Freshwater and Society

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Freshwater and Society

• Module 1, part C

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Water quality degradation
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Water quality degradation

• Beneficial uses
• Aquatic life and wildlife support
• Fish/shellfish consumption
• Drinking water supply
• Recreation
• Agriculture

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Water quality designations

• Fully supporting overall use
• Threatened overall use
• Partially supporting overall use
• Not supporting overall use
• Not attainable

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Water quality designations

• The Clean Water Act of 1972 established means by
  which states and tribal governments report
  assessed water quality to the EPA
• Rivers
• Lakes not including Great Lakes
• Estuaries
• Great Lakes shoreline waters
• Ocean shoreline waters
• Coral reefs

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Causes of water quality degradation
Rivers Streams Lakes, Ponds Reservoirs Estuaries
Pathogens Nutrients Metals (primarily mercury)
Siltation (Sedimentation) Metals (primarily mercury) Pesticides
Habitat Alterations Siltation (Sedimentation) O2-depleting substances
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Sources of water quality degradation
Rivers Streams Lakes, Ponds Reservoirs Estuaries
Agriculture Agriculture Municipal Point Sources
Hydrologic Modifications Hydrologic Modifications Urban Runoff/ Storm Sewers
Habitat Modifications Urban Runoff/ Storm Sewers Industrial discharges
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Water quality degradation Assessed river miles

• 19 of total river miles in the U.S. assessed
• 39 of assessed miles identified as impaired

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Water quality degradation River use support
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Water quality degradation River stressors

• Percentage of assessed river miles impaired by
  leading pollutants or stressors
• (39 or 269,258 miles impaired)

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Water quality degradation River pollutant sources

• Percentage of assessed river miles impaired by
  specific sources
• (39 or 269,258 miles impaired)

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Water quality degradation Assessed lake acres

• 43 of lake acres assessed
• 45 of assessed acres identified as impaired

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Water quality degradation Lake use support
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Water quality degradation Lake pollutants

• Percentage of assessed lake acres impaired by
  pollutants
• (45 or 7.7 million acres impaired)

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Water quality degradation lake pollutant sources

• Percentage of assessed lake acres impaired by
  specific sources
• (45 or 7.7 million acres impaired)

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Water quality Assessments problems

• Not all bodies of water are assessed
• Only a small percentage per year
• Supposedly all within a 5 to 10 year window

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Water quality Assessments problems

• Intermittent and small tributaries are either not
  assessed or are very infrequently measured
• States tend to focus on known problems
• Random surveys are rare
• States have varying standards
• Concentration on 2 of 6 use supports
• Fish advisories not included

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Nonpoint source (NPS) pollution

• What is it?

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Nonpoint source pollution What is it?

• ehpnet1.niehs.nih.gov/docs/1994/
  102-9/focusnonpoint.JPG

ehpnet1.niehs.nih.gov/docs/1994/
102-9/focusnonpoint.JPG
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NPS pollution Characteristics

• Occurs over extensive areas
• Enters receiving water in a diffuse manner
• Carried by water over land or through soil
  profile to receiving water
• Difficult to trace to point of origin
• Magnitude related to climatic events

http//dnr.metrokc.gov/wlr/watersheds/green/img/Gr
een-River-Flooding-1995.jpg
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NPS pollution Sources of pollutants
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NPS pollution Impact from leading stressors
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NPS pollution Urban storm water

• From streets, yards, buildings, and construction
  sites

• Grease, salts, animal wastes, nutrients,
  sediments, lead, others

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NPS pollution

• Agricultural
• Nutrients, sediment, pesticides, herbicides

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NPS pollution

• Forestry / Logging
• Sediments
• Pesticides

http//www.nps.gov/jofl/resources/connie200x150.jp
g
http//www.em.gov.bc.ca/mining/Geolsurv/Surficial/
landslid/plate3.jpg logged
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NPS pollution

• Mining
• Sediments
• Drainage waters with low pH
• Heavy metals and other hazardous mineral

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NPS pollution

• Atmospheric deposition
• Carbon dioxide - acid rain
• Pesticides, herbicides
• Sediment
• Mercury, PCBs, others

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NPS pollution Impacts on ecosystem

• Impacts ecosystem integrity
• Human health
• Good water supply
• Healthy fish and wildlife populations
• Diverse recreational opportunities

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NPS pollution Effects on water quality

• Types of effects
• Eutrophication
• Temperature increase
• Loss of habitat for breading population
• Loss of esthetic value

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Nonpoint source pollution NPS

• What can be done to manage the problem?