ST. PETER — On Tuesday morning I drove south on highway 169 through a thick rain and the car wash-spray of semis, following the Minnesota River south to St. Peter. Even with water puddling in the ditches, the Minnesota remains a piddly remnant of the boiling, gouging glacial river that carved this valley out. All that water is still out there, somewhere on the earth, but never has it been so desired, so sought after, so precious.
The biological holy trinity — hydrogen-oxygen-hydrogen — is the subject of this year’s Nobel Conference at Gustavus Adolphus College in St. Peter. “H20, Uncertain Resource,” Oct. 6-7, includes lectures from six highly credentialed speakers.
The loftiest of these is perhaps R.K. Pachauri, the current chair of the Intergovernmental Panel on Climate Change (IPCC), the organization that shared the 2007 Nobel Peace Prize with former Vice President Al Gore. With doctoral degrees in industrial engineering and economics, Pachauri is credited with playing a major role in laying the groundwork for the Kyoto Protocol.
But how does Pachauri’s expertise in climate change make him qualified to talk about water?
“It’s certainly no coincidence that whenever civilizations and human activity began, it is essentially because of access to water,” Pachauri explained at the start of his address. “And it’s also no coincidence that those societies which ran into problems in the management of their water resources — all had to encounter natural debacles that led to the depletion or vanishing of water resources — are the societies that actually failed.”
Yes, but hasn’t modern technology and science changed all that? It did for a while, perhaps, but two factors are changing how we humans relate to water: Continued population growth means there are more of us than ever who need it; and global climate change is making water, as the Nobel conference title says, an uncertain resource.
“It’s not just a smooth and steady increase in temperatures that climate change brings with it,” Pachauri noted. “It also brings a major disruption for the entire climate system, as a result of which several extreme events are increasing both in frequency and intensity.” Extreme weather might be good for the Weather Channel, but it won’t be good for the people living through it, particularly for those already living in marginal conditions due to poverty or their geographical location.
As Pachauri described it, climate change promises more of everything: heavier rains bringing more flooding; in other areas more severe droughts; more severe typhoons and hurricanes whose power will be augmented by rising sea levels. Other changes will be slow, but no less violent in the long run. The glaciers of the Himalayas are the water cooler for 750 million people living in China and Asia, including Pachauri’s native India. But these glaciers are melting away at an alarming rate, and when they’re gone there will be a lot of thirsty people on the move.
If you’ve read up on the implications of climate change, Pachauri’s presentation might have only come as an impassioned reminder of what could be waiting for us. And Pachauri doesn’t think we’ll have to wait very long. “This is not something that is going to happen two generations from now,” Pachauri cautioned the audience. “It is likely that major changes will take place in the next 10 to 20 years.” And that’s why he sees the here-and-now as crunch time.
“I’ve said this before: The next two or three years are going to be crucial to what’s going to happen, to what’s going to define the future,” Pachauri said.
Pachauri fielded a question from the Internet that seemed to point to North America’s cool summer as proof that global warming is anything but.
“Well, the point is, look: The IPCC and anyone who is researching on climate change is not in the business of predicting weather,” Pachauri responded. “Weather prediction is totally distinct from changes in the climate. The weather will change. Just because you have one cool summer or one cool winter doesn’t mean that climate change has gone away.”
The dead zones
Dr. Nancy Rabalais was the day’s second presenter. As executive director and professor of the Louisiana Universities Marine Consortium (LUMCON), Rabalais has spent her career studying the Mississippi delta ecosystem (all of it provided courtesy of Midwestern topsoil).
Rabalais began her lecture by asking, “What is the second most pressing issue on a global scale other than carbon?” The answer, she explained, is nitrogen, and also phosphorus. Each of these is a critical nutrient for life forms, but they are also key players in the “dead zones” that are appearing each spring and summer in areas along the Louisiana coast.
As Rabalais explains it, the story of excess nutrients in the Gulf is one of too much of a good thing. “The beneficial parts [of nitrogen and phosphorus] are that they increase phytoplankton, which is good — it feeds the marine food web,” she explained. “It also generates more zooplankton, which feed more fish, and we can have some tremendous fisheries in coastal areas offshore of large rivers where a lot of nutrients are entered into the coastal watershed.”
But too much nutrients can lead to the growth of filamentous algae, which choke out the sunlight that powers the sea grass beds which are critical to the survival of younger fish. And as Rabalais explained it, when large amounts of nitrogen-fueled phytoplankton die and sink to the bottom, bacteria feed on them and in the process use up all of the available oxygen. A dead zone is created, where nothing lives. Fish will swim out of these areas if possible, but if they happened to be trapped in one, they’ll die. The size of this annual dead zone is growing, and the most recent one covered an area the distance from Des Moines to Chicago. So who is responsible for all this excess nutrients?
Rabalais is an intelligent woman, she knows she’s the Nobel Conference is in the middle of farm country, but she tells it like it is: The biggest culprit is the agricultural use of fertilizers. In particular, tiles buried in order to better drain wet cropland have made it easier than ever for fertilizers to leave the farm and enter the watershed. The pie graph speaks!
Farm fertilizers may be the major contributor, but the problem is further complicated by a Mississippi River watershed that has been engineered not to flood. Flooding had the effect of spreading nutrients back up onto the land and into the soil; but levees keep the floodwaters at bay, whisking the nitrogen-rich water down to the delta.
Rabalais closed her lecture by discussing various initiatives she’s been involved with that have sought to limit the amount of fertilizer making it into out watersheds. All have been voluntary in nature, and by her description they’ve been disappointingly ineffectual. The dead zones continue to grow, and worse yet, many of the changes of global warming — sea level rise, increased winds, increased temperature, increased flows from heavier runoffs — all seem to have a positive feedback on the bottom low-oxygen phenomenon.
So the question is, can we have our record corn and soybean yields, and our gulf shrimp, too? There must be a way. Let’s be selfish and ask the question, whom do we want to be feeding? These oxygen-sucking bacteria, or ourselves?
Confessions of a wastewater chemist
Dr. David Sedlak is a professor of civil and environmental engineering at the University of California, Berkeley. He’s an expert on the chemistry and toxicology of the human waste stream.
For most of human civilization, humans have used water for personal and agricultural purposes and then sent it down river. This approach worked well under two conditions: There was always a new supply of fresh water to replace the water you dirtied (i.e. no one was living upstream from you, and/or you were living in non-arid climate), and there was no one living downstream who was capable of stopping you.
In an increasingly crowded world, neither of those conditions can be met. According to Sedlak, cities like Los Angeles and New York City spend huge amounts of money on the infrastructure to secure the 4 billion liters of potable water their system needs every day. “New York City acts as a landlord in the area where it gets water,” Sedlak explained, referring to the power the city must use to protect and manage the two upstate watersheds it draws its water from. Of course LA’s water-thirsty tentacles stretch much farther. According to Sedlak, relatively newer big cities like Denver, Dallas, and Atlanta have arrived late to the water rights game, and so they find their growth potential stunted by the lack of water.
“Where can rapidly growing cities find more water?” Sedlak asked the conference attendees. “They can drink out of the toilet,” he suggested, drawing a mix of laughter and “oooh” from the audience. But Sedlak was serious. In the future, more and more of the water we drink will go from the toilet bowl to the tap — not directly, of course. Cities like LA and Singapore are already doing it.
Whether it’s Singapore or St. Peter, all sewage first must go through the same standard treatment to remove suspended solids, ammonia and organic carbon. At this point, the wastewater is called “effluent.”
“It doesn’t look like that brown sewage that came in,” Sedlak told conference-goers. “It looks pretty good. It looks like surface water that you take out of a river.”
And for many communities, that’s where the effluent goes: into the river. Somewhere downstream that water is pulled out, treated, and put into the drinking water system. Depending on a variety of factors, some rivers are in fact mostly effluent. Sedlak pointed to the Trinity River between Dallas and Houston as an example of what he called an “effluent-dominated ecosystem.” By the time the Trinity reaches the Gulf of Mexico, it is 90 percent effluent.
‘If it tastes good, drink it’
The idea of drinking someone else’s treated sewage may take your thirst away, but it doesn’t scare Sedlak. “If it tastes good, drink it — it’s probably safer than some of the foods you eat,” he counseled. Sedlak should know: The focus of his work has been to study the myriad of chemicals — antibiotics, blood-pressure medications, steroids, household chemicals, etc., — that continue to taint our drinking water. That’s because they’re not removed by the treatment of raw sewage or by the process that makes effluent drinkable. These are the chemicals like the birth-control-pill hormones that have been turning some male fish into sterile intersex (both male and female) fish.
As Sedlak’s most recent research has shown, river systems are pretty good at breaking down these chemicals, either by bacteria or by exposure to natural ultraviolet light. Currently, energy-intensive technology like reverse osmosis and treatment with artificial UV light is being used to eliminate these man-made contaminants. Sedlak’s goal is find more natural, low-energy systems that can do the same work but at a lower financial and ecological cost.
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Dr. Craig Bowron is a Twin Cities internist and writer who reports on medical topics for MinnPost. He can be reached at cbowron [at] minnpost [dot] com.