{"id":359145,"date":"2026-04-01T20:53:11","date_gmt":"2026-04-01T20:53:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/359145\/"},"modified":"2026-04-01T20:53:11","modified_gmt":"2026-04-01T20:53:11","slug":"warm-winters-mean-theres-more-nitrate-pollution-in-drinking-water","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/359145\/","title":{"rendered":"Warm winters mean there’s more nitrate pollution in drinking water"},"content":{"rendered":"

When pollution gets bad enough in the rivers supplying Iowa\u2019s largest city with drinking water, it costs Des Moines around $16,000 a day to run a special system to filter out dangerous nitrates. It\u2019s a fact of life in the agriculture-dependent state \u2014 and climate change<\/a> is making the water quality problem even worse.<\/p>\n

The nitrates come from fertilizer and pesticides that make their way into the soil and then waterways like the Raccoon and Des Moines rivers. It\u2019s not usually a problem in winter, but this year Iowa\u2019s capital had to filter in January and February \u2014 just the second time that\u2019s happened in more than 30 years. That\u2019s likely going to mean higher water bills for people who live in a state with some of the nation\u2019s waterways that are most vulnerable<\/a> to nitrate pollution.<\/p>\n

Experts blame weather conditions, including warming winters, for a costly problem they say will only grow across farm country.<\/p>\n

When it comes to winter nitrate pollution events, \u201cWe are more apt to see these in the future. Are they going to occur every year? No. But the ingredients are there for them to potentially occur more often,\u201d said Justin Glisan, Iowa\u2019s state climatologist. <\/p>\n

Why warmer winters lead to more water pollution<\/p>\n

<\/p>\n

\"A<\/p>\n

A field used for corn silage on Blue Spruce Farm is pictured on Tuesday, March 24, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

A field used for corn silage on Blue Spruce Farm is pictured on Tuesday, March 24, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

Add AP News on Google <\/p>\n

Add AP News as your preferred source to see more of our stories on Google.<\/p>\n

Share<\/p>\n

Read More<\/p>\n

The fertilizers and pesticides that farmers use<\/a> leave nitrogen and phosphorus in their fields. Rain or snowmelt then carries the chemicals into drinking water, which is dangerous. Ingesting too many nitrates can cause health issues like cancer or blue baby syndrome, low oxygen levels in infants.<\/p>\n

As Earth warms due to human-caused climate change, the ground isn\u2019t staying frozen as consistently in many places, and snow is often melting or falling as rain on thawed ground. That all adds up to more winter days when nitrates are likely to reach unhealthy levels.<\/p>\n

Scientists say one effect of Earth\u2019s warming is more frequent extreme weather events, including drought and intense bursts of rainfall from an atmosphere that now holds more moisture than in the past.<\/p>\n

Intense dryness followed by intense wetness means massive amounts of water moving through the soil, bringing farm chemicals like nitrogen with it, Glisan said. <\/p>\n

<\/p>\n

\"Dairy<\/p>\n

Dairy cows feed at Blue Spruce Farm on Saturday, March 28, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

Dairy cows feed at Blue Spruce Farm on Saturday, March 28, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

Add AP News on Google <\/p>\n

Add AP News as your preferred source to see more of our stories on Google.<\/p>\n

Share<\/p>\n

Read More<\/p>\n

And a warmer atmosphere is thawing Earth\u2019s polar regions<\/a> and causing more of those winter flip-flops from frigid polar air to warmer, less snowy weather, he said. <\/p>\n

Even though some storms brought a lot of snow this winter, it didn\u2019t stay on the ground for very long. Instead, snow insulated the soil in some areas from freezing too deep, and a quick thaw let melting snow, followed by pounding rain, travel down through the soil and eventually into streams.<\/p>\n

Where the ground isn\u2019t consistently frozen, nutrients aren\u2019t as \u201clocked in\u201d to the soil frost. <\/p>\n

\u201cIn central and southern Illinois, we\u2019ve always dealt with a sort of ephemeral freeze-thaw, freeze-thaw process. What we\u2019re seeing is that\u2019s really tracking farther north,\u201d said Trent Ford, Illinois\u2019 state climatologist.<\/p>\n

Stakes are high for low-income and rural communities<\/p>\n

<\/p>\n

\"University<\/p>\n

University of Vermont graduate student Delaney Bullock gathers runoff samples from two agricultural fields to be analyzed for nutrient concentrations on Thursday, March 12, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

University of Vermont graduate student Delaney Bullock gathers runoff samples from two agricultural fields to be analyzed for nutrient concentrations on Thursday, March 12, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

Add AP News on Google <\/p>\n

Add AP News as your preferred source to see more of our stories on Google.<\/p>\n

Share<\/p>\n

Read More<\/p>\n

Nitrate pollution is a big problem for low-income, rural residents across the United States, said Samuel Sandoval Solis, a professor at the University of California-Davis and an extension specialist in water resources management.<\/p>\n

While some communities already have the infrastructure to manage nitrate levels in drinking water, like filtration systems, many others don\u2019t. Around 15% of the U.S. population relies on drinking water wells that are private, according to the U.S. Geological Survey. Nitrates can seep into those wells.<\/p>\n

Testing well water regularly and correctly filtering it in a home can cost hundreds of dollars a year. Small communities whose water treatment facilities aren\u2019t yet equipped to filter nitrates will also have expensive decisions to make, Sandoval said.<\/p>\n

More research is connecting climate change, runoff and nutrient loss<\/p>\n

<\/p>\n

\"University<\/p>\n

University of Vermont graduate student Delaney Bullock gathers runoff samples from two agricultural fields to be analyzed for nutrient concentrations on Thursday, March 12, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

University of Vermont graduate student Delaney Bullock gathers runoff samples from two agricultural fields to be analyzed for nutrient concentrations on Thursday, March 12, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

Add AP News on Google <\/p>\n

Add AP News as your preferred source to see more of our stories on Google.<\/p>\n

Share<\/p>\n

Read More<\/p>\n

States have been wrestling with nitrate pollution for years, but they\u2019re starting to realize increasingly warm winters are making that tougher \u2014 like in Illinois, where yearly reports on the issue have started to more explicitly mention the role of climate change, said Joan Cox, program manager for the Illinois Nutrient Loss Reduction Strategy. <\/p>\n

Scientists know there\u2019s more nitrogen going downstream in the winter, but they\u2019re still trying to figure out whether that means more pollution overall, said Carol Adair, a professor at the University of Vermont who has studied how rain-on-snow events could worsen nutrient pollution.<\/p>\n

Either way, there\u2019s little known about the consequences of those changes on ecosystems, Adair said. She thinks because there\u2019s less plant life to suck up nitrogen in the winter, more could end up further downstream, like in the Gulf\u2019s \u201cdead zone\u201d where fertilizer pollution contributes to an area of low to no oxygen, which kills fish and marine life.<\/p>\n

Dani Replogle, a staff attorney for Food and Water Watch, a nonprofit for sustainable food and clean water, said factory farm operators try to plan manure and fertilizer applications when precipitation is unlikely. But that is \u201cincreasingly not a successful strategy because everything is becoming so unpredictable,\u201d she said.<\/p>\n

Regulating nutrient pollution has proven difficult<\/p>\n

<\/p>\n

\"Joshua<\/p>\n

Joshua Faulkner, left, research associate professor and director of the Agricultural and Environmental Testing Lab at the University of Vermont, and graduate student Delaney Bullock check on flumes used to collect runoff from two agriculture fields for analysis on Thursday, March 12, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart) (AP Photo\/Amanda Swinhart)<\/p>\n

Joshua Faulkner, left, research associate professor and director of the Agricultural and Environmental Testing Lab at the University of Vermont, and graduate student Delaney Bullock check on flumes used to collect runoff from two agriculture fields for analysis on Thursday, March 12, 2026, in Bridport, Vt. (AP Photo\/Amanda Swinhart) (AP Photo\/Amanda Swinhart)<\/p>\n

Add AP News on Google <\/p>\n

Add AP News as your preferred source to see more of our stories on Google.<\/p>\n

Share<\/p>\n

Read More<\/p>\n

Mandating that producers curb farm chemicals in water has proven difficult in agricultural areas, especially in Iowa<\/a>, where the state\u2019s farm lobby has opposed mandatory rules.<\/p>\n

Trump\u2019s EPA has delisted seven Iowa waterways from the federal Impaired Waters List, which under the Clean Water Act would have required the state to set limits on how much pollution gets into them. Food and Water Watch has announced an intent to sue.<\/p>\n

As for Iowa\u2019s water treatment facilities<\/a>, they are preparing resiliency plans for a future with more winter nutrient pollution, said Amy Kahler, CEO and general manager at Des Moines Water Works. But she thinks polluters upstream should clean up their acts.<\/p>\n

\u201cThere really are two paths. One is conservation efforts and responsible watershed practices. And the other is spending hundreds of millions of dollars in treatment solutions,\u201d Kahler said.<\/p>\n

<\/p>\n

\"Canada<\/p>\n

Canada Geese wade in the waters and ice of Lake Champlain on Tuesday, March 24, 2026, in Addison, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

Canada Geese wade in the waters and ice of Lake Champlain on Tuesday, March 24, 2026, in Addison, Vt. (AP Photo\/Amanda Swinhart)<\/p>\n

Add AP News on Google <\/p>\n

Add AP News as your preferred source to see more of our stories on Google.<\/p>\n

Share<\/p>\n

Read More<\/p>\n

She thinks the best solution is the former, since it also has positive impacts on quality of life.<\/p>\n

In 2015, the agency sued for the millions of dollars it was being forced to spend to filter unsafe levels from drinking water taken from the Des Moines and Raccoon rivers. A judge ultimately dismissed<\/a> the lawsuit.<\/p>\n

___<\/p>\n

Follow Melina Walling on X @MelinaWalling<\/a> and Bluesky @melinawalling.bsky.social<\/a>.<\/p>\n

___<\/p>\n

The Associated Press\u2019 climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP\u2019s standards<\/a> for working with philanthropies, a list of supporters and funded coverage areas at AP.org<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"When pollution gets bad enough in the rivers supplying Iowa\u2019s largest city with drinking water, it costs Des…\n","protected":false},"author":2,"featured_media":359146,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[189556,138,189559,4442,4142,390,189561,71965,65,273,3717,134,118259,1088,189562,189560,189557,111,139,69,4987,189558,147,189563,5021,20323,4998],"class_list":{"0":"post-359145","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-amy-kahler","9":"tag-business","10":"tag-carol-adair","11":"tag-climate","12":"tag-climate-and-environment","13":"tag-climate-change","14":"tag-dani-replogle","15":"tag-des-moines","16":"tag-donald-trump","17":"tag-environment","18":"tag-general-news","19":"tag-health","20":"tag-ia-state-wire","21":"tag-iowa","22":"tag-joan-cox","23":"tag-justin-glisan","24":"tag-melina-walling","25":"tag-new-zealand","26":"tag-newzealand","27":"tag-nz","28":"tag-pollution","29":"tag-samuel-sandoval-solis","30":"tag-science","31":"tag-trent-ford","32":"tag-u-s-news","33":"tag-water-quality","34":"tag-weather"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/359145","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=359145"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/359145\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/359146"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=359145"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=359145"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=359145"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}