Laserfiche WebLink
PFAS Sampling Guidance <br />PFAS at the low concentrations that pose a health risk requires careful planning, sampling and <br />shipping techniques that ensure the integrity of the sample. This sampling guidance provides <br />recommendations to reduce such contamination sources and provides information for samplers <br />to ensure collection of a valid sample. Results from sampling of drinking water sources should <br />be reported electronically by the analyzing laboratory to the Division of Drinking Water. <br />III. QUALITY CONTROL FIELD SAMPLE TYPES <br />Due to the low detection limits of PFAS in the drinking water, the Division of Drinking Water is <br />specifying the use of both a field blank and trip blank. These special quality control sample <br />techniques must be discussed with the laboratory to ensure proper sample containers and <br />materials are on hand when sampling begins in the field. <br />FIELD BLANK <br />A field blank is analyzed to assess the potential for PFAS contamination being introduced <br />during the sampling process and consists of a sample bottled filled at the sample site using <br />reagent water provided by the laboratory. The field blank must be collected at each sample <br />site and stored in the ice chest used to store and transport samples. The laboratory will <br />provide the field blank sample bottle, the reagent water and the preservative (if not already <br />added to the sample bottles). <br />Field Blank Procedure: At the sampling site, the sample personnel must open the field <br />blank sample bottle, pour the reagent water into the sample bottle, seal and label this <br />bottle as the field blank. Record the field blank identification number on the chain of <br />custody (COC) form. <br />This sample is shipped back to the laboratory along with the site samples. The empty <br />container that the field reagent water was poured out of must also be shipped back to the <br />laboratory in the same shipment. <br />TRIP BLANK <br />This sample is to evaluate potential contamination from sample shipping and handling <br />procedures. At least one trip blank per ice chest is required. <br />The laboratory will provide the trip blank. Carry the trip blank as received from the laboratory <br />to the field site. Do not open the trip blank but place it in the ice chest with the water <br />samples collected and submit to the laboratory for analysis along with the field -collected <br />samples. Record the trip blank identification number on the COC. <br />19E-22 <br />