UW Extension

Rocks may be culprits in groundwater contamination

Jay Zambito, assistant professor at the UW-Extension’s Geological and Natural History Survey, thinks our rocks may be the culprit in some cases of groundwater contamination.

Jay Zambito

Jay Zambito, assistant professor at the Geological and Natural History Survey.

Sandstone formations are productive drinking water sources. However, under almost half of the state, they may be sources of naturally occurring contaminants. Rocks known as the Wonewoc Formation and the Tunnel City Group contain trace amounts of metals including arsenic, cadmium, and lead. WGNHS is using rock core and drill cuttings to identify the composition of these rock formations. The cores and cuttings are stored in the Survey’s core repository.

Using our stored samples saves time and money. “It costs about $60-100 per foot to collect new drill core,” said Zambito, “Given the scope of this project, we’d be looking at spending approximately $2 million to collect these samples.”

The stored drill core in the WGNHS repository is estimated to have a value between $120-140 million. Most of which is unique and irreplaceable.

As his study progresses, he will have the baseline of what is in these rocks. Then, Zambito and his colleagues at WGNHS will be able to determine what might end up in our drinking water. For more information, go to http://aqua.wisc.edu/chronicle/Default.aspx?tabid=556 or contact jay.zambito@wgnhs.uwex.edu.