the threads can also lead to release of sample or sample preservative, potentially affecting the viability of the sample and the accuracy of the results. Its not just mud; adding additional labels other than those placed by the lab is also a no-no, as it can add extra weight, throwing off the important pre-set tare weight of the container.

    Improper Containers
    Lab staff have seen everything imaginable used for sample containers from Grandma’s old mason jars to empty beer bottles and motor oil containers. Use of pre-sterilized, lab-prepared sample containers is vital to sample preservation, analytical accuracy and integrity of the results. Some parameters require specific types of glass or plastic, some are clear or amber, others have best-before dates and sample preservatives to consider. Use of non standard containers raises all sorts of bias and quality concerns, not to mention the huge potential for introduced contamination. Be prepared by ordering your specific sample containers in advance from your testing lab.

    Methanol Preservation of Soil Samples
    Many provinces have enacted regulatory requirements for field preservation of soil samples collected for volatile analyses (PHC-F1, VOC). This requires placement of the field sample into lab-prepared sample jars with specific amounts of methanol preservative. Accidental spillage of the methanol by the consultant can occur during sampling. Consultants may store lab-prepared sample containers for an extended period of time prior to use, and storage in an overly warm workshop or hot vehicle can lead to evaporation of the methanol preservative. These issues can potentially skew the test results.

    Next month, I will discuss a few more concerns that testing labs encounter in consultant’s sample submissions.

    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