Get ready to add picograms per liter to your work vocabulary.
The U.S. EPA announced health advisory levels (HAL) for four per- and polyflouroalkyl substances June 15. It is likely you will begin having (or have begun having) conversations about this with customers because the messaging from EPA has reached mass media outlets.
First, there are two interim HALs: PFOA at 0.004 parts per trillion (ppt) and PFOS at 0.02 ppt (ppt). Additionally, GenX has a final HAL of 2,000 ppt and PFBS has a final HAL of 10 ppt.
Secondly, HALs are non-regulatory and non-enforceable levels, and they do not account for the cost or feasibility of detection or treatment. They are, however, identified by the latest science, which means the latest science suggests the HAL for PFOA and PFOS is below detectable limits.
Lastly, EPA noted in its press release that the PFOA and PFOS figures are below the agency’s ability to detect at this time. The science for detecting at this level, even at the most state-of-the-art laboratories is still inconsistent. So how do we communicate this with customers who are worried about these chemicals in their drinking water?
EPA officials have said to continue using the detection limits for these chemicals and to use any PFAS measurement data to have a conversation about a person’s water.
Another important caveat is that only 20% of a person’s exposure comes through their drinking water. This means 80% of exposure to these chemicals comes from clothing, carpets, firefighting foam and other sources. We should use information like this to educate customers on a holistic approach to exposure reduction.
Additionally, EPA said technologies like granular activated carbon, anion exchange and high pressure reverse osmosis are the best treatment technologies available to treat these chemicals in drinking water. The agency is also working on PFAS in wastewater with more information likely to come this fall.
The bigger question, and one that EPA has dodged on multiple occasions: “Is my water safe to drink even below the current detection limits?” It’s a difficult one, and one I wish we had a better answer for.