Water Pollution Chapter 22

Water Pollution Any physical or chemical change in water that adversely affects the health of humans and other organisms. There are 8 categories: Sewage Sewage Disease-causing Agents Disease-causing Agents Sediment pollution Sediment pollution Organic compounds Organic compounds Inorganic compounds Inorganic compounds Radioactive substances Radioactive substances Thermal pollution Thermal pollution

Sewage Sewage is the release of wastewater from drains or sewers into waterways. Sewage is the release of wastewater from drains or sewers into waterways. Enrichment – the fertilization of a body of water that is caused by the presence of high levels of plant and algal nutrients (nitrogen & phosphorus). Enrichment – the fertilization of a body of water that is caused by the presence of high levels of plant and algal nutrients (nitrogen & phosphorus). Biological Oxygen Demand (BOD) – Biological Oxygen Demand (BOD) – – –Measured in

Disease-Causing Agents Infectious organisms that cause diseases including bacteria, virus, protozoa, parasitic worms Infectious organisms that cause diseases including bacteria, virus, protozoa, parasitic worms Fecal coliform tests – test for presences of E-Coli Fecal coliform tests – test for presences of E-Coli –Safe drinking water should contain no more than ___ coliform bacteria per 100 ml. of water –Safe swimming water < ___ per 100 ml of water –General Recreational < ____ per 100 ml of water

Drinking water standards California Title 22 – Safe Drinking water levels California Title 22 – Safe Drinking water levels –MCLs (primary and secondary) State and Federal State and Federal

Sediment Pollution Excessive amounts of suspended soil particles that eventually settle out and accumulate at the bottom of a body of water. Excessive amounts of suspended soil particles that eventually settle out and accumulate at the bottom of a body of water. –Affects light infiltration and turbidity –Often carries metals

Inorganic Plant & Algal Nutrients Nitrogen & phosphorus that stimulate growth of plants and algae Nitrogen & phosphorus that stimulate growth of plants and algae –In estuaries & bays can cause ________________________ –Dead zones – oxygen free environments created by algal blooms resulting from introduction of nutrients –Hypoxia –

Organic compounds Chemicals that contain carbon Chemicals that contain carbon Examples: Examples: –Benzene – –Dioxins – –Trichloroethylene (TCE) –

Inorganic Compounds Lead – from Lead – from –Create problems at concentrations >10 micrograms/deciliter –Biggest problems to middle age men, pregnant women & children causing hypertension, high blood pressure, miscarriages, problems with mental development (respectively) Example – Mercury Example – Mercury –From –Accumulates in muscles of fish & marine mammals –Linked to birth defects such as mental retardation, cerebral palsy and slow development; neurological problems Heavy Metals - chromium Heavy Metals - chromium

Radioactive Substances Unstable isotopes that spontaneously emit radiation Unstable isotopes that spontaneously emit radiation From nuclear power plants & nuclear weapons and research From nuclear power plants & nuclear weapons and research Can be significant as a naturally occurring problem Can be significant as a naturally occurring problem –Radon – which increases the risk of lung cancer when inhaled over long period of time

Thermal Pollution Heated water produced and released into waterways Heated water produced and released into waterways –Results in changes to chemical reactions and reduces the dissolved oxygen

Eutrophication Oligotrophic Oligotrophic – – – Natural Eutrophication Natural Eutrophication – – – –

Artificial/cultural Eutrophication Result of the enrichment of a lake from inorganic nutrients introduced via runoff Result of the enrichment of a lake from inorganic nutrients introduced via runoff Phosphorus is often the limiting factor in freshwater lakes Phosphorus is often the limiting factor in freshwater lakes

What are Sources of Water Pollution? Natural and human activities Natural and human activities Point source pollution – from discharges to water bodies at a specific site Point source pollution – from discharges to water bodies at a specific site Non-point source pollution – pollution to a water body over a wide area from runoff (polluted runoff) Non-point source pollution – pollution to a water body over a wide area from runoff (polluted runoff) –NPDES (National Pollutant Discharge Elimination System) – regulates point-source pollution –Stormwater NPDES – intended to regulate non-point source pollution

Water Pollution from Agriculture Leading source of water quality impairment Leading source of water quality impairment ____________________ leading causes followed by animal wastes ____________________ leading causes followed by animal wastes –>__% of river and streams and ~__% of groundwater contain at least one pesticide

Water Pollution from Municipalities Typically _________ source pollution from runoff Typically _________ source pollution from runoff Includes runoff from roads, untreated garbage/waste dumps, construction sediments & traffic emission Includes runoff from roads, untreated garbage/waste dumps, construction sediments & traffic emission Combined sewers – sewers that direct both stormwater runoff and sewage (San Francisco) Combined sewers – sewers that direct both stormwater runoff and sewage (San Francisco) –At high rains – combined sewer overflow forcing untreated wastes to rivers and streams.

Water Pollution from Industry Top producers include: Top producers include: –_________________

Groundwater ~__% of U.S. population gets water from groundwater ~__% of U.S. population gets water from groundwater Most common pollutants in groundwater are pesticides, fertilizers, and organics (e.g. solvents) Most common pollutants in groundwater are pesticides, fertilizers, and organics (e.g. solvents)

Groundwater (cont) Sources of groundwater pollutants Sources of groundwater pollutants –Leaking underground storage tanks (LUST) –Septic systems –Leaking well casing –Dry well/deep well injections –Landfills with leaky liners (if any) –Surface impoundments –Natural occurring substances (e.g. arsenic)

How can we treat the sewage water? Sewage: Steps - Sewage: Steps - –1. –2. –3. –4. –5. –6.

What is the biggest problem with wastewater treatment? Dealing with all the sludge and water that is left over at the end. Dealing with all the sludge and water that is left over at the end. Solutions: Solutions: –Anaerobic digestion – makes methane and turns sludge to humus –Application to soil as a fertilizer –Incineration –Ocean dumping –Sanitary Landfill

Septic Tanks Used for individual houses Used for individual houses Uses soil to purify wastes Uses soil to purify wastes Must be managed correctly Must be managed correctly

Why is chlorinating water a problem? Needed to disinfect the water Needed to disinfect the water Problem – cancer, increased risk of miscarriages & rare birth defects Problem – cancer, increased risk of miscarriages & rare birth defects

Why is fluoridation a problem? Needed to prevent tooth decay Needed to prevent tooth decay Problem – unknown health effects such as cancer, kidney disease birth defects Problem – unknown health effects such as cancer, kidney disease birth defects

Laws Controlling Water Pollution Safe Drinking Act Safe Drinking Act –Sets federal standards (MCL) for drinking water EPA Website EPA Website EPA Website EPA Website Clean Water Act Clean Water Act –Has 2 goals Eliminate discharge of pollutants in U.S. waterways Eliminate discharge of pollutants in U.S. waterways To attain water quality levels that make these waterways safe To attain water quality levels that make these waterways safe

Clean Water Act (cont) Requires EPA to set up and monitor national emission limitations Requires EPA to set up and monitor national emission limitations –Maximum permissible amount of water pollutants that can be discharged from a point source Set up Nationally Pollutant Discharge Elimination System (NPDES) to limit discharges via permit and set up monitoring and penalty system Set up Nationally Pollutant Discharge Elimination System (NPDES) to limit discharges via permit and set up monitoring and penalty system

Resource Conservation & Recovery Act (RCRA) Deals with the storage and disposal of hazardous waste Deals with the storage and disposal of hazardous waste Requires cleanup of groundwater contamination Requires cleanup of groundwater contamination Penalty system for discharges Penalty system for discharges

California Laws Tend to be more strict than Federal Law Tend to be more strict than Federal Law Title 22 – states version of the Safe Drinking Water Act Title 22 – states version of the Safe Drinking Water Act Porter-Cologne Waterquality Act – states version of the Clean Water Act Porter-Cologne Waterquality Act – states version of the Clean Water Act Proposition 65 Proposition 65