On a small, homemade barge, built from the skeleton of an old ship, a gray slurry of bay bottom sand flows out of a pipe into a bucket. Two scientists, a well driller and two student interns drill a hole in the floor of the Indian River Bay. They’ll install a very long pipe into the hole and use it to monitor groundwater – how much flows into the bay, how salty it is and how many nutrients it carries with it.
University of Delaware scientist Holly Michaels stands on deck, donning an orange hard hat. She’ll take data accumulated from this and other wells, onshore and offshore, and put them into a computer model that will explain the way fresh groundwater reaches the estuary.
“Basically, we’re trying to understand how groundwater flows into the bay and what happens to the nutrients it carries,” she said.
“The big reason we’re doing this is to study the nutrients in groundwater. The big one is nitrate,” she said. Nitrate is the compound that encourages excessive algae growth in the bays and leads to low levels of dissolved oxygen, which kill fish. Michaels said she and her team hope the model they create from several years of taking data will help scientists estimate and predict the nutrients that enter the bay through groundwater.
Michaels said scientists will also test the groundwater to see how old it is. That’s something that can help scientists and policymakers understand when they should start seeing results from nutrient-reducing measures on land. Scientists rely on chemicals in water to help estimate its age, said Scott Andres, hydrologist with the Delaware Geological Survey. He said there is no way to determine water’s absolute age.
The well is tens of feet long, a skinny white pipe punctuated in seven places by fine mesh screen. At the end is a ser