Lecture Outlines Chapter 22 Environment: The Science behind the Stories - PowerPoint Presentation

Lecture OutlinesChapter 22Environment:The Science behind the Stories 4th EditionWithgott/Brennan

This lecture will help you understand:The types of waste we generateManaging wasteThe scale of the waste dilemma Conventional waste disposalWays to reduce wasteIndustrial solid waste managementManaging hazardous waste

Central Case: Transforming New York’s Fresh Kills LandfillThe largest landfill in the world closed in 2001Staten Island residents viewed the landfill as a civic blemishIt was briefly reopened to bury rubble from the World Trade Center after the 9/11/2001 attackIt will take 30 years to turn it into a world-class public park

Approaches to waste managementWaste = any unwanted material or substance that results from human activity or process Municipal solid waste = nonliquid waste from homes, institutions, and small businesses Industrial solid waste = from production of goods, mining, agriculture, petroleum extraction and refining Hazardous waste = solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive Wastewater = used in a household, business, or industryAlso, polluted runoff from streets and storm drains

Aims in managing wasteWaste management aims to:Minimize the amount of waste generated (source reduction)Recover waste materials and recycle themDispose of waste safely and effectivelySource reduction is the preferred approach

Reducing waste entering the waste streamWaste stream = the flow of waste as it moves from its sources toward disposal destinationsUse materials efficiently, consume less, buy goods with less packaging, use goods longerRecovery (recycling, composting) = next best strategy in waste managementRecycling = sends used goods to facilities to manufacture into new goods (e.g., newspaper)Composting = recovery of organic wasteBut there will always be some waste left to dispose of

Waste generation varies from place to placeMunicipal solid waste is also called “trash” or “garbage”In the U.S., paper, yard debris, food scraps, and plastics are the principal components of municipal solid wasteEven after recycling, most solid waste is paperIn developing countries, food scraps are the primary contributorMost municipal solid waste comes from packaging and nondurable goods (discarded after a short time of use)As we get more goods, we generate more wasteU.S. citizens generate 1 ton/person each year

The U.S. municipal solid waste stream

U.S. waste generation is risingSince 1960, waste generation increased 2.8 times Per capita waste generation increased 67%Especially plastics

Developing nations are producing wasteConsumption is greatly increasing in developing nationsRising standard of living, more packaging, poor-quality goods Wealthy consumers often discard items that can still be usedPoor people support themselves by selling items they scavenge from dumps

Disposal methods have improvedPeople dumped their garbage wherever it suited themOpen dumping and burning still occur Most industrialized nations bury waste in lined and covered landfills or burn it in incineration facilitiesIn the U.S., recycling is decreasing pressure on landfillsIn the U.S., recycling is decreasing pressure on landfills

Sanitary landfills are regulatedSanitary landfills = waste buried in the ground or piled in large, engineered mounds to prevent contamination and health threatsU.S. landfills must meet the EPA’s national standardsUnder the Resource Conservation and Recovery Act (RCRA) of 1976Waste is partly decomposed by bacteria and compresses under its own weight to make more spaceSoil layers reduce odor, speed decomposition, reduce infestation by petsClosed landfills must be capped and maintained

A typical sanitary landfillTo protect against environmental contamination, landfills must be located away from wetlands and earthquake-prone faults, and be 20 ft above the water tableLeachate = liquid from trash dissolved by rainwaterIt is collected and treated in landfills But it can escape if the liner is punctured

Landfills have drawbacksCollection systems won’t be kept upWaste doesn’t decay much40-year-old newspapers can still be readThe not-in-my-backyard (NIMBY) syndromeThe “garbage barge” case in Islip, New York in 1987 Full landfills forced a barge to take the waste to North Carolina, Louisiana, and Mexico All rejected the medical-waste-contaminated load After a 6,000 mile journey it returned to New York where the waste was incinerated

Landfills can be transformed after closureThousands of landfills lie abandonedSmaller landfills were closedIn 1988, the U.S. had 8,000 landfills Today there are less than 1,800Cities have converted closed landfills into public parksOnce properly capped, old landfills can serve other purposes such as the Cesar Chavez Park in Berkeley, California.

Incinerating trash reduces landfill pressureIncineration = a controlled process that burns garbage at very high temperaturesIncineration in specially constructed faculties can be an improvement over open-air burning of trashBut the remaining ash must be disposed of in a hazardous waste landfillHazardous chemicals are created and releasedScrubbers = chemically treat the gases produced in combustion Remove hazardous parts and neutralize acidic gases

A typical solid waste incineratorBaghouse = a system of huge filters that physically removes particulate matter

Many incinerators create energyIncineration reduces the volume of waste and can generate electricity Waste-to-energy (WTE) facilities = use the heat produced by waste combustion to create electricityOver 100 facilities are in use across the U.S.They process nearly 100,000 tons of waste per dayBut they take many years to become profitableCompanies contract with communities to guarantee a minimum amount of garbageLong-term commitments interfere with the communities’ efforts to reduce and recycle waste

Landfills can produce gas for energyBacteria decompose waste in a landfill’s oxygen-deficient environmentLandfill gas = a mix of gases that consists of 50% methane Can be collected, processed, and used like natural gas At Fresh Kills, the city sells the gas for $11 million/yearWhen not used commercially, landfill gas is burned off to reduce odors and greenhouse emissions

Reducing waste is a better optionSource reduction = preventing waste in the first placeAvoids costs of disposal and recyclingHelps conserve resourcesMinimizes pollutionCan save consumers and businesses moneyMost waste consists of materials used to package goodsUse minimal packagingUse recyclable packagingReduce the size or weight of goods and materials

Governments fight waste and litterSome government address a major source of litter and waste: plastic grocery bagsGrocery bags can take centuries to decomposeThey choke and entangle wildlife and cause litter100 billion of them are discarded each year in the U.S. Many governments have banned nonbiodegradable bagsCompanies maximize sales by producing short-lived goodsIncreasing the longevity of goods also reduces waste

Reuse is a main strategy to reduce wasteItems can be used again Use durable goods used instead of disposable onesDonate items to resale centers (Goodwill and the Salvation Army)Other actions include:Rent or borrow items instead of buying themBring your own cup to coffee shopsBuy rechargeable batteriesMake double-sided copiesUse cloth napkins instead of paper ones

Composting recovers organic wasteComposting = the conversion of organic waste into mulch or humus through natural decomposition It can be used to enrich soilHome composting:Householders place waste into composting piles, underground pits, or specially constructed containers Heat from microbial action builds up and decomposition proceedsEarthworms, bacteria, and other organisms convert waste into high-quality compost

Municipal composting programsThese programs divert food and yard waste from the waste stream to central composting facilitiesThe resulting mulch can be used for gardens and landscapingHalf of U.S. states now ban yard wastes from the municipal waste streamAccelerating the move to compostingMunicipal composting reduces landfill wasteEnriches soil and encourages soil biodiversityMakes healthier plants and more pleasing gardensReduces the need for chemical fertilizers

Recycling consists of three stepsRecycling = collecting materials that can be broken down and reprocessed to manufacture new itemsRecycling diverted 61 million tons of materials away from U.S. incinerators and landfills in 2008Step 1 = collection and processing of recyclable materials through curbside recycling or designated locationsMaterials recovery facilities (MRFs) = workers and machines sort, clean, shred, and prepare items

The second and third steps of recyclingStep 2 = using recyclables to produce new goodsMany products use recycled materialsStep 3 = consumers buy goods made from recycled materials Must occur if recycling is to functionAs markets expand, prices will fall

Recycling has grown rapidly and can expandThe growth of recycling is “One of the best environmental success stories ….”U.S. recycling rates varyDepending on the product and stateGreenhouse gas emissions equal to 10 billion gallons of gas are prevented each yearThe U.S. recycles 24.4% of its waste stream

Recycling rates vary widely in the U.S.

Growth in recycling results from:Municipalities’ desire to reduce wasteThe public’s satisfaction in recycling Recycling may not be profitable It is expensive to collect, sort, and process materialsPlus, the more material that is recycled, the lower the priceBut market forces do not take into account the health and environmental effects of not recyclingThere are enormous energy and material savings

We can recycle materials from landfillsBusinesses are weighing the benefits of salvaging materials in landfills that can be recycledMetals (steel, copper)Organic waste for compostHarvesting methane leaking from open dumps in Asia and AfricaThese approaches work when market prices are highBut costs and regulatory requirements have made investing in landfill mining risky

Financial incentives can address waste“Pay-as-you-throw” approach = uses financial incentives to influence consumer behaviorThe less waste a house generates, the less it is charged for trash collection Bottle bills = consumers receive a refund for returning used bottlesThey are profoundly successfulBut beverage industries and groceries fight them

A Canadian city showcases reduction and recyclingEdmonton, Alberta has one of the most advanced waste management programsWaste: 40% is landfilled, 15% is recycled, 45% is composted90% of the people participate in curbside recyclingIt produces 80,000 tons/year in its composting plantIts state-of-the-art MRF handles 30,000–40,000 tons of waste annually

Edmonton, Alberta’s waste managementWaste is dumped in the composting plantThe plant is the size of eight football fieldsEach year the plant produces:80,000 tons of compostGas to power 4,600 homeThousands of dollars for the city

Industrial solid wasteU.S. industries generate 7.6 billion tons of waste/year97% is wastewater Industrial solid waste = is not municipal or hazardous wasteThe federal government regulates municipal wasteState or local governments regulate industrial solid wasteWith federal guidanceWaste from factories, mining, agriculture, petroleum extraction, etc.

Regulation and economics influence industrial waste generationMost methods and strategies of waste disposal, reduction, and recycling are similar to municipal solid wasteState and local regulations are less strict than federal rulesIndustries may not be required to have permits or install liners or leachate collection systemsOr even monitor groundwater for contamination It may be cheaper to generate waste than to avoid itIndustries are awarded for economic, not physical, efficiencySo they don’t have incentives to decrease waste

Industrial ecologyIndustrial ecology = redesigning industrial systems to reduce resource inputs while maximizing physical and economic efficiency Industrial systems should function like ecological systems, with little wasteLife cycle analysis = examines the life cycle of a product to make the process more ecologically efficientWaste products can be used as raw materials Eliminates harmful products and materials Creates durable, recyclable, or reusable products

Businesses are adopting industrial ecologyBusinesses are saving money while reducing waste American Airlines switched from hazardous to nonhazardous materials in its Chicago facilityDecreased its need to secure permits from the EPAIt used 50,000 reusable plastic containers to ship goods, reducing packaging waste by 90% It recycled enough aluminum cans and white paper in 5 years to save $205,000 15 ideas from employees saved over $8 million in 1 year

An example of industrial ecologyInterface, a carpet tile company, cut its waste 80%, fossil fuel use 45%, and water use 70% while saving $30 million/year and raising profits 49%

Defining hazardous wasteHazardous waste is a liquid, solid, or gas and is one of the following:Ignitable = easily catches fire (natural gas, alcohol)Corrosive = corrodes metals in storage tanks or equipmentReactive = chemically unstable and readily reacts with other compounds, often explosively or by producing noxious fumesToxic = harms human health when inhaled, ingested, or contact human skin

Hazardous wastes have diverse sourcesIndustry produces the largest amount of hazardous wasteBut waste generation and disposal are highly regulatedHouseholds = the largest source of unregulated hazardous wastePaint, batteries, solvents, cleaners, pesticides, etc.Mining, small businesses, agriculture, utilities, and building demolition all produce hazardous wastesOrganic compounds and heavy metals are particularly hazardous because their toxicity persists over time

Organic compounds can be hazardousSynthetic organic compounds resist bacterial, fungal, and insect activityPlastics, tires, pesticides, solvents, wood preservativesKeep buildings from decaying, kill pests, and keep stored goods intact Their resistance to decay makes them persistent pollutantsThey are toxic because they are readily absorbed through the skinThey can act as mutagens, carcinogens, teratogens, and endocrine disruptors

Heavy metals can be hazardousLead, chromium, mercury, arsenic, cadmium, tin, and copper Used widely in industry for wiring, electronics, metal plating and fabrication, pigments, and dyesThey enter the environment when they are disposed of improperlyHeavy metals that are fat soluble and break down slowly can bioaccumulate and biomagnify

“E-waste” is growingElectronic waste (“e-waste”) = waste involving electronic devices Computers, printers, cell phones, TVs, MP3 players Americans discard 400 million devices/year67% are still in working orderThey are put in landfills, but should be treated as hazardous wasteValuable trace minerals can be recovered – the 2010 Olympic medals were made from e-waste!

Before disposing of hazardous wasteHazardous waste used to be discarded without special treatmentPeople did not know it was harmful to human healthThey assumed the substances would disappear or be dilutedSince the 1980s, cities have designated sites or collection days to gather household hazardous waste

RCRAResource Conservation and Recovery Act (RCRA) = states must manage hazardous waste Large generators of hazardous waste must obtain permitsMaterials must be tracked “from cradle to grave”Intended to prevent illegal dumping

Illegal dumping of hazardous wasteHazardous waste disposal is costlyIt results in illegal and anonymous dumpingIllegal dumping creates health risks Along with financial headaches for dealing with itIndustrial nations illegally dump in developing nationsThe Basel Convention, an international treaty, should prevent dumping, but it still happensHigh costs also encourage companies to invest in reducing their hazardous waste Incineration, bacterial and plant decomposition, etc.

Three disposal methods for hazardous wasteThese do not lessen the hazards of the substances But they help keep the substance isolated from people, wildlife, and ecosystemsLandfills = must have several impervious liners and leachate removal systemsDesign and construction standards are stricter than for ordinary sanitary landfillsMust be located far from aquifers

Surface impoundmentsSurface impoundments = store liquid hazardous wasteShallow depressions are lined with plastic and clayThe water evaporatesThe residue of solid hazardous waste is transported elsewhereThe clay layer can crack and leak wasteRainstorms cause overflow, contaminating nearby areas

Deep-well injectionDeep-well injection = a well is drilled deep beneath the water table Waste is injected into itA long-term disposal methodThe well is isolated from groundwater and humansHowever, the wells can corrode and leak waste

Radioactive waste is especially hazardousRadioactive waste is very dangerous and persistentThe U.S. has no designated single disposal siteWaste will accumulate around the nationThe Waste Isolation Pilot Plant (WIPP) = the first underground repository for transuranic waste from nuclear weapons development Caverns are 655 m (2,150 ft) below ground in a huge salt formation thought to be geologically stableWIPP became operational in 1999 and is receiving thousands of shipments of waste

Contaminated sites are being cleaned upGlobally, thousands of former military and industrial sites are contaminated with hazardous waste Dealing with these messes is difficult, time consuming, and expensive Comprehensive Environmental Response Compensation and Liability Act (CERCLA) (1980) Superfund is administered by the EPAEstablished a federal program to clean up U.S. sites polluted with hazardous waste

SuperfundExperts identify polluted sites, take action to protect groundwater near these sites, and clean up the pollutionThe EPA must clean up brownfields Lands whose reuse or development is complicated by the presence of hazardous materialsTwo events spurred creation of Superfund legislationIn Love Canal, Niagara Falls, New York, in 1978–1980, families were evacuated after buried chemicals rose to the surfaceTimes Beach, Missouri, was evacuated after contamination with dioxin from oil sprayed on roads

The Superfund processOnce a Superfund site is identified, EPA scientists note:How close the site is to human habitation If wastes are currently confined or likely to spreadIf the site threatens drinking water suppliesHarmful sites are placed on the National Priority ListThey are ranked by their level of risk to human healthCleanup goes on a site-by-site basis as funds are availableThe EPA must hold public hearings to inform area residents of its findings and to receive feedback

Who pays for cleanup?CERCLA operates under the polluter pays principle = charge polluting parties for cleanupHowever, the responsible parties often can’t be foundA trust fund was established by a federal tax on petroleum and chemical industriesThe fund is bankrupt and Congress has not restored itSo taxpayers now pay all costs of cleanupFewer cleanups are being completed1,279 sites remain, and only 341 have been cleaned upCleanup costs $25 million and takes 12–15 years

ConclusionSocieties have made great strides in addressing our waste problems Modern methods of waste management are far safer for people and gentler on the environmentRecycling and composting are growing rapidly Our prodigious consumption has created more waste than ever before The best solution to our waste problem is to reduce generation of waste

Which of the following components of waste managementis the most preferred?Minimizing the amount of waste we generate Recovering waste materials and finding ways to recycle them Disposing of waste safely and effectively Any of these components works well – they are all equal in their effectivenessQUESTION: Review

QUESTION: ReviewAnother name for municipal solid waste is: Yard waste Industrial waste Hazardous waste Trash or garbage     

QUESTION: ReviewWithin a sanitary landfill, waste is:       Poured into deep wellsStored in large piles and then burned Buried in the ground or piled up in large, carefully engineered mounds Put onto barges and shipped overseas

QUESTION: ReviewWhat are some ways we can reuse items to keep them from entering the waste stream? Donate used items to charity. Borrow items you need, instead of buying them. Make double-sided copies All of the above are ways to reduce the waste stream.

QUESTION: ReviewThere are several reasons why recycling is increasing; which of the following is NOT a reason? Municipalities want to reduce waste inputs. The public obtains satisfaction from recycling. It is usually profitable. There are enormous energy and material savings.

QUESTION: Review By EPA definition, hazardous waste can be:IgnitableHotLargeMoveable

QUESTION: ReviewSanitary landfillsSpecialized landfillsSurface impoundmentsInjection wells Which of the following disposal method for hazardous waste involves shallow depressions lined with clay to hold liquid waste?

QUESTION: Review Radioactive waste:Is dangerous, but not persistent in the environment.Is not harmful to the environment, but is persistent.Is dangerous to human health and is persistent. Is not dangerous to human health, but is dangerous to the environment.

QUESTION: Interpreting Graphs and DataIncreased recycling and source reduction Each person creating more wasteIncreased waste generationIncreased per capita waste generation The red line representing per capita generation of waste since 1990 can best be explained by:

QUESTION: Interpreting Graphs and DataWhich statement is false for this figure?a) More waste is going to landfills.b) Recycling plays a larger role than in 1985.c) Combustion is still being used.Composting is increasing.

QUESTION: Weighing the IssuesYes; it is worth it to increase recycling.Yes, because I’d get more money from bringing in recyclable materials.No; subsidies are never a good idea.No; I don’t recycle anyway. Should the government subsidize recycling programs, even if they operate at a loss?

QUESTION: Weighing the IssuesGovernment mandates that force manufacturers to use less packagingCharging the consumer more for products that use lots of packagingLetting industries determine how much packaging they want to useLeaving it alone; this is not a high priority for me Which method would you support to reduce the waste stream?