Environmental Health - Toxic Substances
New Paradigm for Fractured Rock Cleanup
Many thought that contaminated sites in fractured bedrock were so uniquely complex that there was little hope for gaining a systematic understanding of how to clean them up. Toxics Program scientists did a comparative analysis of hydraulic tests conducted in a variety of rock environments that showed predictable similarities in the hydraulic responses at each of the sites. The key to these tests was that the major fractures in the test boreholes were isolated from each other, which allowed for the collection of meaningful data. In the past, many hydraulic tests have been conducted on the full length of a borehole(s) without isolating fractures, thus masking the true response of the fractures to the test and making the problem intractable. The scientists further demonstrated that the complex properties of fractured-rock aquifers can be simulated with off-the-shelf computer models used to design monitoring, management, and remediation strategies. This knowledge is leading to an improved approach for cleaning up contamination that was once thought to be intractable.
Tiedeman, C.R., and Hsieh, P.A., 2001, Assessing an open-well aquifer test in fractured crystalline rock: Ground Water, v. 39, no. 1, p. 68-78, doi:10.1111/j.1745-6584.2001.tb00352.x.
Other USGS Information About Fractured Rock Hydrology
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