Water Treatment Revolution

The field of water treatment may appear lethargic on the surface with regard to change and adaptation of new technologies. But if you look deeper there is an apparent shift in how we in North America are thinking about water treatment, and new approaches are slowly being implemented. Certainly, recent regulations such as the Long Term 2 Enhanced Surface Water Treatment Rule are one reason we are starting to see major shifts in use of disinfectants and holistic thinking about implementation of multiple barriers for achieving various water quality goals. However, I believe a good part of this shift in thinking is the result of closer ties to our fellow water treatment warriors in other parts of the world. Yes, globalization has reached water treatment and it is a good thing. It is a two-way street with exchanges coming from both sides, but I believe that North America in particular has a lot to gain.

From an academic standpoint, universities are pushing international collaborations at an unprecedented rate. What major research university does not have some kind of collaboration or exchange with Singapore in the works? We are not so naïve as to think this is just another way to export our technology and engineering. Sure we have much to offer, but we also recognize that we have much to gain, learn, and exchange. Globalization is upon us, and it is a good thing with regard to public health and drinking water treatment.

Look around and the problems are often the same. Decreasing fresh, pristine water resources are forcing regions of the world to implement some drastic levels of water treatment. The Middle East and arid regions are prime examples. Our European friends have been dealing with this issue for years and have adapted with an interesting array of water treatment options, historically quite unique from the traditions in North America. I have often wondered and discussed with my students how it came about that European water treatment can get away with using little to no chlorine residual, especially given the age of their infrastructure in some areas and the fact that many of the source waters (major rivers that receive wastewater effluents and urban runoff) are water quality compromised. What have they done to their water to make it potable? Perhaps the European response to dealing with the specific influent quality requires more of a philosophical interpretation. Biostability is one way to summarize the European water treatment philosophy. Install as many required technologies as possible to make the water biologically stable; is the apparent mantra in Europe. So we see bank filtration, granular activated carbon, membranes, oxidation technologies, ultraviolet light, biological filtration, and even slow sand filtration. These approaches are all in our North American water treatment toolbox, but they are under the heading of “alternative” or “advanced” treatment. Our philosophy in North America has veered more toward maintaining some disinfectant residual as the ultimate stopgap measure, regardless of upstream processes, to protect the consumer.

Well, it seems about time our “alternatives” became our “conventional” processes. When visiting our water treatment plants in North America, it becomes quite obvious that our conventional is slowly becoming our alternative and our water utility managers and operators are championing these changes. Sure, regulations are helping to push us in the direction of decreasing the use of chlorine—maybe by using UV disinfection or other EPA toolbox technologies—but there are many areas of North America that are making changes without or despite regulatory pressures. Upgrading to membranes instead of doubling the filtration footprint to increase water throughput; using ozone to clarify the water and control taste and odor causing compounds, followed by biological filtration; adding in UV disinfection even when the disinfection credits are achieved through chlorine; ground water storage and recovery to naturally attenuate anthropogenic pollutants—these are all examples of our North American water treatment revolution, which is sweeping the continent one treatment plant at a time. Sure, there are some growing pains and misapplications—like using microfiltration membranes followed by chlorine disinfection only to realize the natural organic matter is still in the water and the disinfection by-products are now higher than they would have been with conventional treatment, or coupling different disinfectants and wreaking subsequent havoc on the distribution system by swinging between free and combined chlorine residuals as if it were Dr. Jekll and Mr. Hyde.

Let’s face the reality. Although we still have some excellent sources of water, many of our sources for drinking water are compromised and at times contain significant quantities of effluent from wastewater and urban runoff. We are experiencing indirect potable reuse of water in many of our drier climates. I am not talking only about the USGS-detected trace contaminants that are hot topics right now but also about some basic Mom and Pop contaminants and concerns, like pathogen loading, excess nutrients, and high organic matter levels (not from forest runoff). What are we going to do about this toilet-to-tap reality? We’ve just about ruined any hope of a successful public campaign for acknowledged direct or indirect potable water reuse. Will our affection with all things Singapore translate into our liking of their approach to making “NEWater”? It does sound better than before, but what does it mean? NEWater means high tech, clean, pure. It meets all of our regulations for clean potable water. It’s bottled too.

Would you rather unknowingly have conventionally treated water from a source that is 75% wastewater effluent or knowingly drink wastewater effluent that has been treated (and likely overtreated) with all the most technically savvy treatment processes available? You can visit the NEWater visitors center, tour the “factory,” see these cool technologies in action, and learn more about the water issues facing us all and new ways to combat these pressures. Why not? Could this happen in North America? Are we fooling ourselves and our public into believing our world, and their water, is pristine? Looking at the increased use of bottled water, it is clear: perception is the key. It must be clean and good if it comes in a bottle. Especially if that water is membrane filtered, ozonated, and UV disinfected. Hey, that sounds familiar.

It’s time to invest in our water treatment infrastructure, so we can make the “alternative” technologies the new standard and so we can have “bottled water technology” serving every household. Let’s bring some chic designer European water treatment techniques into the North American market. How about some high-tech Asian processes? We can also learn from the can-do attitude of the Middle East approach to water treatment. Our future in water treatment is starting to sound like a lesson in diversity. Embracing diversity allows us to learn from it and grow, as well as contribute. Our students are more diverse, our faculties are more international, and these ties bring new ideas to water treatment research. Funding agencies like the American Water Works Association Research Foundation (AWWARF) are focusing more on creating and supporting international partnerships, recognizing the inevitable. Embracing changes in water treatment technology is essential to our survival and sustainability. Old water or NEWater, however we want to package it, it is definitely time.