Water pollution


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Water pollution

  1. 1. Water Pollution
  2. 2. Definitions Impaired WatersSection 303(d) of the Clean Water Act requires states todevelop lists of impaired waters, those that do not meetwater quality standards that states have set for them. Total Maximum Daily LoadThe law requires that states establish priority rankings forimpaired waters and develop total maximum daily loads(TMDLs) for them. A TMDL specifies the maximumamount of a pollutant that a body of water can receiveand still meet water quality standards.http://www.epa.gov/owow/tmdl/overviewfs.html
  3. 3. Point Source Pollutionvs.Nonpoint Source PollutionWhat’s the difference?Slides by Christopher C. Obropta, Rutgers University
  4. 4. Point Source Pollution comes from a specificsource, like a pipe factories, industry,municipal treatmentplants can be monitored andcontrolled by a permitsystem
  5. 5. What is nonpoint source pollution? Nonpoint Source(NPS) Pollution ispollution associatedwith stormwater orrunoff NPS pollution cannotbe traced to a directdischarge point suchas a wastewatertreatment facility
  6. 6. Examples of NPS oil & grease from cars fertilizers animal waste grass clippings septic systems sewage & cleaners fromboats household cleaningproducts litter
  7. 7. Pollutant Transport Mechanisms• NPS pollutants build up on land surfaces during dryweatherAtmospheric depositionFertilizer applicationsAnimal wasteAutomotive exhaust/fluid leaks• Pollutants are washed off land surfaces during precipitationevents (stormwater runoff)• Stormwater runoff will flow to lakes and streams
  8. 8. Pollutant build-up and wash off are affected byland use. Imperviousness increases runoff Land use changes impact build up
  9. 9. Linking Land Use to Water QualityMore Imperviousness = More Water
  10. 10. What is impervious cover? roads, rooftops, parking lots, and other hardsurfaces that do not allow stormwater to soakinto the ground “predominant American vegetation”
  11. 11. Impervious Cover• provides a surface foraccumulation ofpollutants• leads to increasedpolluted runoff andflooding• inhibits recharge ofgroundwater
  12. 12. Impact of Nonpoint Source Pollution fish and wildlife recreational wateractivities commercial fishing tourism drinking water quality
  13. 13. Pollutants Found in RunoffSedimentSoil particlestransported fromtheir sourceBiochemical Oxygen Demand (BOD)● Oxygen depleting materialLeavesOrganic materialToxics● Pesticides Herbicides Fungicides Insecticides● Metals (naturally occurringin soil, automotiveemissions/ tires) Lead Zinc Mercury● Petroleum Hydrocarbons(automotive exhaust andfuel/oil)DebrisLitter and illegal dumpingNutrients● Various types of materials thatbecome dissolved andsuspended in water (commonlyfound in fertilizer and plant material): Nitrogen (N) Phosphorus (P)Bacteria/ PathogensOriginating from:● Pets● Waterfowl● Failing septic systemsThermalStressHeated runoff,removal ofstreamsidevegetation
  14. 14. Potential Sources of PollutantsFound in Residential Areas Nutrients: Fertilizersand septic systems Pathogens: Pet wasteand septic systems Sediment:Construction, roadsand, soil erosion Toxic: Pesticides,household products Debris: Litter and illegaldumping Thermal: heated runoff,removal of streamsidevegetation
  15. 15. Pollutants from Agriculture Sediment Nutrients Pathogens Pesticides
  16. 16. Why are these pollutants important? Sediment reduces light penetrationin stream, clogs gills of fish andaquatic invertebrates. Nutrients act as fertilizer for algae &aquatic plants which can causehighly varying dissolved oxygenlevels. At low DO levels, theaquatic life has the potential to beharmed. Toxics can impact life andcontaminate drinking watersupplies. Bacteria/Pathogens are an indicatorof possible viruses present in thesystem.