Water Pollution

WHAT IS WATER POLLUTION Any physical, biological, or chemical change in water quality that adversely affects living organisms can be considered pollution. Any physical, biological, or chemical change in water quality that adversely affects living organisms can be considered pollution. –Point Sources - Discharge pollution from specific locations. Factories, Power plants Factories, Power plants –Non-Point Sources - Scattered or diffuse, having no specific location of discharge. Agricultural fields, Feedlots Agricultural fields, Feedlots

Water Pollution –Atmospheric Deposition - Contaminants carried by air currents and precipitated into watersheds or directly onto surface waters. Estimated 600,000 kg of the herbicide atrazine in the Great Lakes. Estimated 600,000 kg of the herbicide atrazine in the Great Lakes. –Most thought to have been deposited from the atmosphere. Contaminants can also evaporate from lakes. Contaminants can also evaporate from lakes.

TYPES AND EFFECTS OF WATER POLLUTION Infectious Agents Infectious Agents –Main source of waterborne pathogens is untreated and improperly treated human waste. Animal wastes from feedlots and fields is also an important source of pathogens. Animal wastes from feedlots and fields is also an important source of pathogens.

Infectious Agents In developed countries, sewage treatment plants and pollution-control devices have greatly reduced pathogens. In developed countries, sewage treatment plants and pollution-control devices have greatly reduced pathogens. –Coliform bacteria - Intestinal bacteria. –Protists – drinking water contamination –Drinking water generally disinfected via chlorination. At least 2.5 billion people in less developed countries lack adequate sanitation, and about half of these lack access to clean drinking water. At least 2.5 billion people in less developed countries lack adequate sanitation, and about half of these lack access to clean drinking water.

Thermal Pollution Industrial cooling processes often use heat-exchangers to extract excess heat, and then discharge heated water back into original source. Industrial cooling processes often use heat-exchangers to extract excess heat, and then discharge heated water back into original source. –Sources: Coal Burning & Nuclear Plants Warm water lowers the ability to hold oxygen – so…lowers dissolved oxygen Warm water lowers the ability to hold oxygen – so…lowers dissolved oxygen Thermal Shock – rapid temperature change kills fish in the immediate area Thermal Shock – rapid temperature change kills fish in the immediate area

Plant Nutrients and Cultural Eutrophication Oligotrophic - Bodies of water that have clear water and low biological productivity. Oligotrophic - Bodies of water that have clear water and low biological productivity. Eutrophic - Bodies of water that are rich in organisms and organic material. Eutrophic - Bodies of water that are rich in organisms and organic material. –Eutrophication - Process of increasing nutrient levels and biological productivity. Cultural Eutrophication - Increase in biological productivity and ecosystem succession caused by human activities. Cultural Eutrophication - Increase in biological productivity and ecosystem succession caused by human activities.

Organic Chemicals Thousands of natural and synthetic organic chemicals are used to make pesticides, plastics, pharmaceuticals, pigments, etc. Thousands of natural and synthetic organic chemicals are used to make pesticides, plastics, pharmaceuticals, pigments, etc. Two most important sources of toxic organic chemicals in water are: Two most important sources of toxic organic chemicals in water are: –Improper disposal of industrial and household wastes. –Runoff of pesticides from high-use areas & farms. Fields, roadsides, golf courses Fields, roadsides, golf courses

Oxygen-Demanding Wastes Water with a dissolved oxygen content Water with a dissolved oxygen content > 6 ppm will support desirable aquatic life. > 6 ppm will support desirable aquatic life. –Water with < 2 ppm DO will support mainly detritivores and decomposers. Oxygen is added to water by diffusion from wind and waves, and by photosynthesis from green plants, algae, and cyanobacteria. Oxygen is added to water by diffusion from wind and waves, and by photosynthesis from green plants, algae, and cyanobacteria. –Oxygen is removed from water by respiration and oxygen-consuming processes.

Oxygen-Demanding Wastes Biochemical Oxygen Demand - Amount of dissolved oxygen consumed by aquatic microorganisms. Biochemical Oxygen Demand - Amount of dissolved oxygen consumed by aquatic microorganisms. –Dissolved Oxygen Content - Measure of dissolved oxygen in the water. Effects of oxygen-demanding wastes on rivers depend on volume, flow, and temperature of river water. Effects of oxygen-demanding wastes on rivers depend on volume, flow, and temperature of river water. –Oxygen Sag - Oxygen levels decline downstream from a pollution source as decomposers metabolize waste materials.

INPUT of WASTE or THERMAL POLLUTION

Sediment Human activities have accelerated erosion rates in many areas. Human activities have accelerated erosion rates in many areas. –Human-induced erosion and runoff contribute about 75 billion metric tons of suspended solids to world surfaces each year. Sediment can either be beneficial (nourish floodplains) or harmful (smother aquatic life – decrease photosynthesis). Sediment can either be beneficial (nourish floodplains) or harmful (smother aquatic life – decrease photosynthesis).

Inorganic Pollutants Metals Metals –Many metals such as mercury, lead, cadmium, and nickel are highly toxic. Highly persistent and tend to bioaccumulate in food chains. Highly persistent and tend to bioaccumulate in food chains. –Lead pipes are a serious source of drinking water pollution. –Mine drainage and leaching are serious sources of environmental contamination.

Inorganic Pollutants Nonmetallic Salts Nonmetallic Salts –Many salts that are non-toxic at low concentrations can be mobilized by irrigation and concentrated by evaporation, reaching levels toxic to plants and animals. Leaching of road salts has had detrimental effect on many ecosystems. Leaching of road salts has had detrimental effect on many ecosystems. Acids and Bases Acids and Bases –Often released as by-products of industrial processes.

WATER QUALITY TODAY Areas of Progress Areas of Progress –Clean Water Act (1972) established a National Pollution Discharge System which requires a permit for any entity dumping wastes in surface waters. In 1999, EPA reported 91.4% of all monitored river miles and 87.5% of all accessed lake acres are suitable for their designated uses. In 1999, EPA reported 91.4% of all monitored river miles and 87.5% of all accessed lake acres are suitable for their designated uses. –Most progress due to municipal sewage treatment facilities.

Water Quality Today

Remaining Problems Greatest impediments to achieving national goals in water quality are sediment, nutrients, and pathogens, especially from non- point discharges. Greatest impediments to achieving national goals in water quality are sediment, nutrients, and pathogens, especially from non- point discharges. –About three-quarters of water pollution in the US comes from soil erosion, air pollution fallout, and agricultural and urban runoff. Single cow produces 30 kg manure/day. Single cow produces 30 kg manure/day. –Some feedlots have 100,000 animals.

Open Pit Mines (coal, copper, uranium, lead, gold, silver) Open Pit Mines (coal, copper, uranium, lead, gold, silver) Exposes waste rock like pyrite (FeS 2 ) which can react with water to form sulfuric acid. Exposes waste rock like pyrite (FeS 2 ) which can react with water to form sulfuric acid. Releases ferric ions (Fe++) Releases ferric ions (Fe++) Leaches toxic heavy metals (Al3+, Zn2+) Leaches toxic heavy metals (Al3+, Zn2+) Red Staining “Yellow Boy” Red Staining “Yellow Boy” Changes pH (can be higher or lower as it degrades natural buffers Changes pH (can be higher or lower as it degrades natural buffers Increases conductivity and hardness Increases conductivity and hardness

Groundwater and Drinking Water About half the US population, and 95% of rural residents, depend on underground aquifers for drinking water. About half the US population, and 95% of rural residents, depend on underground aquifers for drinking water. –For decades, groundwater was assumed impervious to pollution and was considered the gold standard for water quality. Estimated 1.5 million Americans fall ill from fecal contamination annually. Estimated 1.5 million Americans fall ill from fecal contamination annually. –Cryptosporidium outbreaks

Groundwater and Drinking Water Leaks from storage lagoons, septic tanks, & landfills Leaks from storage lagoons, septic tanks, & landfills Agricultural runoff - pesticides Agricultural runoff - pesticides Other Organic toxins – solvents, paints, oil, MTBE Other Organic toxins – solvents, paints, oil, MTBE (human health risk arise from petrochemicals, organic solvents, pesticide, arsenic, fluorine, & lead) EPA estimates 4.5 trillion liters of contaminated water seep into the ground in the US every day. EPA estimates 4.5 trillion liters of contaminated water seep into the ground in the US every day. 51% of Drinking Water comes from Ground Water 51% of Drinking Water comes from Ground Water

Groundwater Pollution

Surface Waters in Other Countries Sewage treatment in wealthier countries of Europe generally equal or surpass the US. Sewage treatment in wealthier countries of Europe generally equal or surpass the US. In Russia, only about half of the tap water supply is safe to drink. In Russia, only about half of the tap water supply is safe to drink. In urban areas of South America, Africa, and Asia, 95% of all sewage is discharged untreated into rivers. In urban areas of South America, Africa, and Asia, 95% of all sewage is discharged untreated into rivers. Two-thirds of India’s surface waters are contaminated sufficiently to be considered dangerous to human health. Two-thirds of India’s surface waters are contaminated sufficiently to be considered dangerous to human health.

Contain 95% of freshwater (surface) in US; 20% globally Contain 95% of freshwater (surface) in US; 20% globally 14% of US population lives in lake basin; 30% Canada 14% of US population lives in lake basin; 30% Canada Heavily Polluted – suffers from mercury, PCB’s, cultural eutrophication, & bacterial contaminents Heavily Polluted – suffers from mercury, PCB’s, cultural eutrophication, & bacterial contaminents 2/3 of basin wetlands have been lost in the last 400 yrs. 2/3 of basin wetlands have been lost in the last 400 yrs.

Belugas’ body mass is so polluted if they wash ashore they have to be disposed of as “toxic waste” Through improved sewage treatment, treatment of industrial waste, & ban on phosphates have improved water quality drastically