U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

Dense Nonaqueous Phase Liquids (DNAPLs)

Environmental Occurrence

Multi-Component Waste

Coal Tars

Coal tar is a "complex oily liquid mixture" produced as a byproduct of the manufacture of coke or gas made from coal (NYS DEC, Mahler 2005, U.S. EPA 2004). Coal tar varies in consistency depending on the process by which it is made. Gas coal tar's consistency is that of vegetable oil, which is more likely to percolate through soil and into the ground water than coal carbonized tar, which is thicker and far less likely to penetrate low-permeable layers (NYS DEC).

From 1816 to 1947, more than 11 billion gallons of coal tar were generated at manufactured gas plants in the United States (Lee et al. 1992). EPA estimates that at one time, 36,000 to 55,000 manufactured gas plant sites operated in the United States. Of these sites, about 88% are contaminated (U.S. EPA 2004). When the manufactured gas industry was thriving, waste coal tar was often buried on site, dumped into pits, or used as fill to level the land in the gas yards.

For Further Information

Adobe PDF LogoCleaning Up the Nation's Waste Sites: Markets and Technology Trends, Chapter 10
Office of Solid Waste and Emergency Response
U.S. Environmental Protection Agency (U.S. EPA), EPA 542-R-04-015, 9 pp, 2004.

This EPA market study examines the occurrence of hazardous waste problems and costs to clean them up. Chapter 10 evaluates manufactured gas plants.

Adobe PDF LogoEquilibrium partitioning of polycyclic aromatic hydrocarbons form coal tar into water
Lee LS, P. Suresh, C. Rao, et al.
Environ Sci Technol 26:2110-2115, 1992

Parking Lot Sealcoat: An Unrecognized Source of Urban Polycyclic Aromatic Hydrocarbons
Mahler, Barbara J., Peter C. Van Metre, Thomas J. Bashara, Jennifer T. Wilson, and David A. Johns.
Environmental Science & Technology. Vol. 39, No. 15, pp 5560-5566, 2005.

Contamination at MGP Sites
New York State, Department of Environmental Conservation (NYS DEC)

This website discusses manufactured gas plant operations, identifies such sites in New York, and provides information on the types of cleanup conducted on them.

Adobe PDF LogoToxicological Profile for Wood Creosote, Coal Tar Creosote, Coal Tar, Coal Tar Pitch, and Coal Tar Pitch Volatiles
Agency for Toxic Substances and Disease Registry (ATSDR)
U.S. Department Of Health And Human Services, 2002, 394 pp

This profile covers coal tar creosote human health effects, chemical and physical properties, manufacturing volume data, potential for human exposure (environmental fate and transport), and analytical methods.