Development and Research: Passive-Vapor-Diffusion Sampler Delineating Discharge Areas of Contaminant Plumes with Passive-Vapor-Diffusion Samplers in Johns Pond, Cape Cod, Massachusetts CLICK PHOTOS FOR AN ENLARGED VERSION
View of Massachusetts Military Reservation and Ashumet Pond, Cape Cod, Massachusetts. Johns Pond is in lower right corner.	Close-up of passive-vapor-diffusion sampler.	Photo and schematic of passive-vapor-diffusion sampler.
Passive-vapor-diffusion samplers with (A) vial and screw cap, (B) uncapped glass vial sealed in polyethylene tubing and secured to wire surveyor flag, and (C) glass vial sealed in polyethylene sandwich bags and secured to wire surveyor flag (figure from WRIR 02-4186)	Connecting passive-vapor-diffusion samplers to a line before placement in bottom sediments of Johns Pond, Cape Cod, Massachusetts.	Lowering line with diffusion samplers attached to the bottom of Johns Pond, Cape Cod, Massachusetts.
Scuba divers getting ready to place diffusion samplers into bottom sediments of Johns Pond, Cape Cod, Massachusetts.	Scientists collecting ground-water samples from the pond bottom at Johns Pond, Cape Cod, Massachusetts, with a drive-point sampling well to confirm the data obtained with the diffusion samplers. Savoie and others (2000) describe the drive-point sampling wells.	Map of the Storm Drain-5 (SD-5) plume on the Massachusetts Military Reservation, Cape Cod, Massachusetts.
Map of the extent of discharge for storm drain-5 (SD-5) plume in Johns Pond, Massachusetts. Contour lines are TCE concentrations in parts per billion (ppb). Note the TCE "hot spot" separate from the main discharge area. Further investigations showed that the "hot spot" was from another plume.	West to east cross-section of trichloroethylene (TCE) plume. Plume is flowing under Ashumet Pond and discharging to Johns Pond, Cape Cod, Massachusetts. The TCE plume was identified as a branch of the chemical spill-10 (CS-10) plume.	Map of subsurface plumes and discharge areas in the Johns Pond, Massachusetts, area. Black dots are locations of diffusion samplers. The TCE plume flows under Ashumet pond and over the top of the storm drain-5 (SD-5) plume. The TCE plume was identified as a branch of the chemical spill-10 (CS-10) plume.
Map of the chemical spill-10 (CS-10) and storm drain-5 (SD-5) plumes on the Massachusetts Military Reservation (MMR) and the discharge areas in Johns Pond, Cape Cod, Massachusetts. Contour lines are water-table elevations in feet above sea level.	Location of diffusion samplers in Snake Pond, Cape Cod, Massachusetts used to delineate contaminated ground-water discharge areas Modified from WRIR 03-4133

More Information

• Information on Diffusion Samplers in Ground Water (includes users guide)
• Church, P.E., Vroblesky, D.A., and Lyford, F.P., 2002, Guidance on the use of passive-vapor-diffusion samplers to detect volatile organic compounds in ground-water-discharge areas, and example applications in New England: U.S. Geological Survey Water-Resources Investigations Report 02-4186, 79 p.
• Leblanc, D. R., 2003, Diffusion and Drive-Point Sampling to Detect Ordnance-Related Compounds in Shallow Ground Water Beneath Snake Pond, Cape Cod, Massachusetts, 2001-02: U.S. Geological Survey Water-Resources Investigations Report 03-4133, 25 p.
• Savoie, J.G., LeBlanc, D.R., Blackwood, D.S., McCobb, T.D., Rendigs, R.R., and Clifford, Scott, 2000, Delineation of discharge areas of two contaminant plumes by use of diffusion samplers, Johns Pond, Cape Cod, Massachusetts, 1998: U.S. Geological Survey Water-Resources Investigations Report 00-4017, 30 p.
• Sewage-Contaminated Ground Water -- Cape Cod , Massachusetts, A Toxics Program Investigation