Non-Point Sources are dispersed and difficult to pin point
Ex. agricultural run off, run off from live stock feed lots, lawns of suburban neighborhoods, construction sites, streets and parking lots, acid rain etc.
Major Sources of Water Pollution
Agriculture: agricultural runoff, erosion from overgrazed land, microorganisms from live stock, wastes from food processing industries, excess salts from soils of irrigated crop land
Industries: wastes stored can leach to surface and/or ground water
Surface mining: disturbs earth’s surface, runoff of toxic chemicals
Pollution of Fresh Water Streams
As the water is flowing, moderate amounts of biodegradable wastes and excess heat gets diluted easily in a stream
It is a problem when large amounts of pollutants contaminate the stream or
The water flow is reduced due to
Diverted to agriculture or industries
Pollution of Fresh Water Reservoirs
Surface water reservoirs like lakes can easily get contaminated with pollutants as water is mostly stagnant
Additionally, there is little vertical mixing among the stratified layers of a lake which further inhibits the dilution of the pollutant
Air pollutants produced by industries and automobiles, agricultural run off, run off from mining and construction sites, run off from streets and lawns are the major sources leading to nutrient overload of lakes
Construction site runoff in Davidson, North Carolina
Runoff from farm fields reaches sediment-laden stream in southwestern Iowa
1. Nutrient rich runoff from farmlands to surface water reservoirs allows phytoplanktons to grow uncontrollably. So zooplanktons that feed on them grow uncontrollably too.
2. When phytoplanktons & zooplanktons die and sink to the bottom, aerobic decomposers metabolize them, consuming almost all of the dissolved O2 in the water creating a hypoxic zone where no aerobic organisms can live.
Relationship between Dissolved Oxygen Levels and Water Quality
DO (ppm) at 200C
Miller T. G. 2005. Living in the Environment, 14th edition, Brooks/Cole, Page 492.
How Ground Water Gets Polluted?
Leakage from underground septic tanks, industrial waste storage tanks, chemical storage ponds, agricultural runoff can easily contaminate water in an aquifer
The plume of contaminated water may reach a well which is used as a source of ground water for human consumption and/or for agriculture
Pollutants in Drinking Water are Harmful to Human Health
High levels of naturally occurring fluoride(F-) in drinking water may lead to crippling backbone disease, neck damage and is responsible for many dental problems
NO3 ions from agricultural run off can contaminate ground water. NO2 ions in the digestive system react with these NO3 ions in the water after human consumption to form organic intermediates which can be carcinogenic
These NO3 ions when in blood interfere with oxygen circulation especially in infants causing ‘blue baby syndrome’
Arsenic(As) enters drinking water when a well is drilled in the rock naturally rich in it. Long term exposure to As may lead to various cancers
Quick detection system for leakage of underground storage tanks and pipe lines
No dumping of hazardous wastes in landfill, make people aware of recycling centers
Pump up the polluted water to clean up, then return to aquifer (may not be cost efficient)
Prevention is better than cure!
How to Keep Ground Water Safe?
Reduce the use of chemical fertilizers by planting native trees
Increase use of greywater (treated waste water from homes and office buildings)
Use ecologically friendly methods to treat sewage (black water)
Minimize industrial air pollution
Educate public about refuse, reduce, reuse and recycle
How to prevent water pollution? Water pollution can be prevented by educating the public on the following issues:
Why the use of synthetic, chemical fertilizers, and pesticides should be reduced and the use of green fertilizer or manure should be increased
How to compost the kitchen organic waste
Never to dump household chemicals such as oil (frying oil or car oil), paint thinners, paints, pesticides, unwanted medicines etc. onto the ground or down the drain
Never to apply pesticides or synthetic fertilizers near a water reservoir
How to grow your own vegetables or encourage public to buy organic food to support organic food industry
Miller T. G. 2005. Living in the Environment, 14th edition. Brooks/Cole.
Chapter 11. Sustaining Terrestrial Biodiversity: Managing and Protecting Ecosystems. Human impact on ecosystems, managing and sustaining forests, tree harvests, deforestation, logging in U.S. National Forests, etc. Pages 194-223
Chapter 15. Water Resources. Supply, renewal and use of various water resources, withdrawing ground water, depletion of ground water, reducing wastage of purified water, etc. Pages 305-330
Chapter 16. Geology and Nonrenewable Mineral Resources. Surface and subsurface mining, different types of surface mining, environmental impact of surface mining etc. Pages 331-349
Chapter 20. Air Pollution. Primary and secondary pollutants, local and regional effects of air pollution, acid deposition, effects of acid deposition, etc. Pages 433-460
Chapter 22: Water Pollution. Sources of water pollution, point and nonpoint sources, pollution of streams, lakes and ground water, solution, etc. Pages 491-517
Description: Deforestation in the Usambara Mountains in Lushoto District, Tanga Region, Tanzania. Author: Mohsin Karmali Link: http://commons.wikimedia.org/wiki/File:Lushoto.jpg Clearance: CC BY 2.5
Description: Mining; “Schaufelradbagger (Vorraumbagger) im Tagebau Welzo” Author: JaySef Link: http://commons.wikimedia.org/wiki/File:Schaufelradbagger_Welzow_1404.jpg Clearance: CC BY-SA 3.0
Description: Diagram of acid mine drainage at Iron Mountain Mine Author: Believed to be U.S. Geological Survey, Department of the Interior/USGS, U.S. Geological Survey. Link: http://ca.water.usgs.gov/projects/iron_mountain/environment.html Clearance: http://www.usgs.gov/laws/info_policies.html
Description: Acid mine drainage causes severe environmental problems in the Rio Tinto, Spain. Author: Carol Stoker, NASA Link: http://commons.wikimedia.org/wiki/File:Rio_tinto_river_CarolStoker_NASA_Ames_Research_Center.jpg Clearance: This file is in the public domain because it was solely created by NASA. NASA copyright policy states that “NASA material is not protected by copyright unless noted.”
Image Credits cont.
Description: Acid rain formation diagram. Author: Unspecified, EPA Link: https://blog.epa.gov/acidrain/2010/04/what-is-acid-rain/ Clearance: United States Environmental Protection Agency
Description: Photo showing the effects of acid rain, woods, Jizera Mountains, Czech Republic. Author: Nipik Link: http://commons.wikimedia.org/wiki/File:Acid_rain_woods1.JPG Clearance: Released to the public domain by the author.
Slide 18 (left)
Description: Photo of agriculture runoff. Author: Photo by Lynn Betts, USDA Natural Resources Conservation Service. Link: http://commons.wikimedia.org/wiki/File:NRCSIA99139_-_Iowa_%282979%29%28NRCS_Photo_Gallery%29.jpg Clearance: This image is a work of the Natural Resources Conservation Service, part of the United States Department of Agriculture, taken or made as part of an employee's official duties, and accordingly in the public domain.
Slide 18 (right)
Description: Photo of construction site runoff. Author: Brett VA Link: http://commons.wikimedia.org/wiki/File:Construction_runoff_Davidson_%286124078615%29.jpg Clearance: CC BY-SA 3.0
Description: Photo of Lake Maracaibo, Venezuela, contaminated by Lemna minor (duckweed) due to nutrient pollution. Author: “The Photographer” Link: http://commons.wikimedia.org/wiki/File:Aguas_del_lago_de_Maracaibo_contaminadas_por_Lemna_03.JPG Clearance: Released to the public domain by the author.
Description: Diagram showing sources of ground water pollution. Author: Chris Wardle of the British Geological Survey. Link: http://www.groundwateruk.org/Image-Gallery.aspx Clearance: Diagram courtesy of the UK Groundwater Forum; “permission is freely granted for …use in academic and non-commercial publications “ (http://www.groundwateruk.org/Image-Gallery.aspx).