Drilling from barge using ATV-mounted rig (supplied by USGS-WRD-Northborough, MA) to collect groundwater samples from beneath Salt Pond, Salt Pond Bay, and connecting channel.
Location
Salt Pond, Salt Pond Channel, Salt Pond Bay, Cape Cod National Seashore, Massachusetts, United States, North America, North Atlantic;
Summary
Article for Soundwaves by John Bratton, September 9, 2005: Drilling for Submarine Ground Water in Old Cape Cod. In order to test some hypotheses about groundwater flow under and into an estuary at Cape Cod National Seashore, and to constrain results of previous modeling efforts, an interdisciplinary USGS science team conducted a drilling operation in late August (22-26). National Park Service managers are concerned about nutrients that are entering the estuary via submarine groundwater discharge that are leading to eutrophication and harmful algal blooms. The team used a USGS ATV-mounted drilling rig secured to a barge (Fig. 1) to advance an electrical resistivity probe or collect submarine groundwater samples at seven sites in Salt Pond, Salt Pond Channel, and Salt Pond Bay (Fig. 2). Results are consistent with surface electrical resistivity data collected in 2004. Sampling and geophysical measurements indicate that Salt Pond, a kettle pond that has been breached by rising sea level, is underlain by brackish ground water in sediments to a depth of about 45 feet below the sediment surface. The channel connecting the pond to the bay has nearly fresh water at shallow depths (10 feet below sediment surface or less). Most surprisingly, Salt Pond Bay is underlain by a layer of fresh ground water over 50 feet thick as far offshore as measured (about 1300 ft). Groundwater sampling was conducted by John Bratton, John Crusius, and Dirk Koopmans (USGS-GD-Woods Hole). Andy Massey (USGS-WRD-MA/RI) operated the drill rig and Tim McCobb (USGS-WRD-MA/RI) operated the resistivity probe. Contractors Mark Avakian and Len Perry (TG&B, Inc.) operated the barge and secured anchors and spuds. Divers Michael Casso and Sandy Baldwin (USGS-GD-Woods Hole) helped remove drill pipe left in the pond after drilling was complete (Fig. 3). John Colman and Denis LeBlanc (USGS-WRD-MA/RI) provided helpful input during the design and implementation stages of the field effort. The work was supported by the Coastal and Marine Geology Program, and the MA-RI Water Science Center. Captions: Fig. 1 Andy Massey (USGS-WRD-MA/RI) operates a drilling barge that is temporarily stranded during low tide on a mudflat at Cape Cod National Seashore. Fig. 2 Approximate drilling locations in Salt Pond, Salt Pond Channel, and Cape Cod Bay. Fig. 3 Divers Michael Casso and Sandy Baldwin (USGS-GD-Woods Hole) prepare to enter Salt Pond to remove submerged drill pipe near the center of the pond.
Comments
Original Center People field contained: John Bratton, chief scientist; John Crusius, project scientist; Dirk Koopmans, technician, mobilization, laboratory analysis; Michael Casso and Sandy Baldwin, diving to cut off one drilling pipe.
Project = Coastal Ground-Water Systems, Coastal Ground-Water Systems
Andy Massey, USGS-WRD, drill rig operator; Tim McCobb, USGS-WRD, Geoprobe resistivity probe; Nancy Finley and John Portnoy, NPS contacts; Mark Avakian and Len Perry, barge contractors
