If some $40,000 spread over a three-year period for water quality testing seems high, consider the cost of drilling new wells to do the same testing that would have cost hundreds of thousands of dollars.
But thanks to equipment being used around the Island by the United States Geological Survey (USGS), at least 20 sites are being tested by computer mapping for saltwater intrusion into wells with no drilling, according to lead USGS scientist Fred Stumm.
The equipment enables the team to track depths to 800 feet. The more sites the scientists are able to test, the better the data will be that they can provide to the town’s Water Advisory Committee, Mr. Stumm said.
This is the first step in an ongoing process of water quality testing, he said. In the future, tests will involve taking water samples around the Island to determine nitrogen content and other possible contaminants that could be affecting well water.
Mr. Stumm and colleagues Michael Como, Robert Welk and Marie Zuck were in field at Sylvester Manor last week using TDEM Technology — Time Domain Electromagnetic surface geophysical methodology. They have also tested at Klenawicus Field and a number of privately owned sites around the Island.
Testing involves creating a wire area on top of the ground surface to form a square that could be as small as 120 feet or as large as 300 feet, then using a car battery to run current through the wire at computer-controlled intervals.
“Compared to a cell phone, it’s practically harmless,” Mr. Stumm said of the magnetic field created with the equipment.
The Water Advisory Committee has determined that the sites are providing good data, according to member Greg Toner. He and member Ken Pysher have provide reports from USGS data to help inform town officials about drought conditions and, most recently, about the quality of water on the Island.
They’re hoping more land owners with 100 square flat sites with few trees will volunteer use of fields for testing.
Mr. Stumm pointed out there is no damage to property. It takes the team less than an hour to set up a site and another hour to complete tests and dismantle the equipment.
“It’s a great way to monitor the subsurface,” Mr. Stumm said.
He tracks signals from the equipment that indicate the presence of clay, an indication that water is not flowing or flowing at a very slow rate. When the team hits clay or saltwater, the signals don’t go through efficiently, providing an accurate reading of where interfaces between fresh and saltwater are located.
If you have a property that fits the parameters for testing and are willing to cooperate, you can reach Mr. Toner at (631)749-2032. He advises leaving your name, address, phone number and email contact so the USGS can determine whether the site is appropriate for testing.