APES CH 20: water pollution

Water pollution

any change in water quality that can harm living organisms or make the water unfit for human uses such as drinking, irrigation, and recreation

Cleaning up a single contaminated aquifer can cost _________

anywhere from $10 million to $10 billion. Thus, preventing groundwater contamination is the only effective and affordable way to deal with this serious water pollution problem!

when does a dead zone break up?

beginning in early fall when cooler weather, storms, and hurricanes mix the top and lower layers of water and distribute dissolved oxygen throughout the layers

how does fracking cause groundwater contamination?

leaky well pipes and pipe fittings and from contaminated wastewater brought to the surface during fracking operations. Without strict monitoring and enforcement of pollution regulations (which at this point do not exist), fracking could become a serious groundwater pollution threat

about what rate does groundwater flow?

less than 0.3 meter (1 foot) per day

oligotrophic lake

low in nutrients and its water is clear

According to the International Water Association, about how many lakes/coastal zones in china suffer from cultural eutrophication?

more than half of the lakes, along with some of its coastal zones

Latin American & Africa and pollution

most streams passing through urban or industrial areas suffer from severe pollution

an average of _________ premature deaths a day

nearly 4,400. 90% of them among children younger than age 5

Runoff of sewage and agricultural wastes into coastal waters can carry large quantities of _______

nitrate and phosphate plant nutrients, which can cause explosive growths of harmful algae and lead to dead zones during summer months

eutrophic lake

nutrients are added from natural and human sources in the surrounding watersheds

Most ocean pollution occurs _______ and comes from ______

occurs in coastal waters and comes from human activities on land

PUR

a powder containing chlorine and iron sulfate. A user empties a packet of PUR into a large container of dirty water, then stirs the mixture and lets it sit for about 20 minutes. After the water is poured through a piece of clean cloth to filter out the particles, it is ready to drink.

World Health Organization (WHO) estimates ________do not have access to clean drinking water.

about 1 billion people—one of every seven in the world

about how many of the world's 500 major rivers are heavily polluted?

about 1/2

how many people in the U.S. do aquifers provide drinking water for?

about half of the U.S. population and 95% of Americans who live in rural areas

According to the EPA, about how many medium/large lakes near major U.S. population centers have some degree of cultural eutrophication?

about one-third of the 100,000 medium to large lakes and 85% of the large lakes

Fish kills and drinking water contamination problems are caused by...

accidental or deliberate release of toxic inorganic and organic chemicals by industries and mining operations, another cause is malfunctioning sewage treatment plants. A third cause is nonpoint runoff of pesticides and excess plant nutrients from cropland and animal feedlots

Determining the extent of a leak from a single underground tank can cost

$25,000-$250,000

what factors in groundwater slow down chemical reactions that decompose waste?

- flows so slowly that contaminants are not diluted and dispersed effectively. -has much lower concentrations of dissolved oxygen and smaller populations of decomposing bacteria. -cold temperatures slow down chemical reactions

coastal water pollution prevention

- separate swage and storm water lines - require secondary treatment of coastal sewage -use wetlands and other natural methods to treat sewage -ban dumping wastes and sewage by ships in coastal rivers -strictly regulate coastal development, oil drilling, and oil shipping -require double hulls for oil tankers

coastal water pollution cleanup

-improve oil-spill cleanup capabilities -use nanoparticles on sewage and oil spills to dissolve the oil or sewage

How do dead zones form?

-During spring and summer, nitrate-laden freshwater flowing into the Gulf forms an oxygen-rich layer on top of the Gulf's cooler and more dense saltwater. -few storms at this time of year, sun-heated upper layer of water remains calm and doesn't mix with bottom layer of low-oxygen water -combo of sunlight and large inputs of nitrate plant nutrients from fertilizer and sewage into the freshwater layer = massive blooms of phytoplankton -algae die, they sink into the saltier water below where they are decomposed by oxygen-consuming bacteria, which use up nearly all of the dissolved oxygen, leaving less than 2 parts per million in the deeper water -oxygen-depleted bottom layer of water becomes a dead zone for certain species

the Gulf of Mexico: An Extreme Case of Cultural Eutrophication

-level of nitrates discharged from the Mississippi River into the northern Gulf of Mexico has nearly tripled -disrupted the nitrogen cycle and animal life in the area's affected coastal waters -dead zone where oxygen levels were typically less than 2 parts per million

both petroleums reach the ocean from a number of sources and become highly disruptive pollutants

-most visible sources are tanker accident -largest source of ocean oil pollution is urban and industrial runoff from land leaks in pipelines, refineries, and other oil-handling and storage facilities)

Lakes and reservoirs are generally less effective at diluting pollutants than streams are, for what two reasons?

1. lakes and reservoirs often contain stratified layers that undergo little vertical mixing 2. they have low flow rates or no flow at all. The flushing and changing of water in lakes and large artificial reservoirs can take from 1 to 100 years, compared with several days to several weeks for streams

How do you clean up cultural eutrophication?

1. mechanically removing excess weeds, controlling undesirable plant growth with herbicides and algaecides 2. pumping air into lakes and reservoirs to prevent oxygen depletion, all of which are expensive and energy-intensive methods

two steps to help formation of dead zones by capturing nutrients after they leave farm fields

1. protect the remaining inland and coastal wetlands, vegetation in riparian zones (zones along river banks), and floodplains, all act as natural filters to pull nutrients from waters 2. restoring key wetlands that have been destroyed or degraded and, where feasible, restoring and reconnecting rivers to their natural flood-plains. In addition to reducing water pollution, this would restore natural habitats for a variety of species in keeping with the biodiversity

How do you prevent or reduce cultural eutrophication?

1. use advanced (but expensive) waste treatment processes to remove nitrates and phosphates from wastewater before it enters a body of water 2. use a preventive approach by banning or limiting the use of phosphates in household detergents and other cleaning agents, and by employing soil conservation

WHO estimates that each year, more than ________people die from waterborne infectious diseases that they get by drinking contaminated water or adequate hygiene

1.6 million people

Every year, according to the WHO and the World Bank, water pollution causes an estimated _____ million Chinese to become ill and kills about ______

190 million 60,000

why are so many rivers heavily polluted?

A majority of these countries cannot afford to build waste treatment plants and do not have, or do not enforce, laws for controlling water pollution.

Groundwater provides about _____ of China's drinking water

70%

in 2010, about _____of China's shallow groundwater was polluted with chemicals such as toxic heavy metals, organic solvents, nitrates, petrochemicals, and pesticides. _____ of this groundwater is so polluted that it cannot be treated for use as drinking water.

90% 37%

cleanup occurred in Great Britain

950s, the Thames River was little more than a flowing, smelly sewer. Now, after 50 years of effort and large inputs of money from British taxpayers and private industry, the Thames has made a remarkable recovery. Commercial fishing is thriving and the number of fish species in the river has increased 20-fold since 1960.

what are the causes and effects of oxygen depletion?

Cause: When the algae die, they are decomposed by swelling populations of aerobic bacteria, which deplete the dissolved oxygen in the surface layer of water near the shore, as well as in the bottom layer of a lake or coastal area. Effect: can kill fish, shellfish, and other aerobic aquatic animals that cannot move to safer waters. If excess nutrients continue to flow into a lake, anaerobic bacteria take over and produce gaseous products such as smelly, highly toxic hydrogen sulfide and methane.

why are the concentrations of some harmful chemicals are biologically magnified?

Due to the stratified layers and reduced flows in lakes and reservoirs, some harmful chemicals are biologically magnified as they pass through food webs in these waters

blooms

During hot weather or drought, this nutrient overload can produce dense growths of organisms such as algae and cyanobacteria in slow-moving surface waters

China and the Yangtze River

In 2010, Chinese officials reported that huge islands of garbage are threatening to jam the flow of water over the country's massive Three Gorges Dam on the Yangtze River. As it decays, this garbage will pollute the water.

Besides increased nitrate levels, what other human factors have contributed to formation of the dead zone in the Gulf of Mexico?

In efforts to control flooding along the upper Mississippi River, engineers have dredged and straightened parts of the river and raised its banks with levees in many places. This has had the effect of speeding the river's flow of nutrients and sediment pollution into the Gulf. Also, most of the river basin's original freshwater wetlands, which acted as natural filters that helped to remove excess nutrients and sediments from flood water, have been drained for farming and urban development.

china and pollution

Industrial wastes and sewage pollute 54 of the 78 rivers and streams monitored in China. In some parts of China, river water is too toxic to touch, much less drink. Liver and stomach cancer, linked in some cases to water pollution, are among the leading causes of death in the Chinese countryside where many industries have been relocated.

India and pollution

Industrial wastes and sewage pollute more than two-thirds of India's water resources

where is wastewater is being recycled to provide freshwater?

Israel, Singapore, Orange County and San Diego in California, and El Paso, Texas

slowly degradable wastes

It can take decades to thousands of years for contaminated groundwater to cleanse itself of slowly degradable wastes (DDT)

primary sewage treatment

Mechanical sewage treatment in which large solids are filtered out by screens and suspended solids settle out as sludge in a sedimentation tank. Compare secondary sewage treatment.

cultural eutrophication

Near urban or agricultural areas, human activities can greatly accelerate the input of plant nutrients to a lake. inputs involve mostly nitrate- and phosphate-containing effluents from various sources, including farmland, feedlots, urban streets and parking lots, chemically fertilized suburban yards, mining sites, and municipal sewage treatment plants

Groundwater that is used as a source of drinking water can also be contaminated with _______

Nitrate ions , especially in agricultural areas where nitrates in fertilizer can leach into groundwater

infectious disease organisms (pathogens)

One of the major water pollution problems that we face is exposure to this. primarily through contaminated drinking water

how to reduce nonpoint sources of water pollution, most of which come from agricultural practices

Reducing soil erosion and fertilizer runoff by keeping cropland covered with vegetation and using conservation tillage and other soil conservation methods Using fertilizers that release plant nutrients slowly. Using no fertilizers on steeply sloped land. Relying more on organic farming and more sustainable food production to reduce the use and runoff of plant nutrients and pesticides. Planting buffer zones of vegetation between cultivated fields and between animal waste storage sites and nearby surface waters. Setting discharge standards for nitrate chemicals from sewage treatment and industrial plants.

secondary sewage treatment

Second step in most waste treatment systems in which aerobic bacteria decompose as much as 90% of degradable, oxygen-demanding organic wastes in wastewater. It usually involves bringing sewage and bacteria together in trickling filters or in the activated sludge process. Compare primary sewage treatment.

Scientists have identified more than 500 types of disease-causing bacteria, viruses, and parasites that can be transferred into water from the wastes of humans and animals.

They can get into drinking water and cause painful, debilitating, and often life-threatening diseases, including typhoid fever, cholera, hepatitis B, giardiasis, and Cryptosporidium.

The largest of oxygen-depleted zones

U.S. coastal waters forms each year in the northern Gulf of Mexico

septic tank

Underground tank for treating wastewater from a home in rural and suburban areas. Bacteria in the tank decompose organic wastes, and the sludge settles to the bottom of the tank. The effluent flows out of the tank into the ground through a field of drainpipes

Nonpoint sources

broad and diffuse areas where rainfall or snowmelt washes pollutants off the land into bodies of surface water. Examples include runoff of eroded soil and chemicals such as fertilizers and pesticides from cropland, livestock feedlots, logged forests

Agricultural activities

by far the leading cause of water pollution. Sediment eroded from agricultural lands is the most common pollutant.

what are the effects of lakes and reservoirs being more vulnerable to contamination? where does this contamination come from?

contamination by runoff or discharge of plant nutrients, oil, pesticides, and nondegradable toxic substances, such as lead, mercury, and arsenic. These contaminants can kill bottom-dwelling organisms and fish, as well as birds that feed on contaminated aquatic organisms. Many toxic chemicals and acids also enter lakes and reservoirs from the atmosphere

Laws enacted in the 1970s

control water pollution have greatly increased the number and quality of wastewater treatment plants in the United States and in most other more-developed countries; require industries to reduce or eliminate their point-source discharges of harmful chemicals into surface waters

Torben Vestergaard Frandsen

developed the LifeStraw™, an inexpensive, portable water filter that eliminates many viruses and parasites from water that is drawn through it

Point sources

discharge pollutants into bodies of surface or underground water at specific locations through drain pipes, ditches, or sewer lines. Examples include factories, sewage treatment plants (which remove some, but not all, pollutants), underground mines, and oil tankers

What are the effects of dead zones in the Gulf of Mexico?

disrupts the Gulf's food web, because die-offs of such species lead to the deaths of seabird and marine mammal species that depend on the dying fish and shellfish for their survival.

Industrial facilities

emit a variety of harmful inorganic and organic chemicals, are a second major source of water pollution

Coastal areas

especially wetlands, estuaries, coral reefs, and mangrove swamps—bear the brunt of our enormous inputs of pollutants and wastes into the ocean. Roughly 40% of the world's people live on or near coastlines, which helps to explain why 80, and coastal populations are projected to double by 2050.

common groundwater pollutants

fertilizers, pesticides, gasoline, and organic solvent; People who dump or spill gasoline, oil, and paint thinners and other organic solvents onto the groundwater

refined petroleum

fuel oil, diesel, gasoline, and other processed petroleum products

red, brown, or green toxic tides

harmful algal blooms;can release waterborne and airborne toxins that poison seafood, kill fish and some fish-eating birds, and discourage tourism in the affected coastal areas. Each year, harmful algal blooms lead to the poisoning of about 60,000 Americans who eat shellfish contaminated by the algae.

Crude petroleum

oil as it comes out of the ground

U.S. Safe Drinking Water Act of 1974

requires the EPA to establish national drinking water standards, called maximum contaminant levels, for any pollutants that could have adverse effects on human health

most cities in less-developed countries discharge 80-90% of their untreated sewage directly into...

rivers, streams, and lakes whose waters are often used also for drinking, bathing, and washing clothes.

U.S. state of Ohio's Cuyahoga River

success story-so polluted that it caught fire several times;highly publicized image of this combustible river prompted elected officials to enact laws to limit the discharge of industrial wastes into the river and into local sewage systems and to provide funds for upgrading sewage treatment facilities. Today, the river is cleaner, is no longer flammable, and is widely used by boaters and anglers. This accomplishment illustrates the power of bottom-up pressure by citizens

nondegradable wastes

such as toxic lead and arsenic, remain in the water permanently

oxygen sag curve

the breakdown of biodegradable wastes by bacteria depletes dissolved oxygen

blue baby syndrome

the conversion of nitrates in tap water to nitrites in infants under 6 months old can cause a potentially fatal condition in which blood lacks the ability to carry sufficient oxygen to body cells

hydraulic fracturing (aka fracking)

the drilling of thousands of new natural gas wells in parts of the United States

Eutrophication

the name given to the natural nutrient enrichment of a body of water such as a lake, coastal areas at the mouth of a river, or a slow-moving stream. It is caused mostly by runoff of plant nutrients such as nitrates and phosphates from land bordering such bodies of water.

Mining

the third biggest source of water pollution. Surface mining disturbs the land, creating major erosion of sediments and runoff of toxic chemicals into surface waters.

Another form of water pollution is caused by...

the widespread use of human-made materials such as plastics that are used to make millions of products. Much of the plastic that is improperly discarded eventually ends up in waterways and in the oceans

what is the difference in discharge of harmful chemicals in developed/less developed countries?

the world's more-developed countries have laws that help control point-source discharges of harmful chemicals and disease organisms into aquatic systems. the less-developed countries, there is little control of such discharges

disinfection

to kill disease-carrying bacteria and some (but not all) viruses. The usual method for accomplishing this is chlorination

bleaching

to remove water coloration

North Pacific Garbage Patch

two gigantic, slowly rotating masses of small pieces of plastic and other solid wastes in the middle of the North Pacific Ocean near the Hawaiian Islands; trapped there by a vortex where rotating ocean currents called gyres meet

wastewater or sewage treatment plants

urban areas in the United States and other more-developed countries, most waterborne wastes from homes, businesses, and storm runoff flow through a network of sewer pipes

advanced or tertiary sewage treatment

uses a series of specialized chemical and physical processes to remove specific pollutants left in the water after primary and secondary treatment. In its most common form, advanced sewage treatment uses special filters to remove phosphates and nitrates from wastewater before it is discharged into surface waters.