3-D design calculation of soil vapor extraction/injection cleanup, in layered materials.  The geologic layering is reflected in the initial contaminant distribution at the left, with dark zones indicating the greatest gasoline impacts up to 25,000 mg/kg.  At the right is the benzene "cleanup" zone around the central injection well and 2 lateral extraction wells after 1 year.  Notice the "outside-in" cleanup effect and the high effectiveness of central injection at this particular site.

Cleanup design is predicated on a very simple principle: delivery of the cleanup mechanism must be consistent with the distribution of physical and chemical controls and meet the desired time and concentration goals.  While this is simple to state, it is less simple to implement.  One difficulty is that many industry cleanup design standards, such as radius of influence, have little or no relevance to this simple principle.  While some may argue the effectiveness of nonscientific industry standards as useful and the best that can be done, it is clear from a scientific perspective that the accurate and representative methods of calculating flow and mass transfer have been available for many decades.  The environmental groundwater industry, by in large, is simply unaware of this fact and has therefore wasted billions of dollars in cleanup attempts that by scientific definition were destined to fail.  No question, just scientific fact.  What's worse is that the defensible science is really more cost effective in the long term in that quantified expectations, limitations, and uncertainties are defined up front.  Do what's necessary, no more, no less.  If nothing is necessary, do nothing.

Many of our worst contamination spills are oily substances such as fuels and solvents, and many of our most successful cleanup techniques are based on manipulation of more than one fluid phase (combinations of oil, air, and water).   This by definition means that most remediation is multiphase.  That is, essential attributes of many cleanup systems are based on multiphase flow.  Yet, environmental industry standard sampling protocols almost never include the parameters fundamental to the cleanup.  Parameters such as capillarity, interfacial and surface tensions, relative permeability, just to name a few.  Needless to say, the reason these parameters are not collected is because the industry at large is generally, though not always, ignorant of their critical control over cleanup.  Petroleum engineers collect these parameters because they earn a living by recovering oil, but most environmental practitioners are not judged by the harsh real world meter of cause & effect.  Too bad..

At AVI, we understand and apply multiphase hydraulics and multicomponent chemistry to result in sound, physically based cleanup system design.  Uncertainties and limitations are identified up front so that remediation data itself can serve as a reflection of the underlying principles and allow quantifiable identification of areas of success or failure.  Industry measures of "success" such as asymptotic and rebound evaluations, like ROI, have little relevance to real cleanup success or failure without the hydrogeologic and multiphase context.  AVI has reviewed data from sites that pass regulatory muster and have gained closure on the asymptotic principle but have no demonstrable reduction in risk or liability.  The irony, from a liability standpoint, is that failed cleanup is very easy to demonstrate.

Benefits of Multiphase/Multicomponent Remediation

• Remediation is specifically designed toward source zones
• Risk-specific compounds are targeted for cleanup
• Optimization of recovery strategies, time minimization
• Identification & demonstration of physical and chemical limitations
• Accurate sizing and costing of cleanup systems
• Quantified remediation milestones & diagnostics
• Just the facts ma'am, no B.S.; science describes reality

Browse through the remediation specific pages on the left to get a specific flavor for various remediation methods, the multiphase and multicomponent aspects, and the dollar value of a rigorous scientific approach.