Fresh Water Pollution Types Effects and Sources of

Fresh Water Pollution { Types, Effects, and Sources of Water Pollution

Infectious Agents Nitrate, phosphate, ammonium Source: sewage, manure, fertilizers Bacteria, viruses, protozoa, and parasitic worms Source: human and animal wastes Sediment Oxygen-Demanding Wastes Soil, silt Source: land erosion Organic waste (animal manure, plant matter) Radioactive Materials Source: human sewage, feedlots, Iodine, radon, uranium, cesium, paper mills and thorium Inorganic Chemicals Source: Nuclear and coal power plants, mining, nuclear weapons Acids, lead, arsenic, salts, production fluorides Source: surface runoff, industrial Heat (Thermal Pollution) effluents, cleansers Excessive heat Organic Chemicals Source: Water cooling of nuclear, electric, and industrial plants Oil, gasoline, pesticides, detergents Source: industrial effluents, solvents, runoff from farms Plant Nutrients Major Categories of Water Pollutants

{ Sediments are the most common pollutant. Major agricultural pollutants (fertilizers, pesticides, bacteria, food-processing wastes, and excess salts from irrigation) also contribute. Agricultural activities are the leading cause of water pollution!

Bacteria Hepatitis B Poliomyelitis Parasitic Protozoa Typhoid Fever Cholera Bacterial Dysentery Enteritis Viruses Death Related to Dehydration Amoebic Dysentery Giardiasis Cryptosporidium Parasitic Worms Schistosomiasis Ancylostomiasis Common Diseases Transmitted to Humans Through Contaminated Drinking Water

Fecal Coliform Test: measure number of colonies of coliform bacteria present in a 100 m. L sample of water BOD Test: the amount of oxygen demanding wastes in water Safe drinking water contains no colonies Safe swimming water contains a maximum of 200 colonies The amount of dissolved oxygen needed by aerobic decomposers to break down organic materials in a certain volume of water Chemical Analysis: determines the presence and concentrations of inorganic and organic chemicals Indicator Species: can analyze tissues of organisms found in water, or do a biodiversity count Measuring Water Quality

Water Quality DO (ppm) at 20˚C Good 8 -9 Slightly polluted 6. 7 -8 Moderately polluted Heavily polluted Gravely polluted 4. 5 -6. 7 Below 4. 5 Below 4 Dissolved Oxygen Content

{ Point Sources Discharge pollutants at specific locations through drain pipes, ditches, or sewer lines into surface water Factories Sewage treatment plants Underground mines Oil tankers { Nonpoint Sources Scattered and diffuse and hard to trace to a specific site of discharge Acid deposition Runoff Logged forests Urban streets Lawns and parking lots Sources of Water Pollution

Which is easier to monitor and control?

Water that flows recovers rapidly from degradable oxygendemanding wastes and thermal pollution (dilution) This works as long as the stream is not overloaded with pollutants and something does not reduce the flow of the stream (damming, drought, etc. ) Oxygen Sag Curve Freshwater Streams and Rivers

Types of organisms Clean Zone Normal clean water organisms (trout, perch, bass, mayfly, stonefly) Concentration Dissolved oxygen 8 ppm Decomposition Septic Zone Trash fish (carp, gar, leeches) Fish absent, fungi, sludge worms, bacteria (anaerobic) Recovery Zone Trash fish (carp, gar, leeches) Oxygen sag Biological oxygen demand 2 ppm Direction of flow Point of waste or heat discharge Time or distance downstream Clean Zone Normal clean water organisms (trout, perch, bass, mayfly, stonefly) 8 ppm

Dilution does not work as well as in running water Often contain stratified layers that do not mix Have little flow Ponds contain small volumes of water Much more vulnerable to pollution Plant nutrients, oil, pesticides, and heavy metals Can kill benthic life, fish, and birds Cultural eutrophication Freshwater Lakes and Reservoirs

Very vulnerable because it cannot effectively cleanse itself and dilute and disperse contaminants Clean up is also almost impossible Sources: storage lagoons, septic tanks, landfills, hazardous waste dumps, deep injection wells We store gasoline, oil, solvents, and hazardous wastes in metal underground tanks that can leak over time High health risks in drinking water Groundwater Pollution

CWA sets standards for allowed levels of 100 key water pollutants and requires polluters to get permits that limit how much of these pollutants they can discharge into aquatic systems. EPA is experimenting with a “cap and trade” type system Clean Water Act 1977 and 1987 Water Quality Act

Water Pollution Control laws (1970 s) Increased the number and quality of wastewater plants in US and most other developed countries Require industries to reduce or eliminate point -source discharges Problem: the developing world Problem: “accidents” 2014 Elk River chemical spill of MCHM What has been done?

Life. Straw Protecting Wetlands • Natural purification • Better investment than building expensive water treatment facilities Water Purification • New York--$6 billion to build plant or $1. 5 billion to protect watershed? ? ?

EPA establishes national drinking water standards (maximum contamination levels) for any pollutants Currently limits 91 pollutants Some want to weaken the law Eliminate national testing of drinking water Eliminate requirements for public notification about violations of drinking water standards Allow states to give providers permanent exemptions for contaminants they claim they cannot afford to comply with Reduce EPA’s budget U. S. Safe Drinking Water Act of 1974

MATH WINS …by the people that live there. Is bottled water the answer?

Primary sewage treatment—a physical process Secondary sewage treatment—a biological process Screens and grit tank remove large floating objects Sand rock settle out Suspended solids settle out as sludge Removes about 60% of the suspended solids and 30 -40% of the oxygendemanding organic wastes Aerobic bacteria remove 90% of dissolved and biodegradable wastes Removes only a tiny fraction of persistent organic substances like pesticides and pharmaceuticals Does not kill pathogens Tertiary (advanced) treatment—uses series of special chemical and physical processes to remove specific pollutants. Not widely used because of its high cost. Sewage Treatment

Water undergoes bleaching Remove water coloration Kills bacteria and some viruses Chlorination is usually used Reacts with organic materials in water to become chlorinated hydrocarbons These can cause cancers (in test animals), increase miscarriage risk, and damage the nervous, immune, and endocrine systems Alternatives are ozone and UV filters (they are expensive and effects don’t last as long) Water Discharge

Federal law requires primary and secondary treatment for all municipal sewage treatment plants. Exemptions from secondary treatment when cost of installing poses an excessive financial burden on towns and cities According to the EPA… 2/3 of country’s sewage plants have violated water pollution regulations 500 cities have failed to meet federal standards 34 east coast cities only screen out large floating objects before discharging into the Atlantic Skirting the Law

Some cities have two different networks of pipes, one for storm runoff from streets, and another for sewage. 1200 cities have a combined system It is cheaper Can cause overflows (40, 000 each year) Combined Sewer