As water flows off of our streets, parking lots,
and building rooftops, it picks up all kinds
of pollutants like pet waste, sediment, fertilizers, pesticides, oil, and automotive fluids.
If it does not evaporate or soak into the
ground and if untreated or poorly treated,
the contaminated runoff adversely affects
water quality and aquatic life in local
streams, the rivers into which they feed, and
ultimately the Chesapeake Bay.
And it is not only wildlife that is endangered
by stormwater pollution. The state of
Maryland, for example, cautions people not
to swim in waterways for 48 hours after a
heavy rain. Stormwater carrying bacteria has
resulted in serious illnesses. In urban and
suburban areas where ground surfaces have
been hardened and the polluted water has
no place to go, local streets and basements
often flood, causing repeated and costly
damage to homes and businesses.
Stormwater pollution currently supplies
about 15 percent of nutrient pollutants to
the Chesapeake Bay and watershed streams
and rivers. The proportion is much higher in
certain river systems or segments: About 20
percent of nitrogen and 30 percent of sedi-
ment in the Middle Potomac River, for exam-
ple, is attributed to polluted stormwater. The
sediment can smother submerged vegetation
and the excess nutrients fuel harmful algae
growth, which leads to low oxygen levels.
Urban and suburban stormwater is the only
major pollutant sector in the Bay still growing.
Though responsible for greater percentages of
pollution, agriculture and sewage treatment
plants have made progress. Better stormwater
management is an increasingly necessary—
Stormwater is not only a regional issue; it
is a national issue of concern. According
to Bloomberg BNA, a leading source of legal,
regulatory, and business information, the
Bay states “lag behing the rest of the country
in imposing fees to reduce stormwater pollu-
tion (“Urban, Suburban Stormwater
Controls, Necessary, But Funding Poses
Major Problem,” July 10, 2013).
The landscape can be a
filtering pollution as the rainwater
slowly sinks into the ground.
allowing pollution and toxics to be
washed into our waterways.
Maryland advises against swimming in waterways
for 48 hours after a heavy rain.
Flooding such as seen here is a direct result of
poorly managed stormwater.
TOM ZOLPER/CBF STAFF GEOFFREY THULIN