Well, I recall inspecting a wastewater treatment plant in my early regulatory compliance days with a state environmental agency and on the desk of the plant operator was this sign which read, "It may be sh#t to you, but its bread and butter to me"....................
With that said, I have been cleaning up contaminated aquifers from various chemical releases for over 30-years now and when you bring up dry cleaning fluids often referred to in our industry as DNAPL's (dense non-aqueous phase liquids) your talking about real challenges. Dry cleaners used perchloroethylene (perc) for decades before moving on to innocuous cleaners. Besides the old pump and treat methodologies the latest technologies deal with stimulating bacteria with hydrogen release compounds that literally digest the chlorinated solvents. Once the contaminant plume has been delineated through a series of groundwater wells, the hydrogen release compound is injected through a network of injection wells. The "natural occuring" anaerobic bacteria that is stimulated is dehalococoites (sp?), which seems to love chlorinated solvents. DNA testing is used to assess colony populations of the bacteria, however, more critters can be injected into the aquifer as well. The solvents will break down over time. Amazing, a bacteria that will digest chlorinated solvents! The technology was attributed to a Georgia Tech Professor who discovered the benefit of the bacteria during experiments with treatment plant digesters.
Pretty interesting stuff. The military is tackling the issue as every base in the country that has a drycleaning facility has had some release into the environment of perc.
Next time you go to an older dry cleaner, stop and take a look at the parking lot your in, chances are your environmental regulatory agency had a geoprobe punch a hundred holes through it to find this nasty stuff.
Bob
73.5T
