st Manaaement Practice
   United States
   Environmental Protection
                       Hydrocarbons, and Stormwater Pollution
 Minimum Measure
 Pollution Prevention/Good Housekeeping

What Is Coal-Tar Sealcoat?	
Coal-tar sealcoat is a type of sealant used to maintain and
protect driveway and parking lot asphalt pavement. Coal-tar
sealcoat typically contains 20 to 35% coal tar pitch, a byproduct
of the steel manufacturing industry, which is 50% or more
polycyclic aromatic hydrocarbons (PAHs) by weight.

Could Coal-Tar Sealcoat Be a Concern for
Studies found that PAHs are significantly elevated in stormwater
flowing from parking lots and other areas where coal-tar
sealcoats were used as compared to stormwater flowing from
areas not treated with the sealant. For example, one study
found the amount of PAHs in stormwater runoff was 65 times
higher from parking lots sealed with coal-tar sealant vs.
stormwater from unsealed parking lots. Another study found
that coal-tar sealcoat is the largest source of PAHs to urban
lakes. PAHs from coal-tar sealcoat may accumulate  in the
                       sediment of stormwater ponds,
                       requiring expensive disposal of
                       the dredged PAH-contaminated

                       PAHs are of concern because of
                       their harmful impacts on  humans
                       and the environment. They are
                       persistent organic compounds,
                       and several PAHs are known or
                       probable human carcinogens and
                       toxic to aquatic life.
What Are States and Municipalities Doing
to Address PAHs from Coal-Tar Sealcoat?
Several states and cities have taken action to address PAHs
from coal-tar sealcoat. The following are some notable
 The city of Austin, Texas
  banned the sale and use
  of coal-tar containing
  pavement sealants in
  2005: http://austintexas.
 The District of Columbia
  banned the sale and use
  of coal-tar sealcoat in
 In 2009, Minnesota restricted state agencies from purchasing
  undiluted coal tar-based sealant and directed its Pollution
  Control Agency to study the environmental effects of coal
  tar-based sealants and to develop management guidelines:
 Washington State
  banned the sale of coal-
  tar pavement sealants
  on January 1, 2012 and
  banned the use of such
  sealants after July 1,
  2013: https://fortress.
  summarypages/1104021. html

Alternatives to Coal-Tar Sealcoat	
Pavement options such as pervious concrete, permeable
asphalt and paver systems do not require sealants. These
types of pavements allow for stormwater to naturally infiltrate,
resulting in decreased runoff.
Office of Water, 4203M
                                       November 2012

Stormwater Best Management Practice:
Coal-Tar Sealcoat, Poly cyclic Aromatic Hydrocarbons, and Stormwater Pol
For More Information
For more information you can watch EPA's webinar Stormwater,
Coal-Tar Sealcoat and Polycyclic Aromatic Hydrocarbons
available at:

For information on assessing the toxicity of PAHs in sediment
PAHESB.pdf from EPA's Office of Research and Development.

Additionally, you can visit the USGS webpage on PAHs
and coal-tar-based sealcoat:
Mahler, B.J.; Van Metre, PC.; Crane, J.L.; Watts, A.W.; Scoggins,
M.; Williams, E.S., Coal-tar-based pavement sealcoat and
PAHs: Implications for the environment, human health, and
Stormwater management. Environ. Sci. Technol., 2012.

Van Metre, PC.; Mahler, B.J., Contribution of PAHs from coal-tar
pavement sealcoat and other sources to 40 U.S. lakes. Sci. of the
Total Environ., 2010, v.409, 334-344.

Scoggins, M.; McClintock, N.L.; Gosselink, L; Bryer, P.,
Occurrence of polycyclic aromatic hydrocarbons below
coal-tar-sealed parking lots and effects on stream benthic
macroinvertebrate communities. Journal of the North American
Benthological Society, 2007, 26(4):694-707.

Mahler, B.J.; Van Metre, PC.; Bashara, T.J.; Wilson, J.T.; Johns,
D.A., Parking lot sealcoat: An unrecognized source of urban
PAHs. Environ. Sci. Technol. 2005, 39, (15), 5560-5566.

EPA's Integrated Risk Information  System (IRIS):