AIR POLLUTION WASTEWATER
off parking lots,
roofs, and other
carries pollution like
fertilizer and pet
waste into our
The drain fields of
septic systems deliver
pollution to our rivers
and the Bay through
and factories are
into our rivers and
Air pollution from
power plants and
motor vehicles falls
back to the ground
and is washed into
Animal waste and
fertilizers wash off
agricultural land or
and streams and
June 2013 Source: Chesapeake Bay Program, Phase 5. 3. 2 Model
thousands of acres
thousands of acres
WHERE DOES THE NITROGEN
POLLUTION COME FROM?
Major Sources of Nitrogen Pollution to the
Chesapeake Bay and its Rivers and Streams
The largest source of pollution to the Bay comes from
agricultural runoff, which contributes roughly 40
percent of the nitrogen entering the Chesapeake Bay.
Despite pollution-reduction efforts across sources,
stormwater runnoff is the only major catagory of
nitrogen pollution that is still growing (pollution from
septic systems, a smaller source, is also growing).
Because of population growth and related development, hardened surfaces—roads, driveways, parking
lots—increased by approximately 34 percent between
1990 and 2007, while the Bay watershed population
increased by only 18 percent.
DOES LAND USE DIFFER ACROSS
Agricultural and Developed Land Use
in the Bay’s Major River Watersheds
Across the Chesapeake Bay watershed, 23 percent
of the land is used for agriculture and almost 12
percent has been developed. Most of the remaining
land is forested.
When the watershed is broken down by its major river
watersheds, it is interesting that some areas, like the
Choptank River watershed, are much more agricultural
(48 percent), and others, like the Patuxent River
watershed, are much more developed ( 32 percent).
This is why a one-size-fits-all approach to reducing
pollution across the region will not work.
HAS LAND USE CHANGED ACROSS
The Decline of Agricultural Land
and the Increase in Developed Land
in the Chesapeake Bay Watershed
As the population in the watershed increases, we are
choosing to move away from city centers and live in
bigger houses on larger lots. Sprawling, low-density
residential and commercial areas result in additional
infrastructure like roads and shopping centers that
chew up forests, shorelines, and agricultural lands.
And often, open areas between existing centers and
sprawl eventually fill with more new development.
This type of development increases stormwater pollution and degrades the health of our water.
The remaining land is forested, wetlands, or other use. Source: Chesapeake Bay Program
Source: Chesapeake Bay Program