APES Chapter 20 Water Pollution

What are ways to prevent groundwater pollution?

Find substitutes for toxic metals, keep toxic metals out of the environment, require leak detectors on underground tanks, ban hazardous waste disposal in landfills and injection wells, store harmful liquids in aboveground tanks with leak, detection and collection systems.

What activity is by far the leading cause of water pollution?

Agricultural activities and includes sediment, fertilizers, pesticides, etc...

What are the major pollution problems affecting groundwater?

Chemicals used in agriculture, industry, transportation and homes can spill and leak into groundwater and make it undrinkable. There are both simple ways and complex ways to purify groundwater used as a source of drinking water, but protecting it through pollution prevention is the least expensive and most effective strategy

Scientists call for strengthening the U.S. Safe Water Drinking Act in several ways

Combine many of the drinker water treatment systems that serve fewer than 3,300 people with nearby larger to make it easier smaller systems to meet federal standards, strengthen and enforce requirements concerning public notification of violations of drinking water standards and ban the use of any toxic lead in new plumbing pipes, faucets and fixtures.

Individuals Matter Ashley Murray: Wastewater Engineer Entrepreneur and National Geographic Emerging Explorer

Earned MS and PhD degrees in engineering from the University of California. She has used her background in business, science and engineering to found and run Waste Enterprisers, a company devoted to revolutionizing the way we deal with wastewater and fecal sludge, especially in less-developed countries. Her approach is to promote cleaning up and reusing wastewater by viewing the energy it contains as a financially valuable resource that can be harnessed and sold.

Red tides

Excess nitrogen causes explosive growth of toxic microscopic algae, poisoning fish and marine mammals resulting in a reddish color.

What are the causes and effects of water pollution?

Illness and death in humans and other species and disrupts ecosystems. Chief sources are agricultural activities, industrial facilities and mining. Growth of both human population and our rate of resource use makes it increasingly worse.

How can we cleanup water pollution?

Improve oil-spill cleanup capabilities, and use nanoparticles on sewage and oil spills to dissolve the oil or sewage.

What activities are the second major source of water pollution?

Industrial activities

Why are lakes and reservoirs generally less effective at diluting pollutants than streams are?

Lakes and reservoirs contain stratified layers that undergo little vertical mixing and they have low flow rates or no flow at all.

What activity is the third biggest source of water pollution?

Mining

What are the Major water pollution problems affecting oceans?

Most ocean pollution originates on land and includes oil and other toxic chemicals, as well as solid waste, which threaten fish and wildlife and disrupt marine ecosystems. The key to protecting the oceans is to reduce the flow of pollution from land and air and from streams emptying into ocean waters.

The BP Deepwater Horizon Oil-Rig Spill

Oil-drilling rig that exploded and occurred in the Gulf of Mexico. Happened after the wellhead on the ocean bottom ruptured and released natural gas which resulted in a fire and explosion that killed 11. After 36 hours the rig sank releasing 4.9 million barrels of crude oil before it was capped. Contaminated coastal marshes, mangrove forests, sea-grass beds and fish nurseries. Some economic losses included the area's tourism business, and Gulf Coast fisheries. Causes include failure of equipment that could have detected the leak earlier, a faulty blowout preventer, failure of valves, etc...

2009 Exon Valdez Spill

On the evening of March 23, 1989, Exxon Valdez left the port of Valdez, Alaska. The impact of the collision on tore open the ship's hull, causing some 11 million gallons of crude oil to spill into the water. Skimmers, which collect water and then remove oil from the surface, were deployed over 24 hours after the spill. This resulted in the formation of double hulls for more safety.

What are ways to cleanup groundwater pollution?

Pump to surface, clean and return to aquifer (very expensive), inject microorganisms to clean up contamination (less expensive but still costly) and pump nanoparticles of inorganic compounds to remove pollutants

How to reduce non-point sources of water pollution?

Reducing soil erosion and fertilizer runoff by keeping cropland covered with vegetation and using conservation tillage and other soil conservation methods. Use fertilizers that release plant nutrients slowly. Using no fertilizers on steeply sloped land.

Ocean Garbage Patches

Roughly 80% of this trash comes from the land washed. The North Pacific Garbage Patch is estimated by some scientists to occupy an area at least the size of Texas. Hard to measure since there's a lot of small matter under these patches that accounts for the trash. These patches can be harmful to sea life since they can mistake it for food thus resulting in them to die from starvation, poisoning or choking. When fish ingest these harmful chemicals it can then spread to other aquatic life and then humans.

How can we prevent water pollution?

Separate sewage and storm water lines, require secondary treatment of coastal sewage, use wetlands and other natural methods to treat sewage, require double hulls for oil tankers, and ban dumping of wastes and sewage by ships in coastal waters.

What are the major water pollution problems in streams and lakes?

Streams and rivers around the world are extensively polluted, but they can cleanse themselves of many pollutants if we do not overload them or reduce their flows. Adding excessive nutrients to lakes from human activities can disrupt their ecosystems and prevention of such pollution is much more effective and less costly than cleaning it up.

oxygen sag curve

The curve obtained when the concentration of dissolved oxygen in a river into which sewage or some other pollutant has been discharged is plotted against the distance downstream from the sewage outlet so it tracks when point sources release waste

Black Sea Dead Zone in Soviet Union

The largest dead zone in the world, the lower portion of the Black Sea, occurs naturally. Oxygenated water is only found in the upper portion of the sea, where the Black Sea's waters mix with the Mediterranean Sea. The southern part of the Dead Sea is very bad as well.

Core Case Study The Gulf of Mexico's Annual Dead Zone

Water draining into the Mississippi River and its tributaries from farms, cities, factories an sewage treatment plants in this huge basin contain sediments and other pollutants that end up in the Gulf of Mexico, the major supplier of the countries fish and shellfish. Each spring and summer this huge input of plant nutrients mostly nitrates, from crop fertilizers, enters the northern Gulf of Mexico and over-fertilizes the coastal waters of the US states of Mississippi, Louisiana, and Texas. One result is an explosion of populations of phytoplankton (mostly algae) that eventually die and fall to the sea floor. Hoards of oxygen consuming bacteria go to work decomposing the phytoplankton remains and in process deplete the dissolved oxygen in the Gulf's bottom layer of water. This then results in a dead zone because it contains little animal marine life. Its low oxygen levels (called hypoxia) drive away faster swimming marine organisms and suffocate bottom dwelling fish, crabs, oysters and shrimp that cannot move to less polluted areas.

Nonpoint sources

are broad and diffuse areas where rainfall or snowmelt washes pollutants off the land into bodies of surface water. Runoff of eroded soil and chemicals such as fertilizers, hard to identify and control due to diffuse sources.

toxic sediments

chemicals and toxic metals contaminate shellfish beds, kill spawning fish, and accumulate in the tissues of bottom feeders

Healthy zone

clear, oxygen rich waters that promote growth of plankton and sea grasses and support/promote fish

Point sources

discharge pollutants into bodies of surface or underground water at specific locations through drain pipes, ditches, or sewer lines. Easy to identify, monitor and regulate.

How does cultural eutrophication contributes to dead zones?

especially in warm weather or drought since this overload can produce dense growths or blooms of organisms such as algae and cyanobacteria in slow-moving surface waters. When the algae die they are decomposed by swelling populations of aerobic bacteria which deplete the dissolved oxygen and this can kill aquatic life.

Secondary sewage treatment

is a biological process in which aerobic bacteria remove as much as 90% of dissolved and biodegradable, oxygen demanding organic wastes. A combination of primary and secondary treatment removes 95-97% of the suspended solids and oxygen demanding organic wastes.

Primary sewage treatment

is a physical process that uses screens and a grit tank to remove large floating objects and to allow solids such as sand and rock to settle out. Then the waste stream flows into a primary settling tank where suspended solids settle out as sludge

Septic tank

is a settling tank, where grease and oil rise to the top and solids fall to the bottom and are decomposed by bacteria. The partially treated wastewater that results is discharged in a large drainage field through small holes in perforated pipes embedded in porous gravel or crushed stone just below the soil's surface. As these wastes drain from the pipes and percolate downward, the soil filters out some potential pollutants.

Water pollution

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

What are several to clean up waters suffering from cultural eutrophication?

mechanically removing excess weeds, controlling undesirable plant growth with herbicides and algaecides, and pumping air into lakes and reservoirs to prevent oxygen depletion.

Solutions for water pollution

prevent groundwater contamination, reduce non point runoff, reduce air pollution, reduce poverty, slow population growth and find substitutes for toxic pollutants

The 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. This act strictly limits the levels of 91 potential contaminants contaminants in U.S. tap water.

Oxygen depleted zone

sedimentation and algae overgrowth reduce sunlight, kill beneficial sea grasses, use up oxygen, and degrade habitat results in a greenish color.

Federal Water Pollution Control Act of 1972 (Clean Water Act) and the 1987 Water Quality Act

set standards for allowed levels of 100 key water pollutants and require polluters to get permits that limit the amounts of these various pollutants that they can discharge into aquatic systems. Allowed for 95% of all Americans are served by public drinking water systems that must meet federal health standards. 60% of all tested U.S. streams, lakes and estuaries can be used safely for fishing and swimming, compared to 33% in 1972.

Ohio Cuyahoga River Fire

so polluted that is caught on fire multiple times and lead to elected officials enacting laws that 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, no longer flammable and is widely used by citizens.

What is the major problem that people face due to water pollution?

the exposure to infectious diseases such as typhoid fever, cholera, hepatitis B, giardiasis, etc...

Eutrophication

the name given to the natural nutrients enrichment of a body of water such as a lake, coastal areas at the mouth of a river or a slow moving stream.

Cultural eutrophication

the process near urban or agricultural areas, human activities can greatly accelerate the input of plant nutrients to a lake. These inputs come from phosphate-containing effluents such as farmland, feedlots, urban streets and parking lots.

Can flowing rivers and streams recover?

they can recover rapidly from moderate levels of pollution through a combination of dilution and bacterial biodegradation, but this does not work when streams are overloaded with such pollutants, or when drought, damming or water diversion reduces their flows.

What are several ways to prevent or reduce cultural eutrophication?

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

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.