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Diffusion sampler testing at Naval Air Station North Island, San Diego County, California, November 1999 to January 2000

Water-Resources Investigations Report 2000-4182
Prepared in cooperation with the Southwestern Division Naval Facilities Engineering Command
By:  and 
https://doi.org/10.3133/wri20004182

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Abstract

Volatile organic compound concentrations in water from diffusion samplers were compared to concentrations in water obtained by low-flow purging at 15 observation wells at the Naval Air Station North Island, San Diego, California. Multiple diffusion samplers were installed in the wells. In general, comparisons using bladder pumps and diffusion samplers showed similar volatile organic carbon concentrations. In some wells, sharp concentration gradients were observed, such as an increase in cis-1,2-dichloroethene concentration from 100 to 2,600 micrograms per liter over a vertical distance of only 3.4 feet. In areas where such sharp gradients were observed, concentrations in water obtained by low-flow sampling at times reflected an average concentration over the area of influence; however, concentrations obtained by using the diffusion sampler seemed to represent the immediate vicinity of the sampler. When peristaltic pumps were used to collect ground-water samples by low-flow purging, the volatile organic compound concentrations commonly were lower than concentrations obtained by using diffusion samplers. This difference may be due to loss of volatiles by degassing under negative pressures in the sampling lines induced while using the peristaltic pump, mixing in the well screen, or possible short-circuiting of water from an adjacent depth. Diffusion samplers placed in buckets of freephase jet fuel (JP-5) and Stoddard solvent from observation wells did not show evidence of structural integrity loss during the 2 months of equilibration, and volatile organic compounds detected in the free-phase fuel also were detected in the water from the diffusion samplers.

Suggested Citation

Vroblesky, D.A., Peters, B.C., 2000, Diffusion sampler testing at Naval Air Station North Island, San Diego County, California, November 1999 to January 2000: U.S. Geological Survey Water-Resources Investigations Report 2000-4182, iv, 27 p., https://doi.org/10.3133/wri20004182.

Study Area

Table of Contents

  • Abstract
  • Introduction 
  • Methods 
  • Results and Discussion
  • Summary
  • References
Publication type Report
Publication Subtype USGS Numbered Series
Title Diffusion sampler testing at Naval Air Station North Island, San Diego County, California, November 1999 to January 2000
Series title Water-Resources Investigations Report
Series number 2000-4182
DOI 10.3133/wri20004182
Year Published 2000
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) U.S. Geological Survey, South Atlantic Water Science Center
Description iv, 27 p.
Country United States
State California
County San Diego County
Other Geospatial Naval Air Station North Island
Additional publication details