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J.E. Peterson

Publications and source records attributed to J.E. Peterson.

5 recordsLinked to original sources

Flow-Meter and Passive Diffusion Bag Tests and Potential Influences on the Vertical Distribution of Contaminants in Wells at Galena Airport, Galena, Alaska, August to October 2002

Past activities at Galena Airport, a U.S. Air Force Base in Galena, Alaska, have resulted in ground-water contamination by volatile organic compounds. The primary contaminants are petroleum hydrocarbons and chlorinated aliphatic hydrocarbons. The U.S. Geological Survey and Earth Tech, in cooperation with the Air Force Center for Environmental Excellence, conducted investigations at Galena Airport from August to October 2002 using polyethylene diffusion bag samplers and borehole flow-meter testing to examine the vertical distribution of ground-water contamination in selected wells. This investigation was limited to the vicinity of building 1845 and to the area between building 1845 and the Yukon River. In addition, the U.S. Geological Survey was asked to determine whether additional wells are needed to more clearly define the nature and extent of the ground-water contamination at the Air Force Base. Little or no vertical water movement occurred under ambient conditions in the wells tested at Galena Airport, Alaska, in August 2002. All of the ambient vertical flows detected in wells were at rates less than the quantitative limit of the borehole flow meter (0.03 gallons per minute). In wells 06-MW-07 and 10-MW-01, no vertical flow was detected. In wells where ambient flow was detected, the direction of flow was downward. In general, concentrations of volatile organic compounds detected in the low-flow samples from wells at Galena Airport were approximately the same concentrations detected in the closest polyethylene diffusion bag sample for a wide variety of volatile organic compounds. The data indicate that the polyethylene diffusion bag sample results are consistent with the low-flow sample results. Vertical profiling of selected wells using polyethylene diffusion bag samplers at Galena Airport showed that from September 30 to October 1, 2002, little vertical change occurred in volatile organic compound concentrations along the screen length despite the fact that little or no vertical flow was measured in most of the tested wells in August 2002. Two of the wells (10-MW-03 and 06-MW-01) had slightly greater vertical concentration variation for some constituents. In these wells, the contaminant depth probably is lithologically influenced. The close match between concentrations measured in polyethylene diffusion bag and low-flow samples indicates that the bag samples accurately represent the distribution of volatile organic compounds in the wells. It is unclear, however, whether the distribution of volatile organic compounds in the wells, as indicated by the bag samplers, represents contaminant distributions in the aquifer or transient movement within the wells. The probable change in well hydraulics between August and late September to October indicates that the relatively uniform vertical distribution of volatile organic compounds in some of the wells may represent in-well mixing. This uncertainty could be clarified by the installation and sampling of well clusters at various times of the year. Additional insight into the vertical distribution of contamination and flow possibly could be obtained by conducting flow-meter tests and collecting polyethylene diffusion bag samples from selected wells at different times of the year. The westernmost contaminant plume at Million Gallon Hill appears to be surrounded by sufficient monitoring wells to detect changes in the plume extent; however, the installation of additional wells at Galena Airport has the potential to provide additional information on the extent of ground-water contamination in the remaining plumes. The additional information to be gained includes better definition of the vertical and lateral extents of the plumes and better definition of the ground-water flow directions.

Open-File Report↗

Evaluation of passive diffusion bag samplers, dialysis samplers, and nylon-screen samplers in selected wells at Andersen Air Force Base, Guam, March-April 2002

During March-April 2002, the U.S. Geological Survey, Earth Tech, and EA Engineering, Science, and Technology, Inc., in cooperation with the Air Force Center for Environmental Excellence, tested diffusion samplers at Andersen Air Force Base, Guam. Samplers were deployed in three wells at the Main Base and two wells at Marianas Bonins (MARBO) Annex as potential ground-water monitoring alternatives. Prior to sampler deployment, the wells were tested using a borehole flowmeter to characterize vertical flow within each well. Three types of diffusion samplers were tested: passive diffusion bag (PDB) samplers, dialysis samplers, and nylon-screen samplers. The primary volatile organic compounds (VOCs) tested in ground water at Andersen Air Force Base were trichloroethene and tetrachloroethene. In most comparisons, trichloroethene and tetrachloroethene concentrations in PDB samples closely matched concentrations in pumped samples. Exceptions were in wells where the pumping or ambient flow produced vertical translocation of water in a chemically stratified aquifer. In these wells, PDB samplers probably would be a viable alternative sampling method if they were placed at appropriate depths. In the remaining three test wells, the trichloroethene or tetrachloroethene concentrations obtained with the diffusion samplers closely matched the result from pumped sampling. In all of the tests, the regenerated cellulose dialysis samplers produced lower VOC concentrations than the passive diffusion bag samplers and most of the pumped results. The source of the difference is unknown, but a possible explanation may be the biodegradation of the dialysis membrane during the 22 to 23 days of deployment. Chloride concentrations in nylon-screen samplers were compared with chloride concentrations in dialysis and pumped samples to test inorganic-solute diffusion into the samplers across a range of concentrations. The test showed that the results from nylon-screen samplers might have underestimated chloride concentrations at depths with elevated chloride concentrations. The reason for the discrepancy in this investigation is unknown, but may be related to nylon-screen-mesh size, which was smaller than that used in previous investigations.

Andersen Air Force Base, Guam↗

Geologic map of the Noachis Quadrangle of Mars

The Noachis quadrangle is in the anc i ent cratered highlands of Mars. Craters dominate the surface of the planet in this area; most are of impact origin, some are of volcanic, origin, and some are of undetermined origin. Martian craters are I general similar in morphology of lunar craters but are more degraded. Analogous morphologies and size-frequency distributions of lunar and Martian craters indicate that both populations are mostly of impact or i gin (McCauley and others, 1972). Martian 10 pictures of Mercury suggest similar t rends on that planet, a further indication that the crating process was exogen ous.

IMAP↗

Uranium, radium, and selected metallic-element analyses of spring water and travertine samples from the Grand Canyon, Arizona

Samples for this report were collected from springs and travertine deposits along the Colorado River in the Grand Canyon, Arizona. Sampling was done in April and May of 1976. Data obtained from these samples will be used by R. A. Cadigan and J. K. Felmlee as part of a project designed to determine the value of subsurface waters in prospecting for uranium deposits. Sample sites were preselected at approximately equal intervals, but river conditions and accessibility forced some modification of the sampling plan at each spring visited, a 2-liter untreated water sample was collected to be analyzed for uranium and radium. At two of the sample locations, an additional 4-liter water sample was collected, filtered, acidified, and later analyzed for the 24 additional elements listed in table-2. A more detailed description of the sampling technique is presented in Brown and others, 1970. All samples were placed in full, tightly capped plastic containers. Temperature and conductivity were measured in the field. Measurements of the pH of the non-acidified samples were made in the laboratory a few weeks after the samples were collected. An effort was made to collect the freshest possible travertine samples, but the freshness of the samples varied, as noted in the descriptions of the sample sites. Analyses were performed by laboratories of the U.S. Geological Survey. Radium values were determined by radiochemical methods; uranium, by extraction fluorometry; eU (equivalent uranium), by beta-gamma count; and other elements, by semiquantitative emission spectrography. Table 1 is a description of the sample sites. The analytical results for spring water are presented in table 2. Table 3 gives the analyses of the travertine samples.

Arizona↗