Unit 6 - Human Impact on the Hydrosphere

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W A T E R Q U A L I T Y

W A T E R Q U A L I T Y

• 3 % of Earth’s water is freshwater (drinkable)• 75% of that is frozen

• Pollution- introduction of harmful substances into the environment

• Point-source pollution: pollution from one specific site (wastewater from a factory)

• Nonpoint-source pollution: pollution comes from many sources (runoff from agriculture, urban areas, land clearing, construction, logging)

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VIDEO: Nonpoint Source Pollution (5min)

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H E A L T H Y R I V E R S

Water quality depends upon:• Habitat structure

(riparian vegetation, width/depth, bank stability, channel morphology, gradient, in stream cover, canopy, substrate, current)

• Flow regime (ground water, land use, velocity, high/low extremes, precipitation, runoff)

• Chemical variables (nutrients, pH, DO, temperature, organics, solubles, hardness, absorption, turbidity)

• Biotic factors (disease, parasitism, feeding, predation, competition, reproduction)

• Energy source (sunlight, nutrients, seasonal cycles, organic matter inputs)

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HOW DO YOU DESCRIBE THE WATER?In stream conditions:• Litter/garbage-• Algae- floating, attached, color• Water color- clear, muddy, milky, tea-colored,

red, gray, green black• Water appearance- oily sheen, foam/bubbles,

scum• Water odor- sewage, gas, rotten eggs, fishy,

chlorine, soapy• Discharge pipes- storm drain, industry,

municipal wastewater, sewer,

M O N I T O R I N G W A T E R Q U A L I T Y

PHYSICALturbidity

CHEMICALmeasure pH, nitrates, DO, metals

BIOLOGICALcount species

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VIDEO: Ecosystems on the Edge (8min)

Turbidity-• Measure of the concentration of particles

suspended in water• High turbidity = cloudy/ low light penetration• Suspended sediments of silt, clay, wastewater,

high phytoplankton

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PHYSICAL INDICATORSh

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*VIDEO: Turbidity (5min)

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Habitat structure

Natural river flow is more productive as a habitat than man-made channels.

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Riparian Habitat: land/bank between the water & upland hills

Vegetation on the bank

decreases embeddedness

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Sediment impacts streams:

• Heat is absorbed by particles• Clarity is lower• Organic material can change the chemistry• Extra fertilizer (phosphorus, nitrogen) causes

harmful algal blooms• Heavy metals leach into water

ppm- parts per million*one inch in 16 miles *one ounce in 32 tons*one cent in $10,000 *one minute in two years

THAT’s LIKE:

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DO-Dissolved Oxygen

Temperature • Affects DO (dissolved oxygen) levels:• Cold water holds more O• Thermal pollution: Factories increase lake

temperatures• Loss of shade trees on riparian bank

REMEMBER: Colder water absorbs more gas

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• Fish- respond to chemical, physical, biological change

• Aquatic plants• Insects• Mussels• Leeches• worms

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BIOLOGICAL INDICATORS

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14*VIDEO: Biotic Index (11min)

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PathogensBacteria: e coli (found in feces)• Enter water systems when septic systems leak

or municipal sewage systems fail & through factory farm waste

http://www.cbsnews.com/news/20-sickened-by-e-coli-in-nc-toddler-dies/VIDEO: Ganges Pollution (1:30)

Dissolved oxygen (DO)• Organisms in water need oxygen• Low DO can stress/kill organisms• Pollution reduces DO• Anoxia- lack of oxygen

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CHEMICAL INDICATORS

1. Temperature (lower temp, more O2)2. Altitude (pressure affects gas)3. Plant growth (respiration, transpiration,

photosynthesis cycles gases)4. Decay (cycles gases)5. Turbulence (rough water, catches air bubbles)

*VIDEO: Dissolved Oxygen (13 min)

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pH- power of Hydrogen• The acid/base balance• Normal: 6.5-8.5• Lower or higher pH disrupts availability of

nutrients in water system

VIDEO: Strengths & Weaknesses of acids & bases (3:50)VIDEO: Crash Course Chemistry#30 pH & pOH (11min)

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NEUTRAL

Solubility of heavy metals

Algal blooms

More Hydrogen Less Hydrogen

HIGHER TEMP.

pH

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Dissolved solutions of water can be hard to separate & so collect in Earth’s water supply.

A lot of metals are TOXIC… can

become dissolved into drinking water

http://thisismyfinalyearproject.blogspot.com/2010/07/critique-2-research-and-analysis.html

Industrial storage/contaminated

landtranspiratio

n

Manure spreadingUncovered road salt

Septic tank

Oil storage tanks

Public Water

Pesticides &

fertilizers

Gas station

landfill

Urban runoff

Leaking

sewers

plowing

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Eutrophication-nutrient overload

Nitrates • Soil particles• Decay• Man-made:

• Detergents• Fertilizers• Industry

waste

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Phosphates-

http://reefkeeping.com/issues/2006-08/cj/testpop.htm?images/image003LG.jpg

VIDEO 1: Eutrophication (2min)VIDEO 2: Haber Process

Y O U R W A T E R

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Raleigh

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SOURCES OF THE POLLUTION:• Point source- piped discharges from local

municipal wastewater treatment plants, local industrial facilities, large storm water systems

• Non-Point source- timber harvesting, agriculture, road, building & parking lot construction, failing septic systems

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Coal Ash Spills-• Duke Power spilled 39,000 tons of coal ash into the

Dan River Feb 2014 (Dan feeds into the Yadkin)• 2015- it was discovered that 200 seeps were

occurring at 14 of Duke Power’s retired storage plants- seeping 3 million gallons a day of coal ash into the river

http://www.nbcnews.com/news/us-news/82-000-tons-coal-ash-spill-plant-

north-carolina-river-n23401

http://www.nytimes.com/2014/03/01/us/coal-ash-spill-reveals-transformation-of-north-carolina-agency.html?_r=0

VIDEO 1 Toxic Waste Spill in NC pt 1 (16min)VIDEO 2 Toxic Waste Spill in NC pt 2 (10min)

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Fracking-the process of injecting water & chemicals at high pressure into underground shale to fissure and release natural gas

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Could this enter our water supply?

VIDEO: Fracking explained (5min)

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East Coast bedrock

29VIDEO: Fracking in Lee County, NC (13min)

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S T E W A R D S H I P

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S T E W A R D S H I P

Clean Water Act 1972- to restore and maintain the health of US waters to include wetlands by preventing point and nonpoint pollution

Safe Drinking Water Act 1974- regulates US public drinking supply; amended in 1986 & 1996 to protect drinking water & its sources: rivers, lakes, reservoirs, springs & ground water wells

Sewage treatment plants- facilities that clean waste materials out of water1. Primary treatment

• Dirt, water passes through screens to catch solid objects

• 2nd tank has smaller screens for smaller particles; sludge sinks to bottom; floating oils skimmed off top

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W A T E R T R E A T M E N T

2. Secondary treatment-• Water sent to aeration tank; mixed with

oxygen & bacteria; bacteria eats wastes, use O2

• Water sent to chlorinator to disinfect• Water released into river, lake, ocean

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http://water.me.vccs.edu/courses/env108/lesson1_2.htmVIDEO: Water Resource Recovery (10min)

W A T E R U S A G E

35http://www.greenbiz.com/blog/2010/06/08/triple-threat-coming-water-crisis

36http://www.verdantcommunity.com/conserve-water.html

Agriculture• Evaporation• Runoff• Sprinklers• BETTER: Drip irrigation systems- irrigate roots

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http://www.austinirrigationgroup.com/why-drip-irrigation-makes-perfect-sense-in-dry-climates/

Industry• 19% world water use• Manufacturing goods• Extract minerals• Generate electricity

C O N S E R V I N G W A T E R A T H O M E

• Low-flow shower heads• Low-flush toilets• Native plants• Shorter showers• Turn off water while

brushing teeth• Washing machine &

dishwasher full before running

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VIDEO: Water Crisis (3min)

What Is a Dam?

• Barrier constructed to contain water flow• Sometimes can

generate electricity

• Promotes irrigation

• Controls flooding in local areas

How Does a Dam Work?• Dams are often triangular for strength

• Giant wall withstands pressure

• Excess water stored, released when needed

• Locks and gates can control water flow

Benefits of Dams

• Store flood water for human usage

• 10% of irrigation water from dams

• Navigation occurs on dam water

• Dam water is good for recreation

Recreation38%

Flood Control18%

Fire and Farm Ponds

17%

Irrigation11%

Tailings and Other

8%

Undetermined

4%

Hydroelectric3%

Debris Control

1%

What Dams Are Used For

Hydroelectric Dams

• Water travels to “powerhouse” near dam

• Water then spins turbines repeatedly

• Electricity is created cleanly and resourcefully

Impact on Environment• Environmentalists

protest continued use of dams

• Dams interfere with natural processes

• Different fish species are affected

• Minerals or extra salts may be present in reservoir water