Environmental engineering graduate student Daria Dilparic works at the Ames Water Plant to monitor forever chemicals in the city's water. Photo by Christopher Gannon.
What started as a weekend job for Daria Dilparic turned into a key role in ensuring the safety of Ames drinking water -- the provider of water to campus.
Questions?
For more information about Ames' drinking water, call the water plant at
239-5150.
"Originally, my project was to look at how PFAS transform in wastewater across plants in Iowa," she said. "When my professors found out I was already working for the city, they wanted me to do a project with the department."
For about a year, the environmental engineering graduate student has been sampling water from each of the city's 22 wells looking for Per- and Polyfluoroalkyl Substances (PFAS) -- commonly called forever chemicals. She wants to determine how prevalent they are in the water and how the contamination enters the water source.
Results
Consistent testing for forever chemicals in drinking water allowed the Ames Water Plant to comply with proposed federal standards (see chart) of maximum allowable levels of the chemicals.
On March 14, the Environmental Protection Agency (EPA) proposed national primary drinking water regulations for six PFAS chemicals. Levels for two of the forever chemicals were set at less than 4.0 parts per trillion, and Ames recorded marks of zero and 1.36 parts per trillion in 2022.
The proposal is in a public comment period until May 30 and could be finalized by the end of the year. EPA leaders said adopting the regulations would prevent thousands of deaths and reduce serious PFAS-related illnesses -- like liver disease, thyroid disease and cancer -- by tens of thousands.
"In December 2021, the Iowa Department of Natural Resources tested four of our wells and found an elevated level of PFAS in one of them," said Ames water and pollution control department assistant director Lyle Hammes. "That led to required testing on a quarterly basis. We then tested all of our wells and discontinued using the well with the highest level of PFAS."
The city's water service draws water from wells drilled into an alluvial aquifer under the city and serves Iowa State and those within the Ames corporate limits. Testing at the wells helps identify issues before water reaches the water plant and becomes much more costly to remove, Hammes said.
Impact
Dilparic splits work time between collecting samples and analyzing water using liquid chromatography-mass spectrometry -- the process to identify PFAS in water. Iowa State owns the highly sophisticated equipment needed to do this, and she is one of four students in the civil, construction and environmental engineering department capable of operating it.
"We visited one of the demo labs of the company we bought it from and they taught us about the equipment -- basic maintenance and operation," she said. "When we got it set up, they sent out a representative and technician to help guide us."
Dilparic's ability to use the equipment benefits the water plant because most cities have to send samples to an EPA-certified lab to complete the tests.
Tracking the level of compounds in each well gives water plant staff a better idea of water quality by the time it reaches the plant. Dilparic said regulations for forever chemicals in drinking water would be a step forward for the nation's water supply.
"If the maximum contaminant levels are set, it would impact every water utility, because current health advisories are not enforceable," she said. "Just like with all contaminants, there is a path forward with PFAS."
Graphic by Deb Berger.
Related essay
- Daria Dilparic writes about her experiences as an Iowa State student and student operator for the city, Nov. 4, 2022
