In September 2021, Donala Water and Sanitation District, which serves the area between southern Monument and Gleneagle, informed its customers that their drinking water had high levels of radium and might want to switch to an alternative drinking supply. Donala gets its water from the Denver Basin.

In 2020, the Town of Monument water district informed its residents that their water had a high percentage of radium. That was not the first time Monument faced elevated levels of radium.

In 2016, the Colorado Department of Public Health and Environment (CDPHE) informed the Town of Monument Water Department that it had exceeded the maximum contaminant level of radium. Like Donala, Monument gets its water supply from nine wells tapped into groundwater aquifers in the Denver Basin.

In 2020, the Woodmoor Water and Sanitation District (WWSD) published a report that found in 2019, all of its wells, except Well 7, had elevated levels of radium. WWSD’s groundwater wells are in the Denver Basin. But, because WWSD water sources include both groundwater (from wells) and surface water (Lake Woodmoor, Monument Creek), it can blend its water and lower the overall radium to acceptable drinking levels.

WWSD’s report showed that from 2016 to 2019, radium levels increased in all of its wells. So, the question is, what’s going on with Colorado’s water?

Decreasing Water in the Denver Basin

In El Paso County, many people get their water from domestic wells or from utility companies that operate wells. The Denver Basin Aquifer System (DBAS) supplies these wells.

The DBAS stretches from Greeley on the north to Colorado Springs on the south, and from the Foothills on the west to Limon on the east, according to the Colorado Division of Water Resources. DBAS includes four sandstone aquifers, starting from the top and going down: Dawson, Denver, Arapahoe, and Laramie-Fox Hills.

Suffice it to say, the DBAS is massive, and many might assume it’ll supply water to Colorado residents indefinitely. But, according to a United States Geological Survey (USGS) report, that’s not the case.

The study, overseen by the Associate Director of Hydrologic Studies at the USGS Colorado Water Science Center, Suzanne Paschke, was a large-scale multidisciplinary study of groundwater availability in the Denver Basin Aquifer System. It found, “Bedrock groundwater storage is being depleted in the Denver Basin. While the length of time over which this resource may be available is uncertain, the conclusions of this and other studies indicate that pumping from the Denver Basin bedrock aquifers is not indefinitely sustainable and that renewable water supplies will be needed in the future.”

Some models in the study showed the basin going dry in 50 years depending on growth and pumping. Paschke conducted the study in 2004, before the boom in Colorado’s population — from 2010 to 2020, the population increased by 14.8 percent, compared to the national average of 7.4 percent.  

Additionally, in 2019, the American Water Resources Association (JAWRA) published a study that evaluated groundwater storage changes in the DBAS between 1990 and 2016. Using spatiotemporal geostatistical analysis, JAWRA concluded that groundwater storage was depleting, and it was due to “population growth increasing the demand for water, variable precipitation, and drought influencing recharge, and increased groundwater pumping.”

Non-Renewable in Our Lifetime

According to Cherokee Metropolitan District water engineer Kevin Brown, water trickles down to bedrock aquifers, like DBAS, but it takes a significant amount of time. “It just takes a very, very long time and it happens very slowly, and especially happens slowly compared to how quickly we’re withdrawing water, to the point where they are effectively not being recharged. This water would recharge, but not in a human time timescale,” Brown said to CPR News.

In other words, Colorado residents are draining the DBAS at an unsustainable rate. And the results are starting to show up.

“We had one well that was producing initially around a hundred gallons a minute. We’re lucky to get 40 gallons a minute out of it right now. It’s really a diminishing return that you get on Denver Basin groundwater these days. Every well you drill, you get less and less yield out of, and it takes more and more wells just to maintain your current level of water supply.” said Jessie Shaffer, the manager of the Woodmoor Water and Sanitation District. 

In addition to wells suffering from diminishing production, water and sanitation companies blame increased water demand for increasing radium. KRDO reported that Donala said high water demand was “stirring up” radium in the Arapahoe Basin aquifer, leading to increased radium.

But, researchers from USGS examining water in the Cambrian-Ordovician aquifer pointed to a more scientific explanation. They found water that seeped into aquifers long ago contains higher amounts of dissolved minerals and is low in dissolved oxygen. That results in water that is more likely to leach radium from its surrounding rocks.

Colorado’s Water Problems

Increased radium in drinking water is only one aspect of Colorado’s decreasing water supply. Plus, radium is filterable with the right equipment.

The bigger problem is that you can’t live without water, and Coloradans rely on a diminishing resource. Thus, what happens when the Denver Basin Aquifer System runs dry?

Colorado also struggles with water issues with its neighbor, Nebraska.

The Maverick Observer is an online free-thinking publication interested in the happenings in our region. We launched in February 2020 to hold our politicians and businesses accountable. We hope to educate, inform, entertain, and infuse you with a sense of community.