Sometimes that seemingly lovely white foam you see in waves at the edge of a lake is actually composed of dangerous substances. These include per- and polyfluoroalkyl substances – PFAS – which are chemicals that pollute drinking water and the environment and pose health concerns across the U.S. and internationally. This month, the U.S. state of Michigan took some noteworthy action to protect the public.
As mandated in guidelines finalized by the Michigan Department of Health and Human Services guidelines, the state will now screen for five forms of PFAS, which generally are used by industries and then discarded or left to seep into the ground as leftover contaminants. The screening criteria will set a significantly lower baseline for considering potential health effects for people exposed to PFAS. The state also plans to set maximum contaminant levels for the same five types of per- and poly-fluorinated chemicals by spring 2020.
We need this protection while scientists and engineers work on solutions like those described in Chemical and Engineering News last month. The article “’Forever chemicals’ no more? These technologies aim to destroy PFAS in water supplies explains how engineers are developing new treatments to target and “obliterate fluorinated contaminants in water supplies”
“At the Sweeney Water Treatment Plant in North Carolina, (for example,) engineers are finalizing designs for a new system aimed at removing a mix of persistent industrial chemicals from their drinking water…. The new facility will house four 12 m long beds of granular activated carbon, about 7 m wide and 3.7 m deep, to suck PFAS from the water. These beds are three times as deep as the plant’s existing ones, which it uses to house bacteria that help disinfect the water. Water will trickle through the new beds over the course of 10-20 min before it is considered clean. Every 400 days, the activated carbon, having soaked up a maximum level of contaminants, will need to be replaced—baked in a commercial incinerator to drive out the contaminants, then topped up with fresh carbon before being put back into service. Officials estimate construction of the new system will cost $46 million, with yearly operating costs of $2.9 million.“