Research Study: Microplastic Contamination Found in Groundwater

Feb 7, 2019, 10:58 AM
Feb 7, 2019, 11:00 AM

“Microplastic Contamination in Karst Groundwater Systems” Published in the National Ground Water Association’s Preeminent Technical Journal, Groundwater


(WESTERVILLE, OH – Feb. 7, 2019) – While it is widely known discarded plastic debris and microplastic contamination is widespread in surface water and aquatic ecosystems worldwide, an eye-opening study in Groundwater, the National Ground Water Association’s (NGWA) leading technical journal, indicates the presence of microplastics in the groundwater aquifers we use for drinking water as well.

Led by a team of eight researchers, including NGWA member Walton R. Kelly of the Illinois State Water Survey, the study found microplastic contamination in groundwater through karst aquifers, or open limestone systems that constitute about 25 percent of global drinking water. In the study, 16 out of the 17 groundwater samples collected from springs and wells from two karst aquifers in Illinois contained both microplastics and other contaminants like pharmaceuticals and personal care products.

According to the research, the open nature of karst aquifers makes them vulnerable to the rapid transport of surface-borne contaminants in dissolved and particulate forms. In addition to being important drinking water resources, kart ecosystems are habitats for rare faunal species that may be susceptible to contamination.

“In addition to the consumption of the particles themselves, microplastics may also be substrates that adsorb other contaminants such as pharmaceuticals, metals, or pathogenic microbes. From an ecological point of view, karst groundwater often discharges from springs to surface water, meaning microplastic contamination may be transferred to and affect the vulnerable ecosystems within the karst systems,” said Kelly.

While the study focused on two aquifers in Illinois, Kelly hypothesizes microplastic contamination could be a broader issue. “Karst systems are found around the world, and in the United States they are prevalent in the Midwest, Southeast, and Texas, with Florida made up of nearly 100 percent karst systems. Because these are notoriously vulnerable to contamination, there’s every reason to expect to find microplastics in other karst aquifers.”

The major question? What does this mean for human and ecosystem health? According to Kelly, this critical question needs to be further explored, citing a call for research in The Lancet Planetary Health titled Microplastics and human health – an urgent problem.

As the research around microplastic contamination in karst aquifers and the potential health effects continues, Kelly says the ability for consumers to test or remediate microplastics in their water systems could be met with varying success.

“Some of these microplastics are actually visible to the naked eye; however, identifying and enumerating the contaminants is a specialized and time-consuming process with very few laboratories able to conduct this analysis for the public. Point-of-use filters could possibly remove any particles, but I don’t personally know of any certified products on the market.”   

Since plastics started being manufactured around 1950, humans have created more than 8,300 million metric tons of them. Of that, around 6,300 metric tons is waste, and only nine percent has been recycled. As much as 79 percent has ended up in landfills or in the natural landscape, including surface waters.*

In addition to Kelly, the research team included Samuel V. Panno, Illinois State Geological Survey and lead author; John Scott, Illinois Sustainable Technology Center; Wei Zheng, Illinois Sustainable Technology Center; Rachel E. McNeish, California State University; Nancy Holm, Illinois Sustainable Technology Center; Timothy J. Hoellein, Loyola University, Chicago; and Elizabeth L. Baranski, League of Women Voters of Jo Daviess County.

Full Article: Microplastic Contamination in Karst Groundwater Systems – available free for a limited time through the Wiley Online Library.

Since 1963, Groundwater has published a dynamic mix of papers on topics focused on groundwater such as flow and well hydraulics, hydrogeochemistry and contaminant hydrogeology, application of geophysics, management and policy, and the history of hydrology.



The National Ground Water Association is a not-for-profit professional society and trade association for the global groundwater industry. Our members around the world include leading public and private sector groundwater scientists, engineers, water well system professionals, manufacturers, and suppliers of groundwater-related products and services. The Association’s vision is to be the leading groundwater association advocating for responsible development, management, and use of water.