The EPA and CDPHE are working on drinking water quality standards but do not have set regulations at this time. Health Advisories are used as a reference while they create maximum contaminant levels (MCL) for drinking water.
The EPA Health Advisories, which are not regulations, have previously included two compounds, PFOA and PFOS. The EPA has newly released Health Advisories that expand the lifetime exposure levels. These advisories add the HFPO, or "GenX", and PFBS compounds, and lower the advisory levels for PFOA and PFOS.
Previously, the PFOA and PFOS compounds had a health advisory level of 70 ppt (parts per trillion). The new advisories reduce these to 0.004 ppt and 0.02 ppt respectively. 0.004 ppt is the same as 4 parts per quadrillion. A part per quadrillion is 1 in 1,000,000,000,000,000. This is equivalent to 1 second in 31.7 million years! Current technology can measure these compounds at about 2 ppt.
The advisory levels for PFBS and HFPO are 2000 ppt and 10 ppt respectively.