Water Pollution

Tertiary sewage treatment

Advanced sewage treatment

Which soil test would be most helpful in deciding where to place a septic tank?

Clay

Effluent

Liquid waste or sewage discharged into a river or the sea.

Four diseases transmitted to humans through contaminated water

Giardia, Legionella, Norovirus, & Shigella

Oxygen Sag Curve

illustrates what happens to dissolved oxygen levels and B.O.D. levels in streams where degradable, oxygen-demanding wastes are added.

The availability of clean drinking water for the Earth's human population

- 97.5% of all water on Earth is salt water, leaving only 2.5% as fresh water - Nearly 70% of that fresh water is frozen in the icecaps of Antarctica and Greenland; most of the remainder is present as soil moisture, or lies in deep underground aquifers as groundwater not accessible to human use. - Only 1% of the world's fresh water is accessible for direct human uses. This is the water found in lakes, rivers, reservoirs and those underground sources that are shallow enough to be tapped at an affordable cost. Only this amount is regularly renewed by rain and snowfall, and is therefore available on a sustainable basis.

Groundwater prevention

- Find substitutes for toxic chemicals - Keep toxic chemicals out of the environment - Ban hazardous waste disposal in landfills and injection wells

Discharge Trading Policy

- Uses market forces to reduce water pollution in the United States - A water pollution source is allowed to pollute at levels higher than allowed in its permit if it buys credits from permit holders with pollution levels below what they are allowed.

Septic Tank

A big container or steel tank that is buried in the yard and may hold 1,000 gallons of water. Wastewater flows into the tank at one end and leaves the tank at the other.

Coliform Bacteria

A commonly used bacterial indicator of sanitary quality of foods and water. They are defined as rod-shaped Gram-negative non-spore forming and motile or non-motile bacteria which can ferment lactose with the production of acid and gas when incubated at 35-37°C.

Pfiesteria Piscida

A dinoflagellate species of the genus Pfiesteria that some researchers claim is responsible for many harmful algal blooms in the 1980s and 1990s on the coast of North Carolina and Maryland.

Chlorination

A disinfection process by which chlorine is added to drinking water or sewage effluent to kill bacteria

Trickling Filters

A fixed-bed, biological reactor that operates under (mostly) aerobic conditions. Pre-settled wastewater is continuously 'trickled' or sprayed over the filter. As the water migrates through the pores of the filter, organics are degraded by the biofilm covering the filter material.

Cultural Eutrophication

A form of water pollution. This also occurs when excessive fertilizers run into lakes and rivers. This encourages the growth of algae (algal bloom) and other aquatic plants. Prevent by use of less pollutants. Cleanup by filtering water.

Cryptosporidium

A genus of apicomplexan protozoans that can cause a respiratory and gastrointestinal illness that primarily involves watery diarrhea with or without a persistent cough in both immunocompetent and immunodeficient humans.

Advantages/disadvantages of combined sewage/rainwater runoff pipes

Advantages - Convenience (minimal intervention by users) - Low health risk - No nuisance from smells, mosquitoes or flies - Less maintenance compared to simplified and solids-free sewers - Greywater and possibly stormwater can be managed concurrently - Can handle grit and other solids, as well as large volumes of flow - No problems related to discharging industrial wastewater Disadvantages - Very high capital costs; high operation and maintenance costs - A minimum velocity must be maintained to prevent the deposition of solids in the sewer - Requires deep excavations - Difficult and costly to extend as a community changes and grows - Difficult to construct in high-density areas, difficult and costly to maintain - Recycling of nutrients and energy becomes difficult - Requires expert design, construction and maintenance - Leakages pose a risk of wastewater exfiltration and groundwater infiltration and are difficult to identify

Advantages/disadvantages of separate sewage/rainwater runoff pipes

Advantages - Surface run-off, greywater and blackwater can be managed separately (no contamination of surface run-off by sewage) - Limited or no risk of sewage overflow - Convenience (minimal intervention by users) - Low health risk - No nuisance from smells, mosquitoes or flies - No problems related to discharging industrial wastewater - Moderate operation costs - Surface run-off and rainwater can be reused (e.g. for landscaping or agriculture) after a simplified treatment Disadvantages - Needs a reliable supply of piped water - Difficult to construct in high-density areas, difficult and costly to maintain - High capital costs, more expensive than combined sewer system (two networks are necessary) - Unsuitability for self-help, requires skilled engineers and operators - Need for pumping on flat ground - Problems associated with blockages and breakdown of pumping equipment - Adequate treatment and/or disposal required for a large point source discharge - Higher risk of water pollution by accidents (e.g. oil, chemicals, etc.)

Infectious agents/Biological pollutants

As a result of bacterial contamination in drinking water many peoples become ill. Other examples of biological pollutants include viruses, protozoa, and parasitic worms. These infectious agents enter the environment from human and animal wastes, and they cause a variety of serious diseases.

Biomagnification vs Bioaccumulation

Bioaccumulation is defined as the increase in concentration of a substance(s) in an organism or a part of that organism.Toxic substances are lipophilic or fat-loving, the reason why these substances are deposited and concentrated in the fat tissues of the organisms. The affected organism has a higher concentration of the substance than the concentration in the organism's surrounding environment. The toxic substances are very slowly metabolized or excreted so if the organism keeps on consuming prey or food contaminated with toxic substances, the concentration of the substance will further increase in its body, hence, bioaccumulation results. When a certain threshold level is reached, measured in parts per million (ppm), symptoms due to the type of toxin are manifested. Biomagnification is also called Bioamplification. It is simply the increase in concentration of a substance in a food chain, not an organism. Persistent organic pollutants (POPs) are compounds that biomagnify. Persistent organic pollutants (POPs) are chemical substances that persist in the environment. These substances bioaccumulate through the food web and pose risk not only to humans but also other living organisms because of their adverse effects. These pollutants consists of pesticides (such as DDT), industrial chemicals (such as polychlorinated biphenyls, PCBs) and unintentional by-products of industrial processes (such as dioxins and furans). In essence, biomagnification is similar to bioaccumulation but is descriptive of higher level biological processes, not individual.

B.O.D.

Biological Oxygen demand - the amount of oxygen tht is used or demanded as waste material is digested or oxidized in organisms; higher values remove greater amounts dissolved oxygen from aquaic ecosystems; raw sewage has extremely high values and thus can lower dissolved oxygen very rapidly; measured in mg/L.

Black Mayonnaise

Black Mayonnaise Is at the Bottom of the Gowanus Canal "There is on average about 10 feet of sediment that has accumulated because of industrial waste and New York City discharge. The color is like lava, really black. It just kind of oozes. There is a stench associated with it. And it has the texture of thick mayonnaise, so it's very unpleasant stuff. It's a mixture of products, and a mixture always scares you because you don't have a handle on it. You don't know what it is." —Christos Tsiamis, the Environmental Protection Agency Superfund project manager in charge of determining how dirty sites are and how best to clean them up, has no idea what is at the bottom of the Gowanus Canal

Problems with drinking bottled water

Bottled water is wasteful while tap water is just as safe but does not require plastic.

Nonpoint Source Pollution

Caused by rainfall or snow melt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters and ground waters.

Water quality of coastal wetlands and ways to protect these areas

Coastal wetlands include saltwater and freshwater wetlands located within coastal watersheds. 1. Participate in programs that help protect and restore wetlands. Contact local, state, or federal agencies, community groups, environmental organizations and other non-government organizations. See American Wetlands Month events. 2. Report illegal actions such as unauthorized wetland fill or dredging activities to government authorities, such as the U.S. Environmental Protection Agency or the U.S. Army Corps of Engineers. 3. Pick up litter and dispose in appropriate trash containers. Keep surface areas that wash into storm drains clean from pet waste, toxic chemicals, fertilizers and motor oil, which can eventually reach and impair our wetlands. 4. Use native species when planting trees, shrubs and flowers to preserve the ecological balance of local wetlands. 5. Use "living shoreline" techniques that make use of plant roots to stabilize soil if you own waterfront property and your shoreline or river bank needs to be stabilized. 6. Avoid wetlands if you are expanding your house or installing a shed. 7. Use phosphate-free laundry and dishwasher detergents. Phosphates encourage algae growth, which can suffocate aquatic life. 8. Use paper and recycled products made from unbleached paper. Bleached paper contains toxic chemicals that can contaminate water. 9. Use non-toxic products for household cleaning and lawn and garden care. Never spray lawn and garden chemicals outside on a windy day or on a day that it might rain and wash the chemicals into waterways. 10. Enjoy the scenic and recreational opportunities coastal wetlands offer, while preserving their integrity for future generations by minimizing the use of heavy equipment and staying in designated visitor areas where available.

Sediments

Erosion of soils is the main process contributing sediments, or silts, to water bodies. Sediments can cloud the water of streams and rivers, reducing the amount of available sunlight to aquatic plants. The concurrent reduction in photosynthesis can disrupt the local ecosystem. Soil from croplands deposited in lakes and streams can carry bacteria, pesticides, and other substances that are harmful to aquatic life.

Chesapeake Bay case study

For centuries, the bay supported a rich abundance of valuable fisheries: striped bass, shad, herring, oysters and blue crabs. Extensive oyster reefs once supported a large and lucrative fishery. In the first half of the twentieth century, oysters began a precipitous decline as a result of over-fishing and habitat destruction. The loss of oysters contributed to the overall decline in water quality and increasing turbidity that in turn contributed to the disappearance of the once extensive sea-grass beds. Now, oysters no longer carpet the bay's bottom, which has changed from a hard bottom covered with shells to a soft muddy bottom. Submerged aquatic vegetation covers less than half the area it did ten years ago (despite a partial comeback).

Oxygen depleting wastes

Includes animal manure in feedlot and farm runoff, industrial discharge, plant debris, and urban sewage. They are consumed by aerobic bacteria. Excessive growth of these organisms can deplete water of dissolved oxygen which leads to eutrophication and the eventual death of oxygen consuming aquatic life. That is, excessive growth of these organisms occur corrosion.

Thermal pollution

Industrial discharges are one of the sources of thermal pollution. The increased temperature of the water may locally deplete dissolved oxygen and exceed the range of tolerance of some aquatic species, thus disrupting the local ecosystem. Power generating plant commonly discharges water used for cooling into a nearby river, lake, or ocean. Because the discharged water can be significantly warmer than the ambient environment, it represents a source of thermal pollution.

Lake Baikal case study

Lake Baikal is the world's oldest and deepest lake. It lies in southern Siberia, its watershed extending over the Mongolian border. The lake is revered by the Russian people as a source of beauty and power. Preservation of the lake, however, has recently come to international attention. The Paper-and-Pulp Mill at Baikal has polluted the surrounding region and threatens the pristine conditions that have existed for centuries. The paper mill produces bleached cellulose that is used in clothing manufacture. The process, however, produces chemicals and effluent that threaten the more than 1,500 species unique to the lake. In addition, the economic and political difficulties currently facing Russia pose their own threat - that efforts to preserve the lake may not be instituted due to lack of funding or inability to form a consensus. The success of Lake Baikal has been viewed as critical to other environmental efforts throughout the world.

Dredge Spoils

Materials with toxic waste scraped from the bottoms of rivers to maintain shipping canals.

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.

Major sources of nutrient-overload in lakes and ponds

Most comes from nitrate and phosphate runoff used in agricultural fertilizers, which spurs rapid growth of plants.

Valdez Oil Spill

Occurred in Prince William Sound, Alaska, on March 24, 1989, when Exxon Valdez, an oil tanker bound for Long Beach, California, struck Prince William Sound's Bligh Reef at 12:04 am local time and spilled 11 to 38 million US gallons (260,000 to 900,000 bbl; 42,000 to 144,000 m3) of crude oil over the next few days. It is considered to be one of the most devastating human-caused environmental disasters.

Thermal Shock

Occurs when a thermal gradient causes different parts of an object to expand by different amounts. This differential expansion can be understood in terms of stress or of strain, equivalently. At some point, this stress can exceed the strength of the material, causing a crack to form.

Minamata case study

Over 3,000 victims have been recognized as having "Minamata Disease". It has taken some of these people over thirty years to receive compensation for this inconceivable event. In 1993, nearly forty years later, the Japanese courts were still resolving suitable compensation for the victims. Many people have lost their lives, suffered from physical deformities, or have had to live with the physical and emotional pain of "Minamata Disease". This suffering is all a result of the very wrongful and negligent acts of the Chisso Corporation who dumped mercury into the sea water and poisoned the people of Japan.

Ozonation

Ozone has a greater disinfection effectiveness against bacteria and viruses compared to chlorination. In addition, the oxidizing properties can also reduce the concentration of iron, manganese, sulfur and reduce or eliminate taste and odor problems. Ozone oxides the iron, manganese, and sulfur in the water to form insoluble metal oxides or elemental sulfur. These insoluble particles are then removed by post-filtration. Organic particles and chemicals will be eliminated through either coagulation or chemical oxidation. Ozone is unstable, and it will degrade over a time frame ranging from a few seconds to 30 minutes. The rate of degradation is a function of water chemistry, pH and water temperature.

Why is the cleanup of groundwater difficult?

Pollutants fill aquifers' porous layers and absorb into the sand, gravel, and bedrock like water into a sponge. Furthermore, groundwater cannot cleanse itself of degradable wastes. Because groundwater flows very slowly, contaminants are not diluted and dispersed effectively. Groundwater also has low concentrations of dissolved oxygen and smaller populations of decomposing bacteria. Lastly, the cold temperatures of groundwater slow down chemical reactions that decompose wastes.

Woburn, Massachusetts case study

Pollution was detected as early as 1927, when the city decided to construct a sewer to alleviate the problem. In 1958 the city's public water consultant warned that, "the groundwater of this [Aberjona River] valley are, in general, too polluted to be used for a public water supply." Two years later, W.R. Grace & Co. opened a small machine shop in Woburn. In 1964 the City of Woburn installed Well G in close proximity to the Aberjona River in order to meet the growing demand for public water, and this installation was to be followed three years later by the addition of Well H nearby. In 1975, the Massachusetts Department of Health recommended that Woburn not rely on Wells G & H due to chemical contamination, and one year later ordered the removal of manganese and iron from these wells. The wells were finally closed in 1979, when the Massachusetts Department of Environmental Quality Engineering found them contaminated with several VOCs, including trichloroethylene and tetrachloroethylene.

Activated Sludge

Refers to a mass of microorganisms cultivated in the treatment process to break down organic matter into carbon dioxide, water, and other inorganic compounds.

Water Quality Tests

Scientists test for fecal coliform in water (feces) as well as dissolved oxygen levels through chemical analysis of the concentration of organic chemicals.

Secondary sewage treatment

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

Major pollutants of groundwater

Storage Tanks May contain gasoline, oil, chemicals, or other types of liquids and they can either be above or below ground. There are estimated to be over 10 million storage tanks buried in the United States and over time the tanks can corrode, crack and develop leaks. If the contaminants leak out and get into the groundwater, serious contamination can occur. Septic Systems Onsite wastewater disposal systems used by homes, offices or other buildings that are not connected to a city sewer system. Septic systems are designed to slowly drain away human waste underground at a slow, harmless rate. An improperly designed, located, constructed, or maintained septic system can leak bacteria, viruses, household chemicals, and other contaminants into the groundwater causing serious problems. Uncontrolled Hazardous Waste In the U.S. today, there are thought to be over 20,000 known abandoned and uncontrolled hazardous waste sites and the numbers grow every year. Hazardous waste sites can lead to groundwater contamination if there are barrels or other containers laying around that are full of hazardous materials. If there is a leak, these contaminants can eventually make their way down through the soil and into the groundwater. Landfills Landfills are the places that our garbage is taken to be buried. Landfills are supposed to have a protective bottom layer to prevent contaminants from getting into the water. However, if there is no layer or it is cracked, contaminants from the landfill (car battery acid, paint, household cleaners, etc.) can make their way down into the groundwater. Chemicals and Road Salts The widespread use of chemicals and road salts is another source of potential groundwater contamination. Chemicals include products used on lawns and farm fields to kill weeds and insects and to fertilize plants, and other products used in homes and businesses. When it rains, these chemicals can seep into the ground and eventually into the water. Road salts are used in the wintertime to put melt ice on roads to keep cars from sliding around. When the ice melts, the salt gets washed off the roads and eventually ends up in the water. Atmospheric Contaminants Since groundwater is part of the hydrologic cycle, contaminants in other parts of the cycle, such as the atmosphere or bodies of surface water, can eventually be transferred into our groundwater supplies.

Radioactive materials

Such as iodine-131 and strontium-90, radioactive materials are found in nuclear power plant effluents and fallout from atmospheric nuclear testing. They can be introduced into the food chain through plants and become incorporated in body tissues of humans and animals. Their ionizing radiation can produce cancers, especially in the thyroid and bone where they tend to concentrate.

Great Lakes case study

The Great Lakes contain 20 percent of the world's freshwater resources by volume, and maintaining their sustainability is critical to future dependency on the resource. But unlike many water resources, the Great Lakes region is vast, encompassing one Canadian province (Ontario) and eight U.S. states: Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin. This large region makes problem-solving difficult, as problems cross local governance boundaries, requiring group solutions and agreements across municipal, state and federal agencies. These political boundaries may present challenges for decision makers, but the problems of the water body remain the same, irrespective of politics. In the Great Lakes region, ecological and economic damage is created by invasive aquatic and terrestrial species, as well as pervasive levels of toxic pollutants. Faced with this challenge, in 2010 the U.S. federal government, the EPA and 15 other federal agencies launched a $475 million Great Lakes Restoration Initiative to return the Great Lakes to pristine condition and leave the region in better condition for future generations.

Kesterson National Wildlife Refuge case study

The Kesterson Reservoir is the name of a former unit of the Kesterson National Wildlife Refuge which is part of the current San Luis National Wildlife Refuge. The site gained national attention during the latter half of the 20th century due to selenium toxicity and rapid die off of migratory waterfowl, fish, insects, plants and algae within the Kesterson Reservoir.

Point Source Pollution

The U.S. Environmental Protection Agency (EPA) defines point source pollution as "any single identifiable source of pollution from which pollutants are discharged, such as a pipe, ditch, ship or factory smokestack" (Hill, 1997). Factories and sewage treatment plants are two common types of point sources.

Clean Water Act

The primary federal law in the United States governing water pollution. Its objective is to restore and maintain the chemical, physical, and biological integrity of the nation's waters by preventing point and non point pollution sources, providing assistance to publicly owned treatment works for the improvement of wastewater treatment, and maintaining the integrity of wetlands.

Safe Drinking Water Act

The principal federal law in the United States intended to ensure safe drinking water for the public.

Thermal Pollution vs Thermal Enrichment

Thermal pollution is the degradation of water quality by any process that changes ambient water temperature. Thermal enrichment is warm water from power plants that can also be used for irrigation to extend the growing season in frost-prone areas and cycled through aquaculture pens to speed the growth of commercially valuable fish and shellfish. For example, waste hot water is used to cultivate oysters in aquaculture lagoons in Japan and in New York's Long Island Sound and to cultivate catfish and redfish in Texas.

Organic chemical pollutants

These pollutants encompass a wide variety of compounds including oil, pesticides, gasoline, and organic solvents. They all degrade the quality of the water into which they are discharged. Sources of these organic pollutants include industrial discharge and runoff from farms and urban areas. Sometimes they enter aquatic ecosystems directly when sprayed on lakes and ponds (e.g. for mosquito control). These types of chemicals can cause cancer, damage the central nervous system and cause birth defects in humans,etc.

Plant nutrient pollutants

They are found mainly in urban sewage, runoff from farms and gardens, and household waste water. These chemicals include nitrates (NO3-), phosphates (PO43-) and ammonia (NH4+) salts commonly found in fertilizers and detergents. Excess of plant nutrients in the water can cause excessive algae growth in lakes or ponds. This, in turn, results in the production of large amounts of oxygen depleting wastes. The subsequent loss of dissolved oxygen causes eutrophication of the lakes or ponds.

Inorganic chemical pollutants

This is found in industrial discharge, chemicals in household waste water, and seepage from municipal dumps and landfills. The presence of these pollutants in water can render it undrinkable, as well as cause cancer and birth defects. Sufficient concentrations of these chemicals in water can kill fish and other aquatic life, cause lower crop yields due to plant damage, and corrode metals. These pollutants include mineral acids, toxic metals such as lead, cadmium, mercury, and hexavalent chromium, mineral salts, etc.

Indicator Species

Those whose critical tolerance limits can be used to judge the environmental conditions.

Ways to prevent and ways to reduce surface-water pollution resulting from agriculture

Use fewer pesticides and fertilizers and find substitutes for them.