GUIDANCE - PFAS Sampling & Analysis for Maine DEP
Updated April 1, 2019
NEBRA provides the following information, and correspondence by phone and email, to assist Maine biosolids generators and managers in meeting the Maine DEP requirement to sample and test for PFAS in biosolids.
This information is guidance based on NEBRA’s best understanding of the science and best professional judgment; it has not been approved by Maine DEP.
Pay close attention to the memo from Maine DEP dated Friday, March 22, 2019.
What your test data are likely to show:
All biosolids data we have seen, even from facilities with little to no industrial input, show test levels for PFOA and PFOS above the very low screening values that Maine DEP is using for this biosolids testing process. Therefore, we expect most, if not all, the data from this required testing to exceed those levels (PFOA 2.5 ppb or ng/g and PFOS 5.2 ppb or ng/g). Our compiled data of various state testing and published literature find averages of PFOA at 5 ppb and PFOS at 11 ppb.
Then what will happen next?
Maine DEP’s numbers are just screening values. They allow for things like calculation of loading rate to the soil (the dilution when mixed into soil is about 200 times) and modeling to show groundwater will not be impacted significantly. These take time to figure out, however, and may include DEP requiring soil sampling at any proposed land application site if it has had biosolids in the past. We at NEBRA recommend working together and with DEP to figure out a sensible, feasible approach that does not delay biosolids use this year any further.