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SOLID, TOXIC & HAZARDOUS WASTE. Managing Solid Waste Disposal. Waste Stream – the steady flow of matter from raw materials, through manufacturing, product formation and marketing, and on to its final resting place – a solid waste dump
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Managing Solid Waste Disposal • Waste Stream – the steady flow of matter from raw materials, through manufacturing, product formation and marketing, and on to its final resting place – a solid waste dump • Some waste contain valuable resources – reduce, reuse, recycle • Americans produce 4.5 pounds of solid waste per day • 76% ends up in landfills
Waste • Waste = any unwanted material or substance that results from human activity or process • Municipal solid waste (MSW) = non-liquid waste that comes from homes, institutions, and small businesses • Industrial solid waste (ISW) = waste from production of consumer goods, mining, agriculture, and petroleum extraction and refining • Hazardous waste =solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive • Wastewater = water used in a household, business, or industry, as well as polluted runoff from our streets and storm drains
Sources Greatest source in US – mining & agriculture MSW relatively small proportion of solid waste #1 paper #2 yard trimmings #3 food
WASTE DISPOSAL METHODS • Open dump – unsanitary, dangerous, malodorous, vermin-infested • Poor often live on or near • Sanitary landfill • Lined with layers of clay & plastic to decrease leachate • Leachate collected & treated as wastewater • Trash alternately compacted & covered with soil • Pipes collect methane (source of energy of burned off) • Site selection important (geologically, proximity to source)
Sanitary Landfill To protect against environmental contamination, landfills must be located away from wetlands, earthquake-prone faults, and 20 ft above water table
Landfills have drawbacks • Experts believe that leachate will eventually escape • The liner will become punctured • Leachate collection systems eventually aren’t maintained • It is hard to find places suitable for landfills • The Not-In-My-Backyard (NIMBY) syndrome • The “Garbage barge” case • In 1987, Islip, New York’s landfills were full, and a barge traveled to empty the waste in North Carolina, which rejected the load • It returned to Queens to incinerate the waste, after a 9,700 km (6,000 mile) journey
NYC Garbage Barge • The garbage was finally burned in New York, and the 430 tons of ash sent to Islip to be buried.
Landfills can be transformed after closure • Thousands of landfills lie abandoned • Managers closed smaller landfills and made fewer larger landfills • In 1988, the U.S. had nearly 8,000 landfills • Today there are fewer than 1,700 • Growing cities converted closed landfills into public parks • Flushing Meadows in Queens, New York, was redeveloped for the 1939 World’s Fair
WASTE DISPOSAL METHODS • Toxic Colonialism – send solid & hazardous waste to developing countries • US exports 80% of its e-waste to Asia (contain heavy or toxic metals) • Poor neighborhoods & Native American reservations (no resources to fight waste disposal) • Ocean Dumping • Illegal • Ocean Dumping Ban Act of 1988 • Prohibits dumping sewage sludge, industrial waste, medical wastes, MSW • Great Pacific Garbage Patch
WASTE DISPOSAL METHODS • Incineration • a controlled process in which mixed garbage is burned at very high temperatures • Reduces amount of landfill volume 80-90% • Refuse Derived Fuel – non-combustibles removed • Mass Burn Incinerators – burn anything smaller that a refrigerator • More cost effective • Releases air pollutants & require post-combustion controls
Many incinerators create energy • Incineration is used to reduce the volume of waste and generate electricity • Waste-to-energy facilities (WTE) = use the heat produced by waste combustion to create electricity • More than 100 facilities are in use across the U.S. • They can process nearly 100,000 tons of waste per day • But, they take many years to become profitable • Companies contract with communities to guarantee a minimum amount of garbage • Long-term commitments interfere with the communities’ later efforts to reduce waste
Improved disposal methods • Most industrialized nations now bury waste in lined and covered landfills or burn it in incineration facilities • In the U.S., recycling is decreasing pressure on landfills
DIOXINS • Chlorinated hydrocarbons • Most toxic TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) • Naturally produced during forest fires • Anthropogenic sources – incinerators, smelters, chlorine bleaching at paper mills, tobacco smoke • Bioaccumulate & biomagnify • Teratogenic (birth defects), immunotoxic, carcinogen, liver damage, rashes, skin discoloration • Love Canal, NY & “A Civil Action”
Reducing Waste • Reduce, Reuse, Recycle • Reduce • Decrease packaging • Source reduction (redesign to use less material) • Reuse • Use the waste for another or the same purpose • Reuse plastic grocery bags • Reuse glass containers (glass bottle can be used 15 times) • Recycle • Convert to another product • Open loop recycling – convert to a different product • Closed-loop recycling – recycled to same product
RECYCLING • Must be profitable • Reduces air pollution • Steps • Collection and processing of materials • Materials Recovery Facilities (MRFs)-items sorted, cleaned & prepared • Use recyclables to make new products • Consumers purchase goods from recycled materials
Paper Recycling • Paper making process energy & water intensive, also uses chlorine – makes sense to recycle • Open-loop recycling • 1st – de-ink • Mix with fresh pulp (fibers shorten each time recycled) • Uses less chlorine & water • Reduces air pollution • Fewer trees harvested
Composting • Diverts food and yard waste from the waste stream • Converting organic waste into mulch or humus through natural biological process of decomposition • Enriches soil, reduces erosion • Home composting • Municipal composting • Established area in which yard wastes & tree trimmings converted to mulch (a green fertilizer)
Recycling has grown rapidly and can expand • The EPA calls the growth of recycling “one of the best environmental success stories of the late 20th century” • Recycling rates vary widely, depending on the product • 67% of major appliances are recycled • Only 6% of plastics are recycled
Recycling Difficulties • Plastic difficult to recycle • Soda bottles (PET plastics) recycled into carpets, clothing, bottles & packaging • Contamination with PVC plastic can render PET unusable for recycling • Recycled plastic more expensive • Biodegradable plastics only partially biodegradable • Photodegradable (in a landfill???) • Tires • Can be reused (not recycled – vulcanized rubber cannot be remelted) • Difficult to bury • Shredded to use in playgrounds & as artificial mulch • Incinerated for energy
Recycling Difficulties Lead & Lead Toxicity • Recycled from automobile batteries • Bioaccumulates in bone • Leads to mental retardation, lowered IQs, hyperactivity, ADHD, learning disorders • Max level 10µg/dL of blood
Demanufacturing • Taking apart household items & retrieve recyclable components • Refrigerators, stoves, televisions, air conditioners • Computers, electronics, etc
Hazardous Wastes Any wastes that are flammable, explosive, corrosive or highly reactive Chemicals that are toxic, carcinogenic, mutagenic, teratogenic Not radioactive wastes Most is recycled, stored or converted to less hazardous material
Hazardous Waste • Hazardous waste is defined as: • Ignitable = substances that easily catch fire (natural gas, alcohol) • Corrosive = substances that corrode metals in storage tanks or equipment • Reactive = substances that are chemically unstable and readily react with other compounds, often explosively or by producing noxious fumes • Toxic = substances that harm human health when they are inhaled, are ingested, or contact human skin
Hazardous wastes have diverse sources • Industry = produces the largest amount of hazardous waste • But waste generation and disposal is highly regulated • Mining • Households = now the largest producer of unregulated hazardous waste • Paints, batteries, oils, solvents, cleaning agents, pesticides • Small businesses • Agriculture • Utilities • Building demolition
Organic compounds can be hazardous • Particularly hazardous because their toxicity persists over time • Synthetic organic compounds = resist decomposition • Keep buildings from decaying, kill pests, and keep stored goods intact • Their resistance to decay causes them to be persistent pollutants • They are toxic because they are readily absorbed through the skin • They can act as mutagens, carcinogens, teratogens, and endocrine disruptors
Heavy metals can be hazardous • Lead, chromium, mercury, arsenic, cadmium, tin, and copper • Used widely in industry for wiring, electronics, metal plating, pigments, and dyes • They enter the environment when they are disposed of improperly • Heavy metals that are fat soluble and break down slowly can bioaccumulate and biomagnify
PCBs Polychlorinated biphenyls – chlorinated hydrocarbons Persistent and bioaccumulate & biomagnify Made in US until 1976 Used in electric transformers, capacitors, pumps & turbines Used as adhesive, lubricants, fire retardants, hydraulic fluids Acute exposure - causes nausea, diarrhea, vomiting Chronic – interferes with endocrine system Removed by bioremediation or incineration
“E-waste” is a new and growing problem • Electronic waste (“e-waste”) = waste involving electronic devices • Computers, printers, VCRs, fax machines, cell phones • Disposed of in landfills, but should be treated as hazardous waste • Some people and businesses are trying to use and reuse electronics to reduce waste
Managing Hazardous Wastes • Easiest way to control – avoid using • Green chemistry –redesigning chemical processes to be less hazardous • Physical processes • using charcoal to absorb toxins • Distilling • Incineration (PCBs) – but can release dioxins • Long term storage in secure landfills • Bioremediation –using bacteria or other microbes to break down • Natural or genetically engineered (PCBs, organic solvents, pesticides)
Managing Hazardous Wastes • Phytoremediation – using plants (possibly genetically engineered) to absorb & accumulate toxic materials from the soil • Sunflowers remove lead • Poplar trees remove many contaminants • Canola removes selenium • Plants become contaminated & must be disposed of properly • Slow process • Only works to depth of roots
Hazardous Waste Disposal • For many years, hazardous waste was discarded without special treatment • Public did not know it was harmful to human health • Assumed the substances would disappear or be diluted in the environment • Since the 1980s, cities designate sites or special collection days to gather household hazardous waste
Hazardous Waste Disposal • Resource Conservation and Recovery Act (RCRA, 1976) • Main legislation that controls hazardous waste disposal • States are required to manage hazardous waste • Intended to ensure testing and ensure correct disposal methods (prevent illegal dumping) • Large generators of hazardous waste must obtain permits and must be tracked “from cradle to grave”
Love Canal NY 1978 • NIAGARA FALLS, N.Y.--Twenty five years after the Hooker Chemical Company stopped using the Love Canal here as an industrial dump, 82 different compounds, 11 of them suspected carcinogens, have been percolating upward through the soil, their drum containers rotting and leaching their contents into the backyards and basements of 100 homes and a public school built on the banks of the canal.
Love Canal, NY The first declared national environmental disaster Entire community evacuated Chemical hazardous wastes stored in the canal for decades Dump closed & house built Tanks began leaking, children developed chemical burns Miscarriages & birth defects Years of litigation – company required to clean up site Impetus for passing Superfund Act (CERCLA)
CERCLA & SARA • Comprehensive Emergency Response, Compensation and Liability Act (CERCLA, Superfund Act, 1980) • Amended in 1984 – Superfund Amendments and Reauthorization Act (SARA) • Intended to allow the feds to respond quickly to hazardous waste contamination • Established a federal program to clean up U.S. sites polluted with hazardous waste • Experts identify polluted sites, take action to protect groundwater near these sites, and clean up the pollution
CERCLA & SARA • EPA administers the act & determines which sites require attention • Supertoxic, carcinogenic, mutagenic, teratogenic • Chemicals of greatest concern • Lead • Trichloroethylene • Toluene • Benzene • PCBs • Chloroforms • Phenol • Arsenic • Cadmium • Chromium
Superfund: harmful sites • Harmful sites are: • Placed on the EPA’s National Priority List • Ranked according to the level of risk to human health that they pose • Cleaned up on a site-by-site basis as funds are available • The EPA is required to hold public hearings and inform area residents of its findings and to receive feedback
CERCLA & SARA • Sites placed on the National Priorities List • Currently 1,162 sites (113 in NJ) as of 1/24/14 • Include abandoned factories, smelters, mills, refineries & chemical plants • If unable to determine who is responsible for damage, cleanup is paid for from Superfund • Money generated by taxing chemical & hazardous materials • Tax expired in 1995 and has not been reauthorized • Currently funds come from taxpayers • Companies required to file annual Toxic Release Inventory
Contaminated sites are being slowly cleaned up • Globally, thousands of former military and industrial sites are contaminated with hazardous waste • For most nations, dealing with these messes is too difficult, time consuming and expensive
The Superfund process • Once a Superfund site is identified, EPA scientists evaluate: • How close the site is to human habitation • Whether wastes are currently confined or likely to spread • Whether the site threatens drinking water supplies
Superfund • Later laws charged the EPA with cleaning up brownfields = lands whose reuse or development are complicated by the presence of hazardous materials • Two events spurred creation of Superfund legislation • In Love Canal, Niagara Falls, New York, families were evacuated after buried toxic chemicals rose to the surface, contaminating homes and an elementary school • In Times Beach, Missouri, the entire town was evacuated after being contaminated with dioxin from waste oil sprayed on roads
Brownfields Site contaminated with toxic or hazardous materials Abandoned properties with not enough contamination to be on National Priorities List Many industrial areas in urban areas Subject to remediation so they may be reclaimed and used by humans