Kayaking Chile's Free-Flowing Pascua River
The remote beach was empty except for me and my companions. The broad expanse of sea was empty, too and I squinted at the horizon, looking for a human shape. This was two years ago, deep in southern Chile and five of us had just descended the bottom section of the Pascua—a burly, glacier-fed river—by kayak. We were at the Pascua's mouth, where it empties into a fjord and we were planning to head through the fjord to the small town of Caleta Tortel. Two of the kayakers from our party, Lisa and Roberto, had paddled ahead until they disappeared amid the chop. Now, I was trying to find them in this gray-green world.
Seeing no sign of them, I walked back to the riverbank and kneeled for a drink of agua dulce—freshwater. Cold slid down my throat. The air smelled sweet, of mist and storms and clouds were slung low above the water. Waves jostled and splashed and I breathed deeply, readying myself for what I knew I had to do next: paddle through the tumult that Lisa and Roberto had just vanished into.
There was nothing for the three of us left on the gravel bar to do but load into our boats and point them toward the inlet. The other lives we all lived—an existence with things like showers and email and beds—had become laughably unimportant. Our needs were immediate and self-evident. Stay alive, stay dry, stay together and keep going. Or turn back. But we had no intention of turning back. We gripped our paddles and pushed off the bank.
Where the river hits the sea, we hit the waves—heaving pyramids of whitecapped water that splashed over our spray skirts. My boat partner and I counted aloud to pace our strokes—one, two, three, four—as we dug our paddles into the dark water, hoping that if we paddled hard enough for long enough, we'd stay upright and make it to the nearest shore. Our kayak, about 17 feet long, rose onto the swells, hung in midair, then slammed back down. I clenched my paddle tighter. My forearms stiffened and ached. The land, the water, the weather—all of it became real and close. Although nerve-racking, this was the kind of intensity I lived for. It pulled me into the present and put all of me to work.
We aimed our boat for a beach that we could see between the waves. As we got closer, I spotted two life-jacketed figures pulling brightly colored plastic boats ashore. Lisa and Roberto had made landfall.
Why was I there, paddling as hard as I could on those stormy seas? There's more than one way to answer that question. The Pascua is in a region of Chile called Aysén. I'd spent the past couple of years there doing research on a proposal to build five large dams, two of which would be on the Pascua. During the course of that project, I had learned a lot about river flows, hydropower and electricity transmission lines. But I wanted to know the river that I had thought about so much in a more intimate way. Before the Pascua's power turned to megawatts, I wanted to feel its current against my skin.
I was also in Aysén for less practical reasons. Like many others before me, I'd been drawn by the idea of Patagonia: a place where wind and weather ruled, granite spires rose from the Earth and teal rivers curled through a trackless steppe. Parts of Aysén are practically uninhabited, with less than three people per square mile—a lower population density than that of the Sahara Desert or Mongolia. I'd hitchhiked through the region, kayaked its rivers and explored its valleys, trying to get closer to the place I'd been so fixated on. The ecological philosopher Arne Naess wrote that mountaineering is a way to participate in a mountain's greatness. In the same vein, everything I did in the far south was part of my attempt to participate in the greatness of that landscape.
The Pascua encapsulates all that is wondrous about Patagonia. Other rivers in the area, like the Baker, are strewn with ranches, but very few gauchos—South America's version of cowboys—live along the Pascua. Those who do first arrived in handmade wooden rowboats. To get up the river before motorboats, the gauchos had to stand on the thickly forested banks of the Pascua and pull their boats (which were sometimes full of lambs) upstream with ropes. A spur road from the dirt highway did not arrive until 2006. The Pascua was remote, powerful, isolated—a force to be reckoned with. As a few friends and I talked about a potential trip on the river, we began referring to it as "the wild and unknown Pascua."
So, we decided that in February 2014 we would kayak the lower Pascua from near Lago Quetru to the shores of Tortel. Our crew would be Weston Boyles, a then-27-year-old Colorado native; Tyler Williams and Lisa Gelczis, husband-and-wife guides from Flagstaff, Arizona; and Roberto Haro, a middle-aged gym teacher from the town of Cochrane who taught local kids how to whitewater kayak. The four of them had met through an organization Weston started, Rios to Rivers, which had facilitated an exchange between some of Roberto's teenage kayakers and some American kayakers to paddle the Baker and Colorado Rivers while learning about the effects of dams.
Simply getting ready for the trip was challenging. There were no reports from other paddlers or even any detailed maps. So we huddled around a laptop in Roberto's kitchen, scrolling through satellite images to sketch a route.
Maps of the area show a shredded coastline where the continent encounters the sea. Islands are splattered across bays and fjords slice into the mainland, carvings left over from the last ice age. Patagonia's topography is similar to that of Southeast Alaska and Norway, except with more places where glaciers meet the sea.
The journey promised heavy rain, cold temperatures and high winds. Friends of ours could not understand why we would suffer through it. When we told people in Cochrane that we would kayak from Lago Quetru to the mouth of the Pascua, then up the coast to Tortel, one person asked, "Do you want to die?"
I struggled to explain why we wanted to go there. I often felt like using the clichéd response: "If you have to ask, you'll never understand." What drives anyone on this kind of quest? For me, it came from a desire to be part of something giant and wild, a yearning to participate in something beautiful. To do that fully, I needed to give up control.
At the beginning of our journey, on the banks of the Pascua, we had packed our boats and loaded them into the water. The river was so wide, it often looked like a moving lake. Boils wrinkled the surface. The water split into braids around sandy shoals and bent sharply around unnamed mountains. We paddled up creeks and made sandwiches with manjar (Chile's version of dulce de leche) on our spray skirts. On our second day, we reached the Pascua's mouth, where the river emptied into the fjord and where our group dispersed and came together again on that wind-whipped beach to wait out the bad weather.
We took naps and ate snacks and read books, then eventually set out again. Frothing water exploded against cliffs to our left. To our right, the sea spread outward until it welded itself to a skyscape of gray clouds. No more beaches appeared on the coast. The headwind blew so hard that if we paused our paddle strokes, the Klepper went backward. I couldn't stop to scratch my nose. Weston and I synchronized our strokes. Much of the time, we couldn't see our friends.
After four hours of struggling against the wind, we ducked into a protected cove where iridescent clumps of ice emerged from the dark water—sedan-size pieces of glacier that had calved off from a tongue of the Southern Patagonian Ice Field. Most of the mountains had darkened by that time, except for one ridge behind us that was gilded by the only shaft of sun we had seen all day.
We paddled toward the coast, to where a few of these icebergs were beached on the front lawn of an abandoned ranch. Aysén is a ranching region, settled by homesteaders in the early 20th century, when border tensions with Argentina led the Chilean government to give away free land. Though more and more Ayséninos are moving to towns and making a living from tourism, the region remains a gaucho stronghold. These hardy souls live the life that many people hope will continue but few people want to live themselves.
We poked around the ranch—walking around the sagging fence that surrounded the cabin, pushing through the overgrown bushes, peeking into the shed where the family once hung their meat. Richard White, a Stanford environmental historian, has written that outdoor recreation like kayaking and mountaineering represents a type of "rugged play" that mimics the hard life of the pioneer. We gringos were trying to re-create the experience of those early gaucho pioneers—only we were doing it for entertainment rather than survival.
This rugged play demands that we use our bodies to move through the land until our thighs quiver and burn, our calves tighten and tire. It also demands that we look closely at whatever is around us: rapids and waves, discoloration and indentations in snow-covered ice, the outcroppings and contours of rock. We often feel closest to the land when it requires attention and labor from us and so such play is a way of reconnecting to the Earth. Among those of us who work with papers and pens, screens and keyboards, rugged play represents a kind of nostalgia. It's a yearning for the days when we knew the land the way the family at this ranch would have—when we knew it because we had to know it, when we knew it with our bodies.
My musings were swept away by the immediate demands of hunger, cold and fatigue. We set up our nylon tents near the old wooden buildings, made fire and food on the beach and slept.
We woke the next morning to wind hurtling over the water. The waves were even larger than they had been the day before. We set out, making spurts of progress up the coastline. I had a plane to catch in four days, but it was foolish to believe that we could control our rate of progress.
The next several days blurred together: a montage of driving wind and rain, Weston yelling at me whenever my hood wasn't up and paddling furiously whenever the wind abated. We hung around on beaches when the weather was especially bad, then got back in our boats during the small openings when the wind died down.
One morning, we reached a beach at the tip of the string of islands we had been following since leaving the icebergs. The beach faced a seven-mile open crossing. The weather remained windy and wavy, with whitecapped water and biting gusts. There was no way we could head into open water in such conditions, so we waited again.
We knew exactly how much food we had left: two rolls of coconut cookies, two packets of saltine crackers, a bag of oatmeal, a bag of pasta, a few pieces of stale bread and three bags of dried milk. The five of us shared half a bag of pasta for dinner.
The next day, the rains fell so heavily and continuously that Lisa and Tyler never took off their dry suits. The rest of us shivered in soaked-through rain gear, holding our pruney hands over a fire, taking turns gathering wood. At one point, Lisa and I walked to a nearby beach and heaved large rocks onto pieces of driftwood, trying to split them, joking that we'd become cavewomen.
None of us mentioned our hunger. We had chosen to give up control and there was nothing we could do now but wait out the wind. We were all elated that night when Roberto caught a small fish. I ate the head—including the eyes. Tyler, who doesn't smoke, asked for one of the cigarettes we had brought as gifts for gauchos. He thought it would lighten the mood.
In the beginning of the trip, when optimism and awe had reigned, we'd fondly nicknamed each snacking and sleeping spot. Tranquilo Bay. Love Beach. We dubbed this waiting spot Desolation Cove.
The next morning, hope displaced our desolation. Smaller waves passed by, free of whitecaps. We packed up our gear and readied our boats in silence, pointing our bows toward the lanky waterfalls and forested mountains that we could see across the open water. New snow dusted the peaks.
We crossed the previously treacherous passage with ridiculous ease, aiming toward a gap between the continent and an island. The seven miles passed quickly. We soon entered a protected channel, drifting by misty cascades and a curving coastline, enjoying Roberto's secret stash of lollipops and opening up the two emergency rolls of coconut cookies. We were giddy with proximity. There were no more open crossings between us and Tortel. We guessed that we would make it to town that evening.
Midmorning, we spotted a gray wooden boat in a cove. Since reaching the mouth of the Pascua, we'd seen some detritus left from human activity on a few beaches—two deserted and collapsing cabins, empty gas canisters in the sand, rusty nails in pieces of beached wood—but this boat seemed to signal that someone was close by. A tin roof caught light between the trees. We could see chickens and dogs moving about, laundry swinging from a line and smoke puffing from a chimney.
A couple stood outside the house, both wearing black rubber boots and baggy pants. We landed and walked up to their cabin. The man had a mustache, a hat and a tentative posture. The woman had a wide smile and thick hair that fell around her ears. She exuded enthusiasm as soon as we introduced ourselves, ushering us into her house for mate, the ubiquitous South American tea sipped through a metal straw and apologizing for the mess. They didn't get many visitors, she said.
It was a simple one-room cabin with a wood-burning cookstove in the corner. In another corner, clothes were piled on top of a mattress. Newspaper, pieces of cardboard and a poster of the Virgin Mary covered the walls. A flattened cat food box was pressed against the door and often flapped, letting the wind enter. We sat shivering around the stove, swallowing mate, then bread, then rice, then fish. I was awed by the intense abundance; even the plate was warm. I went back for more.
We described our trip to the couple. The woman nodded. She told us that she'd grown up on the unoccupied ranch near the Jorge Montt Glacier—the ranch where we'd camped next to icebergs. She'd had to cross from there to Tortel many times as a child. It was the route her family had taken to get to town.
When we described Desolation Cove, she nodded again, adding that the wind always blew hard there. Once, she said, she had waited at that spot for seven days before she could cross the channel. Often, gauchos would wait together on that beach, all on their way to Tortel and all stopped by the wild winds of the open channel. Many would bring lambs in their boats for beachside asados. They would make tortas in the sand.
What many in Cochrane had warned us would be a lethal journey was, for the gauchos, just part of their routine. Our rugged play had once been someone's commute.
In the following days, after we reached Caleta Tortel, forces other than wind, weather and water would take control. I'd hitchhike hundreds of miles to the nearest airport, try to weasel my way onto an interhemispheric flight and apologize to my professors for being late to a new semester. I'd be quickly jolted back into a life of papers and pens, screens and keyboards, showers and email and a bed.
But those gauchos, of course, would stay and often I would think of them: still there, watching the water, waiting out the weather, intertwining their lives with the land and paying close attention to its details. I was only a visitor to that place the gauchos call home, but paddling was my way of weaving the land and sea into my life. Beyond the picture of a place, the postcard version of it, was the possibility of participation.
Salvation for the Pascua
When my friends and I kayaked the lower reaches of the Pascua River in early 2014, we thought we were undertaking a kind of farewell adventure. For eight years, Chilean environmentalists and their international allies had been fighting to prevent the construction of five dams on the Pascua and Baker Rivers. Many people feared that the dams were a done deal and that these wild rivers—gems of rugged Patagonia—would become reservoirs.
Then a massive citizens' movement overturned the political conventional wisdom. Anti-dam protests in Chile's south and marches in the capital, Santiago, made the dams a major issue in the 2014 presidential campaign. Not long after President Michelle Bachelet came into office, her cabinet voted to cancel the dams.
The decision was a landmark victory for Chile's environmental movement. Today, the Pascua and Baker Rivers continue to flow freely.
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By Frank La Sorte and Kyle Horton
Millions of birds travel between their breeding and wintering grounds during spring and autumn migration, creating one of the greatest spectacles of the natural world. These journeys often span incredible distances. For example, the Blackpoll warbler, which weighs less than half an ounce, may travel up to 1,500 miles between its nesting grounds in Canada and its wintering grounds in the Caribbean and South America.
Blackpoll warbler. PJTurgeon / Wikipedia<p>We used this information to determine how the number of migratory bird species varies based on each city's level of <a href="https://www.britannica.com/science/light-pollution" target="_blank" rel="noopener noreferrer">light pollution</a> – brightening of the night sky caused by artificial light sources, such as buildings and streetlights. We also explored how species numbers vary based on the quantity of tree canopy cover and impervious surface, such as concrete and asphalt, within each city. Our findings show that cities can help migrating birds by planting more trees and reducing light pollution, especially during spring and autumn migration.</p>
Declining Bird Populations<p>Urban areas contain numerous dangers for migratory birds. The biggest threat is the risk of <a href="https://doi.org/10.1650/CONDOR-13-090.1" target="_blank">colliding with buildings or communication towers</a>. Many migratory bird populations have <a href="http://dx.doi.org/10.1126/science.aaw1313" target="_blank">declined over the past 50 years</a>, and it is possible that light pollution from cities is contributing to these losses.</p><p>Scientists widely agree that light pollution can <a href="https://doi.org/10.1073/pnas.1708574114" target="_blank">severely disorient migratory birds</a> and make it hard for them to navigate. Studies have shown that birds will cluster around brightly lit structures, much like insects flying around a porch light at night. Cities are the <a href="https://doi.org/10.1002/fee.2029" target="_blank" rel="noopener noreferrer">primary source of light pollution for migratory birds</a>, and these species tend to be more abundant within cities <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13792" target="_blank" rel="noopener noreferrer">during migration</a>, especially in <a href="https://doi.org/10.1016/j.landurbplan.2020.103892" target="_blank" rel="noopener noreferrer">city parks</a>.</p>
Composite image of the continental U.S. at night from satellite photos. NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA's Goddard Space Flight Center
The Power of Citizen Science<p>It's not easy to observe and document bird migration, especially for species that migrate at night. The main challenge is that many of these species are very small, which limits scientists' ability to use electronic tracking devices.</p><p>With the growth of the internet and other information technologies, new data resources are becoming available that are making it possible to overcome some of these challenges. <a href="https://doi.org/10.1038/d41586-018-07106-5" target="_blank">Citizen science initiatives</a> in which volunteers use online portals to enter their observations of the natural world have become an important resource for researchers.</p><p>One such initiative, <a href="https://ebird.org/home" target="_blank" rel="noopener noreferrer">eBird</a>, allows bird-watchers around the globe to share their observations from any location and time. This has produced one of the <a href="https://doi.org/10.1111/ecog.04632" target="_blank" rel="noopener noreferrer">largest ecological citizen-science databases in the world</a>. To date, eBird contains over 922 million bird observations compiled by over 617,000 participants.</p>
Light Pollution Both Attracts and Repels Migratory Birds<p>Migratory bird species have evolved to use certain migration routes and types of habitat, such as forests, grasslands or marshes. While humans may enjoy seeing migratory birds appear in urban areas, it's generally not good for bird populations. In addition to the many hazards that exist in urban areas, cities typically lack the food resources and cover that birds need during migration or when raising their young. As scientists, we're concerned when we see evidence that migratory birds are being drawn away from their traditional migration routes and natural habitats.</p><p>Through our analysis of eBird data, we found that cities contained the greatest numbers of migratory bird species during spring and autumn migration. Higher levels of light pollution were associated with more species during migration – evidence that light pollution attracts migratory birds to cities across the U.S. This is cause for concern, as it shows that the influence of light pollution on migratory behavior is strong enough to increase the number of species that would normally be found in urban areas.</p><p>In contrast, we found that higher levels of light pollution were associated with fewer migratory bird species during the summer and winter. This is likely due to the scarcity of suitable habitat in cities, such as large forest patches, in combination with the adverse affects of light pollution on bird behavior and health. In addition, during these seasons, migratory birds are active only during the day and their populations are largely stationary, creating few opportunities for light pollution to attract them to urban areas.</p>
Trees and Pavement<p>We found that tree canopy cover was associated with more migratory bird species during spring migration and the summer. Trees provide important habitat for migratory birds during migration and the breeding season, so the presence of trees can have a strong effect on the number of migratory bird species that occur in cities.</p><p>Finally, we found that higher levels of impervious surface were associated with more migratory bird species during the winter. This result is somewhat surprising. It could be a product of the <a href="https://www.epa.gov/heatislands" target="_blank">urban heat island effect</a> – the fact that structures and paved surfaces in cities absorb and reemit more of the sun's heat than natural surfaces. Replacing vegetation with buildings, roads and parking lots can therefore make cities significantly warmer than surrounding lands. This effect could reduce cold stress on birds and increase food resources, such as insect populations, during the winter.</p><p>Our research adds to our understanding of how conditions in cities can both help and hurt migratory bird populations. We hope that our findings will inform urban planning initiatives and strategies to reduce the harmful effects of cities on migratory birds through such measures as <a href="https://www.arborday.org/programs/treecityusa/index.cfm" target="_blank" rel="noopener noreferrer">planting more trees</a> and initiating <a href="https://aeroecolab.com/uslights" target="_blank" rel="noopener noreferrer">lights-out programs</a>. Efforts to make it easier for migratory birds to complete their incredible journeys will help maintain their populations into the future.</p><p><em><span style="background-color: initial;"><a href="https://theconversation.com/profiles/frank-la-sorte-1191494" target="_blank">Frank La Sorte</a> is a r</span>esearch associate at the </em><em>Cornell Lab of Ornithology, Cornell University. <a href="https://theconversation.com/profiles/kyle-horton-1191498" target="_blank">Kyle Horton</a> is an assistant professor of Fish, Wildlife, and Conservation Biology at the Colorado State University.</em></p><p><em></em><em>Disclosure statement: Frank La Sorte receives funding from The Wolf Creek Charitable Foundation and the National Science Foundation (DBI-1939187). K</em><em>yle Horton does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</em></p><p><em>Reposted with permission from <a href="https://theconversation.com/cities-can-help-migrating-birds-on-their-way-by-planting-more-trees-and-turning-lights-off-at-night-152573" target="_blank">The Conversation</a>. </em></p>
EcoWatch Daily Newsletter
By Lynne Peeples
Editor's note: This story is part of a nine-month investigation of drinking water contamination across the U.S. The series is supported by funding from the Park Foundation and Water Foundation. Read the launch story, "Thirsting for Solutions," here.
In late September 2020, officials in Wrangell, Alaska, warned residents who were elderly, pregnant or had health problems to avoid drinking the city's tap water — unless they could filter it on their own.
Unintended Consequences<p>Chemists first discovered disinfection by-products in treated drinking water in the 1970s. The trihalomethanes they found, they determined, had resulted from the reaction of chlorine with natural organic matter. Since then, scientists have identified more than 700 additional disinfection by-products. "And those only represent a portion. We still don't know half of them," says Richardson, whose lab has identified hundreds of disinfection by-products. </p>
What’s Regulated and What’s Not?<p>The U.S. Environmental Protection Agency (EPA) currently regulates 11 disinfection by-products — including a handful of trihalomethanes (THM) and haloacetic acids (HAA). While these represent only a small fraction of all disinfection by-products, EPA aims to use their presence to indicate the presence of other disinfection by-products. "The general idea is if you control THMs and HAAs, you implicitly or by default control everything else as well," says Korshin.</p><p>EPA also requires drinking water facilities to use techniques to reduce the concentration of organic materials before applying disinfectants, and regulates the quantity of disinfectants that systems use. These rules ultimately can help control levels of disinfection by-products in drinking water.</p>
Click the image for an interactive version of this chart on the Environmental Working Group website.<p>Still, some scientists and advocates argue that current regulations do not go far enough to protect the public. Many question whether the government is regulating the right disinfection by-products, and if water systems are doing enough to reduce disinfection by-products. EPA is now seeking public input as it considers potential revisions to regulations, including the possibility of regulating additional by-products. The agency held a <a href="https://www.epa.gov/dwsixyearreview/potential-revisions-microbial-and-disinfection-byproducts-rules" target="_blank">two-day public meeting</a> in October 2020 and plans to hold additional public meetings throughout 2021.</p><p>When EPA set regulations on disinfection by-products between the 1970s and early 2000s, the agency, as well as the scientific community, was primarily focused on by-products of reactions between organics and chlorine — historically the most common drinking water disinfectant. But the science has become increasingly clear that these chlorinated chemicals represent a fraction of the by-product problem.</p><p>For example, bromide or iodide can get caught up in the reaction, too. This is common where seawater penetrates a drinking water source. By itself, bromide is innocuous, says Korshin. "But it is extremely [reactive] with organics," he says. "As bromide levels increase with normal treatment, then concentrations of brominated disinfection by-products will increase quite rapidly."</p><p><a href="https://pubmed.ncbi.nlm.nih.gov/15487777/" target="_blank">Emerging</a> <a href="https://pubs.acs.org/doi/10.1021/acs.est.7b05440" target="_blank" rel="noopener noreferrer">data</a> indicate that brominated and iodinated by-products are potentially more harmful than the regulated by-products.</p><p>Almost half of the U.S. population lives within 50 miles of either the Atlantic or Pacific coasts, where saltwater intrusion can be a problem for drinking water supplies. "In the U.S., the rule of thumb is the closer to the sea, the more bromide you have," says Korshin, noting there are also places where bromide naturally leaches out from the soil. Still, some coastal areas tend to be spared. For example, the city of Seattle's water comes from the mountains, never making contact with seawater and tending to pick up minimal organic matter.</p><p>Hazardous disinfection by-products can also be an issue with desalination for drinking water. "As <a href="https://ensia.com/features/can-saltwater-quench-our-growing-thirst/" target="_blank" rel="noopener noreferrer">desalination</a> practices become more economical, then the issue of controlling bromide becomes quite important," adds Korshin.</p>
Other Hot Spots<p>Coastal areas represent just one type of hot spot for disinfection by-products. Agricultural regions tend to send organic matter — such as fertilizer and animal waste — into waterways. Areas with warmer climates generally have higher levels of natural organic matter. And nearly any urban area can be prone to stormwater runoff or combined sewer overflows, which can contain rainwater as well as untreated human waste, industrial wastewater, hazardous materials and organic debris. These events are especially common along the East Coast, notes Sydney Evans, a science analyst with the nonprofit Environmental Working Group (EWG, a collaborator on <a href="https://ensia.com/ensia-collections/troubled-waters/" target="_blank">this reporting project</a>).</p><p>The only drinking water sources that might be altogether free of disinfection by-products, suggests Richardson, are private wells that are not treated with disinfectants. She used to drink water from her own well. "It was always cold, coming from great depth through clay and granite," she says. "It was fabulous."</p><p>Today, Richardson gets her water from a city system that uses chloramine.</p>
Toxic Treadmill<p>Most community water systems in the U.S. use chlorine for disinfection in their treatment plant. Because disinfectants are needed to prevent bacteria growth as the water travels to the homes at the ends of the distribution lines, sometimes a second round of disinfection is also added in the pipes.</p><p>Here, systems usually opt for either chlorine or chloramine. "Chloramination is more long-lasting and does not form as many disinfection by-products through the system," says Steve Via, director of federal relations at the American Water Works Association. "Some studies show that chloramination may be more protective against organisms that inhabit biofilms such as Legionella."</p>
Alternative Approaches<p>When he moved to the U.S. from Germany, Prasse says he immediately noticed the bad taste of the water. "You can taste the chlorine here. That's not the case in Germany," he says.</p><p>In his home country, water systems use chlorine — if at all — at lower concentrations and at the very end of treatment. In the Netherlands, <a href="https://dwes.copernicus.org/articles/2/1/2009/dwes-2-1-2009.pdf" target="_blank">chlorine isn't used at all</a> as the risks are considered to outweigh the benefits, says Prasse. He notes the challenge in making a convincing connection between exposure to low concentrations of disinfection by-products and health effects, such as cancer, that can occur decades later. In contrast, exposure to a pathogen can make someone sick very quickly.</p><p>But many countries in Europe have not waited for proof and have taken a precautionary approach to reduce potential risk. The emphasis there is on alternative approaches for primary disinfection such as ozone or <a href="https://www.pbs.org/wgbh/nova/article/eco-friendly-way-disinfect-water-using-light/" target="_blank" rel="noopener noreferrer">ultraviolet light</a>. Reverse osmosis is among the "high-end" options, used to remove organic and inorganics from the water. While expensive, says Prasse, the method of forcing water through a semipermeable membrane is growing in popularity for systems that want to reuse wastewater for drinking water purposes.</p><p>Remucal notes that some treatment technologies may be good at removing a particular type of contaminant while being ineffective at removing another. "We need to think about the whole soup when we think about treatment," she says. What's more, Remucal explains, the mixture of contaminants may impact the body differently than any one chemical on its own. </p><p>Richardson's preferred treatment method is filtering the water with granulated activated carbon, followed by a low dose of chlorine.</p><p>Granulated activated carbon is essentially the same stuff that's in a household filter. (EWG recommends that consumers use a <a href="https://www.ewg.org/tapwater/reviewed-disinfection-byproducts.php#:~:text=EWG%20recommends%20using%20a%20home,as%20trihalomethanes%20and%20haloacetic%20acids." target="_blank" rel="noopener noreferrer">countertop carbon filter</a> to reduce levels of disinfection by-products.) While such a filter "would remove disinfection by-products after they're formed, in the plant they remove precursors before they form by-products," explains Richardson. She coauthored a <a href="https://pubs.acs.org/doi/10.1021/acs.est.9b00023" target="_blank" rel="noopener noreferrer">2019 paper</a> that concluded the treatment method is effective in reducing a wide range of regulated and unregulated disinfection by-products.</p><br>
Greater Cincinnati Water Works installed a granulated activated carbon system in 1992, and is still one of relatively few full-scale plants that uses the technology. Courtesy of Greater Cincinnati Water Works.<p>Despite the technology and its benefits being known for decades, relatively few full-scale plants use granulated active carbon. They often cite its high cost, Richardson says. "They say that, but the city of Cincinnati [Ohio] has not gone bankrupt using it," she says. "So, I'm not buying that argument anymore."</p><p>Greater Cincinnati Water Works installed a granulated activated carbon system in 1992. On a video call in December, Jeff Swertfeger, the superintendent of Greater Cincinnati Water Works, poured grains of what looks like black sand out of a glass tube and into his hand. It was actually crushed coal that has been baked in a furnace. Under a microscope, each grain looks like a sponge, said Swertfeger. When water passes over the carbon grains, he explained, open tunnels and pores provide extensive surface area to absorb contaminants.</p><p>While the granulated activated carbon initially was installed to address chemical spills and other industrial contamination concerns in the Ohio River, Cincinnati's main drinking water source, Swertfeger notes that the substance has turned out to "remove a lot of other stuff, too," including <a href="https://ensia.com/features/drinking-water-contamination-pfas-health/" target="_blank" rel="noopener noreferrer">PFAS</a> and disinfection by-product precursors.</p><p>"We use about one-third the amount of chlorine as we did before. It smells and tastes a lot better," he says. "The use of granulated activated carbon has resulted in lower disinfection by-products across the board."</p><p>Richardson is optimistic about being able to reduce risks from disinfection by-products in the future. "If we're smart, we can still kill those pathogens and lower our chemical disinfection by-product exposure at the same time," she says.</p><p><em>Reposted with permission from </em><em><a href="https://ensia.com/features/drinking-water-disinfection-byproducts-pathogens/" target="_blank">Ensia</a>. </em><a href="https://www.ecowatch.com/r/entryeditor/2649953730#/" target="_self"></a></p>
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