Water Pollution – Sources and Effects Sources Other factors

1. Water Pollution – Sources and Effects • Sources • Other factors • Factors besides chemical pollutants can degrade water quality • Removal of adjacent vegetation • Destabilization of shoreline • Removal of shade  destabilizes temperatures • Siltation • Increased turbidity  vision, photosynthesis • Burial of organisms, filling of water body • Alteration of drainage patterns • Damming, dredging, channelization • Changes in vegetation cover in watershed • Changes flow patterns, predictability, chemistry, sediment load • Leaching of chemicals from natural sources (geogenic, biogenic) • Salts, metals (Ex: As), nutrients (Ex: P), acids (Ex: tannins) • Warm weather • Raises temperatures, reduces oxygen solubility, may dry up • Interfere with designated beneficial uses • Different beneficial uses for different water bodies  different factors of interest, different methods for remediation

2. Water Pollution – Components • Oxygen-Depleting Substances • Pollutants may lower O2 concentrations directly or indirectly • Usually biodegradable (organic wastes) • Reduced O2 levels can influence species composition in a water body • Ex: Salmon and trout sensitive to O2 levels • Low O2 levels also favor survival of anaerobic bacteria, many of which produce noxious gases (H2S, CH4) • Examples • Sewage (including animal and plant materials) • Agricultural waste (leaves, plant debris, manure) • Food processing wastes • Toxic wastes can kill aquatic organisms, leading to O2 depletion by decomposing bacteria • Warm temperatures exacerbate O2 depletion • Reduce solubility of oxygen • Accelerate bacterial decomposition rates

3. Water Pollution – Components • Infectious Agents • Pathogenic bacteria • Common components of animal wastes • Can produce outbreaks of typhoid, cholera, salmonellosis, infectious hepatitis, dysentery (affect billions of people) • Examples • Giardia causes swimmer’s itch by irritating skin but can cause intestinal problems internally • Cryptosporidium contaminated Milwaukee water supply in 1993 • More than 400,000 people with symptoms and 100+ deaths • Cysts passed through filtration in water treatment system and went undetected • Very difficult to scan water bodies for all potential pathogens (problem: lag time b/w test & results) • Use of indicator organisms (coliform bacteria, enterococci) • Possible sources (source identification challenging) • Municipal sewage – Inadequately treated or spilled • Stormwater drains • Septic systems • Runoff from livestock pens • Sewage from recreational vehicles (boats, campers)

4. Water Pollution – Components • Toxic Organic Chemicals (TOCs) • Usually synthetic chemicals • Persistent organic pollutants (POPs) • Polychlorinated biphenyls (PCBs) • Polycyclic aromatic hydrocarbons (PAHs) • Dioxins • Herbicides, pesticides (Ex: chlordane, DDT) • Characteristics • Bioavailable – readily assimilated • Lipid soluble – incorporated into lipid deposits • Bioaccumulate – concentrations increase with time and exposure • Biomagnify – concentrations increase through food web • Tend to be resistant to degradation • Facilitates wide dispersal • Long residence times (persistence) • Ex – DDT near White Point • Effects – Poorly understood for most compounds • CNS damage • Liver damage • Birth defects

5. Time Magazine - 1947

6. Beach on Long Island, NY - 1945

7. Water Pollution – Components • Toxic Organic Chemicals (TOCs) • Usually synthetic chemicals • Persistent organic pollutants (POPs) • Polychlorinated biphenyls (PCBs) • Polycyclic aromatic hydrocarbons (PAHs) • Dioxins • Herbicides, pesticides (Ex: chlordane, DDT) • Characteristics • Bioavailable – readily assimilated • Lipid soluble – incorporated into lipid deposits • Bioaccumulate – concentrations increase with time and exposure • Biomagnify – concentrations increase through food web • Tend to be resistant to degradation • Facilitates wide dispersal • Long residence times (persistence) • Ex – DDT near White Point • Effects – Poorly understood for most compounds • CNS damage • Liver damage • Birth defects

9. Water Pollution – Components • Toxic Organic Chemicals (TOCs) • Usually synthetic chemicals • Persistent organic pollutants (POPs) • Polychlorinated biphenyls (PCBs) • Polycyclic aromatic hydrocarbons (PAHs) • Dioxins • Herbicides, pesticides (Ex: chlordane, DDT) • Characteristics • Bioavailable – readily assimilated • Lipid soluble – incorporated into lipid deposits • Bioaccumulate – concentrations increase with time and exposure • Biomagnify – concentrations increase through food web • Tend to be resistant to degradation • Facilitates wide dispersal • Long residence times (persistence) • Ex – DDT near White Point • Effects – Poorly understood for most compounds • CNS damage • Liver damage • Birth defects

10. http://www.epa.gov/region9/superfund/pvshelf/images/ddtconcbig.gifhttp://www.epa.gov/region9/superfund/pvshelf/images/ddtconcbig.gif

12. Water Pollution – Components • Toxic Organic Chemicals (TOCs) • Usually synthetic chemicals • Persistent organic pollutants (POPs) • Polychlorinated biphenyls (PCBs) • Polycyclic aromatic hydrocarbons (PAHs) • Dioxins • Herbicides, pesticides (Ex: chlordane, DDT) • Characteristics • Bioavailable – readily assimilated • Lipid soluble – incorporated into lipid deposits • Bioaccumulate – concentrations increase with time and exposure • Biomagnify – concentrations increase through food web • Tend to be resistant to degradation • Facilitates wide dispersal • Long residence times (persistence) • Ex – DDT near White Point • Effects – Poorly understood for most compounds • CNS damage • Liver damage • Birth defects