title: A photographic method for estimating wear of coal tar sealcoat from parking lots.
abstract: Coal-tar-based sealcoat has been recognized as an important source of PAHs to the environment through wear and transport via stormwater runoff. Sealcoat removal rates have not been measured or even estimated in the literature due to the complex array of physical and chemical process involved. A photographic study was conducted that incorporates all sources of wear using 10 coal tar-sealed parking lots in Austin, Texas, with sealcoat age ranging from 0 to 5 years. Randomly located photographs from each parking lot were analyzed digitally to quantify black sealed areas vs lighter colored unsealed areas at the pixel level. The results indicate that coal tar sealcoat wears off of the driving areas of parking lots at a rate of approximately 4.7% per year, and from the parking areas of the lots at a rate of approximately 1.4% per year. The overall annual loss of sealcoat was calculated at 2.4%. This results in an annual delivery to the environment of 0.51 g of PAHs per m2 of coal tar-sealed parking lot. These values provide a more robust and much higher estimate of loading of PAHs from coal tar sealcoated parking lots when compared to other available measures.
authors: City of Austin, Watershed Protection and Development Review Department, Environmental Resource Management Division, 505 Barton Springs Road, 11th Floor, Austin, Texas 78704, USA. mateo.scoggins@ci.austin.tx.us
authors: Mateo
authors: M
authors: Scoggins
authors: Tom
authors: T
authors: Ennis
authors: Nathan
authors: N
authors: Parker
authors: Chris
authors: C
authors: Herrington
mesh_terms: D003033:Coal Tar / Q000737:chemistry*; D003252:Construction Materials / Q000032:analysis*; D004391:Dust / Q000032:analysis*; D004779:Environment Design; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis*; D010781:Photography / Q000379:methods; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D013781:Texas; D013997:Time Factors; D014507:Urbanization
chemical_list: D004391:Dust; D004785:Environmental Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; D003033:Coal Tar