Nutrient (aka nitrogen and phosphorus) pollution is one of America’s
most widespread, costly and challenging environmental problems.
It is caused by excess nitrogen and phosphorus in the air and water.
Nutrients are chemical elements that all living organisms—plants and
animals—need to grow. When too much nitrogen and phosphorus enter
the environment—usually from a wide range of human activities—the
air and water can become polluted.
Sources of Nutrient Pollution
e primary sources of nutrient pollution are fertilizer, animal manure,
sewage treatment plant discharge, detergents, storm water runo, cars
and power plants, failing septic tanks and pet waste. In the Mississippi
River Basin, which spans 31 states and ultimately drains into the Gulf of
Mexico, nutrients from row crops, large farms and concentrated animal
feeding operations contribute the most nutrient pollution.
Eects of Nutrient Pollution
Excessive nitrogen and phosphorus in water and the air can cause
health problems, damage our land and water, and take a heavy toll
onthe economy.
Human Health
Nutrients can lead to a massive overgrowth of algae, known as an algae
bloom. Certain types of algae emit toxins that are absorbed by shellsh;
consuming these tainted shellsh can lead to stomach illness and short-
term memory problems. Drinking or coming into contact with toxins
from algae blooms can cause stomach aches, rashes and more serious
problems. Excess nitrogen is a common drinking water contaminant
in agricultural areas and can pose particular risk to infants younger
than six months old. Chemicals used to treat nutrient-polluted drinking
water can pose additional risks to human health. ese chemicals,
including chlorine, can react with the algae in the water to form
disinfection by-products that have been associated with reproductive
and developmental health problems. Nitrogen pollutants in the air from
burning fossil fuels can contribute to a variety of respiratory problems
for children, the elderly and those with lung ailments.
e Environment
Nutrient pollution damages the environment and harms water quality.
Algal blooms consume large amounts of oxygen that sh, shellsh and
other organisms need to survive. Algal blooms can make water cloudy,
reduce the ability of aquatic life to nd food, and clog the gills of sh.
Some algal blooms produce toxins that can cause illnesses or death for
animals like turtles, seabirds, dolphins, sh and shellsh.
Nutrient pollution causes green slime that aects drinking water,
recreation, businesses and property values. In Tennessee alone,
nutrients impair nearly 3,000 river/stream miles and more than
15,000 acres of lakes and reservoirs.
Photo credit: U.S. Geological Survey, Binder Lake, Iowa.
The Facts about
Nutrient Pollution
Nutrient Pollution: The Numbers
15,000 Estimated number of water bodies in the
United States impaired* by nutrients
101,000 Miles of rivers and streams impaired* by
nutrients in the
United States**
3,500,000 Acres of lakes and reservoirs impaired* by
nutrients in the
United States**
78% Percentage of the continental U.S. coastal
waters that exhibit an overgrowth of algae*
> 20% Percentage of shallow household wells in
agricultural areas with nitrate levels above
drinking water standards. More than 90% of
people living in Mississippi get their drinking
water from ground water.
60% Percentage of Americans whose actions or
food choices consume (directly or indirectly)
freshwater from the Mississippi River Basin
*Waters that do not meet one or more basic uses like swimming
or shing
**Based on state Clean Water Act 305 (b) reports available in
EPA’s Assessment and Total Maximum Daily Load Tracking and
Implementation System (http://www.epa.gov/waters/ir) as of
March 14, 2012.
For More Information
Contact: Travis Loop, EPA Oce of Water
202-564-0183, [email protected]
On the Web, visit:
EPA Nutrient Pollution website:
www.epa.gov/nutrientpollution
Natural Resources Conservation Service website:
www.nrcs.usda.gov/wps/portal/nrcs/main/
national/water
U.S. Geological Survey website:
http://water.usgs.gov/nawqa/nutrients/
April 2012
Airborne nitrogen can also pose environmental risks. Nitrogen compounds released into the air by burning fossil fuels
can react with water, oxygen and other chemicals to form nitric acid. When it falls to earth, the acid rain can damage
an entire ecosystem, including streams, estuaries, forests and grasslands. Airborne compounds like nitrogen oxides
contribute to the formation of other air pollutants, such as ozone—a component of smog—which can restrict visibility.
Wind and weather can carry ozone many miles from urban to rural areas, where it can damage trees.
e Economy
Nutrient pollution has diverse and far-reaching eects on the U.S. economy, impacting many sectors that depend on clean
water. e tourism industry loses close to $1 billion each year, mostly from lossesin shing and boating activities because
of nutrient-polluted water bodies. In Mississippi alone, tourism in
the three counties that border the Gulf Coast accounts for about
$1.6 billion in visitor expenditures, 32 percent of state travel and
tourism tax revenues, and 24,000 direct jobs.
Nutrient pollution causes annual losses to the commercial shing
and shellsh industry in the tens of millions of dollars. When
oxygen levels are low, shery yields are reduced. During harmful
algal blooms, consumers become wary that seafood could be tainted
by toxins. Algal blooms can also negatively impact waterfront
property values. Algal blooms in drinking water sources can
drastically increase treatment costs and subsequently increase
consumer utility bills. Costs to clean up polluted water bodies,
such as the Chesapeake Bay, can cost billions of dollars. Airborne
nutrient pollution can also aect visibility at outdoor tourist
destinations, like national parks. Airborne nitrogen compounds can
damage structures, especially ones made of marble and limestone.
How Are We Addressing Nutrient Pollution?
EPA is working with its many partners to address nutrient pollution across the country. EPA
▶ Provides technical guidance and resources to help states develop water quality criteria for nitrogen and
phosphorus
▶ Awards grants to states, watershed groups, and wastewater facilities to address nutrient-driven water quality
problems
▶ Oversees permits that restrict nutrient discharges from industries
▶ Conducts research
▶ Works with state and federal partners on the Mississippi River/Gulf of Mexico Watershed Nutrient Taskforce to
reduce the dead zone in the Gulf
State environmental agencies are working to develop water quality criteria for nutrients. Some states have already
developed statewide nutrient criteria for certain types of water bodies. Other states have developed site-specic nutrient
criteria. Still others are just beginning to develop criteria and have identied important milestones toward proposing and
approving nutrient criteria.
What Can You Do?
We can all take action to reduce nutrient pollution through the
choices we make on our farms, around our homes, with our pets, in
lawn care and in transportation. Families, individuals, students and
teachers can access online resources to nd out more about the
health of their local waterways and to learn how to join community
eorts to restore and protect them for the benet of people and
wildlife. A variety of resources and links is provided online at
www.epa.gov/nutrientpollution.
Impacts on Drinking Water and the Economy
Algal blooms in drinking water sources can increase treatment
costs and consumer utility bills.
Photo credit: Bill Yates, St. John’s River, Florida