Waste Management

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Waste Management
A Brief History of Waste Disposal
The Early Years Dilute and Disperse
-Waste production was taken care of by
dumping, either into unused land areas (swamps)
or into rivers.
Many cities have areas that once were
dumps, and are now covered by parks or
buildings.
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Most trash or waste was either buried loose,
or in barrels.
Big Problem Early trash dumps were used
for everything, and unregulated. Many toxins
were dumped with no thought as to the
repercussions.
In Delaware, several sites that were formerly
sand and gravel pits were used as dumps.
EX Army Creek Landfill, Tybouts Corner
Landfill, Delaware Sand and Gravel Landfill
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Most of these dumps were open pit dumps,
with no effort made to cover up the trash and
waste.
In some instances, the waste was
periodically burned, to provide more space.
Sanitary Landfills
Later designs were not open pit, because the
waste was covered with a layer of soil.
Landfills today use this method of covering the
trash.
The layer of soil prevents access to the waste
by birds, insects and rodents.
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Sanitary Landfills have distinct alternating
layers of compacted trash and soil.
Soil Layer
Layer of Compacted Trash
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Problems Associated with Landfills
1) Landfill space is very limited
Ex Philadelphia is out of landfill space (it
used to be near the airport), and now has to
ship its trash elsewhere (very costly!)
In Delaware The Cherry Island Landfill is
near capacity, and studies are underway to
determine if the hill of trash can be made even
higher.
Understandably, people living near the
landfill are quite upset about the prospects of
more trash.
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2) Creating newer, safer landfills is an uphill
battle.
NIMBY Syndrome
The sites chosen for landfills often are located
near poor, politically disconnected populations.
3) Leachate from the Landfill
Probably the biggest environmental problem
with landfills, leachate is the movement of water
through the waste, into the groundwater or a
nearby body of water.
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The nature of the leachate depends on the nature
of the waste,the quantity of water, and the time
it takes to percolate through the pile.
4) Atmospheric Pollution
Since the waste is cut off from the air, it
degrades anaerobically.
Anaerobic degredation takes longer, and
produces different products.
Rather than decomposing into CO2, the trash
decomposes into CH4, methane gas.
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The Composition of Our Solid Waste
Solid waste varies in composition depending on
its source.
Paper is the largest component of the
waste stream, at about 38.
The single largest item is newspaper, which
accounts for over 18 of solid waste.
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The Composition Of the Solid Waste Stream
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Waste Management, or What Do We DO With All
This Stuff?
Integrated Waste Management (IWM)
a set of management alternatives that
include reuse, source reduction, recycling,
composting, landfills, and incineration

• Reduce, Reuse, Recycle the ultimate goal
• of waste management is to reduce the amount
• of waste that must be dealt with in the
• first place.

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Studies have indicated that waste could be
reduced by as much as 70.
But HOW?
-Reduction in packaging wastes
-Reusable packages, deposits on containers
-Packages made of easily recycled materials
-Increased markets for recycled materials
-Increased public support for recycling
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2) Composting
Composting is a biochemical process that breaks
down organic materials into rich soil-like
material.
It involves microscopic aerobic organisms, so the
compost must be aerated to keep them alive.
Piles of compost may be turned over
periodically, allowing air to penetrate the pile.
Large digesters continually turn the compost,
making a very efficient system.
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Problems with Composting
Compost having left over pesticides may kill
plants that it is applied to. (herbicides)
Compost can only be made when the organic
material is collected separately from other
trash. (plastics/metals, etc..)
Composting does have a good future, because
it can be done on a small scale, in yards
and gardens.
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3) Sanitary Landfill (improved designs)
Sanitary landfills are not going to be eliminated
from any integrated system. There is always
going to be a need for them.
Improved designs will better handle leaching,
and prevent contamination of air and groundwater.
Landfills by design, not by accident, built to
take specific types of waste.
Built in monitoring systems, wells, liners, and
leachate collection pipes.
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An Idealized Sanitary Landfill
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4)Incineration also known as trash to steam,
has an advantage that the energy in the trash can
be converted to heat energy.
Also reduces the volume of trash up to 95.
Problems with Incineration
-Creates air pollution, including SO2, NOx
and all kinds of heavy metals (mercury, lead,
etc) -can be lowered with specialized equipment
()
-The ash produced is very toxic, and needs to be
handled as toxic waste.
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Human Waste Disposal
Since the dawn of human evolution, solid human
waste has posed a problem as to its disposal.
Wherever large populations of people lived, the
waste became a big problem.
For thousands of years in China and India, waste
was used on crops as fertilizer.
By the early 20th century, land application was
taking place in many places, including the U.S.
Sewage Sludge
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Major Problems with Human Waste Disposal
-Contamination with infectious agents, and
their spread to waterways and treated crops
Ex Chi-Chis green onion problem (e-coli
bacteria)
-Pollution with heavy metals, industrial
solvents, and pesticides.
Industrial contributors could pre-treat their
sewage, thereby eliminating many pollutants.
()
If the price of oil continues to climb, making
man-made fertilizers more expensive,the use of
human waste as fertilizer may gain favor again.
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Ocean Dumping
Types of things that get dumped into the oceans
of the world
Dredge spoils solid materials, generally
silt,sand and pollutants dug up as navigation
channels are deepened.
Industrial wastesacids, pesticide wastes,
all matter of solvents, heavy metals
Construction Debris
Sewage Sludge
Radioactive waste, explosives, garbage
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Ocean Dumping Laws (U.S.)
1972 Ocean Dumping ActProhibited the dumping
of chemical weapons, high level radioactive
waste, biological warfare agents.
1988 Expanded to include sewage sludge,
industrial waste, and medical waste.
1992 Provisions for a coastal water
quality monitoring program were added
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Convention on the Prevention of Marine Pollution
by Dumping of Wastes and Other Matter, 1972
Permitted dumpingArticle 4 states that
Contracting Parties "shall prohibit the dumping
of any wastes or other matter with the exception
of those listed in Annex 1."
1. Dredged material
2. Sewage sludge
3. Fish waste, or material resulting from
industrial fish processing operations
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4. Vessels and platforms or other man-made
structures at sea
5. Inert, inorganic geological material
6. Organic material of natural origin
7. Bulky items primarily comprising iron, steel,
concrete and similar unharmful materials for
which the concern is physical impact and limited
to those circumstances, where such wastes are
generated at locations, such as small islands
with isolated communities, having no practicable
access to disposal options other than dumping.
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Hazardous Waste and its Disposal
In the U.S., over 35,000 chemicals are classified
as hazardous to the health of people or to
ecosystems (Table 28.1 in textbook)
The U.S. produces an average of 700 MILLION
metric tons of hazardous waste annually.
Most is generated by the chemical industry,
followed closely by the electronics industry,
and oil/petroleum industries.
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Another great source of hazardous waste is US!
Almost every household has used pesticides,
oil, solvents, paints, batteries, etc.
When these get thrown into the regular
trash, they end up in a landfill not designed for
hazmat, or, even worse, incinerated in a plant
not made for burning hazmat.
In the U.S., there are an estimated 2000
sites polluted with hazmat, and the number keeps
going up as new sites are found.
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Love Canal
In 1976, toxic chemicals began oozing out of
the soil covering what once had been a toxic
dumping ground.
Chemicals had been dumped by a company that
produced pesticides, such as DDT, as well as
lots of chlorinated solvents.
The company sold the land to the city of
Niagara, NY for 1 (it was pressured by the city
to do so)
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Homes and a school were eventually built over
the buried waste.
Studies in the late 70s suggested high rates of
cancer and birth defects among the residents of
Love Canal, although results were debated.
Efforts were made to clean and neutralize the
site and the homes were eventually sold again to
new owners.
By 1990, 275 million had been spent on cleanup
and relocation costs.
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Hazmat Disposal
There are several methods of dealing with hazmat
disposal (Table 28.2 in textbook)

• Secure Landfill similar to a sanitary landfill,
  but
• with more durable liners, closer inspection of
• wells, etc.

Secure landfills also usually have a
leachate pond, which collects the liquid as it
runs through the pile. The leachate is then sent
to a treatment facility designed for hazmat.
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Hazardous Waste Landfill
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2) Surface Impoundments natural or
man-made holes, in which liquid waste is held
May include a plastic liner but not all do. Some
rely on clay, rock or impermeable soil.
Big Problems with Impoundments

• They are open to the air, so evaporation takes
• place, especially of solvents, etc..

2) They can be flooded with heavy rain, and
overflow into a nearby waterway or groundwater
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3) Deep Well Injection drilled to a depth that
is below any underground aquifers, and the
liquid waste is injected under high pressure into
the Earth.
The well has to be sited so that it penetrates a
permeable rock layer far underground, but is
under an impermeable layer
Well
Impermeable Rock
Porous Rock
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Problems with Deep Well Disposal
There have been instances where deep
well injection has been implicated in causing
earthquakes deep underground.
The high pressure liquid lubricates rock layers,
allowing them to slide. (Rocky Mtn. Arsenal,
1980s)
There is no guarantee that the waste will not
find its way into a water system at some time.
(no way to monitor the waste)
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4) Incineration
Destruction by high temperatures
Is considered a treatment, rather than disposal,
because the leftover ash must still be disposed
of in a landfill
Is the chosen method for treatment of chemical
weapon stocks (Johnston atoll)
Also conducted on ships that are purpose built
for incineration (very controversial)
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Incinerators for hazmat are designed to reduce
waste as much as is possible.
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Hazardous Waste Legislation
Ultimately, it would be far better to reduce the
amount of waste, rather than dispose of or treat
it.
Resource Conservation and Recovery Act (RCRA)
Identification of hazardous products and
regulations regarding their disposal.
Cradle to Grave regulation
Promotes recycling, re-use of chemicals