Will EPA's detour from its PFAS road map cause confusion or worse?

Today we learned EPA is deviating from its less than one year old PFAS road map by issuing new health advisory levels for certain PFAS ahead of the finalization of EPA's PFAS Toxicity Assessment and the establishment of actual drinking water standards for any PFAS.

EPA's well thought out and very aggressive PFAS road map had called for EPA to do the important work necessary to address what EPA called "significant gaps" in the science about the toxicity of many of the hundreds of "forever chemicals" known as PFAS on the way to establishing enforceable drinking water standards for those PFAS.  In the meantime, EPA was going to publish new health advisory levels only for two groups of PFAS that didn't yet have health advisory levels.

Now EPA has decided to dramatically decrease the Obama Administration EPA health advisory levels for certain PFAS that already had them and to do so before finalizing its PFAS Toxicity Assessment.   Some of the new health advisory levels are so low that they can't be reliably detected.

Presumably EPA has concluded that the health risks associated with these PFAS is so great that EPA has to take this detour.  But that puts states and municipalities and pretty much everyone else in a pretty tough spot.  PFAS still aren't "hazardous substances" under federal law even though EPA says we need to be concerned about them at the tiniest of concentrations.  Some states have acted ahead of EPA but those states' conclusions about what levels of PFAS might be of concern were, for the most part, based on EPA's prior health advisory levels.  For these reasons, and others, we may not yet appreciate the consequences of EPA's detour from its PFAS road map.  But it would seem that more panic and confusion are distinct possibilities.