Chapter 29: Waste Management

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Chapter 29 Waste Management
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Early Concepts of Waste Disposal

• Start of Industrial Revolution, the volume of
  waste produced in the US was relatively small.
• Managed through the concept of dilute and
  disperse.
• Factories located near water.
• Easy transport of materials by boat
• Sufficient water for processing and cooling
• Easy disposal of waste into the river
• Few factories and a sparse population
• Method was sufficient to remove the waste from
  the immediate environment.

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Early Concepts of Waste Disposal

• As industrial and urban areas expanded, the
  concept became concentrate and contain
• Containment not always achieved.
• Containers leak or break and allow waste to
  escape.
• People are facing a serious solid-waste disposal
  problem.
• We are producing a great deal of waste and the
  acceptable space for permanent disposal is
  limited.
• Difficult to site new landfills (NIMBY).

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NIMBY

• Not
• In
• My
• Back
• Yard
• Many people want projects such as landfills,
  powerplants, etc. but no one wants it near them

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Modern Trends

• Environmentally correct concept is to consider
  wastes as resources out of place.
• Waste would be a resource to be used again.
• Referred to as the zero waste movement.
• Industrial ecology
• Study of relationships among industrial systems
  and their links to natural systems.
• Waste from one part of the system would be a
  resource for another part.

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Modern Trends

• Countries have moved to cut waste by imposing
  taxes.
• Taxation of waste in all its various forms, from
  emissions from smokestacks to solids delivered to
  landfills.
• As taxes increase people produce less waste.
• Landfills produce methane gas which can be burned
  as fuel.

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Integrated Waste Management

• A set of management alternatives that includes
• 3 Rs- Reuse, Reduce, Recycle
• Composting
• Landfill
• Incineration

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Reduce, Reuse, Recycle

• Ultimate objective of the three Rs is to reduce.
• Study of the waste stream in areas that utilize
  IWM technology suggests that the amount of refuse
  disposed of in landfills or incinerated can be
  reduced by at least 50
• Reduction facilitated by
• Better design of packaging to reduce waste, an
  element of source reduction (10 reduction).
• Large-scale composting programs (10 reduction).
• Establishment of recycling programs (30
  reduction).

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Reduce, Reuse, Recycle

• Recycling is a major player in the reduction of
  urban waste stream.
• Estimated that as much as 80-90 of the U.S.
  waste stream might be recovered through intense
  recycling.
• Partial recycling can provide a significant
  reduction 50.

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Public Support for Recycling

• Encouraging signs
• An increase in the willingness of industry and
  business to support recycling on a variety of
  scales.
• People are now more likely to purchase products
  that can be recycled or that come in containers
  that are more easily recycled or composted.

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Markets for Recycled Products

• In communities where recycling has been
  successfully implemented, it has resulted in
  glutted markets for the recycled products.
• If recycling is to be successful,
• markets and processing facilities will also have
  to be developed to ensure that recycling is a
  sound financial venture.

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Recycling of Human Waste

• The use of human waste or night soil on
  croplands is an ancient practice.
• Early uses of human waste for agriculture
  occasionally spread infectious diseases.
• One of the major problems of recycling human
  waste today is that thousands of chemicals and
  metals flow through our waste stream.
• Because many toxic materials are likely to be
  present with the waste, we must be very skeptical
  of utilizing sewage sludge for land application.

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Materials Management

• Futuristic waste management has the goal of zero
  production of waste.
• Consistent with the ideals of industrial ecology.
• Goal will require more sustainable use of
  materials combined with resource conservation in
  what is being termed materials management.

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Materials Management

• The goal could be pursued in the following ways
• Eliminate subsidies for extraction of virgin
  materials.
• Establish green building incentives that
  encourage the use of recycled-content materials
  and products in new construction.
• Assess financial penalties for production that
  uses negative materials management practices.

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Materials Management

• Provide financial incentives for industrial
  practices and products that benefit the
  environment by enhancing sustainability.
• Increase the number of new jobs in the technology
  of reuse and recycling of resources.

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Solid-Waste Management

• Continues to be a problem in many parts of the
  world.
• Many practices inadequate.
• Open dumps, illegal roadside dumping
• Social problem as much as a physical one, because
  many people are simply disposing of their waste
  as inexpensively and as quickly as possible.

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Composition of Solid Waste

• Paper is by far the most abundant content.
• Excavations into modern landfills using
  archeological tools have cleared up some
  misconceptions concerning other items.
• Fast-food packaging accounts for about 0.25 of
  the average landfill
• Disposable diapers, approximately 0.8
• Polystyrene products, about 0.9

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On-Site Disposal

• A common on-site disposal method in urban areas
  is the mechanical grinding of kitchen food waste.
  
• Garbage-disposal devices are installed at the
  kitchen sink, and the garbage is ground and
  flushed into the sewer system.

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Composting

• Biochemical process in which organic materials
  decompose to a rich, soil-like material.
• The process involves rapid partial decomposition
  of moist solid organic waste by aerobic
  organisms.
• As a waste management option, large-scale
  composting is generally carried out in the
  controlled environment of mechanical digesters.

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Incineration

• Combustible waste is burned at temperatures high
  enough (9001,000C, or 1,6501,830F) to
  consume all combustible material.
• Leaving only ash and non-combustibles to dispose
  of in a landfill.
• Process of incineration can be used to supplement
  other fuels and generate electrical power.

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• When waste is burned, it releases many air
  pollutants, including dioxins, furans, lead,
  mercury and cadmium.
• These toxins are more prevalent in fly ash- thus
  require more post-combustion control mechanisms
  to prevent their release- such as electrostatic
  precipitators and bag house filters
• Pre-combustion methods including separating out
  batteries and plastics before burning

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Open Dumps

• In the past, solid waste was often disposed of in
  open dumps, where the refuse was piled up without
  being covered or otherwise protected.
• Located wherever land is available, without
  regard to safety, health hazards, or aesthetic
  degradation.
• Common sites
• Abandoned mines and quarries, natural low areas,
  such as swamps or floodplains and hillside areas
  above or below towns.

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Sanitary Landfills

• Designed to concentrate and contain refuse w/o
  creating a nuisance or hazard to public health or
  safety.
• Confined to the smallest practical area
• Reduced to the smallest practical volume
• Covered with a layer of compacted soil at the end
  of each day of operation.

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Leachate

• The most significant hazard from a sanitary
  landfill is pollution of groundwater or surface
  water.
• If waste comes into contact with water, leachate
  is produced.
• noxious, mineralized liquid capable of
  transporting bacterial pollutants

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Site Selection

• A number of factors must be taken into
  consideration when selecting a site, including
• Topography
• Location of the groundwater table
• Amount of precipitation
• Type of soil and rock
• Location of the disposal zone in the surface
  water and groundwater flow system.
• Best sites are arid sites

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Site Selection

• The waste is buried above the water table in
  relatively impermeable clay and silt soils.
• Leachate produced remains in the vicinity of the
  site and degrades by natural filtering action.
• Site selection also involves important social
  considerations.
• Chosen where they expect local resistance to be
  minimal or where they perceive land to have
  little value.
• Frequently located in areas of low socioeconomic
  status

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Monitoring Pollution in Sanitary Landfills

• Once a site is chosen for a sanitary landfill and
  before filling starts, monitoring the movement of
  groundwater should begin.
• Accomplished by periodically taking samples of
  water and gas from specially designed monitoring
  wells.
• Monitoring the movement of leachate and gases
  should continue as long as there is any
  possibility of pollution.

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How Pollutants Can Enter the Environment from
Sanitary Landfills

• 1. Methane, ammonia, hydrogen sulfide, and
  nitrogen gases can be produced from compounds in
  the soil and the waste and can enter the
  atmosphere.
• 2. Heavy metals, such as lead, chromium, and
  iron, can be retained in the soil.

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How Pollutants Can Enter the Environment from
Sanitary Landfills

• 3. Soluble materials, such as chloride, nitrate,
  and sulfate, can readily pass through the waste
  and soil to the groundwater system.
• 4. Overland runoff can pick up leachate and
  transport it into streams and rivers.

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How Pollutants Can Enter the Environment from
Sanitary Landfills

• 5. Plants growing in the disposal area can
  selectively take up heavy metals and other toxic
  materials.
• Passed up the food chain as people and animals
  eat the plants.
• 6. If plant residue return toxic substances to
  the soil.

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How Pollutants Can Enter the Environment from
Sanitary Landfills

• 7. Streams and rivers may become contaminated by
  waste from groundwater seeping into the channel
  (3) or by surface runoff (4).
• 8. Toxic materials can be transported to other
  areas by the wind.

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How Pollutants Can Enter the Environment from
Sanitary Landfills

• Modern sanitary landfills are engineered to
  include multiple barriers
• Clay and plastic liners to limit the movement of
  leachate
• Surface and subsurface drainage to collect
  leachate
• Systems to collect methane gas
• Groundwater monitoring to detect leaks of
  leachate below and adjacent to the landfill.

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Federal Legislation for Sanitary Landfills

• Resource Conservation and Recovery Act of 1980.
• Legislation intended to strengthen and
  standardize design, operation, and monitoring of
  sanitary landfills.
• Landfills that cannot comply with regulations
  face closure.
• States may choose between two options
• 1. Comply with federal standards.
• 2. Seek EPA approval of solid-waste management
  plans, which allows greater flexibility.

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Federal Legislation for Sanitary Landfills

• Provisions of federal standards include the
  following
• Landfills may not be sited on floodplains,
  wetlands, earthquake zones, unstable land, or
  near airports.
• Landfills must have liners.
• Landfills must have a leachate collection system.
• Landfill operators must monitor groundwater for
  many specified toxic chemicals.
• Landfill operators must meet financial assurance
  criteria to ensure that monitoring continues for
  30 years after the landfill is closed.

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Federal Legislation for Sanitary Landfills

• EPA approval of its landfill program
• Groundwater monitoring may be suspended.
• Alternative types of daily cover over the waste.
• Alternative groundwater protection standards and
  schedules for documentation are allowed.
• Under certain circumstances, landfills in
  wetlands and fault zones are allowed.
• Alternative financial assurance mechanisms are
  allowed.

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Reducing the Waste You Produce
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Hazardous Waste

• In the US, approximately 1,000 new chemicals are
  marketed each year, and about 70,000 chemicals
  are currently on the market.
• 35,000 chemicals used are classified as
  definitely or potentially hazardous to the health
  of people or ecosystems.
• The US currently produces about 700 million
  metric tons of hazardous chemical waste per year,
  referred to more commonly as hazardous waste.

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Hazardous Waste

• Uncontrolled dumping of chemical waste has
  polluted soil and groundwater in several ways
• Chemical waste may be stored in barrels.The
  barrels eventually corrode and leak.
• When liquid chemical waste is dumped into an
  unlined lagoon, contaminated water may percolate
  through soil and rock to the groundwater table.
• Liquid chemical waste may be illegally dumped in
  deserted fields or even along roads.

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Resource Conservation Recovery Act

• Passed in 1976
• Identification of hazardous wastes and their life
  cycles.
• Cradle to grave management
• The act classifies hazardous wastes in several
  categories
• Materials highly toxic to people and other living
  things
• Wastes that may ignite when exposed to air
• Extremely corrosive wastes
• Reactive unstable wastes that are explosive or
  generate toxic gases or fumes when mixed with
  water.

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Comprehensive Environmental Response,
Compensation, and Liability Act

• Passed in 1980
• Act defined policies and procedures for release
  of hazardous substances into the environment.
• Mandated development of a list of the sites where
  hazardous substances were likely to or already
  had produced the most serious environmental
  problems
• Established a revolving fund (Superfund) to clean
  up the worst abandoned hazardous-waste sites.

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Comprehensive Environmental Response,
Compensation, and Liability Act

• Strengthened by amendments that made the
  following changes
• Improved and tightened standards for disposal and
  cleanup of hazardous waste.
• Banned land disposal of certain hazardous
  chemicals.
• Initiated a timetable for phasing out disposal of
  all untreated liquid hazardous waste in landfills
  or surface impoundments.
• Increased the size of the Superfund.

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Hazardous-Waste Management Land Disposal

• Management of hazardous chemical waste involves
  several options, including
• Recycling
• On-site processing to recover by-products with
  commercial value
• Microbial breakdown
• Chemical stabilization
• High-temperature decomposition
• Incineration
• Disposal by secure landfill or deep-well
  injection

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Secure Landfill

• A secure landfill for hazardous waste is designed
  to
• Confine the waste to a particular location
• Control the leachate that drains from the waste
• Collect and treat the leachate
• Detect possible leaks
• This type of landfill is similar to the modern
  sanitary landfill.

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Land Application Microbial Breakdown

• Intention application of waste materials to
  surface soil.
• May be a desirable method of treatment for
  certain biodegradable industrial wastes.
• A good indicator of the usefulness of land
  application for a particular waste is the
  biopersistence of the waste.
• How long the material remains in the biosphere.
• Greater the biopersistence, the less suitable for
  land application

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Land Application Microbial Breakdown

• Land application of biodegradable waste works
  because,
• when materials are added to the soil, they are
  attacked by microflora that decompose the waste
  material in a process known as microbial
  breakdown.

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Surface Impoundment

• Both natural topographic depressions and
  human-made excavations formed primarily of soil
  or other surface materials but lined with
  manufactured materials such as plastic.
• Examples include aeration pits and lagoons at
  hazardous-waste facilities.
• Prone to seepage, resulting in pollution of soil
  and groundwater.
• Evaporation from surface impoundments can also
  produce an air pollution problem.

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Deep Well Disposal

• A deep well penetrates to a depth below and
  completely isolated from all freshwater aquifers.
• Waste is injected into a permeable rock layer
  several thousand meters below the surface in
  geologic basins.
• Capped by relatively impervious,
  fracture-resistant rock such as shale or salt
  deposits.

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Deep Well Disposal

• Important control of water pollution in oil
  fields.
• Injection of oil field brine.
• Should not be viewed as a quick and easy solution
  to industrial waste problems.

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Alternatives to Land Disposal of Hazardous Wastes

• Advantages to source reduction, recycling,
  treatment, and incineration include the
  following
• Useful chemicals can be reclaimed and reused.
• Treatment of wastes may make them less toxic and
  therefore less likely to cause problems in
  landfills.
• The actual waste that must eventually be disposed
  of is reduced to a much smaller volume.
• Because a reduced volume of waste is finally
  disposed of, there is less stress on the
  dwindling capacity of waste-disposal sites.

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Alternatives to Land Disposal of Hazardous Wastes

• Source Reduction
• The object is to reduce the amount of hazardous
  waste generated by manufacturing or other
  processes.
• Recycling and resource Recovery
• May contain materials that can be recovered for
  future use.

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Alternatives to Land Disposal of Hazardous Wastes

• Treatment
• Waste can be treated by a variety of processes to
  change the physical or chemical composition of
  the waste and so to reduce its toxic or hazardous
  characteristics.
• Incineration
• Destroyed by high-temperature incineration.
• Incineration is considered a waste treatment
  rather than a disposal method because the process
  produces an ash residue, which must then be
  disposed of in a landfill.

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Ocean Dumping

• Oceans have long been dumping grounds for many
  types of waste, including industrial waste,
  construction debris, urban sewage, and plastics
• Many locations in the worlds oceans are
• Accumulating pollution continuously
• Have intermittent pollution problems
• Or have potential for pollution from ships in the
  major shipping lanes

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Ocean Dumping

• Marine pollution has a variety of specific
  effects on oceanic life, including the following
• Death or retarded growth, vitality, and
  reproductivity of marine organisms.
• Reduction in the dissolved oxygen content
  necessary for marine life because of increased
  BOD.
• Eutrophication caused by nutrient-rich waste in
  shallow waters of estuaries, bays, and parts of
  the continental shelf.
• Habitat change caused by waste-disposal practices
  that subtly or drastically change entire marine
  ecosystems.

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Ocean Dumping

• Microlayer
• The upper 3 mm of ocean water.
• Planktonic life abundant (base of the marine food
  chain)
• Home to young fish and shellfish in the early
  stages of their life.
• Microlayer also tends to concentrate pollutants,
  such as toxic chemicals and heavy metals.
• Fear that disproportionate pollution will have
  especially serious effects on marine organisms.

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Ocean Dumping

• Marine pollution can have major impacts on people
  and society.
• Contaminated marine organisms may transmit toxic
  elements or diseases to people who eat them.
• When beaches and harbors become polluted there
  may be damage to marine life as well as a loss of
  visual appeal and other amenities.
• Economic loss is considerable.
• Tourism and fishing industry

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Pollution Prevention

• Involves identifying ways to prevent the
  generation of waste rather than finding ways to
  dispose of it.
• Approaches include
• Purchasing the proper amount of raw materials so
  that no excess remains to be disposed of.
• Exercising better control of materials used in
  manufacturing processes so that less waste is
  produced.

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Pollution Prevention

• Substituting nontoxic chemicals for hazardous or
  toxic materials currently in use.
• Improving engineering and design of manufacturing
  processes so that less waste is produced.

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E-Waste

• The Basel Convention of 1989 banned trade of
  hazardous waste from developed to developing
  countries
• The U.S. failed to ratify the Basel Convention
  and exports as much as 80 of our e-waste to
  Asia.
• E-waste is comprised of discarded computers, cell
  phones, printers technology waste

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E-waste

• Only about 10 of electronic components are
  currently recycled and they contain lead,
  mercury, gallium, germanium, nickel, palladium,
  arsenic and other heavy or toxic metals, as well
  as gold, silver, copper and steel which are
  valuable metals

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Dioxins

• A groups of chlorinated hydrocarbons
• TCDD (most toxic)
• Naturally produced during forest fires
• Produced by incinerators, smelters, chlorine
  bleaching at paper mills and tobacco smoke
• Bioaccumulate in fat and biomagnify
• Highly persistent (HPOP)
• Causes skin issues, liver damage and can cause
  cancer

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Lead and Lead Toxicity

• Lead is easily recycled from used automobile
  batteries
• Bioaccumulates in bone
• Toxicity leads to mental retardation, lower IQ,
  hyperactivity and attention deficit and learning
  disorders

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Where does Lead come from?

• Atmospheric sources of Lead include leaded
  gasoline (banned in U.S. in 1976), smelters and
  incinerators
• Lead also contaminates soil and water from
  improperly treated leachate, lead pipes, lead
  solder, and leaded paint

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Problems with PBCs

• Polychlorinated biphenyls or PBC- group of
  chlorinated hydrocarbons persist and
  bioaccumulate in fat
• They also biomagnify in food chain
• Used in electrical, adhesives, lubricants, fire
  retardants, and hydraulic fluids
• Exposure can cause nausea, diarrhea, and
  vomiting. Chronic exposure interferes with
  endocrine system and can cause cancer.

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Brownfields

• Site contaminated with toxic or hazardous
  materials
• These abandoned properties are not contaminated
  enough to be placed on the National Priorities
  List
• Many industrial areas in the interior of urban
  areas are brownfields