Time - How quickly do PAH contaminants from pavement sealants wear off a sealed lot?

There are a variety of forces that wear sealant off of lots and driveways, but the abrasion of tires is probably the dominant one.  In temperate northern climates, snow plows are probably another major factor.  The City of Austin did a photographic coal tar sealant wear study, finding that drive areas wear at about 5% per year, and parking areas at about 1.5%, with an average of about 2.5% per year.  A study in 2010 by the University of New Hampshire found that export of PAHs off of parking lots was much greater in the first three months (1357ug/L) than in the two years following application (17-116 ug/L), although elevated concentrations (52ug/L) of PAH from coal tar lots can persist for at least 5 years (Selbig, 2005).