8.1: Water Pollution

water pollution

physical, chemical, or biological change in water quality that makes it unsuitable for specific use or harmful to organisms

what are the 3 largest activities that result in water pollution (biggest to smallest)

agriculture

industry

mining

water pollution activities- agriculture

adds fertilizers, pesticides, bacteria from livestock waste, food processing wastes, sediment from erosion, and excess salt from irrigated cropland

water pollution activities- industry

emit inorganic and organic chemicals

water pollution activities- mining

adds toxic chemicals to water, causing erosion of sediment into bodies of water

point source pollution

single identifiable source of a pollutant

point source pollution examples

drainage pipes, sewer line, smokestack

non-point source pollution

large source-arts with diverse pollutants

non-point source pollution examples. how do they enter?

yards and agricultural land-fertilizer, pesticides, sediment

parking lots- accumulate oil and toxic metals

microplastics leach toxic chemicals

enter through runoff

what is the worst problem that comes from pollution

exposure to infectious diseases

3 tests for water pollutants

specific tests for organic and inorganic chemicals

turbidimeters

E.Coli tests

how much e coli in 100 ml is safe for…

drinking?

swimming?

how much in sewage?

none

no more than 200 colonies

millions/100 ml

indicator species are a good way to measure __________

how does it work?

pollution

presence or absence indicates water quality, or accumulation in plants

________________ are an indicator of overall water quality. why?

dissolved oxygen levels

water with too much nutrients have algae and plankton blooms, causing lower DO levels

warmer water from thermal pollution contains less DO

what causes an oxygen sag curve to develop

explain it

biodegradation of organic wastes by bacteria using up DO

DO levels increase and species with high oxygen requirement are reduced or eliminated

once waste is degraded and DO levels increase species can recover

what is another example of a pollution sag curve

heated water discharges

flowing rivers and streams can recover from moderate levels of degradable, oxygen depleting wastes by _______ and __________ by bacteria

dilution

biodegradion

biodegradation

only occurs when streams are not overloaded with pollutants or reduced in flow

only removes biodegradable waste, not non-degradable pollutants like chemicals and heavy metals

water pollution zones

clean zone

decomposition zone

septic zone

recovery zone

water pollution zones- clean zone

normal clean water organisms

high DO

low Biochemical oxygen demand

water pollution zones- decomposition zone

pollution tolerant fish
decreasing DO

high biochemical oxygen demand

water pollution zones- septic zone

fish absent, fungi, sludge, worms, anaerobic bacteria

low DO

decreasing biochemical oxygen demand

water pollution zones- recovery zone

pollution tolerant fish

increasing DO

low biochemical oxygen demand

aquatic pollution in developed countries

regulations halt increase in pollution, even with population, industrial, and resource use growth

clean water act (1969)

created because of the highly polluted area caught fire from flammable chemicals dumped into the Cuyahoga river

In what 3 ways will water contamination still occur in developed countries

dumping toxic inorganic or organic waste from industry or mines

malfunctioning/overloaded sewage plants during heavy rainfall

discharge of pesticides and fertilizers from cropland and feedlots

most cities in developing countries discharge _________ of their untreated sewage into rivers and lakes

80-90%

__ of China’s diverse are too polluted for agriculture or industrial use

1/3

what is the most polluted river in the world? why? what is an environmental solution introduced to help with this?

Ganges river

cremated remains get thrown into the river, depleting oxygen and adding pathogens to the water

imported snapping turtles to eat the corpses

2 reasons for lakes/ reservoirs being less effective at diluting wastes and recovering

little flow, pollution stays

stratified layers means little vertical mixing

effect of pollution on organisms in lakes

sediment buries benthic organisms

kills benthic organisms, fish, and birds that feed on contaminated organisms

biological magnification

eutrophication

increase in nutrients and sedimentation of a lake slowly filling it in

where to nutrients in eutrophication come from

erosion animal waste, eat plant material

3 stages of eutrophication

oligotrophic

mesotrophic

eutrophic

cultural eutrophication

human activities speed up eutrophication by adding excess nutrients from fertilizer runoff, sewage, and sediment from mining or deforestation

what happens with cultural eutrophication during warmer weather

nutrient excess causes algae and plant blooms, when they die it increases aerobic bacteria which depletes DO, this kills fish and other organisms

anaerobic bacteria takes over if DO stays low

3 methods of clean up of lakes

mechanically remove excess plants

control plant growth with algaecides and herbicides

pump air to prevent dead zones

4 ways to prevent/ reduce cultural eutrophication

ban or limit phosphates in detergents and cleaning products

advanced waste water treatment that removes nitrates and phosphates

regulate and reduce fertilizer use

use soil conservation methods and land use methods to reduce runoff

3 lessons learned from the lake washington and puget sound incident

sever water pollution can be reversed relatively quickly

scientific research and citizen action can work together

solutions cannot work indefinitely if we continue to overwhelm natural systems

the Great Lakes contain ___ of freshwater in the US and ___ of freshwater in the world

95%
20%

why are the Great Lakes susceptible to pollution

less than 1% of water entering leaves, so pollutants take long to get flushed out