College of Liberal Arts and Sciences at Iowa State University

Water quality

Bill Simpkins leads three-year study to determine just how good Ames' water is.
Even with the popularity of bottled water, the City of Ames is concerned with the quality of the city's drinking water.

And they have turned to Bill Simpkins, professor of geological and atmospheric sciences, for the answer.

For the next three years, Simpkins will be conducting a study of the quantity and quality of the groundwater available to Ames for drinking water.

"We went to the city with a plan to reexamine the water supply," Simpkins said. "It's been more than 10 years since the last study and one of my concerns is that while the city has a great water supply from the Ames aquifer, it's only a matter of time before others will want to use that water source."

One potential user is an ethanol-producing plant, many of which are springing up throughout the Midwest. Estimates vary, but it can take as little as four to as much as 37 gallons of water to produce one gallon of ethanol.

"That's a lot of water and companies will be looking to locate such plants in locations with a good aquifer, such as Ames," Simpkins said.

The Ames City Council agreed that a study was needed and is funding Simpkins' study to the tune of $125,000. He is seeking almost $100,000 more in research grants to complete the project.

The study has begun with the investigation of the hydrogeology of the Ames aquifer and includes an examination of groundwater flow and nutrient transport to the lakes in Ada Hayden Heritage Park. The lakes currently serve as the backup water supply for the city.

Last April 16 monitoring wells were installed at Ada Hayden in five different locations as a result of Simpkins' project.

Not only will the wells and computer models help Simpkins and graduate student Evan Christianson determine the source and direction of groundwater flow but the groundwater quality as well.

"We should be able to get an idea of what the concentration of the nitrogen and phosphorus is in the groundwater entering and exiting the lake," Simpkins said. "This is critical to understanding whether groundwater can contribute nutrients that might degrade water quality."

Less than 12 months into the three-year study, Simpkins says the study at the Ada Hayden well sites is already producing results.

"It's early but our preliminary data seems to indicate that the groundwater in the Ada Hayden lakes comes from the northwest and southwest sides and flows out of them from the east and southeast sides," Simpkins said. "The shape of the underlying bedrock valley is also a bit different than has been assumed for the past 30 years.

"There's a ton more work still to do however. This study should provide great insights into the water supply potential of these systems and into the interaction of bedrock and alluvial aquifers in Iowa."

Those include regular monitoring of the groundwater levels and trying to better visualize configuration of the buried valley underneath the park.

"We have to get the configuration of underlying bedrock surface just right in order for Evan's groundwater model to simulate realistically the groundwater interaction with the lake."

There are benefits as well for hydrogeology students.

"I used this in our Field Methods in Hydrogeology course in the summer," Simpkins said. "In the long term I would like to develop the Ada Hayden site as an educational site for that and my other classes."