5Chesapeake Bay The largest Estuary in the US Receives water from numerous rivers and streams that mixes with salt water of the ocean to produce an extremely productive estuary.Drains water from a large watershed of urban, suburban and agricultural areas.
6Bay contains an abundance of nutrients,Million of lbs of Nitrogen & Phosphorus→ algae bloomssediments,Current estimate = 8.2billion kg of sediment each year.chemicals.Damage to fish endocrine systems → hermaphroditesAll causing poor water quality, decreased biodiversity
7Chesapeake Bay 2000 Chesapeake Bay Action Plan 2010 many goals were being met↑water clarity↓nitrogen↑crab pop↑water quality
8The BasicsWater Pollution: Any chemical, biological or physical change in water quality that has a harmful effect on living organisms (including humans!) or makes it unusable for agriculturePoint Sources - Discharge pollution from specific locations (single point). EASY TO MONITOR/REGULATEFactories, power plants, oil wellsNon-Point Sources - Scattered or diffuse, having no specific location of discharge. HARDER TO CONTROL!!Agricultural fields, feedlots, golf courses
1015_21.JPG Figure 15-21 Title: Freshwater pollution sources. Caption: Point-source pollution comes from discrete facilities or locations, usually from single outflow pipes. Nonpoint-source pollution (such as runoff from streets, residential neighborhoods, lawns, and farms) originates from numerous sources spread over large areas.Notes:Keywords:fresh water, pollution, nutrients, ponds, lakes, rivers, streams, sewage, wastewater, energy resources, fossil fuels, oil, petroleum, spills, agriculture, agricultural land, food, farms, farming, pesticides, fertilizers
11Major Water Pollutants Human wastewater: sewage & gray water-- Decomposition of organic waste → Huge O2 demandExcess nutrients (N & P) eutrophicationDisease-causing organisms (esp. E. Coli & Cholera)Metals (Pb, Hg, As, Cd)AcidSynthetic Organics (pharma; pesticides; Military & Industrial compounds)OilSolid Waste (especially plastic!)SedimentThermal & Noise pollution
12Water Quality Indicators The measurements that are used to decide if the water quality is in good condition or not.Water must meet different requirements for different uses (fishing versus drinking)Drinking water must have 0 coliform bacteria colonies, very low turbidity and low nutrient levelsWater for fishing can have thousands of coliform bacteria colonies and high turbidity, but must have at dissolved oxygen levels of at least 6 ppm to support life.
13TemperatureWhat is measured – the temperature (oC or oF) of the water body. Should change according to hydrology and season.How to measure – use a thermometerDesired range – varies depending on location, but should fit the range of tolerance of native species and change seasonally as appropriate to the regionImpacted by – stream flow and lake depth, thermal pollution from industry or power plants, turbidity level
14pHWhat is measured – the concentration of H+ ions. Indicates how acidic or basic the water is.How to measure – use a pH probe or litmus paperDesired range – most species can survive between 5 and 8Impacted by – acid rain, acid mine drainage, buffering capacity, geology of the watershedpH = -log[H+]
15Nitrate (NO3-)What is measured – the concentration (ppm) of nitrate ions. Indicates how nutrient rich the water is.How to measure – use a digital probe or a nitrate titration kitDesired range – less than 1 ppmImpacted by – agricultural runoff, fertilizers, feedlots, sewage treatment plants
16Phosphate (PO43-)What is measured – the concentration (ppm) of phosphate ions. Indicates how nutrient rich the water is.How to measure – use a digital probe or a phosphate test kitDesired range – less than 0.1 ppmImpacted by – agricultural runoff, fertilizers, detergents
17Dissolved Oxygen (DO)What is measured – the concentration (ppm or mg/L) of oxygen dissolved in the water. Indicative of the amount of life the water can support.How to measure – use a digital probe or a DO test kitDesired range – above 6 ppmImpacted by – temperature, photosynthesis, nutrient levels, turbidity, organic wastes
18Biochemical Oxygen Demand (BOD5) What is measured – the rate of oxygen use. Specifically the amount of oxygen consumed over 5 days. Indicative of the amount of organic matter in the water.How to measure – Measure the DO, cover water sample and allow to sit for 5 days. Measure DO again. BOD = DOi-DOfDesired range –pristine rivers <1 mg/L,polluted river 2mg/L-8 mg/Lsewage effluent <20 mg/LImpacted by – respiration, nutrient levels, organic wastes
19Fecal ColiformWhat is measured – the number of bacteria colonies present in the sample.Indicator species - Indicates the presence of bacterial pathogens in the water.How to measure – place a 1 mL of of water on a agar petri dish. Incubate for hours. Count bacteria colonies.Desired range –Drinking water 0/100 mLswimming <200/100 mLnaturally present in ecosystemsImpacted by – animal waste, sewage
20TurbidityWhat is measured – the amount of light that can pass through water. Indicates the amount of dissolved solids in the water.How to measure – Collect a sample and use a turbidity meter, compare to known samples, lower a Secchi disk and record depth at which it can be seen.Desired rangeDrinking water <1 NTUEcosystem < 5 NTU over backgroundImpacted by – sediment, flooding, animal waste, sewage, riparian habitat, land disturbances, nutrients
21Macroinvertebrates / Species Diversity GoodWhat is measured – the size, diversity and distribution of organisms in the aquatic habitatHow to measure –Macroinvertebrates – scoop and screen sediment samples to collect organisms. Use keys to identify and count species.Species diversity – use sampling techniques to estimate diversity and size of populationsMayfliesStonefliesSnipefly larvaePond MusselsBadDesired range –Want a wide variety of native speciesHealthy populations of pollution sensitive speciesLow populations of pollutant tolerant speciesImpacted by – all of the previously discussed indicators, but mostly DOLeechesPouch SnailsTubifex wormsMidgeflies larvae21
22Fish Species Intolerant of Pollution Tolerant of Pollution Fish SpeciesIntolerant of PollutionTolerant of PollutionSalmon and TroutStreamline chubLampreyCarpCreek ChubBlackstripe Minnow
23Emerging Contaminants Sources of emerging contaminatesExcess drug concentrations are urinated out and end up in waste water.Improper disposal of medication (i.e. flushing medication down the toilet)Excess antibiotics and hormones fed to cattle enter the water cycle via waste lagoonsChemicals in everyday products like stabilizers, humectants and fragrances
25NutrientsSources - agricultural runoff (fertilizer, feedlots), detergents (P only), disturbed soil, products of decompositionEffects – Eutrophication nutrients ↑, algae grows, blocks sunlight, dies and decomposes, O2 ↓Dead zonesIndicators -Elevated N and P levelsDecreased DO levels, increased BOD levelsCloudy water: resembles pea soup from algae and cyanobacteriaReduction - reduce runoff, treat stormwater, improve farming techniques, use organic fertilizer, avoid detergents with phosphates
28Eutrophication Oligotrophic: nutrient-poor water Eutrophic: nutrient-rich waterAs nutrients are added from pollution:an oligotrophic condition rapidly becomes eutrophic.OligotrophicEutrophic
29Natural Vs. Cultural Eutrophication Natural eutrophicationaquatic successionoccurs over several hundreds of yearsmostly from runoff of plant nutrients from the surrounding landCultural eutrophicationdriven by human activitiesoccurs rapidlymostly nitrate- and phosphate-containing effluents85% of large lakes near major population centers in the U.S. have some degree of cultural eutrophication.
30Combating Eutrophication Attack the symptomsChemical treatmentAerationHarvesting aquatic weedsDrawing water down
31Combating Eutrophication Getting at root causeControlling point sourcesBan phosphate detergentsSewage-treatment improvementsReduce /control runoff fromControlling nonpoint sources: Difficult to address runoffUrbanAgricultural fieldsDeforested woodlandsOvergrazed pastures
32Excess nutrients Ocean – dead zone Lakes – Eutrophication Lakes – EutrophicationPut in order:Decomposers consume lots of oxygen, reducing DO levels in the lakeFish kills occurAlgae grows, blocking sunlightPlants and other aquatic producers die due to lack of sunlight and spaceAlgae and other plants die and sink to the bottom of the lakeFertilizer or animal waste runs off into the lake
34Biochemical Oxygen Demand (BOD) BOD- the amount of oxygen a quantity of water uses over a period of time at a specific temperature.Lower BOD - water is less polluted andhigher BOD -more polluted by wastewater.Example:decomposition of leaves = BOD of 5 to 20 mg of oxygenDecomp of human waste = BOF of 200 mg.
35Organic Matter (also called oxygen demanding waste) Sources - agricultural runoff, sewage, paper mills, food processing – feeds microbesEffects - Organic material must be broken down leading to an increase in biological activity and oxygen demand until waste is broken down.IndicatorsSlightly elevated N and P levelsDecreased DO levels, increased BOD levelsPossible increase in fecal coliform depending on sourceIncrease in turbidityLoss of sensitive speciesReduction - reduce runoff, increase riparian habitat, treat sewage, improve farming techniques
36Oxygen Sag Curve Clean Zone DO high BOD low Pollution enters stream Decomposition ZoneDECOMPOSITION increases to break down pollutionOXYGEN decreases as it is used up by decomposersSeptic zonedissolved oxygen levels are very low and very few species can surviveRecovery ZoneWaste concentrations decreaseDO , BOD DO is high, BOD is low and normal biodiversity levels are present.
37Pathogens Sources - human and animal waste (fecal matter) Effects – diseases in humans and animals: cholera, typhoid fever, hepatitis, Cryptosporidium, Giardia, E. coli, Guinea wormSymptoms: nausea, vomiting, diarrhea, dehydrationCholeraIndicatorsPresence of fecal coliform bacteria (these are harmless themselves, but indicate the presence of pathogens)Reduction – treat sewage using disinfection, separate drinking and waste water, boil water before drinking, use filters for parasitesGuinea WormCryptosporidiumE. ColiRota Virus
39Global ProblemsAccording to the World Health Organization, an estimated 1.1 billion people (1/6 of pop) do not have access to safe drinking waterDiarrheal diseases kill around 3.1 million people globally each year,mostly children in developing countries.
40Heavy Metals Sources - natural deposits (arsenic, mercury, etc) mining (all)coal burning (mercury)e-waste (cadmium, mercury, lead)industrial processes like smelting (lead, mercury, arsenic, etc)High salinity, low pHs and O2 deficiencies increase metal concentrations in waterEffects – heavy metals bioaccumulate and biomagnifyOften have the largest impacts at the top of the food chainMost are toxic at low doses and nuerotoxinsIndicators - Positive tests for metalsReductionminimize mining and perform effective remediationburn coal in larger coal plants with advanced air pollution control devicesrecycle e-wasteregulate industry and require the use of advanced air pollution control devicesArsenic (natural)
41Health EffectsLead and mercury are poisonous. Mercury exposure to developing fetuses in pregnant women has been linked to a variety of conditions such as mental retardations, cerebral palsy, and developing delays, causes kidney disorders and several damage the nervous and cardiovascular systems.Low levels of mercury in the brain cause neurological problems such as headache, depression, and quarrelsome behavior.
42Heavy Metals: Mercury & Lead Mercury - burning coal and mining goldThe mercury dumped in Minamata Bay by a factory entered humans through their diet of fish by bioaccumulation caused Minamata disease.People showed mental impairments, birth defects, and death caused by the chronic effects of exposure to mercury.Lead - mining and refining processes but is also in paint, water pipes, lead glazes or ceramics and burning fossilMercury and lead are toxic heavy metalsMininata disease – effects of being exposed to mercury: birth defects, nervous system/brain damage, learning disabilities, mental retardation or paralysis.How else can metals enter the body? Inhaling dust or vapors.
44Arsenic - a Natural Threat Toxic Arsenic (As) can naturally occur at high levels in soil & rocks.Drilling into aquifers can release As into drinking water supplies.According to WHO, more than 112 million people are drinking water with As levels times the 10 ppb standard.Mostly in Bangladesh, China, and West Bengal, India.
45Synthetic Organic Compounds Chemicals that contain carbon atoms.Most of the thousands of organic compounds found in water are synthetic chemicals that are produced by human activities;these included pesticides, solvents, industrial chemicals and plastics, and seepage from landfills.Wide variety of affectsToxicCancersGenetic defectsInterfers w/ hormonesGrowth & sexual developmentGender benders
46Pesticides Developed during WWII Herbicides, fungicides, insecticides Unintended effectsKill not just intended target, but wide varietyMosquito insecticide kills amphibiansAlter other physiological functionsDDT: target insect nervous system – accumulates in food chain and thins eggshellsInert ingredientsAdditives aren’t necessarily harmlessRoundup additive to penetrate waxy leaves – ruptures tadpole gills
47Pharmaceuticals Very common in US streams 50% antibiotics & hormones80% nonprescription drugs90% steriodsMost are very low concentrationsBut hormones at low concentrations cause problemsAntibiotics – contributing to resistance issues
48Military compounds Perchlorates In soil from rocket fuel Affect thyroid & metabolism
49Industrial compoundsCuyahoga River in OH caught fire several times in 50’s and 60’s – mostly from industrial wastePCB’s – polychlorinated biphenylsTo make plastic, insulation,Lethal, persistent, bioaccumulatesDump into rivers – settles in sedimentsIn 2009, GE finally dredge river from dumpingNo longer manufactured/used in USBanned by Stockholm Convention in 2001PBDE’s - polybrominated diphyenyl ethersFlame retardantsBrain damageBanned in EU and several states
50Acid RainSources - burning fossil fuels (SOx, NOx), especially coal (SOx)In the eastern US, most acid rain is caused by SO2 from coal burningIn So. Cal, most acid rain is caused by NOx emissions from carsNOx + SOX + H2O H2SO4 and HNO3EffectsLoss of the most sensitive species first (very young, very old)Increased leaching of metal from sedimentLoss of biodiversity food web disruptionHNO3 can also cause eutrophicationIndicatorsNormal rain is around , acid rain is below 5.5Reduced pH in water bodiesReduced soil pHReductionRemove SO2 and NOx from emissions before release (install scrubbers on power plants)Switching to less polluting alternative fuelsAdd lime to aquatic ecosystems to absorb H+ ions (expensive)
52Thermal PollutionSources - industry, power plants, reduced water flow, increased sedimentEffects – increased temperatures reduce the amount of oxygen the water can hold, thus reducing DO levels and causing fish killsIndicatorsIncreased water temperatureDecreased DOFish killsReduction - reduce runoff, cool water before releasing, maintain adequate water flow, maintain healthy riparian zones for shade
53Sediment PollutionSources - erosion, runoff from farms, construction, mining, etcEffects – clogs waterways, blocks sunlight, may choke fish, increases water temperatures, fish killsIndicatorsIncreased turbidityIncreased temperaturesPossible decrease in DOReduction – protect/replace riparian habitat, minimize erosion, practice soil conservation strategies, maintain wetlands around water bodies
54Noise Pollution Sounds travels better underwater than thru air Sounds from ships & subsEspecially sonarInterferes with marine animal communicationBeached whales
57Groundwater Pollution Over 50% of the people in the U.S. rely on groundwater for drinkingLand fills, agricultural lands and underground storage tanks can leak pollutants leech into groundwater
58Groundwater Pollution Sources - underground storage tanks, older unlined landfills, modern landfill leaks, buried waste, etcEffects – aquifer contamination, drinking water contamination, plume movement into surface waterIndicatorsPositive well testsReductionline landfills and lagoonsbury waste in appropriate hazardous waste facilitiescleanup superfund and brownfield sitesreplace underground storage tanks before leaks occur.
59Oil SpillsSources natural oil seeps 2. surface runoff 3. transport 4. extractionEffects – See case studiesIndicatorsPresence of oil byproducts including benzene, toluene, xylene, napthalene, benzo(a)pyreneReductionImprove safety standards for extracting and transporting oilPerform routine inspectionsRequire back-up systems and a disaster management plan in case of unexpected eventResearch oil spill cleanup techniques prior to a spill
68Preventing Water Pollution Protect wetland and riparian habitatUse less chemicals, energy, and manufactured products that contain plastic or metalMinimize the use of agricultural chemicals (inorganic fertilizer, pesticide, soil stabilizers, etc)Develop effective storm water runoff systemsDevelop and enforce strict safety requirements for oil drilling and transportMinimize runoff from all sourcesTreat contaminated water prior to release into the environment (waste water treatment)
69Cleaning Up Polluted Water Immediately reduce or eliminate pollution discharges into the water bodyBacteria can be used to clean up organic or oil pollutionDredge contaminated soil out of the water body – will temporarily increase water pollution
71Septic SystemRequires space to lay out a septic tank and leach field. Usually found in rural areas.Septic tank: receives waste water from the houseHarmful pathogens settle in sludge , decompose in tank or degraded by soil microbes in leach fieldThree layers develop:Scum - floatsSeptage Flows to leach fieldSludge-pumped out every 5-10 yrs.Leach field – pipes with small holesWastewater slowly seeps and is filtered and decomposedNutrients are recycled by other plants / organisms
72Sewage TreatmentSewage includes all waste water that has been used by a household or industry.It does not include storm-water from road and property runoff, which is usually diverted directly into waterways.In some cities, sewage and storm-water systems may be partly combined, and sewage may overflow into storm-water during high rainfall.Trickling filters at a waste treatment plantSewage pipes discharging into a holding tank
74Primary sewage treatment: a physical process that uses screens and a grit tank to remove large floating objects and allows settling.Secondary sewage treatment: a biological process in which aerobic bacteria remove as much as 90% of dissolved and biodegradable, oxygen demanding organic wastes..
75Disinfection Options Chlorine – the most common disinfectant not effective against cryptosporidiumcan create dangerous byproductsmust be removed prior to discharge into ecosystemsResidual left in water for residual disinfection (pro/con – depends)UV – new technology, very effective, damages DNACan catalyze undesirable reactionsIneffective against adenovirusesNo residual disinfection (for drinking water)Ozone – new technologymore expensiveozone is a regulated air pollutantCan form unintended byproducts
76Problems with Waste Water Treatment Water is often removed from one source and returned to another, this is unsustainable (open loop)Many municipalities only use primary and secondary treatment for residential waste waterNitrogen, phosphorus, pharmaceuticals, synthetic organics not removed.Need expensive tertiary stepmay use no treatment for storm waterExpensive to build and mantain
77Animal Wastewater Concentrated Animal Feeding Operations Feed Lots - Manure lagoons- large, human-made ponds line with rubber to prevent the manure from leaking into the groundwater. After the manure is broken down by bacteria, it is spread onto fields as fertilizers.
78Using Nature to Purify Sewage Ecological wastewater purification by a living machine.Uses the sun and a series of tanks containing plants, snails, zooplankton, crayfish, and fish (that can be eaten or sold for bait).Figure 21-1
79Reducing Water Pollution through Sewage Treatment Natural and artificial wetlands and other ecological systems can be used to treat sewage.California created a 65 hectare wetland near Humboldt Bay that acts as a natural wastewater treatment plant for the town of 16,000 people.The project cost less than half of the estimated price of a conventional treatment plant.
80Green Waste Water Modern waste water treatment plants expensive Use a series of greenhouses & wetlands - Purify water: effective & affordableAesthetically pleasing – no odorMany of the same processes of traditional treatment plantsWaste water flows into holding tanksPumped into series of transparent tanksMicrobes, snails algae, plants – grow & consume nutrientsAir is bubbled thru to get aerobic decomp - Anaerobic decomp = smellLiquid coming out held – solids settleWater is filtered thru sand then artificial wetlandsDenitrifying bacteria removes NitrogenWater is exposed to UV light to kill viruses & bacteriaReleased to leach field to by filtered by soil
82Clean Water ActThe Clean Water Act is a 1977 amendment to the Federal Water Pollution Control Act of 1972Set the basic structure for regulating discharges of pollutants in the USThe law gave EPA the authority to set water quality standards for industry and for all contaminants in surface watersDesigned to protect fishing, swimming and the ecosystem healthGoal: Make lakes & streams fishable & swimmable
83Clean Water ActSets up the National Pollutant Discharge Elimination System (NPDES)Regulates point sources of pollution by requiring a permit to discharge any pollutant into a navigable waterway.Total Maximum Daily Load (TMDL)sets daily limits for total pollutant discharges into impaired water bodies (on 303d list)Set based on the maximum pollution levels the water body can receive and still meet water quality standards
85Safe Drinking Water Act The Safe Drinking Water Act (1974) was established to protect the quality of drinking water in the U.SThis law focuses on all waters actually or potentially designed for drinking use, whether from above ground or underground sources
86Safe Drinking Water Act EPA sets Maximum Contaminant Levels (MCLs) for drinking waterStandards for dozens of contaminantsSubjective and sensitive to political pressureIndustry & cities: resist reducing levels - say it’s too expensivePollutantStandardHealth ImpactNitrate10 mg/LFertilizers: Blue Baby SyndromeLead0.015 mg/LLead pipes: Neurotoxin, decreased IQChloramines4 mg/LByproduct of chlorine disinfection: eye and nose irritant, stomach discomfortPCBsmg/LIndustrial processes: increased cancer risk, reproductive issues
88Pollution in Developing Countries Water in many of central China's rivers are greenish black from uncontrolled pollution by thousands of factories.Figure 21-5
89India’s Ganges River: Religion, Poverty, and Health Daily, more than 1 million Hindus in India bathe, drink from, or carry out religious ceremonies in the highly polluted Ganges River.Figure 21-6
90India’s Ganges River: Religion, Poverty, and Health Religious beliefs, cultural traditions, poverty, and a large population interact to cause severe pollution of the Ganges River in India.Very little of the sewage is treated.Hindu believe in cremating the dead to free the soul and throwing the ashes in the holy Ganges.Some are too poor to afford the wood to fully cremate.Decomposing bodies promote disease and depletes DO.