{"id":782511,"date":"2026-05-08T18:27:27","date_gmt":"2026-05-08T18:27:27","guid":{"rendered":"https:\/\/www.europesays.com\/us\/782511\/"},"modified":"2026-05-08T18:27:27","modified_gmt":"2026-05-08T18:27:27","slug":"as-a-colorado-aquifer-runs-low-dangerous-heavy-metals-threaten-rural-communities-drinking-water","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/782511\/","title":{"rendered":"As a Colorado Aquifer Runs Low, Dangerous Heavy Metals Threaten Rural Communities\u2019 Drinking Water"},"content":{"rendered":"

Julie Zahringer hears a common refrain at her environmental laboratory in Alamosa, Colorado: A customer has been drinking well water on family land where they\u2019ve lived for years, but recently noticed it has changed. They want to know why.<\/p>\n

\u201cAll of a sudden it looks different, tastes different, there\u2019s odor, there\u2019s color,\u201d said Zahringer.<\/p>\n

Zahringer\u2019s SDC Laboratory is one of the few testing water in the San Luis Valley, an 8,000-square-mile, high-altitude desert in south-central Colorado. She has tested thousands of wells during more than 30 years in the field.<\/p>\n

\u00a0<\/p>\n

Residents of the valley, which has large Hispanic populations and a high poverty rate, have been concerned about naturally occurring heavy metals in their water for decades, she said. But in the past five years, the rate of change has accelerated.<\/p>\n

\u201cEvery year it just seems like this is the climax of it, and the next year, it gets worse,\u201d said Zahringer. \u201cThis year, we\u2019re looking at probably the worst as far as water quality.\u201d<\/p>\n

The San Luis Valley relies on surface water from the Rio Grande and a massive aquifer system, one of the largest in North America, to drive its agricultural economy. But the aquifer is severely overallocated, losing an estimated 1.2 million acre-feet of water between 1976, when tracking began, and 2013\u2014equivalent to more than five times what the city of Denver consumes each year. This year, the aquifer could hit another record low, as Colorado\u2019s snowpack, which recharges the state\u2019s aquifers, is at the lowest level since record-keeping began in 1941<\/a>.<\/p>\n

\"TheThe sun sets over agriculture fields in San Luis, Colorado on Tuesday, May 5, 2026. The Rio Grande recharges the aquifer, which is the source of water for the entire San Luis Valley, including its agriculture, which is the industry which economically sustains the area. The amount of water necessary for large scale agriculture is also the primary reason for the aquifer\u2019s depletion. Credit: Jacob Spetzler\/Inside Climate News<\/p>\n

\"AA water control gate controls flow in an irrigation ditch in Manassa, Colorado. Credot: Jacob Spetzler\/Inside Climate News<\/p>\n

Researchers are finding that as groundwater levels drop, the remaining water contains higher concentrations of carcinogenic heavy metals.<\/p>\n

The valley\u2019s well water users, many of them in historically underserved communities, are increasingly concerned about what\u2019s in their drinking water. But with little governmental oversight of private wells or resources to help track and manage quality, they have few options to make it safe.<\/p>\n

Shifting Chemistry\u00a0<\/strong><\/p>\n

Anna Vargas, a sixth-generation resident of the San Luis Valley, remembers making snowmen often as a child, and her mother talking about the daily rains during the summer monsoon season. Now, monsoon season barely exists here, Vargas said.<\/p>\n

\u201cAs the years have gone by, there\u2019s less rain, less snowfall. I\u2019ve lived in the valley long enough to see the changes in weather patterns,\u201d says Vargas, project manager with the SLV Ecosystem Council. \u201cWe depend a lot on snowpack, and we have hardly any this year. It\u2019s concerning for all of us in the Rio Grande basin\u2026The heavy metals will just become more concentrated.\u201d\u00a0<\/p>\n

\"\"<\/p>\n

Heavy metals like arsenic, tungsten, uranium, manganese and selenium occur naturally in rocks and soils and come up with groundwater that is pumped to the surface. With drought, Zahringer said, they can become a problem.<\/p>\n

\u201cWe\u2019re not seeing a dilution of any of the contaminants\u2026so anything that\u2019s in the geologic makeup is just really concentrating,\u201d said Zahringer, whose tests have documented contaminant levels rising in the wells during dry periods.<\/p>\n

\"JulieJulie Zahringer, owner and laboratory director of the Sangre de Cristo (SDC) Laboratory, in her office in Alamosa, Colorado. The SDC Laboratory, the only lab testing water in the San Luis Valley, serves private well owners, municipalities and agricultural water users. (Photo by Jacob Spetzler\/Special to Inside Climate News)<\/p>\n

In addition, as aquifer levels drop during droughts\u2014and due to overpumping\u2014its geochemistry shifts, says Kathy James, Ph.D., associate professor with the Colorado School of Public Health. More anaerobic conditions are created as water sinks deeper below the surface, which can cause more naturally occurring metals to dissolve into the water.<\/p>\n

This year, James led a study finding that up to one in four private wells producing drinking water in the San Luis Valley contain elevated levels of heavy metals like arsenic and uranium<\/a>.<\/p>\n

Zahringer\u2019s estimates mirror these results: Of all the well waters her lab tests in southern Colorado, about 25 percent exceed the U.S. Environmental Protection Agency\u2019s maximum contaminant level for arsenic in drinking water<\/a>.\u00a0<\/p>\n

And \u201cthat\u2019s just going up,\u201d Zahringer said.<\/p>\n

Unanswered Questions<\/strong><\/p>\n

Exposure to arsenic in drinking water is linked to cancer<\/a>, cardiovascular disease and diabetes, and can impair children\u2019s cognitive development. James\u2019s previous research also found that long-term exposure to low levels of arsenic can increase the risk of coronary heart disease<\/a>.<\/p>\n

Other studies have shown that both uranium and arsenic in irrigation water can stunt crop growth and accumulate in plants<\/a>, compounding public health risk through the food supply.<\/p>\n

Zahringer said that some customers come to her lab on referrals from their primary care physicians trying to determine the root cause of elevated levels of heavy metals in their bloodstream. Her own well water is high in arsenic, but her filtration system thoroughly treats it before it enters her house.<\/p>\n

\u201cI\u2019m in a unique situation where I\u2019m educated and vigilant, and I have the resources to test and make sure it\u2019s OK,\u201d said Zahringer. \u201cA lot of my neighbors, I know they\u2019re just drinking it right out of the ground.\u201d<\/p>\n

This story is funded by readers like you.<\/p>\n

Our nonprofit newsroom provides award-winning climate coverage free of charge and advertising. We rely on donations from readers like you to keep going. Please donate now to support our work.<\/p>\n

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Half of the U.S. population relies on groundwater<\/a> for drinking, irrigation, industry and livestock. Much of it is pumped through public water systems, which must limit contaminants to comply with the federal Safe Drinking Water Act, in addition to state requirements that may be more stringent. But private wells, which are the main source of drinking water for 15 percent of Americans<\/a> and about a third of San Luis Valley residents, are not regulated or monitored. In effect, about 51 million Americans are responsible for monitoring the safety of their own drinking water.<\/p>\n

In the San Luis Valley, residents are asking more questions about how their water is impacting their health, crops and cattle, Vargas said, making it easy for her to recruit some of the more than 800 private well owners involved in James\u2019s study.\u00a0<\/p>\n

\u201cWe filled it up so fast that that just shows how much the community members wanted their wells tested,\u201d says Vargas.<\/p>\n

After a few months of recruiting, the study group was nearly at capacity.<\/p>\n

Later, neighbors would stop her at the grocery store to tell her about their results:\u00a0manganese, arsenic, uranium or other contaminants were often above the EPA thresholds.\u00a0<\/p>\n

Today, many residents in Vargas\u2019s community have turned to bottled water. \u201cThey just don\u2019t know if they can drink the water,\u201d she said.<\/p>\n

Climate Justice<\/strong><\/p>\n

With the ongoing megadrought and this year\u2019s record-low snowpack in Colorado, small communities, private well owners and municipal water systems alike will struggle to keep up with changing groundwater supply, Zahringer said. Researchers estimate that U.S. drought conditions could expose roughly 1 in 10 well-water users to unsafe arsenic levels.<\/a><\/p>\n

\u201cAs those contaminants are increasing, we are going to start to see these rural areas really can\u2019t afford these treatment plants and mitigation for it,\u201d said Zahringer. \u201cWe\u2019re dealing with a lot of really small communities that are really struggling to pay for their water testing, let alone to build these new plants.\u201d<\/p>\n

San Luis Valley is one of the poorest rural areas of Colorado, with an estimated 21.4 percent poverty rate. Even if well users can access a water test, consistent filtration remains an economic burden.<\/p>\n

\"WaterWater from a natural spring pours out of a pipe in the town of San Luis in the San Luis Valley of Colorado. Credit: Jacob Spetzler\/Inside Climate News<\/p>\n

\"TheThe town of San Luis in the San Luis Valley, Colorado on Tuesday, May 5, 2026. Credit: Jacob Spetzler\/Inside Climate News<\/p>\n

Household reverse osmosis systems can remove up to 99 percent of contaminants, including arsenic. But they are expensive\u2014often costing thousands of dollars to install and hundreds more annually to maintain\u2014and can waste up to 80 percent of the water that passes through them. And because the San Luis Valley has moderately to extremely hard water, compounds and metals accumulate much faster on filtration systems, requiring replacement more than twice as frequently as in areas with soft water.\u00a0<\/p>\n

\u201cI come from a rural and impoverished community, and my community members can\u2019t always be changing out these filters for this reverse osmosis filtration system,\u201d Vargas said.<\/p>\n

Researchers at Arizona State University are planning to field test a new type of filter that removes a range of heavy metals from hard water systems without losing water in hopes of providing more accessible water quality mitigation for residents. Alireza Farsad, a postdoctoral research scholar at ASU who founded AmorPH2O, the company developing the filter,<\/a> expects it to be commercially available next year.<\/p>\n

Meanwhile, Vargas and James have presented the water quality study results to local county commissioners and talked with state lawmakers about the increasing concentrations of heavy metals.\u00a0<\/p>\n

But, for now, the issue has seen little action beyond testing.\u00a0<\/p>\n

\"ShirleyShirley Romero Otero, an educator and activist in San Luis, Colorado, has spent decades organizing for land and water rights in the San Luis Valley. Credit: Jacob Spetzler\/Inside Climate News<\/p>\n

For Shirley Romero Otero, a local educator and activist who helped implement James\u2019s study, water quality in the San Luis Valley is an issue of environmental justice. She says the valley, home to the state\u2019s largest native Hispanic population, is often left out of policymaking conversations.<\/p>\n

\u201cThose folks in Denver that make those decisions for testing and resources need to pay attention\u2026We are part of Colorado. We should have equality when it comes to testing and finding out what the hell is really going on,\u201d says Otero, who lives in San Luis, the state\u2019s oldest continuously occupied town, which has fewer than 600 residents.<\/p>\n

\u201cRegardless of socioeconomic status, political affiliation or racial geographic areas, water is the most precious resource that we have. It is the lifeblood of every community. You don\u2019t have water, you die. It\u2019s that simple.\u201d<\/p>\n

\"AnAn acequia, a traditional community-managed irrigation ditch that channels water from rivers and streams to farms and towns, flows into San Luis, Colorado. Credit: Jacob Spetzler\/Inside Climate News<\/p>\n

\t\t\t\t\tAbout This Story<\/p>\n

Perhaps you noticed: This story, like all the news we publish, is free to read. That\u2019s because Inside Climate News is a 501c3 nonprofit organization. We do not charge a subscription fee, lock our news behind a paywall, or clutter our website with ads. We make our news on climate and the environment freely available to you and anyone who wants it.<\/p>\n

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Thank you,<\/p>\n","protected":false},"excerpt":{"rendered":"Julie Zahringer hears a common refrain at her environmental laboratory in Alamosa, Colorado: A customer has been drinking…\n","protected":false},"author":3,"featured_media":782512,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[23],"tags":[320147,211974,320148,4439,7962,6772,746,25234,21172,166234,159,87395,67,132,68],"class_list":["post-782511","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-aquifers","tag-arsenic","tag-arsenic-water","tag-colorado","tag-drinking-water","tag-drought","tag-environment","tag-groundwater","tag-rio-grande","tag-san-luis-valley","tag-science","tag-snowpack","tag-united-states","tag-unitedstates","tag-us"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/116540371487017532","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/782511","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=782511"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/782511\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/782512"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=782511"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=782511"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=782511"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}