Water Vs. Wastewater: Do You Know The Difference?
The Struggle Is Real In Minnesota Where A New Report Finds The Cost Of Cleaning Up PFAS In Wastewater Could Be Billions. Plus: A Scientist With A Solution.
We all know the importance of water in our everyday lives and particularly drinking water to keep us hydrated, but we also use water for bathing, washing dishes, doing our laundry, and more. Ever wondered what happens to the water after you’ve used it?
That’s the wastewater. It flows out of your home through a sewer system usually to a wastewater treatment plant, though about 20 percent of U.S. homes use septic systems that locally treat their wastewater. Issues can occur when a septic system is improperly managed, releasing harmful compounds into local water bodies or ground water.
Wastewater treatment facilities in this country process about 34 billion gallons of wastewater every day. This water is regulated by the U.S. EPA under the Clean Water Act (CWA).
The National Pollutant Discharge Elimination System (NPDES) issues permits to all wastewater dischargers and treatment facilities. These permits establish specific discharge limits, monitoring, and reporting requirements and also require these facilities to carry out special measures to protect the environment from harmful pollutants.
What is there to monitor? Wastewater contains nitrogen and phosphorus from human waste, food scraps, oil, soaps, and detergents. It can also contain chemicals. Once the water is cleaned, it is typically released into a local water body, where it can become a source of nitrogen and phosphorus pollution.
One of the biggest causes of water pollution is actually poor wastewater management.
For years, we’ve followed the adage that “the solution to pollution is dilution,” but the toxins have only increased with time, and we have reached a point where even large bodies of water can’t possibly dilute the constant barrage of toxins.
The PFAS Problem In Wastewater
PFAS, which stands for per-and polyfluoroalkyl substances, are a group on manmade chemicals that have become a hot topic in wastewater management.
They’re often called “forever chemicals,” because they are hard to break down both in our bodies and in the environment. You could also call them, “everywhere chemicals,” because they’ve become so common in the products we use every day from stain-resistant sprays to nonstick cookware and food packaging to water-resistant fabrics and clothing.
Now, a new report published by the Minnesota Pollution Control Agency found it would cost up to $28 billion in the next two decades to clean up forever chemicals from wastewater streams across the state.
That’s a staggering number!
PFAS can enter wastewater through everyday use of consumer products that contain the chemicals, through industrial processing, or when products containing PFAS are discarded in landfills.
Both manufacturing processes and waste storage and treatment sites release PFAS into the air, soil, and water. The Environmental Working Group (EWG) has found 41,828 industrial and municipal sites in the U.S. that are known or suspected of using PFAS.
Most wastewater facilities are skilled at removing organics and nutrients, but PFAS is another story. These pollutants are outside of the realm of contaminants that treatment plants have been designed to remove, which means the chemicals can remain in treated water and biosolids (recycled sewage) that are sometimes used in agriculture.
PS: Our first ever newsletter story covered the tragedy of biosolids used in agriculture throughout Maine.
Some wastewater treatment plants have started monitoring for PFAS and working to identify where they’re coming from, but they lack the ability to remove and destroy the chemicals.
What’s worse, the report found that newer types of PFAS touted by chemical manufacturers as safer alternatives to traditional PFAS are more difficult and expensive to remove and destroy. Gah!
And that’s just one class of chemicals.
Thankfully, there’s someone working to solve this problem.
Meet organic chemist Will Dichtel. He’s a professor of chemistry at Northwestern University.
He and his team have been working on ways to remove PFAS from the environment. Using cyclodextrin, a sugar derived from cornstarch, they designed a polymer that can remove PFAS from water.
This is what I call better living through chemistry!
He and his team have identified a way to destroy PFAS using basic chemistry.
That’s because they have discovered that a significant portion of PFAS compounds have what they call a “head group” composed of oxygen atoms, and a “tail” of carbon-flourine bonds. Heating the PFAS in a solvent with sodium hydroxide, a common reagent, decapitated the head group so that only the tail remained.
“That was really the eureka moment,” Dichtel told Northwestern Magazine. “When that head group falls off, … the tail falls apart like a row of dominos.” What’s left behind, Dichtel said, is fluoride, “the safest form of fluorine,” and carbon byproducts that are known to be safe.
Dichtel estimates that about half of PFAS have this particular structure and could be destroyed using his lab’s technique. The researchers are optimistic that other classes of PFAS compounds will fall apart using similar principles.
His team is currently testing their PFAS removal and destruction techniques in wastewater in both Chicago and the Middle East, thanks to a grant through the Northwestern Center for Water Research, in collaboration with investigators in Israel and the U.S.
The aim of the grant is to enable wastewater reuse, particularly in Israel, which already uses wastewater for agriculture. Removing PFAS so that these compounds don’t end up in agricultural products or meat is a huge goal, according to Dichtel.
This kind of optimism is what we need right now. Funding scientists to help solve some of our biggest problems.
What did you learn about wastewater and PFAS? Let us know in the comments below!