Water Pollution

Nashua River

Types of Pollution Sewage

• Nutrients• Sediments• Disease Causing Agents• Inorganic Chemicals• Organic Compounds• Radioactive Substances• Thermal Pollution

Eutrophication

Vocabulary and Concepts:Nutrient EnrichmentNatural and CulturalOxygen Sag CurveDissolved OxygenBiological Oxygen DemandHypoxiaDead ZonesCauses

Controlling Water Pollution

• Identifying Sources– Point and Nonpoint Sources

• Treatment Technologies• Point Source– Eliminate Pollutants from Waste Stream• RCRA and other laws

– Individual Wastewater Treatment– Municipal Wastewater Treatment

• Nonpoint Source– Agriculture– Mining and Forestry– Urban Runoff

Individual Sewage Disposal Systems (ISDS)

RequiresSufficient Area for treatmentManagement of Wastes

Septic Tank Settling of solids Requires Pumping

Leaching Field or Drainfield

Municipal Wastewater Treatment

Municipal Sewage Treatment

• Primary• Secondary• Tertiary or Advanced

Packaged Waste Water Treatment

Nonpoint Sources

• Urban Runoff• Agriculture• Mining (largely controlled by SMCRA)• Forestry

Urban Runoff

• Urbanization increases the variety and amount of pollutants carried into our nation's waters. In urban and suburban areas, much of the land surface is covered by buildings, pavement and compacted landscapes with impaired drainage. These surfaces do not allow rain and snowmelt to soak into the ground which greatly increases the volume and velocity of stormwater runoff. In addition to these habitat-destroying impacts, pollutants from urban runoff include: – Sediment– Oil, grease and toxic chemicals from motor vehicles– Pesticides and nutrients from lawns and gardens– Viruses, bacteria and nutrients from pet waste and failing septic

systems– Road salts– Heavy metals from roof shingles, motor vehicles and other sources– Thermal pollution from dark impervious surfaces such as streets and

rooftopshttp://www.epa.gov/owow_keep/NPS/urban.html

Urban Runoff Control Technologies

Retention PondsCatch BasinsEducation

Agriculture

Buffer stripsErosion ControlIntegrated Pest Management (IPM)

Forestry and Mining

Clean Water Act

• Criteria• Point Sources– NPDES Permits– Funding for WWT

• Protection of Wetlands– Section 404

• Research and Control of non-point sources

Safe Drinking Water Act

• 1974 (amended 1986, 1996,• Requires EPA to determine Maximum Contaminant Level

http://www.pbs.org/wgbh/pages/frontline/poisonedwaters/

International Water Pollution Issues

• Access to clean water• Reduction of contamination• Competition for scarce resources

http://video.pbs.org/video/2203388630