Transcript Water - Purdue University

WATER QUALITY
Some Sources of Pollutants
NIFA Report
• National Institute of Food and Agriculture (NIFA),
Conservation Effects Assessment Project
• Study to evaluate the impacts of interactions among
conservation practices at a watershed scale
• Results released October, 2012
• Data:
• 6,908 water bodies listed as being nutrient impaired
• 6,165 are sediment impaired
• Conclusion: agricultural nonpoint source pollution
contributes, in part, to impaired water resources in many
of these watersheds
Sources of Pollution
• Point Sources – easily defined and relatively easy
to control - examples include:
• Pipes
• Sewage outlets
• Landfills
• Nonpoint Sources – Not easily defined and
difficult to regulate - examples include:
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Farms
Roads
Cars
Homes
Mississippi River Basin
The Mississippi River basin drains approximately 41% of the
land area of the contiguous United States, ranging as far west as
Idaho, north to Canada, and east to Massachusetts
Mississippi River Nutrients
• Nitrogen and phosphorous occur in four inorganic forms in
the river:
• nitrate (NO3-)
• nitrite (NO2-)
• ammonium (NH4+)
• orthophosphate (PO4-3)
• These nutrients make the Gulf nutrient-rich
• The nutrients cause a profuse growth of algae and
phytoplankton
• The algae and phytoplankton die and decay causing a
deficit of oxygen
Eutrophication
• Eutrophication – increase in nutrients
• Nutrient-enhanced plant production process: an accumulation of
nutrients supports a dense growth of algae and other organisms
that decay deplete the shallow waters of oxygen
• Gulf of Mexico
• Rain in the Mississippi watershed washes soil, organic
debris, nitrogen-rich fertilizers, and atmospheric deposition
of oxidized nitrogen from the combustion of fossil fuels
• A marked increase in the concentration of nitrogen and
phosphorous in the Lower Mississippi River was first
observed in 1972
Stratification
• Stratification – the temperature, density and salinity of the
water are not uniform from top to bottom
• In the spring and summer, freshwater flowing from the
Mississippi River and the seasonally warmed surface
water of the Gulf have a lower density than the saltier,
cooler and more dense water near the bottom
• Stratification leaves the bottom layer isolated from the
surface layer and cut off from a normal resupply of oxygen
from the atmosphere
Hypoxia
• When the algae and phytoplankton die they drop to the
ocean floor and are decomposed by bacteria
• The decay process uses oxygen, which results in hypoxia
– oxygen deficient water
• The water is considered hypoxic when oxygen levels fall
to < 2mg/l (2 ppm)
• Hypoxia begins in late spring
• Reaches a maximum in midsummer
• Disappears in the fall
• Most aquatic species cannot survive in hypoxic water due
to the very low oxygen levels
Hypoxia animation
The GULF of MEXICO “Dead Zone”
Hypoxic zone in the Gulf Coast
Scale: note the oil drilling
platform
NOAA graphic
Explanation
The majority of land in the Mississippi's watershed is farm land (in green). Each
spring, as farmers fertilize their land in preparation for crop season, rain washes
fertilizer off the land and into streams, rivers, and then the Gulf of Mexico. This leads
to a Dead Zone in the Gulf.
Recommendations
Modify farming practices to decrease nitrogen and
phosphorous loss:
• Manure handling (primarily concern, phosphorous)
• Don’t apply in winter
• Incorporate in soil
• Use filter strips between field & stream (first flush)
• Row crops (primary concern, nitrogen)
• Alternate crops
• Reduced fertilizer use (min. needed)
• Careful timing
Recommendations, continued
• Tile drainage management (90% of nitrate inputs
from row crop tile drains)
• Increase wetland acreage
• May be relatively expensive to install
• Generally relatively inexpensive to maintain
• Use bioreactors (wood chips) to remove nutrients
from runoff and tile drains
Atrazine
• Atrazine is a triazine herbicide currently registered for
the control of grass and broadleaf weeds
• Atrazine is one of the most extensively used agricultural
herbicides in the United States, especially in pesticides
for corn and sorghum
• Note: there is a 66 foot set-back required
Concerns
• Atrazine is water soluble (What are the implications?)
• Atrazine has been found in groundwater (including
drinking water) at levels of 0.01 to 0.05 micro grams/liter
• Human health concerns: short-term Atrazine exposure
above the drinking water maximum contaminant level
(MCL) can potentially cause heart, lung, and kidney
congestion, low blood pressure, muscle spasms, weight
loss, and damage to the adrenal glands
• Aquatic animal concerns: scientists say atrazine causes
hermaphroditic effects in frogs
• Syngenta Crop Protection, the manufacturer, debates this
Atrazine Litigation Settlement
• Class action law suit filed against Syngenta
• May 24, 2012 – Syngenta filed a proposed settlement
• Water systems joining the class will be eligible for
payments from a $105 million settlement funded by
Syngenta
• The settlement was reached “in order to end the business
uncertainty and expense of protracted legal proceedings”
• Syngenta acknowledges no liability and continues to
stand by the safety of atrazine.
• They say that the scientific evidence continues to make it
clear that no one ever has or ever could be exposed to
enough atrazine in water to affect their health
Runoff from
Flooding
• North Carolina
• Hurricane event
Each Dot = 1 swine farm
• Thousands of hogs and other animals drowned
• No hog waste lagoons failed, but they were covered by over
20 feet of flood water and overflowed.
• Wastes and hogs flowed to the ocean, causing
eutrophication
Albemarle and Pamlico Sounds
Contamination plumes through the Barrier Islands
Impacts
• Hogs, waste, and other pollutants entered the surface
water
• Ocean temperatures increased to 80+°F
• Dissolved oxygen levels plummeted
• The limited mixing with ocean water:
• Increased overall impact
• Low oxygen levels killed fish, shellfish, and oysters
• Destroyed the local economy
• Impacted the area for years
Recycled sewage water aids biofuel crops
• Tel Aviv University researchers are trying to
reduce humanity's carbon footprint by growing
forests in the most unlikely place — deep in
Israel's Aravah Desert
• To conserve fresh water, the researchers used
• Local plant species
• Recycled sewage water unsuitable for agriculture
• Arid lands unusable for crops
• TAU researchers believed that encouraging
growth on a piece of land that was traditionally
barren, such as desert land, is better than
planting trees for biofuel on agricultural soils
Tamarix, a botanical
genus that includes
salt cedar trees and
is indigenous to
old-world deserts
Urban Contamination Sources
Pharmaceuticals and Personal Care
Products (PPCPs)
• Pharmaceuticals and Personal Care Products (PPCPs)
refers to any product used by individuals for personal
health or cosmetic reasons or used by agribusiness to
enhance growth or health of livestock
• PPCPs comprise a diverse collection of thousands of
chemical substances, including prescription and over-thecounter therapeutic drugs, veterinary drugs, fragrances,
cosmetics, and illegal drugs
• Studies have shown that pharmaceuticals:
• Are present in our nation's water bodies, sometimes at therapeutic
levels
• Certain drugs may cause ecological harm
PPCPs
Types
• Prescription, over-the
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counter, and illegal drugs
Veterinary drugs
Fragrances
Cosmetics
Sun-screen products
Diagnostic agents
Nutraceuticals (e.g.,
vitamins)
Sources
• Human activity
• Residues from
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pharmaceutical
manufacturing (well defined
and controlled)
Residues from hospitals
Illicit drugs
Veterinary drug use,
especially antibiotics and
steroids
Agribusiness, esp. CAFOs
PPCPs in U.S. Waters
• U.S. Geological Survey monitoring study
• 139 streams analyzed in 30 states
Kolpin, D.W. et al. 2002
Study by Kolpin et al.,
• First Comprehensive Survey by USGS
• Data collected for 142 streams, 55 wells and 7
effluents in 36 states
• 1999 and 2000
• Results:
• Contaminants were identified in 80% of the
streams sampled
• 82 different contaminants identified (many were
pharmaceuticals)
• Co-occurrence common; average 7 distinct
contaminants identified per stream
PPCP Concerns
• Large quantities enter the environment
• Found in most places sampled
• Over 100 individual PPCPs have been identified (as of 2007) in
environmental samples and drinking water
• The number of PPCPs are growing.
• Steroids were the most frequently found PPCP
• Neither municipal sewage treatment plants nor septic
systems are equipped for PPCP removal
Major PPCP Concerns
• Human:
• Actual risks posed to humans are unknown
• Increased resistance to antibiotics
• Possible connections o steroids & environmental estrogens
• Puberty is accelerated in girls
• Puberty is delayed in boys later who have decreased sperm counts
• Aquatic:
• Exposure risks are much larger than those for humans because
aquatic organisms have:
• Continual exposures
• Multi-generational exposures
• Exposure to higher concentrations
• Possible low dose effects
• Disruption of aquatic endocrine systems by natural and synthetic
sex steroids
Agricultural Products
• Injectable medications – antibiotics, vitamins and
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minerals, mastitis tubes
Oral medications – dewormers, antibiotics, vitamins and
minerals
Topical Medications – sprays, dewormers, ointments
Sharps – needles, syringes, scalpels
Drug containers – empty drug or vaccine vials and
outdated drugs
Other, including bandages & medical gloves
Note: rural areas may not have a lot of people but large
numbers of animals will use as much antibiotics (and
discharge as much waste) as a large city
Proper Disposal of Unused Medicines
• Follow specific disposal instructions on the drug label or
patient information
• Do not flush prescription drugs down the toilet unless
written information specifically instructs you to do so
• Take advantage of community (& Purdue) drug take-back
programs
• If no take-back program is available
• Take medicines out of their original containers and mix them with
an undesirable substance, such as used coffee grounds or kitty
litter
• Place medicines in a sealable bag, empty can, or other container to
prevent the medication from leaking or leaking
Plastic – it’s Everywhere
• In the last 25 years, our consumption rate of plastic bags has
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grown from almost zero to our use of over 500,000,000,000
(that’s 500 billion) plastic bags annually … almost 1 million per
minute.
The U.S. goes through 100 billion plastic shopping bags
annually. An estimated 12 million barrels of oil is required to
make that many plastic bags
Four out of five grocery bags in the US are now plastic
Plastic bags cause hundreds of thousands of birds, sea turtle
and other marine animal deaths every year because these
creatures mistake plastic trash for food
Countries including China, Ireland, Australia, Bangladesh have
banned or have placed restrictions on, single use plastic bags
Plastic in Our Oceans
• Giora Proskurowski, an oceanographer and a researcher
at the University of Delaware, has discovered there is
about two and a half times more plastic debris in the
oceans than previously estimated
• Previous estimates were based on surface water
measurements and did not account for how wind drives
the debris beneath the surface
• He found plastic debris down as far as 25 meters (82 feet)
deep
Peak Water: The Preeminent 21st
Century Commodity Story
• Morgan Stanley's Global Investment Committee report
• Defines the "perfect storm"
Declining water supply
Rising demand
Water: The Critical Limiting Factor of 21st
Century Production
• Conclusion: water will become the critical
limiting resource of our time
• The report
1. Paints a convincing picture of a world that is
on the brink of severe water crisis
2. Offers hope by presenting emerging
opportunities for new technological solutions
Issues
• Steadily Increasing Demand, due to:
• Population growth (major cause)
• Overall rise in demand for water - outpaced population
growth 2x
• Estimated U.S. withdrawal rate 10-20% above the 1995
levels by 2025
• Extreme Drought Risk:
• Cause: increasing temperatures from climate change and
global exploitation of water resources
• Result: significantly increased threat of drought
• Prediction: by 2030 nearly two thirds of the US is likely to be
drastically drier which will put large parts of the nation at risk
for extreme drought
Issues, continued
• Disappearing Snow Cover:
• Snow cover declined 1.3% in the Northern Hemisphere,
every year for the last decade
• The United Nations Environment Program (UNEP) predicts
that Earth’s middle latitudes will experience snow losses of
60 to 80 percent by the end of the century
Issues
• Mounting Agricultural Pressures:
• Agriculture uses account for about 70% of all water withdrawals
• Growing global affluence is increasing demand for more waterintensive foods like meat, which requires 10 times more water than
rice to produce
• Global efforts to reduce poverty and famine will also require
increasing agriculture output, and therefore increased water use
• Rapid Urbanization:
• More than half of the global population now lives in an urban area
• Urbanization is associated with an increasing standard of living
which increases the demand for water five times that of the basic
water requirement per person
Investments Needed
• More Efficient Irrigation:
• Need: increased agricultural output to feed the growing population
• This requires more efficient irrigation techniques to produce more
“crop per drop.”
• Note: The use of drip irrigation can increase efficiency by 50% over
flooding, which is the most common irrigation method used in
developing countries
• Result: if these improvements are adopted, they are expected to
more than double global crop output by 2050
• Drought-Tolerant Crops:
• Cause: climate change is making the world both warmer and drier
• Need: Genetic engineering and conventional breeding needed to
develop crop varieties that maintain output even in drought
conditions
Investments Needed
• Advances in Water Treatment and Reuse:
• Finding new sources: wastewater treatment costs about a third less
than desalination
• Output from water-reuse facilities is predicted to increase by 52%
from 2010 to 2016
• Cheaper Desalination:
• Innovations in desalination technology using more efficient
membranes and energy recovery devices have been able to
significantly drive down the cost of this traditionally expensive
process
• These innovations include a biomimetic membrane that mimics the
water-transport process of living cell membranes
• Global desalination capacity is expected to more than double from
2009 to 2016
Assignment
Read: Measuring Farm Pollution: By the river or by the
farm?
• MPR, Sept. 15, 2011
• Linked on the class website
• Due: Friday, August 30, 2013