Study finds Iowa groundwater is extracted at unsustainable rate

The Jordan Aquifer lies beneath most of Iowa; locations with water use permits for tapping into the aquifer are shown above. (Iowa DNR)
Jenna Ladd | February 7, 2017

A recent study found the groundwater in Iowa’s Jordan Aquifer to be much older than previously known, and scientists say that could have implications for water use in the state.

Researchers from the Iowa Geological Survey at the University of Iowa in collaboration with Grinnell College, the UI Geology Department and Iowa Department of Natural Resources used isotopic age dating to estimate the age of groundwater in the Jordan Aquifer. The study measured major and minor ions, stable isotopes (d18O and dD) and
the radioactive isotope Chlorine 36 in eight wells scattered across the aquifer. The peer-reviewed journal article explains that the groundwater in northern and central Iowa is somewhere between 70,000 to nearly 180,000 years old.

The study points out that ethanol production in the state relies heavily on groundwater from the Jordan aquifer, which also provides roughly 300,000 residents with drinking water. From 2003 to 2013, annual use of groundwater from the aquifer for ethanol production increased by 7.4 billion liters per year.

Keith Schilling is a research scientist at the Iowa Geological Survey at the University of Iowa and the study’s leading author. He said,

“The implications for biofuel refineries and any water use of the aquifer is the realization that the groundwater is very old. It is not going to be recharged in any human timeframes so we should make sure that water from the aquifer is being managed appropriately.”

Beyond the lagging groundwater regeneration rate, the study also notes that increased groundwater pumping can result in detrimental water quality changes such as radium contamination. The authors conclude with a call for new ethanol refineries to steer clear of the Jordan Aquifer and utilize more sustainable groundwater sources instead.

Iowa DNR worried about state’s water supply

Photo by whatmeworry101, Flickr.

The Iowa Department of Natural Resources is concerned that Iowa’s underground water supplies might not be sufficient enough to meet the demand created by urban sprawl and a growing biofuels industry.

These concerns stem from the DNR’s effort to inventory and measure Iowa’s network of aquifers – a project that began four years ago, and is the first large-scale effort of it’s kind.

“We can now look 20 to 30 years into the future with the models we are developing,” state geologist Robert Libra said. “We’re telling people, ‘You may not be able to produce the water you’re counting on.’ It’s a call to take a smart tool and plan. These towns need water. The towns need businesses. The businesses need water.”

For more information, read the full article at the Des Moines Register.