&EPA
www.epa.gov/ord
science   in   ACTION
BUILDING A  SCIENTIFIC  FOUNDATION  FOR SOUND  ENVIRONMENTAL DECISIONS
                                                                  ECOLOGICAL
                                                                  RESEARCH  PROGRAM
     RESTORED STREAMS ENHANCE ABILITY TO REMOVE NITROGEN
     Issue:
     Excess nitrogen from fertilizer,
     septic tanks, animal feedlots, and
     runoff from pavement can threaten
     human and aquatic ecosystem
     health. Degraded ecosystems like
     those impacted by urbanization
     have reduced ability to process
     and remove excess nitrogen from
     the environment.  Restoring
     ecological condition of streams
     may be a cost-effective,
     sustainable means to reduce
     nitrogen pollution in watersheds.

     Science Objective:
     Scientists at the U.S.
     Environmental Protection
     Agency's Office of Research and
     Development evaluated the effects
     of stream restoration on nitrogen
     removal capacity at an urban
     stream undergoing intensive
     restoration in Towson, Md.

     Restoration of the stream was
     completed in 2005 using various
     techniques that reshaped the
     stream banks and channel,
              reconstructed natural stream
              features, and re-established
              riparian plants.  Research began
              before restoration and continued
              afterwards to determine the effects
              of restoration practices on nitrogen
              removal.

              Scientists found restored streams
              more effectively removed nitrate
              nitrogen than unrestored streams.
              The total amount of nitrogen
              removed in restored streams can
              be significant and may help to
              reduce the total nitrogen load
              reaching water bodies of concern
              like the Chesapeake Bay.

              Application and Impact:
              The research represents one of the
              most intensive efforts to date to
              quantify the effects of stream
              restoration on nitrogen processing
              in urban streams.  Municipal
              natural resource agencies such as
              Baltimore County have used this
              information to help develop
              regional stream restoration
              strategies to improve ecosystem
health and water quality. This
research also has contributed to
efforts by EPA's Chesapeake Bay
Program to model the effects of
stream restoration on Bay
ecosystem health. Results of this
ongoing research effort on stream
restoration continue to be used to
develop regional and national
approaches to implementing and
prioritizing stream restoration to
manage nitrogen in watersheds.

REFERENCES:

Helping streams help themselves, naturally.
Available at:
www.epa.gov/ord/sciencenews/scinews_helpin
g_streams.htm

Minebank Run restoration hits pay dirt in
reducing nitrogen loads. Chesapeake Bay
Journal. Oct. Vol. 17, Number 6.
Available at:
http://www.bayjournal. com/article. cfm?article=2
904)

Groffman, P.M.; Dorsey, A.M. and Mayer, P.M.
N processing within geomorphic structures in
urban streams. Journal of the North American
Benthological Society, 2005, 24:613-625.

CONTACT
Paul Mayer, Ph.D., ecologist, EPA's Office of
Research and Development. 580-436-8647,
maver.paul@epa.gov
     U.S. Environmental Protection Agency
     Office of Research and Development
                                             EPA/600/F-07/003
                                             June 2007

-------