Robowell Featured in the Water Tech On-Line News 02/19/2001

PROVINCETOWN, MA — The Provincetown Water Department, the US Geological Service (USGS) Technology Enterprise office and the USGS Massachusetts-Rhode Island Water Science Center Project for Analysis of Water Resources in the lower Cape Cod aquifer system are teaming up to monitor how much saltwater is seeping into the groundwater.

The groups will be using an automated sampling machine, called Robowell, to track the water quality readings and provide comparable results for sampling methods. Robowell pumps and purges the well in each measurement cycle.

The agencies hope that the real-time monitoring will provide reliable information that can be used by the town, the USGS Project for Analysis of Water Resources in the Lower Cape Cod Aquifer System, and the USGS Groundwater Resources Program Regional Assessment of the Freshwater-Saltwater Interactions along the Atlantic Coast, to better understand the processes in play and to better manage the available water resources on Cape Cod.

"Groundwater resources along the Atlantic coastal zone of the United States are vulnerable to saltwater intrusion, which is the movement of saline water into freshwater aquifers," said Paul Barlow, the Atlantic coastal zone assessment coordinator for the USGS in Northborough, MA. "Saltwater intrusion is most commonly caused by groundwater pumping near the coast, and the resulting high salinity can make groundwater unfit for public consumption."

The Robowell prototype is monitoring groundwater quality below the screen zone of a public supply well to help establish the position of the freshwater-saltwater interface.

"Groundwater pumping can reduce freshwater flow toward coastal discharge areas and cause saltwater to be drawn toward the freshwater zones of the aquifer," Barlow said.

Saltwater intrusion decreases freshwater storage in the aquifers and, in extreme cases, can result in the abandonment of supply wells, according to Barlow.

For more detailed information about the testing process, visit http://water.usgs.gov/ogw/gwrp/saltwater/ or http://ma.water.usgs.gov/automon/Ptown.htm