Water PollutionWater Pollution

Chapter 22Chapter 22

Water PollutionWater Pollution

Any physical or chemical change in water that Any physical or chemical change in water that adversely affects the health of humans and other adversely affects the health of humans and other organisms. organisms.

There are 8 categories:There are 8 categories:• SewageSewage• Disease-causing AgentsDisease-causing Agents• Sediment pollutionSediment pollution• Organic compoundsOrganic compounds• Inorganic compoundsInorganic compounds• Radioactive substancesRadioactive substances• Thermal pollutionThermal pollution

SewageSewage

• Sewage is the release of wastewater from Sewage is the release of wastewater from drains or sewers into waterways.drains or sewers into waterways.

• Enrichment – the fertilization of a body of Enrichment – the fertilization of a body of water that is caused by the presence of water that is caused by the presence of high levels of plant and algal nutrients high levels of plant and algal nutrients (nitrogen & phosphorus).(nitrogen & phosphorus).

• Biological Oxygen Demand (BOD) – Biological Oxygen Demand (BOD) – – – Measured inMeasured in

Disease-Causing AgentsDisease-Causing Agents

• Infectious organisms that cause diseases Infectious organisms that cause diseases including bacteria, virus, protozoa, parasitic including bacteria, virus, protozoa, parasitic wormsworms

• Fecal coliform tests – test for presences of Fecal coliform tests – test for presences of E-ColiE-Coli– Safe drinking water should contain no more than Safe drinking water should contain no more than

___ coliform bacteria per 100 ml. of water___ coliform bacteria per 100 ml. of water– Safe swimming water < ___ per 100 ml of waterSafe swimming water < ___ per 100 ml of water– General Recreational < ____ per 100 ml of waterGeneral Recreational < ____ per 100 ml of water

Drinking water standardsDrinking water standards

• California Title 22 – Safe Drinking California Title 22 – Safe Drinking water levelswater levels– MCLs (primary and secondary)MCLs (primary and secondary)

•State and Federal State and Federal

Sediment PollutionSediment Pollution

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

Inorganic Plant & Algal Inorganic Plant & Algal NutrientsNutrients

• Nitrogen & phosphorus that Nitrogen & phosphorus that stimulate growth of plants and algaestimulate growth of plants and algae– In estuaries & bays can cause In estuaries & bays can cause

________________________________________________– Dead zones – oxygen free environments Dead zones – oxygen free environments

created by algal blooms resulting from created by algal blooms resulting from introduction of nutrients introduction of nutrients

– Hypoxia – Hypoxia –

Organic compoundsOrganic compounds

• Chemicals that contain carbonChemicals that contain carbon

• Examples:Examples:– Benzene – Benzene – – Dioxins –Dioxins –– Trichloroethylene (TCE) – Trichloroethylene (TCE) –

Inorganic CompoundsInorganic Compounds

• Lead – fromLead – from– Create problems at concentrations >10 Create problems at concentrations >10

micrograms/decilitermicrograms/deciliter– Biggest problems to middle age men, pregnant women Biggest problems to middle age men, pregnant women

& children causing hypertension, high blood pressure, & children causing hypertension, high blood pressure, miscarriages, problems with mental development miscarriages, problems with mental development (respectively)(respectively)

• Example – Mercury Example – Mercury – FromFrom– Accumulates in muscles of fish & marine mammalsAccumulates in muscles of fish & marine mammals– Linked to birth defects such as mental retardation, cerebral Linked to birth defects such as mental retardation, cerebral

palsy and slow development; neurological problemspalsy and slow development; neurological problems

• Heavy Metals - chromiumHeavy Metals - chromium

Radioactive SubstancesRadioactive Substances

• Unstable isotopes that spontaneously Unstable isotopes that spontaneously emit radiationemit radiation

• From nuclear power plants & nuclear From nuclear power plants & nuclear weapons and researchweapons and research

• Can be significant as a naturally Can be significant as a naturally occurring problemoccurring problem– Radon – which increases the risk of lung Radon – which increases the risk of lung

cancer when inhaled over long period of cancer when inhaled over long period of timetime

Thermal PollutionThermal Pollution

• Heated water produced and released Heated water produced and released into waterwaysinto waterways– Results in changes to chemical reactions Results in changes to chemical reactions

and reduces the dissolved oxygenand reduces the dissolved oxygen

EutrophicationEutrophication

• OligotrophicOligotrophic– – –

• Natural EutrophicationNatural Eutrophication– – – –

Artificial/cultural Artificial/cultural EutrophicationEutrophication

• Result of the enrichment of a lake Result of the enrichment of a lake from inorganic nutrients introduced from inorganic nutrients introduced via runoffvia runoff

• Phosphorus is often the limiting Phosphorus is often the limiting factor in freshwater lakesfactor in freshwater lakes

What are Sources of Water What are Sources of Water Pollution?Pollution?

• Natural and human activitiesNatural and human activities• Point source pollution – from discharges to Point source pollution – from discharges to

water bodies at a specific sitewater bodies at a specific site• Non-point source pollution – pollution to a Non-point source pollution – pollution to a

water body over a wide area from runoff water body over a wide area from runoff (polluted runoff)(polluted runoff)– NPDES (National Pollutant Discharge Elimination NPDES (National Pollutant Discharge Elimination

System) – regulates point-source pollutionSystem) – regulates point-source pollution– Stormwater NPDES – intended to regulate non-Stormwater NPDES – intended to regulate non-

point source pollutionpoint source pollution

Water Pollution from Water Pollution from AgricultureAgriculture

• Leading source of water quality Leading source of water quality impairmentimpairment

• ____________________ leading causes ____________________ leading causes followed by animal wastesfollowed by animal wastes– >__% of river and streams and ~__% of >__% of river and streams and ~__% of

groundwater contain at least one groundwater contain at least one pesticidepesticide

Water Pollution from Water Pollution from MunicipalitiesMunicipalities

• Typically _________ source pollution from runoffTypically _________ source pollution from runoff

• Includes runoff from roads, untreated Includes runoff from roads, untreated garbage/waste dumps, construction sediments garbage/waste dumps, construction sediments & traffic emission& traffic emission

• Combined sewers – sewers that direct both Combined sewers – sewers that direct both stormwater runoff and sewage (San Francisco)stormwater runoff and sewage (San Francisco)– At high rains – combined sewer overflow forcing At high rains – combined sewer overflow forcing

untreated wastes to rivers and streams. untreated wastes to rivers and streams.

Water Pollution from Water Pollution from IndustryIndustry

• Top producers include:Top producers include:– __________________________________– __________________________________– __________________________________

GroundwaterGroundwater

• ~__% of U.S. population gets water ~__% of U.S. population gets water from groundwaterfrom groundwater

• Most common pollutants in Most common pollutants in groundwater are pesticides, groundwater are pesticides, fertilizers, and organics (e.g. fertilizers, and organics (e.g. solvents)solvents)

Groundwater (cont)Groundwater (cont)

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

How can we treat the sewage How can we treat the sewage water?water?

• Sewage: Steps - Sewage: Steps - – 1.1.– 2.2.– 3.3.– 4.4.– 5.5.– 6.6.

What is the biggest problem What is the biggest problem with wastewater treatment?with wastewater treatment?

• Dealing with all the sludge and water that Dealing with all the sludge and water that is left over at the end. is left over at the end.

• Solutions:Solutions:– Anaerobic digestion – makes methane and Anaerobic digestion – makes methane and

turns sludge to humusturns sludge to humus– Application to soil as a fertilizerApplication to soil as a fertilizer– IncinerationIncineration– Ocean dumping Ocean dumping – Sanitary LandfillSanitary Landfill

Septic TanksSeptic Tanks

• Used for individual housesUsed for individual houses

• Uses soil to purify wastesUses soil to purify wastes

• Must be managed correctlyMust be managed correctly

Why is chlorinating water a Why is chlorinating water a problem?problem?

• Needed to disinfect the waterNeeded to disinfect the water

• Problem – cancer, increased risk of Problem – cancer, increased risk of miscarriages & rare birth defectsmiscarriages & rare birth defects

Why is fluoridation a Why is fluoridation a problem?problem?

• Needed to prevent tooth decayNeeded to prevent tooth decay

• Problem – unknown health effects Problem – unknown health effects such as cancer, kidney disease birth such as cancer, kidney disease birth defects defects

Laws Controlling Water Laws Controlling Water PollutionPollution• Safe Drinking ActSafe Drinking Act

– Sets federal standards (MCL) for Sets federal standards (MCL) for drinking waterdrinking water•EPA WebsiteEPA Website

• Clean Water ActClean Water Act– Has 2 goalsHas 2 goals

•Eliminate discharge of pollutants in U.S. Eliminate discharge of pollutants in U.S. waterwayswaterways

•To attain water quality levels that make To attain water quality levels that make these waterways safethese waterways safe

Clean Water Act (cont)Clean Water Act (cont)

• Requires EPA to set up and monitor Requires EPA to set up and monitor national emission limitationsnational emission limitations– Maximum permissible amount of water Maximum permissible amount of water

pollutants that can be discharged from a pollutants that can be discharged from a point sourcepoint source

• Set up Nationally Pollutant Discharge Set up Nationally Pollutant Discharge Elimination System (NPDES) to limit Elimination System (NPDES) to limit discharges via permit and set up discharges via permit and set up monitoring and penalty systemmonitoring and penalty system

Resource Conservation & Resource Conservation & Recovery Act (RCRA)Recovery Act (RCRA)

• Deals with the storage and disposal Deals with the storage and disposal of hazardous wasteof hazardous waste

• Requires cleanup of groundwater Requires cleanup of groundwater contaminationcontamination

• Penalty system for dischargesPenalty system for discharges

California LawsCalifornia Laws

• Tend to be more strict than Federal Tend to be more strict than Federal LawLaw

• Title 22 – states version of the Safe Title 22 – states version of the Safe Drinking Water ActDrinking Water Act

• Porter-Cologne Waterquality Act – Porter-Cologne Waterquality Act – states version of the Clean Water Actstates version of the Clean Water Act

• Proposition 65Proposition 65