"We don't know how fast the soup changes or in what ways," she explained. "It may be that it completely self-cleanses through the soil by the time it reaches groundwater. It may be that it doesn't. But in the absence of replacing leaking pipes and excavating or pumping away all industrial pollution, which isn't going to happen, we need to know what's going on and how to make the preferred outcomes processes that could obliterate the soup, many of which are naturally occurring happen better and faster."
"I'm hoping that we can learn enough about the rate and extent of natural attenuation processes to discover passive, or minimally engineered, solutions," Holden added. For instance, there may be cost effective ways to manipulate subsurface soils which, she said, are teeming with microorganisms that can destroy all sorts of pollutants versus the more expensive approach of "pumping things out and treating them."
With the ultimate goal of informing and influencing how groundwater is protected in the future, Holden said the ideal outcomes would be ones that are affordable and simple.
"We hope to find situations where, as pollutants migrate from beneath the pavement or infiltration basins (as in the case of low-impact development options for stormwater) downward to groundwater, there's enough natural attenuation that the contamination never actually reaches groundwater," she explained. "Then, if we can understand how to make this happen in a variety of field situations, we've got something that's really important for c
|Contact: Shelly Leachman|
University of California - Santa Barbara