How should WWTPs manage PFAS in Biosolids?

Water reclamation facilities are inherently the protectors of the environment. They attain all sanitary waste, and we take the respon­si­bil­ity of making sure that it's entering the river, the ocean, and the groundwater within the limits set. The current problem is that PFAS is everywhere; it is in our blood, in the water and in the soil. Everywhere we have looked, we have found it. On the drinking water side, there is the challenge of very low limits. On the water reclamation side, the verdict is still to be determined on how the EPA and state regulatory bodies plan to monitor it and whether they decide to impose limitations and regulations. These fears are already driving costs for water treatment upwards.  

In 2021, we worked with the Water Environment Foundation (WEF) and the Northeast Biosolids and Residual Association (NEBRA) to develop a cost study. We surveyed twenty-eight facilities across the country and inquired about their biosolids management costs and their fluc­tu­a­tions over the years. We have been seeing vast impacts on end-use cost. From 2018, which was around when PFAS hit the map for water reclamation, to 2021, we saw a 72% average increase in end-use cost. Since then, there have been even more dramatic increases in Maine. As a state with a moratorium on land application, we've seen up to a 300% increase. In other states, including some facilities in Mass­a­chu­setts, there have been increases as dramatic as 200% before having regulations in place. Overall, we are starting to see dramatic impacts on these utilities. 

The state of Michigan has had a pragmatic approach to measuring PFAS in the wastewater by cate­go­riz­ing facilities that are industrial-impacted and non-industrial impacted. They have also started working with their industrial pretreat­ment programs to identify the industries that are discharging PFAS-laden wastewater and putting in pre-treatment for best management practices. In one case, I spoke to a facility in town, and they were able to talk about using just carbon filtration before sending to the collection system, and it decreased their PFAS concen­tra­tions in the plant. Michigan is a great example of a state that has a proactive approach to combating this problem.  Other states are taking different approaches. Mass­a­chu­setts is modeling PFAS from finished biosolids in the soil column and into the groundwater below. They are also thinking about applying drinking water limits to that groundwater and their models. This is a very science-based approach, but the challenge there is that different PFAS compounds migrate in different ways, and we do not yet understand the toxicology of these compounds. 

We need to do this prag­mat­i­cally with a science-based approach. Right now, there is fear around PFAS and we need to advance the science to understand how we can mitigate this problem properly. To do this, we must understand what our sources are, and to do that we need to do these sampling programs that many utilities are already starting. We also need to understand the toxicology. Much of the research and development that CDM Smith is doing addresses how these compounds migrate through the environment. There are so many benefits to be gained from water reclamation facilities, whether it's the fertilizers that we produce in biosolids or energy that water reclamation facilities can produce. We need to continue to take advantage of these benefits, especially as biosolids contain phosphorus.