PFAS Testing at a Waste Treatment Combustion Facility

Opportunity

Montrose Air Quality Services and Enthalpy Analytical Laboratories (EAL) were contracted to be part of a team by a major waste treatment facility to conduct stack testing and analyses, respectively, at their Western U.S. location to measure destruction and removal efficiencies (DRE) of 4 spiked per- and polyfluoroalkayl (PFAS) compounds, and an additional 45 PFAS compounds for mass emission rate results. EPA OTM-45 was used to sample the PFAS and EPA Method 26A was used to sample HF simultaneously. EAL analyzed all stack gas samples and all process stream samples.

Besides the DRE objective of 99.9999% for the 4 spiked compounds, a secondary object of performing a material balance is being performed.

Montrose assembled an experienced team of PFAS testers from Portland, OR; New Braunfels, TX; Spanish Fork, UT; Denver, Colorado and Bakersfield, CA to conduct the planned PFAS demonstration. The multiple offices staff allowed for increased staff training in EPA OTM-45 sampling and recovery protocols.

Challenge

The biggest challenge of the demonstration was to prevent contamination of the stack gas samples from sources such as the 4 spiked feed compounds and the many process stream samples, particularly the sludge feed that contained high concentrations of PFAS. This was accomplished by keeping stack gas and process samples apart and by using best practices detailed in a Montrose standard operating procedure (SOP) for sampling PFAS in stack gas based on EPA OTM-45.

Also, turning sampling trains around efficiently from run to run to meet schedule expectations was critical to the clients. This was accomplished by having the next OTM-45 train heated up and leak checked on the stack location as the current train was ending. Most turnaround times were less than 30 minutes.

The biggest challenge for EAL was the analyses of the various influent and effluent process streams due to the complex sample matrices that can be present that can potentially cause elevated detection limits.

Because of some of those samples having high PFAS levels, EAL could not extract and serial dilutions were performed for direct inject.

Solution

Testing revealed that the results were relatively successful to meet the objectives.

At the current time the client may have 4-5 additional test programs scheduled, while Montrose continues to work to ensure that in-house PFAS testing expertise is a focal point for Montrose’ air quality program.