Class Session 22>

I. Waste

There are all different kinds of words used to describe waste…garbage, refuse, scrap, junk, cast-offs, rubbish, and trash. No matter what the term, it’s all pretty much the same stuff…unwanted, solid, liquid, or gaseous material discarded from factories, stores, commercial operations, institutions and homes.

Now that you’ve had a chance to examine types of waste yourself, let’s see how other groups and organization classify waste. In the United States, waste management falls under the jurisdiction of the Environmental Protection Agency – the E.P.A.

The E.P.A. breaks waste into two major groups, controlled waste, and non-controlled waste and these two types of waste are exactly what they sound like. Let’s start with non-controlled waste, which is any kind of waste that E.P.A. does not have the legal authority to regulate. E.P.A. gets their authority to regulate when Congress passes environmental laws and regulation. This includes waste from farms, mines, and quarries.

Controlled waste, on the other hand is waste that EPA does have the authority to regulate. Controlled waste includes waste from industries, commerce, and homes. So, the first major cut that EPA makes is based on their regulatory authority.

So, for now we can forget about uncontrolled waste and just focus on what comes of industries, commercial establishments (i.e. businesses), and homes. There are two types of controlled waste, hazardous and non-hazardous. We’ve already looked at hazardous waste in the chemicals section of the course. The U.S.E.P.A. defines a hazardous waste as any solid, liquid, or containerized gas that can catch on fire (ignitable), corrosive, explode (reactive), or toxic.

If a waste is not classified as hazardous, it’s more than likely considered to be a solid waste. Most, if not, all of what you found in your trash bag is solid waste. Solid waste is any unwanted or discarded material that is not in liquid or gaseous form.

There are two categories of solid waste, municipal & commercial. Municipal solid waste, also known MSW, is the kind of garbage or trash we're most familiar with and it's the kind we carry to the curb once or twice a week or the neighborhood dog knocks over and so it's the kind we are most familiar with. Commercial solid waste consists of waste material from all different kinds of facilities; hospitals, strip malls, shopping centers, farms, construction sites, mines, office buildings, factories and schools. Solid waste typically consists of paper, metal, glass, plastic, food waste, yard waste, and other forms of material.

Americans generated more than 229 million tons of solid waste in 2001, which is approximately 4.4 pounds of waste per person per day. The amount of solid waste generated has been increasing steadily since 1991, as shown in the chart below.

Source: http://www.epa.gov/epaoswer/non-hw/muncpl/facts.htm

The U.S. is the world’s leader in solid waste generation. Our closest “competitors” are Canada (3.75 lbs. per day) and the Netherlands (3.0 lbs. per day). Sweden and Germany generate under 2 pounds of trash per person per day.

We tend to believe that that most solid waste comes from homes. However, commercial solid waste accounts for a considerable proportion as well. So, where’s all the commercial solid waste? Behind every major indoor mall, shopping plaza, strip mall, or major store, there is an access road that runs behind the facility. Lined up along this access road are the trash containers for commercial establishments.

Municipal solid waste by weight consists primarily of paper and paperboard (35.7%). Of this amount, newspaper accounts for one fifth of the paper and paperboard waste. The next largest portion of municipal solid waste is yard waste (12.2%), followed by food waste and plastics, both at 11%. Metals make up 7.9%. Rubber, leather and textiles make up 7.1%, wood is 5.7%, glass is 5.5% and miscellaneous other material is about 3.5%. These percentages are proportions by weight, not by volume.

In addition to the materials listed above, you'd also find a lot of hazardous substances and waste. These include mothballs, roach sprays, batteries, drain cleaners, and bleaches, as well as some window cleaners and paint. To give you some idea of how serious household hazardous waste can be, 1/2 of all EPA Superfund National Priority List sites are municipal landfills.

II. Where Does Our Trash Go?
Most solid waste, about 57%, is deposited in landfills. Disposing of the remainder of the includes incineration (15%) and recycling (28%). Let’s look at each of these disposal methods beginning with landfills. A landfill is basically a hole dug in the ground. The bottom of the hole is covered with non-permeable clay soil to discourage fluid, known as leachate, from leaking out of the landfill. On top of the clay layer is a rubberized liner and a series of collection pipes. The landfill is filled up with solid waste and then eventually covered with soil, or capped, when full.

One of the problems with landfills is that as rain falls on the top surface of the material in the landfill, the water makes its way downward. As is travels through the material in the landfill it combines with all kinds of fluids as well as corrodes materials and metals off trash surfaces. The result is a slurry of chemicals, fluids, and metals known as leachate.

Leachate is not a problem if it is collected in a timely manner and disposed of correctly. Newer landfills are lined with clay and a rubberized liner and are equipped with leachate collection systems. A leachate collection systems is a series of pipes under a landfill that collect leachate. The picture below shows leachate being pumped out of a collection pipe.

Many of the older landfills, however, are not equipped with leachate collection systems and the leachate eventually percolates downward through the soil. It some cases, it can contaminate groundwater, the same groundwater that may be used for drinking supplies. Landfills can sometimes attract unwanted pests, as well as being sources of unwanted noise and foul odors. Methane is also created in landfills from the decomposition of biological material. The problem with methane, also known as natural gas, is that it can sometime collect and explode. To fix this problem, methane vent pipes are sometimes installed (see picture to left below) or piped off and used for fuel (see picture to right).

The number of operating landfills in the U.S. is decreasing pretty rapidly. In the 1970s, approximately 20,000 landfills were in operation in the United States. By 1988, this number had dwindled to 8,000. Currently, there are less than 2,000 operating landfills.

III. What is Incineration?
Incineration involves burning or combusting solid waste in huge, specially constructed boilers. Incineration has the advantage of reducing the weight of solid waste by 75% and volume by 90%. Municipal solid waste can also be burned to produce electricity and steam. These types of facilities are known as waste-to-energy facilities.

While incineration offers some advantages over landfills, it has problems of its own. The ash that remains after combustion is often toxic and contains heavy metals and hazardous substances. Also, because waste incinerators are costly to build, in order to fully capitalize the costs of construction, incineration can compete with other long term strategies, like recycling. Following are some pictures of incinerators in Brussels, Japan, and Thailand

IV. Recycling
Recycling involves taking material from the wastestream and using the material to either remake the same product (such as newsprint into newspaper) or an entirely different product. The history of recycling goes back over 300 years in the United States to Philadelphia. There, in 1690, the Rittenhouse Mill, owned by William Rittenhouse, turned discarded rags and cotton into paper.

Recycling had a part to play in the American Revolution. Freedom fighters from New York City melted down a statue of King George III to make bullets. New York City made recycling headlines again in 1896. A gentleman named George Waring, who had been a Colonel in the Civil War, was appointed Commissioner of Street Cleaning. Waring saw waste not just as useless material, but as a resource, and America’s first municipal recycling program was born. City residents separated their household waste into three separate groups -- organic waste, ash, and dry trash. Organic waste was used for fertilizer, ash was taken to landfill and dry materials such as rags and paper were recycled.

The idea that George Waring had over 100 years ago seems to taken hold. In 2001, there were over 9,700 municipal curbside recycling programs in the United States. The amount of material recycled in the U.S. continues to increase. In 1980, about 10 percent of solid waste in the U.S. was recycled and, by 1990, that figure had increased to 16 percent. As of 2001, nearly 30 percent of municipal solid waste was recycled in the U.S. The U.S. joins Switzerland and Japan as among the leaders in recycling rates among industrialized countries.

The table below shows the percentage of different types of materials recycled in the U.S. As you can see, the U.S. collects a significant proportion of a number of materials.

%Recycled U.S. 2001	Type of Material
70.1%	Cardboard Boxes
60.2%	Newspapers
58.1%	Steel Cans
56.5%	Yard Trimmings
49.0%	Aluminum Cans
38.6%	Scrap Tires
35.6%	Plastic Soda Bottles
32.0%	Magazines
25.6%	Other Plastic Bottles
22.0%	Glass Containers

Recycling offers many advantages over landfilling and incineration. For starters, recycling keeps material effectively out of the waste stream and in productive use. It can also lower energy, water, and primary material costs of production and processing.

Many types of products made from recycled materials are now available. The chart below shows the original source material and the recycled product. Sometimes the recycled material is used to make the same exact product, as in the case of aluminum cans. Other times, it is used to produce a completely different product. The list below also shows some products which never make it into the municipal solid waste stream, but are recycled by businesses and commercial establishments. This includes antifreeze, which is now being recycled by automotive repair establishments.

Original Material	Recycled Product
Aluminim Cans	Aluminum Cans
Antifreeze	Antifreeze
Automotive Batteries	Automotive Batteries
Automotive Parts	Automotive Parts
Disaster Debris	Mulch, landscaping
Food Scraps/Yard Trimmings	Compost
Glass	Glass, Fiberglass, Roadbeds, Tile
Oil	Oil
Paper	Newspapers, Packaging, Office Paper
Plastic	Carpet, Textiles, Clothing, Landscaping, Decking
Steel	Steel Cans, Appliances, Building Materials
Textiles	Cloth, Insulation, Seat Stuffing, Compost
Tires	Tire Derived Fuel, Roadway, Railroad Ties

V. Compost – Utter Damned Rot!
Another viable disposal option for solid waste is composting. Composting refers to the natural breakdown of organic material such as leaves, grass clippings, food, tree branches, and Christmas trees. Since organic waste (yard waste and food waste) accounts for over 20% of solid waste, composting can effectively remove a significant volume of waste currently going into landfills.

VI. Source Reduction
Waste is generated at a source, meaning that it comes from a specific point or location. You’ve already looked at two types of sources, your house and commercial establishments. One way to reduce the amount of material in the wastestream is simply to use less material in the first place. This is known as source reduction and it’s really pretty simple. Basically what it entails is changing a technology (remember technology) to get the same service but use less material. One example would be simply to carry canvas bags to the supermarket for transporting groceries home. Using your own bags would mean that you wouldn’t need to bring either plastic or paper bags home with you from the supermarket and VOILA! LESS TRASH. AMAZING! There are lots and lots of ways to accomplish source reduction in your house, work, school, in factories, hospitals, you name it.

VII. Waste Exchanges
Waste exchanges usually involve industrial or commercial waste streams and refer to one facilities waste becoming an input, or raw material, for another. Waste exchanges can simply involve one company listing the materials it throws away on a computer bulletin board. Go to http://www.govlink.org/hazwaste/business/imex/ and check out their website. You’ll see that both companies that have excess material as well as those looking for excess material are listed. Think of waste exchanges as trashy dating services, so to speak, because that’s what they are.

VIII. Repair
Repairing items such as washing machines, electronic devices, furniture, bicycles, clothing, and shoes reduces the total amount of solid waste and can also save money. Repair, also known as “fixing stuff” can greatly reduce the amount of material headed to landfills or incinerators.

IX. Reuse
Reusing material goods, either for their intended purpose, or a new and different one, can also result in significant environmental benefits. Thrift stores, yard sales, and flea markets all provide an environmental benefit by fostering product reuse.