Everything people do on land affects water and groundwater.
That was the theme of a groundwater conference held by the University of Delaware Sea Grant Program earlier this summer.
“The marketplace treats water as a free resource, so we tend to waste it,” said Jerry Kauffman, of the University of Delaware Institute for Public Administration/Water Resources Agency. He said clean water is key to the state’s economy.
Groundwater is both the source of drinking water and the method of disposing of wastewater, said Scott Andres, hydrogeologist with the Delaware Geological Survey. There is plenty of water to be had, he said, but the challenge is protecting public and environmental health.
As nutrient-pollution limits increase the cost of septic, land-based disposal systems are becoming more economically appealing, said Andres.
Different methods of disposal add different amounts of water to the groundwater system. They also add contaminants, including nutrients, household chemicals and pharmaceuticals. Andres said there is no data yet on the human health effects of those pollutants.
Scott Ator, hydrogeologist with the United States Geological Survey, said chemicals reach groundwater from soils, fertilizer, manure and pesticide applications, urban activities and sewage disposal. The peninsula remains largely agricultural, said Ator, but land use is diversifying with development.
Land use adds pollutants to groundwater, and, when the flow of water changes, so do rates of natural filtration, said Ator. Less natural filtration could mean fewer contaminants are pulled out of the water.
Ator said scientists testing groundwater are finding various chemical compounds, including pesticides and the daughter compounds they morph into as they break down.
They also find nutrients and other material fr