PFAS MCLs are Final: What’s Next?

On April 10, The EPA announced that the Maximum Contaminant Levels (MCLs) for PFOS, PFOA, PFNA, PFBS, PFHxS and HFPO-DA have been finalized, and SGS is ready to support your measurement needs!

Here’s Everything You Need to Know

The EPA has a helpful presentation that provides more information, and as we read the final rule we will provide more updates on details. While PFOS and PFOA values stay unchanged at 4 ppt from the initial proposal, the MCLs for PFNA, PFHxS, and HFPO-DA are now also set at 10 ppt in addition to the hazard index calculation that may include PFBS if detected. As we have discussed previously, the hazard index is calculated using a weighed sum of the 4 PFAS using the HBWC as the weights.

PFAS Health Based Water Concentration (HBWC ng/L)
PFHxS

10

HFPO-DA

10

PFNA

10

PFBS

2000

These 6 PFAS are to be reported using EPA 537.1 or EPA 533. SGS has multiple accredited lab  locations and high capacity to perform either of these methods to support these MCLs.

What’s next?

Pending litigation, drinking water utilities will have to

  • Start/continue monitoring for these PFAS
  • Notify the public on the results
  • In case of exceedances, reduce PFAS levels in drinking water

Monitoring Requirements

The frequency of monitoring depends on the source and size of the water system, and monitoring must commence within 3 years after rule promulgation. Initial monitoring is quarterly with flexibility to reduce monitoring if levels are low enough to warrant. Exceedance of the MCL will require action to reduce these levels by 2029.

How can we help you?

SGS with its large network of accredited PFAS labs and high capacity is well placed to help you fulfil your monitoring requirements. Contact our team at: