In Montana we require that the method requirements for preservation, ie temperature, be followed.
Manual for Certification of Laboratories Analyzing Drinking Water, 5th edition, Chapter IV,
Section 6.4 Sample Collection and Transport
There must be strict adherence to correct sampling procedures, sample handling, complete identification of the sample, and prompt transfer of the sample to the laboratory when required by the method. When the laboratory is not responsible for sample collection and transport, it must verify that the paperwork, preservatives, containers and holding times are correct as required by the methods or reject the sample. The rejection criteria should (EPA Order 5360.1) be documented in writing.
Supplement 1 to the Fifth Edition of the Manual for Certification of Laboratories Analyzing Drinking Water, Page 6,
Chemistry Sample Collection, Supplement to: Chapter IV Critical Elements for Chemistry 6. Sample Collection, Handling, and Preservation,
Sample temperatures should be noted upon receipt. Samples that arrive at the laboratory within 24 hours of sample collection, due to the close proximity of the public water system to the laboratory, may not yet have reached the appropriate temperature by the time they arrive at the laboratory. These samples should be considered acceptable ONLY if packed on ice or with frozen gel/ice packs immediately after sample collection and hence, delivered while the samples were in the process of reaching an appropriate equilibrium temperature.
As the certification laboratory for Montana laboratories running drinking water samples, we accept that there are a couple of EPA documents that allow sample temperatures other than those contained in the method, ie <6 degrees C versus <4 degrees C. When using these alternate preservation temperatures, we require that laboratories reference the EPA document in their SOP for traceability. The reference must be to an EPA approval document or supplement to the method. As an example, for Method 317 arriving at the laboratory at 10 degrees C does not meet the <6 degrees C required by the method. The Laboratory MUST reject the sample for drinking water compliance. If the temperature requirements of the method are not met and the above exceptions are also not met, the Public Water Supply client should be notified and a resample requested for compliance with Laboratory certification requirements for analyzing drinking water.
If there are any questions on this issue, please contact Russ Leu, Laboratory Manager at RLeu2@mt.gov.