Waste

Solid and Hazardous Waste Generation and Collection of Solid Waste Activity One Collection of Solid Waste 4 pp Activity Two Reduce/Reuse/Repair 3 pp Educator Information Composting Activity One Composting Column Experiment 7 pp Activity Two How Do Things Decompose? 5 pp Activity Three Design a Full-Sized compost Pile 3 pp Educator Information 10 pp Household Hazardous Waste Activity One Environmental Impact of Household Chemicals 3 pp Activity Two Hazardous Waste in the Home 2 pp Educator Information 3 pp Landfills and Leachate Activity One 6 pp Activity Two 10 pp Activity Three 6 pp Educator Information 1 p Location and Sizing of Landfills Activity One The Location and Sizing of Landfills 3 pp Activity Two 6 pp Educator Information 1 p Recycling Activity One Automobile Recycling 6 pp Activity Two Recycling Consumer Products 7 pp Activity Three Recycling Tires 3 pp Educator Information 1 p Glossary 6 pp

Solid & Hazardous Waste – Generation and Collection of Solid Waste

Activity One Collection of Solid Waste

Purpose: To provide an understanding of the relationships between packaging, collection methods and consumer waste generation.

Materials: Waste Collection Worksheet and Packaging Waste Generation

exercises. Methods: Students should complete the worksheet exercises. A Discussion/Writing exercise is included to determine how well

students comprehend the concepts of waste collection and related costs.


Waste Collection Worksheet What happens to the material we place at the curb for collection? Solid waste is generally collected for recycling or for disposal. These two categories represent the bulk of the waste generated in homes. The method in which waste is collected can have an impact upon the amount and type of waste generated. Most communities provide for collection of trash and recycling. Yard waste is often accepted at drop-off locations or collected in the spring and fall of the year. Exercise 1: Determine the collection needs for Wasteville, USA Wasteville has a population of 56,000 residents who generate 4 pounds of waste each day. The waste is composed of three fractions:

1. Fifty percent of the waste is trash that is to be disposed of at a landfill. 2. Thirty-five percent of the waste is recyclable and is to be taken to a Materials Recycling

Facility. 3. The last 15% of the waste is yard waste, which is to be taken to a composting site.

A. Determine the amount of waste generated each year by a resident of Wasteville. B. Determine the amount of trash that needs to be collected and hauled to the landfill each

week. Determine the amount of recyclable material that needs to be collected and hauled to the Materials Recycling Facility.

C. A trash collection truck can hold 16,000 pounds of trash per load. A recycling collection

truck can hold 8,000 pounds of material per load. Determine how many truckloads of trash and how many truckloads of recyclable material need to be collected each week in Wasteville.


Exercise 2: Cost of waste collection for Wasteville. There is a cost associated with collection of trash and recyclables. The cost is a combination of many items including; truck purchase, driver wages, fuel, and processing fees. The sum of these costs will determine how much is paid to collect trash and recyclables. In the following problems you will calculate the cost of collection in Wasteville. A. Wasteville spends $50 for every ton of trash collected in the city, and $65 for every ton of

recyclable materials collected. Determine how much money Wasteville needs to spend each year on the collection of trash and recycling.

Wasteville has decided to charge its residents (“Pay as you throw”) $1.00 for every 100 pounds of trash they need to have collected. The residents will not be charged for collection of their recyclable material. B. How much will a family of four have to pay each year to have their trash picked up? Discussion/Writing Exercise

What are some of the side affects you think will happen as a result of a “Pay as you throw” collection program? (For example: Will there be more littering? Will people recycle more? etc.)


Packaging Waste Generation Packaging materials can account for up to 30% of the waste generated in a community. Over the course of the last 100 years the packaging of consumer goods has changed dramatically. Very few items are now sold in refillable, natural or reusable containers. Most packages are designed to be disposable– from fruit juice boxes to plastic bags that hold only a handful of raisins. The purpose of packaging is to maintain the integrity of the product, provide information about the product, and for product advertising. Modern packaging materials increase the shelf-life of perishable products and reduce the amount of waste generated by spoiled goods. Exercise 1: To illustrate the amount of packaging we use each day in our homes have the students list the waste packaging created from the preparation of one meal eaten at home. Have the students list the amount of waste produced by eating at a fast food restaurant. Have the students discuss ways to reduce the amount of packaging.


Activity Two 1

Activity Two Reduce / Reuse / Repair

Purpose: To understand the final fate of products used in everyday life. Explore the steps that occur in product design that will affect whether a product ends up in a landfill or being recycled.

Materials: Life Cycle of a Product and Product Packaging exercises. Methods: Students should complete the exercises.


Activity Two 2

Life Cycle of a Product Many of the items sold in stores today are designed to be used for a short period of time and then thrown away. Many of today’s convenience items replace items that were used for many years. Products such as these increase the amount of material that is ending up in landfills. Exercise 1: Explore the life history of a common product A. Determine the resources that went into making a common product. Try to identify the

types of materials were used to manufacture the product. B. When the end of its useful life has been reached, what will happen to the components of

the product ? Identify some alternative uses for this product. C. What are product design changes that could have been made to reduce the amount of

waste generated by this item? Example: Plastic disposable razor

1. The razor is composed of a metal blade and a plastic handle. The metal was mined from an ore and then processed at a steel mill. The plastic handle is made from oil. The oil is refined to its individual components and specific compounds are used to manufacture the plastic handle.

2. After the blade on the razor becomes too dull to be used the razor will most likely be

thrown into the trash. One way to extend the life of this product would be to use the dull razor as a “clothes shaver” to remove loose bits of thread from clothing.

3. Use a traditional strait edge razor in place of the disposable type.


Activity Two 3

Product Packaging Product packaging represents up to 65% of all the waste we generate in our homes each day. Packaging consists of boxes, plastic wrap, Styrofoam, metal cans, etc... Choices made when purchasing products have an effect upon the total amount of waste we generate. Exercise 2: How much waste is packaging waste? A. Collect and weigh the product packaging produced during one day (week) in your home. B. How does this relate to the total amount of waste produced during the same time period?

C. What can you do to reduce the amount of waste produced by the packaging of the products that are being used? (Example: Single-serve juice drink boxes are very popular, but produce a lot of waste compared to buying the same juice in a larger container, such as one-gallon plastic bottles.)


Educator Information 1

Educator Information

Title: Collection of Solid Waste Grade Level: Core Activity 7-8 + Expanded Activity 9-11 Content Areas: Mathematics, Science Standards/Benchmarks:

Performance Standards: C.8.6 State what they have learned from investigations, relating

their inferences to scientific knowledge and to data they have collected.

C.8.11 Raise further questions which still need to be answered.

G.8.5 Investigate a specific local problem to which there has

been a scientific or technological solution, including proposals for alternative courses of action, the choices that were made, reasons for the choices, any new problems created, and subsequent community satisfaction.

A.12.5 Show how the ideas and themes of science can be used to make real-life decisions about careers, work places, life-styles, and use of resources.

C.12.1 When studying science content, ask questions suggested by current social issues, scientific literature, and observation of phenomena; build hypotheses that might answer some of these question; design possible investigations; and describe results that emerge from such investigations.

E.12.1 Using science themes, distinguish between internal energies (decay of radioactive isotopes, gravity) and external energies (sun) in the earth’s systems and show how these sources of energy have an impact on those systems.

Overall Objective: To understand the collection practices and volumes of solid

waste generated in homes.

Solid & Hazardous Waste -- Composting

Activity One 1

Activity One: Composting Column Experiment Purpose: To determine what factors affect the rate of decomposition for

selected substances within a student-constructed 2-liter bottle compost column.

Materials: Three 2-liter plastic beverage bottles Knife to cut bottles Scissors Clear tape Marker (dark color) Sharp needles to poke air holes Cotton or mesh material Organic material for composting, such as: leaves, non-fatty food

scraps, newspapers, animal manure, grass clippings, hay, straw, biodegradable plastic, etc.

Method: Students should read the composting background information

before conducting the composting column experiment. Construct the composting column – Composting in a Bottle – and

complete associated lab. This lab will demonstrate the decomposition of organic materials. This activity will allow students to create compost columns from common materials and study the many organisms that assist in the decomposition process. Students will select what organic materials they would like to add to their compost column. Then they will study the overall biological activity that will eventually turn their organic food and waste material into nutrient-rich compost that may be used as an organic fertilizer.


Activity One 2

Composting Column Experiment Food and yard wastes make up almost 25% of all the waste generated from your household (EPA, 1998). Although Wisconsin has banned yard waste material from the municipal landfill since 1993, most municipalities provide some sort of yard waste collection service to handle the large volume of leaves and grasses. This material then is hauled to a central composting facility. Meanwhile, the majority of the food waste generated in the state continues to be disposed of in municipal landfills. Food waste itself makes up about 8-10% of the entire municipal waste stream. Food waste can be classified as being organic (vegetables, fruit, egg shells, coffee grounds, or any other non-fatty food) or inorganic (any fatty food or meat). Food wastes and yard wastes from your household do not have to be disposed of in a landfill; they can be composted instead. A compost pile is a mass of decaying organic matter. Potato peelings, eggshells, onion skins, grass clippings, leaves, fruits and vegetables, coffee grounds – practically every organic material except meats and fats can be added to a compost pile. These organic materials decompose and change into nutrient-rich, organic fertilizer called humus. Organic materials that decompose readily in a compost pile do not decompose easily in a landfill because a landfill lacks one of the essential ingredients for decomposition – air. When these materials are trapped on the bottom of the landfill, bacteria and other organisms cannot break them down.


Activity One 3

The purpose of this lab is to explore the process of decomposition. Composting is based on the biological process of decomposition. What turns plants and animals into compost? Microscopic bacteria and fungi, which feed on dead tissue, are the chief agents. What affects the composting process? The amount of moisture, air, temperature, light, sources of both bacteria and fungi, and the nature of the decomposing material are all critical. The presence or absence of air (oxygen) is one of the most important factors in composting. Air and moisture speed the natural process of biodegradation. Air may be added to the compost pile be simply turning the pile after it appears to slump in height. Moisture can be added by watering the pile when it appears dry.

Here in Wisconsin, compost piles can remain active even in the coldest times of the year. However, the pile needs to be turned regularly when the pile appears to “slump” its shape in order to allow the aerobic bacteria to continue their activity. The heat generated by the biological activity will melt enough of the snow to keep the pile moist. If the pile is left alone, the pile will become relatively dormant until the climatic conditions allow the microbial activity to resume. Making a compost column lets you see and experiment with this process and witness nature’s world of recycling! COMPOSTING IN A BOTTLE Lab Warm-up The conversion of wastes into compost through decomposition requires five essential ingredients:

1. “Brown” organic material to be decomposed (Carbon)– This supplies the carbon essential for the decomposition process and the minerals that make nutrient-rich compost. These include paper, sawdust, leaves, wood chips, and straw.

2. “Green” organic material (Nitrogen) – some organic material is higher in nitrogen like grass clippings, food scraps, alfalfa, clover, leather, dust, nut shells, hair, and manure. A 30:1 ratio of carbon to nitrogen is ideal for a compost pile. In targeting a carbon/nitrogen ratio for your pile, estimate the amounts of materials by weight, not volume. Too much nitrogen reduces the speed of the decomposition process, since nitrogen is needed for bacteria to break down organic matter.

3. Decomposers – These can be found in garden soil and freshly pulled weeds (many microorganisms are found on the roots of weeds).

4. Water – The heap should be kept moist but not soggy. It should feel like a squeezed out sponge. If the pile is too soggy, the materials may become matted, preventing proper aeration.


Activity One 4

5. Air – Although the decomposing microorganisms can survive without air, they will change to anaerobic cellular respiration. Anaerobic respiration slows the decomposition process and produces a foul-smelling hydrogen sulfide gas.

Procedures: 1. Draw cutting lines around the bottle, make incisions with the knife and cut with scissors and

assemble as illustrated. 2. Most columns will require air holes for ventilation and these can be poked into the plastic

with a sharp cold needle or with a needle that is first heated in a candle flame. 3. A piece of mesh fabric or cotton is put over the lower end to allow for drainage. Refer to the

illustrations. 4. Add ingredients for decomposition through the top of the column. 5. Cover column with the inverted top of bottle #3 and place a piece of cotton in the opening to

limit the movement of macro-organisms in and out of the column. 6. Observe the changes over time.


Activity One 5

Answer the following questions:

1. What is the purpose of composting?

2. What turns plants and animals into compost?

3. Describe the factors that affect the composting process?

4. Explain 3 things that could be done to speed up the process of composting using

biotechnology and/or bioremediation techniques.


Activity One 6

5. What are 2 things can you do to best prepare materials for composting?

6. Describe the organisms that you noticed in your compost container – what are each and

explain why each are found in your compost container?

Data table: 1. Mass of completed compost column before water is added: _____________ 2. Mass of each substance added:

Substance Mass (g) C/N ratio ___________________________ _______________ ________ ___________________________ _______________ ________ ___________________________ _______________ ________ ___________________________ _______________ ________ ___________________________ _______________ ________ 3. Determine the overall C/N ratio of your compost pile: multiply the mass of each of the

carbon substances by its ratio, and then add all of the carbon products together. Next multiply the mass of the each of the nitrogen containing substances with its ratio, and compare this value of the total to that of the carbon. You will need to reduce this to lowest terms to see how close you come to the 30:1 C/N ratio.


Activity One 7

Observations: Describe what you see and record what you did. Make certain to label and date the bottles of the height of the material each time you make an observation. Also, label any new organisms you see in your compost container. Date Observations Measurements Appearances, texture, smell, color Column length _____cm

Water added ______ ml Temperature ______ C


Activity Two 1

Activity Two How do Things Decompose - Design an Experiment Purpose: To design an experiment to best determine what environmental

factors will decompose a variety of common organic/inorganic materials.

Materials: Each group will need:

6 Jars (3 that can be covered and sealed) of equal size Compost material:

Sterile potting mix of potting soil and vermiculite Water Some groups may use redworms Selected everyday waste material, choices could include: Apple core, orange rind, or other fruit or vegetable Paper waste Plastic waste (grocery bags, milk container) Straw Styrofoam pieces Egg shells Coffee grounds Uncooked pasta noodles Leaves

Method: Students will:

• Use the scientific method and design an experiment to test how common everyday wastes break down (decompose).

• Compare the decomposition rates in different materials including compost, commercial potting soil mix, and air.

• Discover what environmental factors (moisture, sunlight, oxygen, microorganisms, macroorganisms, etc.) are best for decomposition to take place, or are none of these needed.

• Discover what types of common everyday wastes will break down the easiest.

• Determine how we can better prepare waste materials so that they can more efficiently decompose.


Activity Two 2

How do Things Decompose - Design an Experiment Directions: 1. Discuss the experimentation process with the students using the scientific method steps.

Remind the students that they are to pick only one variable to change while keeping all other conditions constant. They also should use a control (keep the conditions as normal as possible) for comparison of the results.

2. Divide the class into lab groups of 2 students each and each group should select which

variable they want to study. Make sure that a wide range of the materials are represented throughout the class. Encourage each group to select a unique environmental factor to test.

3. Each group should test their waste material in the air (control group), compost material, and

sterile potting soil mixture. They will have two containers of each, then change the environmental factor between the two. For example: one set of 3 without water, and one set with the materials staying just moist.

4. Set the materials aside, and observe the changes you see over a three-week period. Measure

the mass of each, observe the qualitative components (odor, color, etc). 5. Compare between groups as to which environmental factor will allow for the most efficient

decomposition process to occur.


Activity Two 3

Observations: 1. In which environment did the wastes break down most

completely? Why? 2. In what situation did the material break down the least? 3. What were the differences between the best and the worst?


Activity Two 4

4. Miss Rodger’s Science class has started a composting pile. What environmental factors would be needed for the materials to break down the quickest?

5. Marvin’s compost pile has stopped composting. What can he

do to get the pile to compost again? 6. Discuss a future experiment that you would design to

investigate this further: (What would your variable be and list your control. What material would you study?)


Activity Two 5

Expanded Activity: FEED ME YOUR FOOD SCRAPS! Determine how much organic (non-fatty) food scraps each of the following households generates on average per day. This calculated average would then determine how big the worm bin must be to be effective in creating an excellent household and garden fertilizer. Example: Katie and her family from Green Bay separated their organic kitchen scraps from the rest of the garbage for 1 week. She then weighed her total kitchen organic kitchen scraps for 1 week to be 14 pounds. Find out much kitchen scraps that her family averages per day? 14 lb. kitchen scraps per week = 2 lb. of kitchen scraps per day average 7 days in one week Directions: Complete the following showing all work and correct units. 1. If you measured 10 lb. kitchen scraps in one week, what was the average amount of garbage

produced per day?

2. Lombardi Middle School was considering starting a worm bin program for their school to process the waste from its organic kitchen scraps. The 8th grade class measured the amount of food scraps they generated to be about 162 pounds over 10 days. What was the average amount of garbage produced per day?

3. Mr. Robinson’s class at Einstein Middle School measured its lunchroom food waste for 8 days. They collected a total of 156 pounds of organic food scraps. What was their average amount of organic food scraps per day?

4. Calculate the amount of organic food scraps your family produces each day. Measure the amount of food scraps you generate over a one-week period.


Activity Three 1

Activity Three Design a Full-Sized Compost Pile Purpose: To discover first-hand how to setup and care for a full-scale

compost pile. Materials: For each compost pile:

• Organic material including leaves, grass, wood chips, etc. This material could either be brought in from a student’s home or collected from your local municipality’s organic waste facility.

• Fence for each compost setup (fence must be at least 3 feet in height)

• Posts for corners of fence • Ruler or marked stick for the center of the pile • Thermometer • Container and marker to collect macro-invertebrates

Method: Students will:

• Come to understand the biological activities that occur within a composting system.

• Develop a working knowledge of how to best create finished compost and where it can be used.

• Discover how easy it to compost and the benefits. We will also discuss any pre-conceived myths each student has about composting.


Activity Three 2

Background: Composting both yard and organic food scraps is an easy way to reduce the amount of waste that must be picked up and processed by your local municipality. Making a compost pile in your backyard is easy to setup and creates a great soil conditioner and fertilizer for your garden. As long as you only add organic materials that do not have fat or meat in them, your pile of organic waste will eventually break down into earthy-smelling humus material that is ready to add to the soil. The length of this process depends upon how active you are in caring for your compost pile. The best results occur when you turn the pile directly after you see the pile slump in height. This adds oxygen to the middle of the compost material and promotes aerobic bacteria to once again become active. This causes the internal temperature of the pile to reach the ideal range of 90-140 degrees Fahrenheit within several days. If the temperature within the compost pile is able to remain above 130 degrees Fahrenheit for an extended period of time, noxious weed seeds will be killed off. Besides oxygen, compost piles also need the right amount of water to keep the pile moist. Procedure: Student teams of 2-5 will design an experimental compost pile to be set up outside the school building. A total of 9-12 different compost piles can be created, each made with different components and/or percentages of materials. Then each class hour, all of the students can observe every compost pile to collect data from each of the piles. They will measure the height of the pile, internal temperature, dimensions of the piles and the composition of material from various sample locations within the piles. The students can also collect the macro-organisms found within the compost pile and use field guides to identify the genus and species of each organism. Students can also make observations as to the extent of biological activity that is occurring within the compost pile in the middle of a cold winter, like we experience in northeastern Wisconsin. Ideas for the different compost piles (each student group should decide on their own compost pile based upon the type of materials the group can bring from home) are as follows:

1. Pile with a C/N ratio of 30:1 (considered the ideal ratio so it will be used as our control). 2. Correct pile ratio but lacks moisture. 3. Correct pile ratio but lacks oxygen (pile is not turned at all). 4. Correct pile ratio but lacks both moisture and oxygen. 5. Pile contains only leaves. 6. Pile contains only grass. 7. Pile contains only wood chips. 8. Pile containing shredded leaves. 9. Pile includes ¼ finished compost. 10. Pile includes ½ finished compost. 11. Pile contains only organic food scraps. 12. Compare commercial compost bins to homemade versions.


Activity Three 3

Remember to give at least one week for all student groups to get their organic materials to school to begin the setup of the compost piles.

Data: • Have each class design a data table to collect the daily temperatures of the piles and the

height. • Keep a daily log as to the collection of data. Results:

• Student groups may present an overview of the research and results collected to the class. • Finished compost may be provided to the community as a good will gesture and to help

educate the public into how easy it really is to compost. • Write a summary of the students’ findings and class results.



Educator Information Title: Composting Grade Level: Mid-School / High School Content Areas: Life Sciences, Biology, Agriscience Performance Standards:

C.8.1 Identify questions they can investigate using resources and equipment they have available.

C.8.4 Use inferences to help decide possible results of their

investigations use observations to check their inferences. C.8.5 Use accepted scientific knowledge, models, and theories to

explain their results and to raise further questions about their investigations.

C.8.6 State what they have learned from investigations, relating to

their inferences to scientific knowledge and to data they have collected.

C.8.7 Explain how their data and conclusions in ways that allow an

audience to understand the questions they selected for investigation and the answers they have developed.

C.8.9 Evaluate, explain, and defend the validity of questions,

hypotheses, and conclusions to their investigations C.8.10 Discuss the importance of their results and implications of

their work with peers, teacher, and other adults. C.8.11 Raise further questions which still need to be answered. F.8.2 Show how organisms have adapted structures to match their

functions, providing means of encouraging individual and group survival within specific environments.

F.8.8 Show through investigations how organisms both depend on

and contribute to the balance or imbalance of populations and/or ecosystems, which in turn contribute to the total system of life on the planet.



F.12.7 Investigate how organisms both cooperate and compete in ecosystems.

Overall Objectives:

• To determine what factors affect the rate of decomposition for selected substances,

• To determine what environmental factors will best decompose a variety of common organic/inorganic materials,

• To understand the biological activities that occur within a composting system,

• To develop a working knowledge of how to best create finished compost and where it can be used.

Background Information on Composting

Backyard composting is a viable component of solid waste management. It has been

utilized by garden enthusiasts for centuries to help improve the condition of their soil.

Composting is generally defined as the controlled decomposition of organic matter by

microorganisms into a humus-like product (Aquino, 1995). Compost piles can contain leaves,

grass clippings, woodchips and organic food scraps (nonmeat or nondairy). Backyard or home

composting programs developed in the mid-1980s due in part to the increased pressure to ban

recyclable material (organic and inorganic) from our nation’s landfills because of higher costs to

site and manage a landfill facility (Aquino, 1995). Home composting reduces the amount of

material that must be collected, transported to a central facility, and disposed or otherwise

processed (Applied Composting Consulting, 1996).

Today there are more than 2000 backyard composting programs found across the United

States, with additional programs located throughout Canada and across Europe (Aquino, 1995).

Components of the residential waste stream

Yard trimmings accounted for about 28 million tons, or 13.4% by weight, and 5.7% of

the total volume of the United States municipal solid waste stream in 1996 (USEPA, 1998a). The

average American generates 280 pounds of yard trimmings per year (Aquino, 1995). The amount

of yard trimmings entering the municipal waste stream has continued to decline nationally due to

an increasing number of states enacting yard trimming disposal bans since 1992 (USEPA, 1998a).

Yard trimmings include grass, leaves, and tree and brush material. Grass is the largest component

of “yard trimmings” by weight (75%), followed by leaves (20%), and brush (5%) (Aquino, 1995).

The percentages of each component of yard trimmings vary across the United States due to



different climatic conditions. Variability in the amount of yard trimmings also occurs from

season to season. During peak months of their generation (i.e., during the spring and fall

months), yard trimmings can be the largest component of the municipal solid waste stream

(MSW) at 25 - 50% (USEPA, 1989). This is due to three main reasons: increased growth rate of

the grasses, shrubs and trees are often pruned during this time, and lawns are often raked or

dethatched. During the summer months, higher temperatures and drier conditions often

contribute to a decrease in the generation of yard trimmings due to the grasses slowing their

growth rate with less pruning of trees or shrubs taking place. During off-peak months, especially

in winter, little or no yard trimmings are generated due to cold, often frozen conditions in

Northeastern Wisconsin (Tracinski, 1998).

Food scraps account for another or 10.4% (21.9 million tons) of the United States

municipal waste stream (USEPA, 1998a). Approximately 72% (15.8 million tons) of food scraps

are compostable. This includes all food scraps except meat, fish, cheese, milk and fats and oils

(USEPA,1998b). The residential sector generates an estimated 50% (11 million tons) of food

scraps. The portion of food scraps, therefore, that is generated by the residential sector and that is

compostable is about 7.9 million tons (USEPA, 1998a and USEPA, 1998b). Together,

approximately one quarter of our waste stream can be removed and organically processed into a

useful byproduct. Many of these compostable food scraps are high in nitrogen content making

them an important addition to the home composting system. Food scraps help compost piles

decompose yard trimmings as well (Keyser, 1990a).

Statewide laws that ban yardwaste from municipal landfills

On January 1, 1993, the State of Wisconsin imposed a complete ban on the disposal of

yard trimmings into any landfill facility. Currently, Wisconsin is one of 17 states which have a

landfill ban or a disposal ban on yard trimmings. No state has enacted a disposal ban on organic

food scraps.

United States Yard Trimming Laws

State

Alabama

Arkansas

Connecticut

District of Columbia

Florida

Georgia

Legislation

State agencies must recycle trimmings

Disposal ban

Disposal ban

Landfill ban

Landfill ban

Landfill ban

Effective

1/91

7/93

10/97

10/89

1/92

9/96



Illinois

Indiana

Iowa

Maryland

Massachusetts

Michigan

Minnesota

Missouri

Nebraska

New Hampshire

New Jersey

New York

North Carolina

Ohio

Oregon

Pennsylvania

South Carolina

South Dakota

Virginia

West Virginia

Wisconsin

Landfill ban

Landfill ban, brush and leaves only

Landfill ban

Source separation required

Disposal ban on source-separated yard trimmings

Landfill ban

Disposal ban

Disposal ban

Landfill ban

Landfill ban

Disposal ban

Source separation required, leaves only

Source separation required, if economical

Landfill ban

Disposal ban on source separated yard trimmings

Source separation required for Portland area only

Source separation required, leaves only

Landfill ban, source separation required

Landfill ban

Local governments may ban leaves or grass if a collection program is offered Disposal ban

Disposal ban

Source: Apotheker, Resource Recycling, 1996

7/90

10/94

1/91

3/91

10/92

4/93

3/95

1/92

1/92

9/94

7/93

4/89

9/92

1/93

2/95

7/92

9/90

5/93

1/95

1/95

6/96

1/93

History and background on home composting programs in U.S. and Green Bay, WI

Over 2000 communities from throughout the world are actively promoting home

composting and other on-site yard management methods as a cost-effective way to manage

leaves, grass clippings, garden debris and other household organic materials. The City of Green

Bay, Wisconsin currently has collections for yard trimmings, brush, and leaves (spring and fall).

At the present time, the city does not have an established program to promote on-site organic

waste management techniques. Backyard composting, grasscycling and garbage disposal source



separation techniques reduce waste at the source, eliminating the transportation of yard and food

waste. There are no charges for fuel, labor, equipment, maintenance, municipal land and

administration (Pennsylvania Energy Office, 1992b). Backyard composting can reduce the

amount of waste requiring expensive disposal or processing at a centralized facility by diverting

up to 3% of the entire waste stream (Benton, 1990). In certain municipalities, it can reduce the

need to purchase plastic and paper yard waste bags. Composting in their own yard is also

convenient for the residents who save time by not having to haul their own trash or yard

trimmings to either their curb or to a central facility (Benton, 1990). By educating people to

generate less yard trimmings and turning the remainder into a valuable soil amendment, everyone

benefits. Generators can have better yards, and communities can save through reduced waste

management costs (Johnson, 1995b).

In comparison, the City of Green Bay is thought to have a participation rate of about 5%

of households that actively backyard compost (Hartman, 1998). It must be noted that reaching a

100% participation rate in backyard composting is very unlikely. There is often a small sector of

residents (20%) who will begin backyard composting initially just because they know that it is a

beneficial activity for both themselves and for the environment. On the other end of the

spectrum, there exists about 20% of the population that will not participate no matter how much

education they receive (e.g., physical restrictions, personal objections, lack of space to place a

composting system). The remaining part of the population needs to be reached by either word of

mouth, advertising, or through hands-on workshops before they begin composting, even though

they may know that it is a good idea. This is often called the 20-60-20 rule (Keyser, 1998).

Biological Processes within Compost Pile

Composting is a natural process to stabilize biologically decomposable organic material

(Leege, 1993). Compost comes from the Latin root compositus, “to put together” (Southeastern

Oakland County Resource Recovery Authority, Michigan, 1992) The forest floor is a natural

compost system in which a leaf mulch decomposes, recycling nutrients and conditioning the soil

(Alabama Cooperative Extension, 1992). Compost, or “humus,” is produced from the carbon

content of yard waste while water and carbon dioxide dissipate into the atmosphere (Aquino,

1995). Included into a compost pile are a mixture of green materials (e.g., grass clippings) which

are high in nitrogen, brown materials (e.g., leaves) that are high in carbon and microorganisms

(e.g., bacteria, fungi) which occur naturally in the soil or old compost. Other naturally occurring

macroorganisms (e.g., earthworms, isopods, millipedes) also aid in the composting process

(Harmonious Technologies, 1992).



Three major factors affect the rate of decomposition within the compost pile: availability

of moisture, availability of oxygen, and attainment of high temperature. Moisture is needed by

microorganisms for growth with an optimum moisture content of 40-60% (Aquino, 1995). The

compost pile should feel like a damp sponge (Hamilton County Environmental Services, Ohio,

1994). As a rough test for this moisture level, it should be possible to squeeze a few drops of

water from a fistful of leaves. Low levels of moisture (below 40%) will slow the decomposition

process. Below 25% moisture, microbiological activity virtually ceases and the material enters an

inert state until rewetted (Manser and Keeling, 1996). Moisture levels above 60% can lower

internal temperatures by inhibiting the proper oxygen flow, resulting in odor problems (USEPA,

1989).

Adequate oxygen penetration into the compost pile is needed for the decomposition to

occur. An oxygen level of greater than 5% is needed, otherwise anaerobic conditions can occur.

This will result in low pH levels (below 6) and the generation of malodorous compounds, which

can be detected by the human nose as a pungent odor (USEPA, 1989). Internal oxygen levels can

be maintained by periodically turning the compost pile. This turning process can be

accomplished by the manual use of a pitchfork or shovel or mechanically by the use of a rotating

drum or cylinder. A compost pile that has visibly “slumped” in height (noticeable decrease in the

volume) is a very good indication that the compost pile is ready to be turned.

The composting process can generate enough heat energy to destroy weeds and plant and

human pathogens (Aquino, 1995). The temperature level inside the compost pile is generally

dependent on the size of the pile. Simply stated, the larger the compost pile the higher the

internal temperatures will become. A properly made compost pile with a dimensional size of 3

feet X 3 feet X 3 feet will reach a temperature of 90-140 degrees F in four to five days (Hamilton

County Environmental Services, Ohio, 1994). One visible sign that the decomposition is

occurring is that the compost pile will begin to settle. Another approximate measure of the

internal temperature is to reach your hand into the middle of the compost pile to compare the

temperature to the human body’s temperature of approximately 98 degrees F. A more accurate

method would be to use a temperature probe or soil thermometer that can be purchased at garden

and hardware stores. The temperature must remain between 90 degrees F and 140 degrees F for

favorable composting to occur. Effective composting procedures require that all materials be

exposed to high temperatures in the interior of the pile long enough to kill pathogens (i.e., disease

causing microorganisms), neutralize insects such as flies, and help to keep weed seeds from

germinating (Hamilton County Environmental Services, Ohio, 1994). If the temperature drops

below 70 degrees F, composting will still occur but at a much slower rate. If the temperature

goes above 140 degrees F for several days, this will kill many of the desirable microorganisms



that are necessary for aerobic decomposition to occur (USEPA, 1989). Different microorganisms

live and proliferate at different temperatures: psychrophiles are active up to 95 degrees F,

mesophiles up to 122 degrees F, and thermophiles from 122 degrees upward (Manser and

Keeling, 1996). After the compost pile is created, psychrophiles become active. They generate

enough heat from their activity to allow the mesophiles to also become active. When the

temperature rises to above 122 degrees F, the thermophiles become active. The temperature will

continue to increase above 140 degrees F, but this high temperature will cause the

microorganisms to die off resulting in the rate of decomposition to quickly decrease. A greater

number of microorganisms exist within the mesophillic phase where the rate of decomposition is

the greatest. The thermophilic phase above 132 degrees F must occur for a sufficient amount of

time (at least two days) in order to control pathogens and weed seeds (Manser and Keeling, 1996,

Aquino, 1995, and Hamilton County Environmental Services, Ohio, 1994).

Efficient composting must also have an adequate carbon to nitrogen (C/N) ratio.

Nitrogen is essential to composting. Grass, coffee grounds, manure, urea and food wastes are

high in nitrogen, with a C/N ratio of about 20:1. Leaves, wood chips, straw, paper, and corn

stalks are high in carbon. The ideal mix is about one part “green” (nitrogen) with three parts

“brown” (carbon). Without a good mix of carbon and nitrogen sources, the pile will decompose

too slowly or cause odor problems. The materials in a compost pile may have to be physically

mixed to create a good blend of carbon and nitrogen sources (Hamilton County Environmental

Services, Ohio, 1994). Materials added to a compost pile do not need to be shredded in order to

be composted successfully, but this will speed up the process (Johnson, 1993).

Food Waste

Food wastes are generated commercially (e.g., restaurants, schools, government

institutions, nursing facilities) and residentially. Currently, food waste may be discarded in the

public landfill as regular trash and constitutes 14% (21 million tons) and 5.3% in volume of the

United States municipal waste stream (USEPA, 1998a). And yet a large part of the unprocessed

food materials from our homes: fruit and vegetable trimmings, apple cores, egg shells, coffee

grounds, and so on, are easily and readily composted through a variety of means, with the

potential for reducing that solid waste burden right at home (Keyser, 1990a). These compostable

food items, make up 72% of the food waste entering the municipal waste stream. One half of the

food waste entering our landfills is generated from the residential sector (USEPA, 1998b).

According to investigators associated with the University of Arizona Garbage Project who also

studied the makeup of residential waste, American families waste between 10 and 15 percent of

the food they buy. Of this, the study found that fresh produce accounted from 35 to 40 percent of



the total edible food discarded by weight. This figure does not include the inedible portion of the

produce, including the rinds, peels, skins, etc. Of all the food that is thrown away, edible and

inedible, the potato peel accounts for seven percent of the total weight (Rathje and Murphy,

1992). These materials are high in nitrogen content, a terrific natural fertilizer for yard

application and one of the most important elements in effective home composting, which means

that adding food scraps to your compost pile helps to decompose other yard trimmings as well.

These materials also contain trace minerals that are beneficial to growing plants and root

development (Keyser, 1990a). Many kitchen wastes can be successfully included in a home

composting system. They include:

• canning/preserving wastes (e.g., pomace) • citrus rinds (best if chopped fine) • clam/oyster shells (must be ground) • coffee grounds and filters • corn cobs (broken up or shredded) • egg shells (best if ground) • fruit and vegetable stems • fruit peels (e.g., apple peels, cores) • hard-shelled nuts (best if ground or crushed) • peanut shells • rotten or spoiled fruits • spoiled vegetables (e.g., wilted lettuce) • tea leaves and bags • vegetable trimmings (e.g., potato peels)

It is best not to add materials to a compost pile that may attract pests or putrefy. These

include: dairy materials (e.g., eggs, cheese, milk, cream), oils, grease or fatty materials, meat

scraps, bones (whole with meat/gristle attached), and starchy or vegetable materials that have

been cooked or prepared with the above. These materials may be effectively composted by

burying them directly into the soil, a method called trench and pit composting. This method

involves digging a hole into the soil, deep enough to deposit the food scraps inside, and finished

with a six to eight inch cover of soil. Trench and pit composting is applicable for redeveloping or

improving garden beds (Keyser, 1990a).

Completed Compost Material

The amount of time that it takes for a composting system to create finished compost

depends upon the amount of maintenance one wants to provide during the compost process.

Depending upon the materials in the compost pile, the organic materials will naturally decompose

in about 12 to 24 months with no maintenance required. But if the composted materials are well

mixed with proper moisture level and are turned periodically, finished compost can be available



in as little as three months (Hamilton County Environmental Services, Ohio, 1994). Finished

compost will be loose and crumbly with a sweet and earthy smell like that of the forest floor. Its

temperature should be the same as the outside air temperature (Southeastern Oakland County

Resource Recovery Authority, Michigan, 1992).

Finished compost increases the porosity of soil enabling plant roots to easily penetrate the

soil surface. Although compost is considered a soil conditioner rather than a fertilizer, it adds

organic bulk, humus, and cation exchange to regenerate poor soils. Compost also suppresses

certain plant diseases and parasites. Finished compost increases water retention in both clay and

sandy soils (USEPA, 1998b). When mixed with clay soils, compost loosens the soil particles and

allows for better drainage and aeration. Adding compost to soils will aid in erosion control

(Harmonious Technologies, 1992). It will also help the soils retain nutrients and minerals

essential for healthy plant growth and slowly releases them throughout the growing season

(Southeastern Oakland County Resource Recovery Authority, Michigan, 1992). Finished

compost restores soil structure after natural soil microorganisms have been reduced by the use of

chemical fertilizers. Compost reduces the fertilizer requirements by at least 50 percent (USEPA,

1998b).

The preceding was an excerpt from: Rohr, Dennis. 1998. Thesis. A Spreadsheet Model for Determining the Feasibility of Incorporating Backyard Composting, Grasscycling, and Household Garbage Disposals in Waste Management Systems: A Green Bay, Wisconsin Case Study. University of Wisconsin – Green Bay. References: Alabama Cooperative Extension. 1992. Agriculture and Natural Resources Compost Handbook: Selecting a Compost System for Your Yard. Auburn University. Apotheker, Steve. 1996. Clippings, prunings and leaves oh no!. Resource Recycling. January 1996. p. 17-25. Applied Compost Consulting. 1996. National Backyard Composting Program: Cost-Benefit Analysis of Home Composting Programs in the United States. The Composting Council. Aquino, John. 1995. Waste Age/Recycling Times’ Recycling Handbook. Lewis Publishers. Benton, Craig H. 1990. How to Establish a Home Composting Program. Wisconsin Master Composter Training Program Guide Book. Damro, Dave. 1998. Personal communication. Operations Superintendent, City of Green Bay, Wisconsin. Operations Division.



Hamilton County Environmental Services, Ohio. 1994. Yardwaste at Home Handbook. Hamilton County Environmental Services, Solid Waste Management District. Hartman, Paul. 1998. Personal Communication. Horticulturist. University of Wisconsin Extension Office - Brown County, Wisconsin. Harmonious Technologies. 1992. Backyard Composting: Your Complete Guide to Recycling Yard Clippings. Harmonious Press. Johnson, Holly. 1993. Waste Education Series: Options For Managing Leaves. 125.HJ.9309. University of Wisconsin-Extension. Keyser, Joseph. 1998. Personal Communication. Education Specialist. Department of Environmental Protection. Montgomery County, Maryland. Keyser, Joseph. 1990a. Composting Factsheet 5: Composting Food Scraps. National Home Composting Park and American Horticultural Society. Leege, Phil. 1993. “Composting Infrastructure in the United States”. Science and Engineering of Composting: Design, Environmental, Microbiological and Utilization Aspects. The Ohio State University. Renaissance Publications. Manser, A.G.R. and Keeling, Alan. 1996. Practical Handbook of Processing and Recycling Municipal Waste. Lewis Publishers. Pennsylvania Energy Office. 1992b. Yard Waste Management Fact Sheet #2. Finding the Best Yard Waste Management System For You. Pennsylvania Energy Office and Rodale Institute. Rathje, William and Murphy, Cullen. 1992. Rubbish! The Archaeology of Garbage. HarperCollins Publishers; p. 62-64. Ripp, Grace. 1998. Engineer, City of Green Bay Public Works Department. Personal Communication. Southeastern Oakland County Resource Recovery Authority, Michigan. 1992. Giving Back Earth’s Riches--Using Compost to Build Healthy Soil. Michigan Department of Natural Resources. Tracinksi, Bob. 1998. Personal Communication. John Deere Co. U.S. Environmental Protection Agency(EPA). 1998a. U.S. Environmental Protection Agency. Characterization of Municipal Solid Waste in the United States, 1997 Update. EPA/530-R-98-007. Washington D.C.: Office of Solid Waste and Emergency Response. U.S. Environmental Protection Agency(EPA). 1998b. U.S. Environmental Protection Agency. Organic Materials Mangement Strategies. EPA530-R-97-003. Washington D.C.: Office of Solid Waste and Emergency Response. U.S. Environmental Protection Agency(EPA). 1989. U.S. Environmental Protection Agency. Yard Waste Composting. EPA/530-SW-89-038. Washington D.C.: Office of Solid Waste and Emergency Response.

Solid & Hazardous Waste – Household Hazardous Waste

Activity One 1

Activity One Environmental Impact of Household Chemicals Purpose: To show students the potential hazardous effects of common

household products. Materials, Equipment, and Preparation: (quantities will vary with class size) 90 – 100ml disposable petri dishes, bottoms only 9 – 500ml beakers 100ml graduated cylinder Balance Metric rulers Tablespoons Masking tape Waterproof marking pens Newspaper 4 lbs. Potting soil 2 lbs. Clean silica sand 6 liters distilled water 90 rubber bands (thin) 600 seeds, each of lettuce, rye, and radish 3 liquid household products (bleach, rubbing alcohol, and

ammonia) Plant food (mix according to manufacturer’s directions) Method: Explain the importance of the environmental impact of household

chemicals. We need to decide how best to use and dispose of these chemicals. By conducting this experiment we can understand the impact of three common household products on soil by observing the growth of different plant seedlings.


Activity One 2

Environmental Impact of Household Chemicals Procedure: 1. Prepare three solutions of each of the household products, using the 100ml

graduated cylinder to measure and the three 500ml beakers to mix the different solutions:

#1 (1%) solution – Measure and mix 5 ml household product with 495 ml of distilled water in

a beaker. #2 (3.2%) solution – Measure and mix 16 ml household product with 484 ml distilled water

in a beaker.

#3 (10%) solution – Measure and mix 50 ml household product with 450 ml distilled water in a beaker.

2. With the masking tape and waterproof marking pen, label all the prepared beakers. There

should be 3 solutions of each household product, for a total of 9 solutions. 3. Spread out the 90 petri dishes on a table. Preparation will be three dishes for each seed

product for each solution combination tested. Therefore, to test three different mixture solutions of three household products on three kinds of seeds, 81 petri dishes are needed (3x3x3x3). In addition, three petri dishes are needed as controls for each kind of seed, which equals nine petri dishes. Altogether, 90 petri dish bottoms will be used.

4. Fill the bottom of each of the 90 petri dishes full of the air-dried potting soil. Use the balance

to weigh out the same amount of soil for each petri dish. 5. Prepare the plant food according to the manufacturer’s directions. Add 10 drops of plant

food to each of the petri dishes. Allow it to soak for 10 minutes. 6. Plant 30 dishes with each type of seed (30 lettuce seeds, 30 rye seeds, and 30 radish seeds).

Put 20 seeds in each dish. 7. Sprinkle two tablespoons of silica sand over each prepared dish with soil, plant food, and

seeds. 8. Measure out 15 ml of distilled water into three dishes of each seed type for a total of nine

petri dishes. Enclose each dish in a plastic bag and close with a rubber band. With making tape and marker, label these nine petri dishes as controls by seed types (control-lettuce, control-rye, and control-radish).

9. Prepare remaining solutions in petri dishes. For each of the nine solutions previously mixed

in the beakers, place 15 ml of the solution into three petri dishes of each type of the three seeds. For example, put 15 ml of the #1 (1%) bleach solution into three lettuce dishes, three rye dishes, and three radish dishes. Followed by the #2 (3.2%) bleach solution into three of each, and so on, until the entire series of solutions has been completed, using 81 seed dishes.

10. Cover each of the dishes with a plastic bag and seal with a rubber band. Label each dish with

making tape and waterproof marker.


Activity One 3

11. Place all the dishes so they receive a good indirect source of sunlight, where they can be observed for two weeks.

12. Prepare data charts for recording daily observations. Group information according to type of

household product, number or percent of solution, and type of seed. 13. After five days, count the number of seeds emerged in each dish. Record the findings for

each product tested and for the controls. 14. After 14 days, measure and average the height of the three tallest seedlings in each dish.

Record the findings for each product tested and for the controls. Average the number of seeds that emerged for each seed type in each solution. Record results.

15. Write conclusions of recorded observation. Report which concentration of contaminate had

the most impact on emergence and seedling height; which product was the most toxic overall; and which seed was the most sensitive to contaminants.

Expanded Activity Average the number of seeds that emerged for all types in each solution of each product and record this data. Find the percentage of emergence for each seed for each solution of each product and control (no. seeds emerged/no. seeds planted x 100). Determine what happens to the percentage of emergence and seedling height as the contaminant concentration increases. Discuss ways that household chemicals might be introduced into the soil environment.


Activity Two 1

Activity Two Hazardous Waste In The Home Purpose: To show students alternatives to household products that are not as

hazardous to the environment. Materials, Equipment, and Preparation: Examples of household chemicals (drain openers, bleach, deodorizers,

etc.) Newspaper grocery ads Magazine ads Household Hazardous Waste Article (Educator Information - Appendix 1) Household Hazardous Waste Inventory Sheet (Educator Information -

Appendix 2) Method: Explain what household hazardous waste is to your students and have

products or pictures of products available for your students to look at. By conducting this activity, we can better understand how to: identify and classify hazardous products; determine proper disposal methods of hazardous wastes; and describe less hazardous alternatives.


Activity Two 2

Hazardous Waste In The Home Procedure: 1. Provide background information by having students read the Household Hazardous Waste Article in Appendix 1. Discuss this article with them. 2. Pass out Household Hazardous Waste Inventory sheets; tell students they will be identifying

potential household hazardous wastes. 3. Display a variety of household products in several groupings around the room. Have the

students rotate around the room looking at these products carefully. Students should then decide if the product could be hazardous waste and in which room of the home it is typically found. They fill this information in on their inventory sheet.

4. Provide local information to the students on the proper disposal of these hazardous wastes,

including looking up local information on the Internet. Expanded Activity A) Have the students make posters of hazardous household products and possible less-toxic

alternatives by cutting out pictures of the products from newspapers and magazines. B) Contact your local household hazardous waste disposal site and set up a tour for your

students.



Educator Information Title: Household Hazardous Waste Grade Level: Core Activity 7-8 + Expanded Activity 9-11 Content Areas: Science and Mathematics Performance Standards: Science:

A.8.7 Design real or thought investigations to test for both usefulness and limitations of a model.

B.12.4 Show how basic research and applied research contribute to

new discoveries, inventions, and applications. C.8.1 Identify questions they can investigate using resources and

equipment they have available. C. 8.3 Design and safely conduct investigations that provide

reliable quantitative or qualitative data, as appropriate, to answer their questions.

C. 8.9 Evaluate, explain, and defend the validity of questions,

hypotheses, and conclusions to their investigations. H. 8.3 Understand the consequences of decisions affecting

personal health and safety. Mathematics: D. 8.1 Identify and describe attributes in situations where they are

not directly or easily measurable.

D. 8.3 Determine measurement directly using standard units. Overall Objective: To understand what a hazardous waste is by identifying

common household products that are considered toxic. Once identified, students should be aware of proper procedure for disposing of such products. Students will explore options for reducing the toxicity of products through alternative product use.



Appendix 1 HOUSEHOLD HAZARDOUS WASTE ARTICLE Steps to Safe Management What is a Household Hazardous Waste? Some jobs around the home may require the use of products containing hazardous components. Such products may include certain paints, cleaners, stains and varnishes, car batteries, motor oil, and pesticides. The used leftover contents of such consumer products are known as “household hazardous waste.” There are four major categories of hazardous waste: Toxic – poisons, or substances that cause adverse physiological reactions Reactive – substance that is explosive Ignitable – substance that is capable of burning rapidly

Corrosive – materials capable of dissolving or wearing away substances (especially metals).

Americans generate 1.6 million tons of household hazardous waste per year. The average home can accumulate as much as 100 pounds of household hazardous waste in the basement or garage and in storage closets. When improperly disposed of, household hazardous waste can create a potential risk to humans and the environment. What Are the Dangers of Improper Disposal? Household hazardous wastes are sometimes disposed of improperly by individuals pouring wastes down the drain, onto the ground, into storm sewers, or putting them out with the trash. The dangers of such disposal methods may not be immediately obvious, but certain types of household hazardous waste have the potential to cause physical injury to sanitation workers; contaminated septic tanks or wastewater treatment systems if poured down drains or toilets; or present hazards to children and pets if left around the house. Try to Reduce, Recycle, and Use Alternative Products! One way to reduce the potential concerns associated with household hazardous waste is to take actions that use nonhazardous or less hazardous components to accomplish the task at hand. Individuals can do this by reducing the amount and/or toxicity of products with hazardous components, and use only the amount needed. Leftover materials can be shared with neighbors or donated to other community organizations. Some communities have even organized waste exchanges where household hazardous waste can be swapped or given away. Recycling is an economical and environmentally sound way to handle some types of household hazardous waste, such as used car batteries and oil. Many communities and service stations have begun collecting used oil as a service to their customers. Alternative products can also be a very effective way to reduce household hazardous waste. “Green products” is a term used to refer to products that are environmentally friendly. Here are some examples of toxic products and nontoxic substitutes:

• Turpentine – Use water with water-based paints instead. • Drain cleaner – Plunger or boiling hot water mixed with baking soda. • Flea repellent – Garlic, brewers yeast; herbs such as fennel and rosemary. • Mothballs – Cedar chips or herbal sachets. • Air fresheners – Baking soda, fresh flowers. • Chemical fertilizer – Compost. • Window cleaner – Vinegar and water.



Appendix 2 Household Hazardous Waste Inventory List hazardous household products in each room of a typical house. Classify each in at least one of the categories of hazardous waste. One example is shown. Kitchen Products: Category: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ( Example: drain openers -------------------- toxic, corrosive ) Laundry room: Category: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Garage: Category: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Bathroom: Category: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Workshop: Category: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Other rooms: Category: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Solid & Hazardous Waste – Landfills and Leachate

Activity One 4

Activity One Purpose: Background reading for information about sanitary landfills. Materials: Sanitary Landfills handout (Source: Keep America Beautiful,

Inc.) Reading Response worksheet. Method: Each student should read the informational handout and fill

in the reading response worksheet. Expanded activity includes students finding an article on the Internet or other source that discusses the problems that have been observed in sanitary landfill operations. Students will then write a discussion paper about the pros and cons of sanitary landfills and possible solutions.


Activity One 5

Reading Response Worksheet for Sanitary Landfills

Directions: Following the reading, write in the best answers. After reading the entire article, fill-in short answer questions and true or false questions. Following the Reading

Communities use landfills to dispose of __________________ of tons of the trash they

create. Prior to the mid- __________, several landfills around the nation were indeed

basically _____________________ that accepted all forms of garbage including

_______________________________. Municipal ______________________________

__________________________ are now tightly regulated. Because a landfill is filled so

systematically, often modern landfill operators can ______________________ where a

specific _____________________________ of garbage was ______________________

even days, weeks or months afterward. A layer of earth called _____________________

is spread across the compacted waste in the cell to minimize ____________________,

_________________________________________, and prevent ___________________

and __________________________ problems. Today's landfills include multiple

__________________________ to contain wastes and isolate them from surrounding

_______________________ and ______________________. Rain, snow, and other

liquids created by the _______________________ and __________________________

of solid waste that can seep from a landfill cell is known as _______________________.

_______________ emanating from the landfill are also closely ____________________

and ________________________. Once a landfill is __________________, the landfill's

operators are obligated to ______________________ the site for ____________ and


Activity One 6

______________________ for a minimum of _______________ years after the closure

date.

True or False

T F Only the EPA monitors landfills to make sure they are properly monitored.

T F Many times it takes five or more years from the planning stages to opening of a new sanitary landfill.

T F When garbage is hauled to a landfill, the bottom of the landfill is covered before the next layer is started.

T F Operators of landfills try to expose as much garbage as possible to rain and snow to accelerate decomposition.

T F Leachate can only contaminate groundwater.

T F Leak detectors are located under liners of landfills.

T F Energy may be recover from the combustion of methane from landfills.

T F Once a landfill closes, it is forgotten and fenced-off.

Short Answer

How is the gas from landfills contained?

What happens to landfills once they reach final capacity?


Activity One 7

Activity One – Expanded Activity

Are Sanitary Landfills the Best Option for Handling our Municipal Solid Waste?

CHALLENGE: Find an article on the Internet or other sources that either discusses the drawbacks of sanitary landfills or proposes an alternate disposal method. PRODUCT: If you found an article on the drawbacks of sanitary landfills, discuss the pros and cons of landfills in a two-page, double-spaced typed paper. Cite both the article that you have found as well as the article Sanitary Landfills. If you found an article on an alternative to sanitary landfills, compare and contrast that disposal method to sanitary landfills in a two-page, double-spaced typed paper. Cite both the article that you have found as well as the article Sanitary Landfills.


Activity One 8

Source: Keep America Beautiful, Inc. MSW Management

Sanitary Landfills The sanitary landfill is an engineered method of disposing of Municipal Solid Waste (MSW) in the minimum amount of space using means that protect human health and the environment. Communities use landfills to dispose of millions of tons of the trash they create. In 1994, U.S. landfills, all of them now state-of-the-art facilities, managed about 61 percent of MSW, according to the United States Environmental Protection Agency (EPA).

Environmental Considerations Properly operated modern landfills are environmentally safe means of disposal, and are closely monitored for their environmental impact by the EPA, as well as state and local authorities. By no means are modern landfills anywhere near to being "simply a hole in the ground where garbage is buried." In fact the enforcement of strict environmental standards in the last decade has played a major role in decreasing the overall number of landfills. Prior to the mid-1970s, several landfills around the nation were indeed basically open pits that accepted all forms of garbage including hazardous wastes. Practices like these are no longer permitted, and are in fact closely monitored by government authorities as well as civic and environmental groups. Municipal solid waste landfills (MSWLs) are now tightly regulated. Because today's landfills need to operate with unquestioned safety and efficiency, it often can take five or more years from the time a site is selected until designs, permit applications, and public hearings are completed and the facility is built. In addition to complying with EPA rules, many factors are taken into consideration when siting a landfill.

How a Landfill Operates Obviously, in its most basic sense, a landfill is a place where garbage is hauled, deposited and then buried. But if you look at a modern landfill in closer detail it is really much more complicated than that. A typical, modern landfill is divided into a series of sections called cells. When the solid waste is hauled to a landfill, it isn't just strewn haphazardly. Rather it is placed on what is called a working face, which is a portion of a landfill cell that is currently exposed and available for trash disposal. Only limited sites in the landfill are exposed at any given time to minimize exposure of the landfill's contents to elements like wind and rain. In fact, because a landfill is filled so systematically, modern landfill operators can often pinpoint where a specific truck's load of garbage was deposited even days, weeks or months afterward. At the conclusion of each day's activity in a cell, a layer of earth (or as noted before, another material such as ash) called daily cover is spread across the compacted waste in the cell to minimize odor, prevent windblown litter, and prevent insect and vermin problems. The daily cover may also consist of a layer of foam materials or sheets of synthetic materials. The landfill operator moves from working face to working face, and from cell to cell as the landfill gradually fills over periods of many years, even decades. But as noted, a modern landfill is more than just a hole in the ground where we dump trash and forget it. Today's landfills include multiple safeguards to contain wastes and isolate them from surrounding water and soil. In many cases, for example, such safeguards involve a protective liner to prevent filtration. Liners may be made of compacted clay or impermeable materials such


Activity One 9

as plastic. When clay is used, the layer may be as much as ten feet thick. All this site preparation is done so that any liquid entering the landfill can be controlled and treated externally, or retained inside the landfill, rather than being permitted to pass through the site and come out the other side. Rain, snow, and other liquids created by the compaction and decomposition of solid waste that can seep from a landfill cell is known as leachate. Leachate is considered by EPA and landfill operators as a potential pollutant of surface waters like lakes, rivers, streams or the ocean—or groundwater which is the source of most of our drinking water. With this in mind, a network of drains is installed at the bottom of the landfill to collect any leachate that has percolated through the wastes of the landfill. The leachate is then pumped to waste water recovery points for treatment. Groundwater monitoring wells are installed around the perimeter of the landfill to ensure that surrounding groundwater is not contaminated with leachate. Should a liner system fail by breaking or deteriorating, leak detectors installed under the liners would signal the presence of leachate, allowing immediate corrective action to take place that prevents any further movement of leachate from the landfill toward nearby groundwater or surface waters. Gases emanating from the landfill are also closely monitored and controlled. As the organic portion of waste (i.e., food and yard wastes) decomposes in a landfill, large amounts of methane gas and carbon dioxide are produced. Methane is controlled. As a result, under the Resource Conservation and Recovery Act (RCRA) and the Clean Air Act, landfills are required to monitor gas both on their surfaces and around their boundaries. As cells to the landfill are sealed off, venting systems are installed that prevent the methane from diffusing underground. Equipment is also installed in the vents to collect the gas that emanates from the landfill and burn it off. In many cases, energy is recovered from the combustion of the gases which is used on site or sold to local homes or businesses. All landfills are required to close consistent with certain "final cap" environmental requirements imposed by EPA. When landfills as a whole have reached their capacity, they are covered with a final layer of clay and dirt and then are re-landscaped according to closure plans drawn up in accordance with the community. Just to be granted their license to operate in the first place (even from day one in the case of new landfills) operators must have a complete plan for when the site is eventually closed, which in some case can be fifty or more years down the road. They are also required to provide financial assurance that ensures that financial means will exist for all closure, post-closure and corrective action activity over the lifetime of the landfill. Once a landfill is capped, the landfill's operators are obligated to monitor the site for gas and leachate for a minimum of 30 years after the closure date. They also are often involved in the ongoing efforts to reclaim the land for other uses. Landfills can end up in time as open space for communities to use as parks, ski slopes or even golf courses. Building any permanent structures on landfills is less common because, as solid waste decomposes in the landfill, the entire landscape can settle.


Activity Two 1

Activity Two Purpose: Investigation will be on the subject of groundwater

contamination within close proximity of a landfill and the units used to measure contaminants. Expanded activity will include dilution lab, which helps students visualize what is meant by parts per million, parts per billion and parts per trillion.

Materials: Core Activity: Citizen’s Guide to Municipal Landfills handout

Did You Know… handout

Expanded Activity: Activity Two – Expanded Activity Worksheet

• red or blue food coloring • droppers (25 drops=1ml) • Four (4), one liter beakers per lab group or individual • Four (4), 250 ml beakers per lab group or individual

Method: Read through handouts either individually or as a class. Discuss how landfills are not perfect systems and that leachate leaves the landfill. Include the need for constant monitoring of the groundwater or waterways around the landfill to provide a guard against drinking water source contamination. Have students try thought experiments on how ppm, ppb, or ppt would look with different reference points besides time or distance. For example, estimate how much space one million ping-pong balls would take up (in a classroom? Cafeteria? Gymnasium?), then imagine that one ping-pong ball is red while the rest are white.

For the expanded activity, each student or lab group will start with four, one liter beakers and proceed to make successive dilutions of 1 ml food coloring solution (the first 1 ml straight food coloring) to 999 ml water. Students should receive visual confirmation of the small size of the units ppm, ppb, and ppt. Students are challenged to find a method of creating several dilutions from the parts per thousand, ppm, ppb, and ppt solutions.


Activity Two 2

Adapted from:

Friends of the Earth's

Citizen's Guide to Municipal Landfills http://www.foe.org/ptp/manual.html

Leachate forms when liquid coming from rain, melted snow, or the waste itself percolates through and moves to the bottom or sides of a landfill. Flowing through the waste, leachate transports a variety of chemicals to the edges of a landfill. The quantity of leachate produced by a landfill depends mainly on the amount of precipitation around the landfill. In areas with high precipitation rates, the production of leachate can be greater than in drier areas since much of the precipitation percolating through a landfill becomes leachate. The amount of liquid in landfilled waste also affects the amount of leachate the landfill generates. Municipal landfill leachate often contains many toxic and carcinogenic (cancer causing) chemicals, which may cause harm to both humans and the environment. Uncontrolled leachate often migrates to groundwater and sometimes into surface waters. Because leachate production is unavoidable, careful monitoring and control of leachate is necessary for safe waste handling practices. Leaking landfills are of great concern for people whose source of drinking water is groundwater wells located near landfills. These wells may draw up groundwater that is highly contaminated with leachate (Figure 1). In addition to posing health threats to communities whose drinking water is supplied by wells, leachate-contaminated groundwater can also negatively affect industrial and

Figure Leachate can be pumped up to


Activity Two 3

agricultural activities that depend on well water. For certain industries, contaminated water may affect product quality, decrease equipment lifetime, or require pretreatment of the water supply. The use of contaminated water for irrigation can decrease soil productivity, contaminate crops, and move possibly toxic pollutants up the food chain as animals and humans consume crops grown in an area irrigated with contaminated water. Though new landfills must be built with liners that act as temporary barriers to leachate migration, the large majority of landfills built before 1993 do not have such liners. In such unlined landfills, or in landfills with leaking liners, gravity causes leachate to move through the landfill, out the bottom and sides, and through the underlying soil until it reaches the groundwater zone or aquifer (Figure 2). There, the leachate mixes with and

travels with the groundwater along its underground path. Leachate contains hundreds of different chemicals and the quality of municipal landfill leachate varies greatly within individual landfills over time and space as well as among different landfills. Many factors influence leachate composition including the types of wastes deposited in the landfill and the amount of precipitation in the area. The rates of biological and chemical activity taking place in a specific landfill or landfill cell can also affect leachate quality. Laboratory tests can determine whether surface water or groundwater samples contain some of the harmful substances that can be present in leachate, indicating that leachate contamination may have occurred. Three specific categories of substances are often analyzed in these tests: volatile organic compounds, metals, and general water quality parameters. Volatile Organic Compounds Volatile organic compounds, also called VOCs or hydrocarbons, are often toxic or carcinogenic and frequently human-made chemicals that are widely used in household, commercial and industrial products or activities. Called "organic" because their structures are based on carbon and hydrogen atoms, and "volatile" because they evaporate into the

Figure 2. Leachate moving from a landfill tounderlying groundwater


Activity Two 4

air, VOCs are used in cleaners; the manufacturing of chemicals, plastics and other products; agricultural chemicals; fossil fuel products; oil-based paints; and other common products. TABLE 1. Health Effects of Selected Volatile Organic Chemicals Found in Landfill Leachate Benzene Causes cancer and mutations; affects nervous system; affects immune

system and gastrointestinal system; blood cell disorders; allergic sensitization; eye and skin irritation

Chloroform Probably cancer causing; affects nervous system; affects gastrointestinal system; kidney and liver damage; toxic to developing embryo; eye and skin irritation

Methylene Chloride

Possibly cancer causing; affects nervous system, lung/respiratory system, and cardiovascular effects; blood disorders; eye and skin irritation

Vinyl Chloride Causes cancer; causes mutations; affects nervous system; kidney and liver damage; blood cell disorders; and skin irritation

SOURCE:Adapted from The Poisoned Well (Sierra Club Legal Defense Fund, 1989) Metals Metals occur naturally in the environment. Along with nutrients, minerals, and salts, metals are termed "inorganic" chemicals since they are not based on carbon and hydrogen structures. Metals are used in many industrial and manufacturing processes, such as the making of alloys and metal products; in electroplating; and in products like paint, glass, plastic, and pesticides. Common items made of metal include cars, appliances, aluminum foil and other household goods. Most metals are not cancer causing when consumed in drinking water, but they produce other serious toxic effects. TABLE 2. Health Effects of Selected Metals Found in Landfill Leachate Arsenic Causes cancer; cardiovascular, peripheral nervous system, reproductive and

lung/respiratory effects; liver and skin damage Cadmium

Probably cancer causing; toxic to developing embryo; affects nervous system, reproductive and lung/respiratory; kidney damage

Chromium

Causes cancer: probably causes mutations, lung/respiratory effects, allergic sensitization, eye irritation

Lead Kidney and brain damage, affects nervous and reproductive systems, blood cell disorders.

Mercury Affects nervous system, cardiovascular and lung/respiratory effects; kidney and visual damage

Nickel Probably causes cancer, lung/respiratory effects, allergic sensitization, eye and skin irritation, liver and kidney damage

SOURCE: New Jersey Fact Sheets (from Right-to-Know Network) Both volatile organic compounds and metals are measured in very small amounts because it only takes small amounts of these substances to produce some of the effects listed in


Activity Two 5

the two tables above. The units that these substances are measured in are parts per million (ppm), parts per billion (ppb), or parts per trillion (ppt).

General Water Quality Parameters A set of general water quality parameters can be used to roughly determine if leachate has contaminated groundwater. Parameters such as pH (indicator of acidity or alkalinity), total dissolved solids (dissolved compounds), and conductivity (ability to conduct electricity, indirect measurement of dissolved ions) may indicate contamination. Elevated levels of these parameters occurring in the groundwater near a landfill compared with levels in neighboring areas may signify leachate movement.


Activity Two 6

Did You Know . . .

Residues of chemicals in our food and water supply are expressed in parts per million (ppm) or parts per billion (ppb) or sometimes in parts per trillion (ppt) . Sometimes these numbers seem to be very large, but they need not be overwhelming. The following comparisons will help keep these types of figures in perspective.

One part per million (ppm) is approximately: - 1 inch in 16 miles - 1 second in 11 days

One part per billion (ppb) is approximately:

- 1 inch in 16,000 miles - 1 second in 32 years

One part per trillion (ppt) is approximately:

- 1 inch in 16,000,000 miles (33 trips to the moon and back)

- 1 pinch of salt in 10,000 tons of potato chips (approximately 1,000 18-wheelers loaded with potato chips)

Adapted from: Grodner, Mary L. 1996. A Proper Perspective on Pesticide Toxicity. Southern Region Pesticide Impact Assessment Program Fact Sheet. 2 pp.


Activity Two 7

Activity Two– Expanded Activity

“Parts Per” Lab CHALLENGE: Using food coloring and water, visualize the terms parts per million, parts per billion and parts per trillion. After gaining experience with this exercise, use conversion factors to mix solutions of designated parts. PRODUCT: You will have four beakers with the initial solution concentrations. The instructor will inspect these beakers for the proper dilution. In addition to observing the solution in the beakers, answer questions found in the lab directions and hand in your results to your instructor on a separate piece of paper. You will be asked to use these four solutions to make four new solutions of designated dilution. Show all conversions and calculations used to determine what amount and which solution to add to water. The instructor will inspect these beakers for proper dilution and you will hand in your calculations. PROCEDURE: Hint: It will be helpful to use a white piece of paper behind or underneath the beaker to see the differences in dilutions. 1. Place twenty-five drops (1 ml) of food coloring into a one-liter beaker. 2. Add 999 ml of water to the beaker. Stir the solution. You now have a solution in which food coloring comprises one part (1 ml) of the total solution volume of 1000 ml. The prefix milli means one-thousandths (1/1000) of a given unit. It is a ratio of one part of food coloring to 1000 parts of solution. If we write the ratio as a fraction and divide, the solution can be expressed as .001 concentration in food coloring:

How could I also say I have a 999 parts per thousand solution? 3. Place twenty-five drops (1 ml) of the parts per thousand solution in a second one-

liter beaker. 4. Add 999 ml of water to the beaker. Stir solution.

1 part food coloring

1000 parts solution = .001


Activity Two 8

You now have a solution that is one part per million of food coloring. This concept can be described using the ratio relationship: (initial concentration)• (volume of initial concentration) = (final concentration)• (total volume of solution) Therefore, we obtain the correct answer by multiplying the concentration of the first solution times the volume added and set it equal to the concentration of the solution being made (unknown) times the ending volume.

a. (.001)• (1 ml) = (concentration)• (1 ml first solution + 999 ml water)

b. .001 ml = (concentration)• (1000 ml)

c. .001/1000 = concentration [ml cancels]

d. concentration is .000001, which is one millionth, or one part per million.

5. Place twenty-five drops (1 ml) of the parts per million (ppm) solution in a third

one-liter beaker. 6. Add 999 ml of water. Stir solution You now have a solution that is one part per billion of food coloring. Using the model above, express this mathematically. 7. Place twenty-five drops (1 ml) of the parts per billion (ppb) solution in a fourth

one-liter beaker. 8. Add 999 ml of water. Stir solution. What is the designation for the solution you have just created? Using the model above, express this mathematically. Exercises: Show all mathematical calculations on a separate piece of paper. 1. Make a solution that is 350 ppm of food coloring.

2. Make a solution that is 10 ppb of food coloring.

3. Make a solution that is 0.2 ppb of food coloring.

4. Make a solution that is 200 ppt of food coloring.

What do you notice about the concentrations and calculations for both 3 and 4?


Activity Two 9

Best Answers for “Parts per” Lab How could I also say I have a 999 parts per thousand solution? Thinking of the solution as being water added to food coloring, I would have 999 parts water to 1 part food coloring- a total of 1000 parts—hence parts per thousand. Expressing parts per billion mathematically: (.000001)• (1 ml) = (concentration)• (1 ml ppm solution + 999 ml water)

.000001 ml = (concentration)• (1000 ml)

.000001/1000 = concentration [ml cancels]

Concentration is .000000001, which is one billionth, or one part per billion.

What is the designation for the solution you have just created? Parts per trillion (ppt) Expressing parts per trillion mathematically: (.000000001)• (1 ml) = (concentration)• (1 ml ppb solution + 999 ml water)

.000000001 ml = (concentration)• (1000 ml)

.000000001/1000 = concentration [ml cancels]

Concentration is .000000000001, which is one trillionth, or one part per trillion.

Make a solution that is 350 ppm of food coloring. First, convert 350 ppm to a concentration value by dividing 350/1,000,000 = .000350 Utilizing the ratio relationship and using the ppt solution:

(.001)• (unknown volume (ml) of ppt solution) = (.000350)• (250 ml)

unknown volume of ppt solution = [(.000350)• (250 ml)]/.001

unknown volume of ppt solution = 87.5 ml

(875 drops or measure to nearest mark on beaker then add drops for correct ml)

250 ml (beaker size) – 87.5 ml ppt solution = 162.5 ml water

999 parts water

1000 parts solution = .999


Activity Two 10

Make a solution that is 10 ppb of food coloring. First, convert 10 ppb to a concentration value by dividing 10/1,000,000,000 = .000000010 Utilizing the ratio relationship and using the ppm solution:

(.000001)• (unknown volume (ml) of ppm solution) = (.000000010)• (250 ml)


unknown volume of ppm solution = 2.5 ml (25 drops)

250 ml (beaker size) – 2.5 ml ppm solution = 247.5 ml water

Make a solution that is 0.2 ppb of food coloring. First, convert 0.2 ppb to a concentration value by dividing 0.2/1,000,000,000 = .0000000002 Utilizing the ratio relationship and using the ppb solution:

(.000000001)• (unknown volume (ml) of ppb solution) = (.0000000002)• (250 ml)


unknown volume of ppm solution = 50 ml


250 ml (beaker size) – 50 ml ppb solution = 200 ml water

Make a solution that is 100 ppt of food coloring. First, convert 200 ppt to a concentration value by dividing

200/1,000,000,000,000 = .0000000002 Utilizing the ratio relationship and using the ppb solution:

(.000000001)• (unknown volume (ml) of ppb solution) = (.0000000002)• (250 ml)


unknown volume of ppm solution = 50 ml


250 ml (beaker size) – 50 ml ppb solution = 200 ml water

What do you notice about the concentrations and calculations for both 3 and 4? The concentrations and calculations are the same because 0.2 ppb is equal to 200 ppt.


Activity Three 1

Activity Three Purpose: Modeling disposal methods and leachate produced.

Interpreting results and making correlations to real-life landfills.

Materials: • 3 clear plastic shoeboxes • Roll of white paper towels • 3 plastic cups • 12 cups fine gravel • Plastic trash bag • Construction paper • Water • Group direction handouts and Landfill Model question

sheets Preparation: Educator needs to perform the following tasks prior to the

student activity: (1) paint straight food coloring onto three sheets of craft-colored construction paper and let dry (2) cut three pieces of plastic bag large enough to cover bottom and halfway up the sides of the shoebox; make puncture holes (1”) intervals in two pieces of the plastic.

There will be three groups, each making one model. For large classes, divide into six groups with two groups making the same type model. Organize the model kits for each group. Each kit contains: One clear plastic shoebox, two squares of white paper towel, plastic cup, four cups fine gravel, kit directions, one "treated" sheet of construction paper, and three "untreated" sheets of construction paper. Kit one should contain one punctured piece of plastic bag. Kit two should have two pieces of plastic, one punctured and one not punctured. Kit three will not contain any plastic.

Method: Each group will construct the landfill model as directed on their kit's insert. As water is added to model, students will be able to observe color leaching through the gravel to the paper towels below. The color appearing below the landfill can be correlated to leachate carrying toxins into the environment surrounding landfills if they are not constructed in a way to limit contamination. Each model will have a different degree of colors bleeding through. Each group should answer questions on Landfill Model question sheet for their own kit and comparing with other kits following a class discussion on each group's results.


Activity Three 2

Group One Procedure Handout 1. Cut the sheets of paper from your kit into small pieces (1 cm squares) and mix them

together. Separate into three piles. 2. Place both pieces of paper towel in the shoebox in a way that the entire bottom is

covered. It is good if the paper towel also reaches up the sides of the box. 3. Line the bottom of the box with the piece of plastic with puncture holes. 4. Evenly spread one cup of gravel on top of the plastic. 5. Sprinkle one pile of paper squares on top of the gravel, and then repeat the gravel/paper

layers until all materials used up. 6. Write a hypothesis describing what you think will happen to the paper towel at the

bottom of your model. 7. At 5-10 minute intervals, evenly poor ¼ cup water over your landfill model. 8. Observe the paper towel at the bottom of the box by carefully picking the box up. Note

your observations on the lab worksheet. Some things to look for: pattern and pattern changes over time on the paper towel, changes with more water, where do changes occur on the paper towel, color of changes, intensity of color changes.


Activity Three 3

Group Two Procedure Handout 1. Cut the sheets of paper from your kit into small pieces (1 cm squares) and mix them

together. Separate into two piles. 2. Place both pieces of paper towel in the shoebox in a way that the entire bottom is

covered. It is good if the paper towel also reaches up the sides of the box. 3. Line the bottom of the box with the piece of plastic with puncture holes. 4. Evenly spread one cup of gravel on top of the plastic. 5. Sprinkle one pile of paper squares on top of the gravel, and then repeat the gravel/paper

layer. 6. Line the top of your landfill model with the non-punctured piece of plastic, then the last

cup of gravel. 7. Write a hypothesis describing what you think will happen to the paper towel at the




Activity Three 4

Group Three Procedure Handout 1. Cut the sheets of paper from your kit into small pieces (1 cm squares) and mix them

together. Separate into three piles. 2. Place both pieces of paper towel in the shoebox in a way that the entire bottom is

covered. It is good if the paper towel also reaches up the sides of the box. 3. Evenly spread one cup of gravel on top of the paper towel. 4. Sprinkle one pile of paper squares on top of the gravel, and then repeat the gravel/paper

layers until all materials used up. 5. Write a hypothesis describing what you think will happen to the paper towel at the




Activity Three 5

Landfill Model Worksheet Questions to be answered: 1. What happened to the white paper towel? 2. What does this represent in a real landfill? 3. What problems existed in your landfill and what does that represent

in the real world? 4. How are real landfills managed so as not to have the same problems? 5. List the differences in the construction of each group’s landfill. 6. How would these differences impact the environment? 7. Which system do you think is better and why? 8. Where do you think landfills should be located? Data Collection: After each water application, note any changes in the white paper towel. Use the following chart to record observations. Group Number: Application

Number Observation


Activity Three 6

LAB REPORT: A lab report contains an introduction, which describes the experiment and any information that is necessary to understand the experiment. Write an introduction that describes your model and a description of the other groups’ models. Also include your hypothesis. After the introduction, a paragraph that states the procedure of the experiment should be included. Describe: how you constructed the landfill model, what each part was supposed to represent, how much water was sprinkled each time, and what kinds of observations were made.

Tables of data are often included in scientific work so other scientists can repeat your experiment and compare their data with yours. Also, it is important for other scientists to be able to examine your data to think of new hypotheses to test. Recreate the data table and rewrite your observations very neatly so others will be able to understand what you saw. Label your table "Table 1." One of the most important parts of a scientific study is to interpret the data collected. Write a paragraph that answers all the questions in the question section of the lab report worksheet and compare and contrast the observations for your model and other groups’ models. Use specific examples from your data table in your analysis. The last paragraph of a report is a conclusion. This is where scientists state whether their hypothesis was supported or disproved. Then they state reasons why they think it was either supported or disproved. Write a paragraph that states your hypothesis and why it was supported or disproved. Also include a sentence or two describing something new that you have learned. Include a question about waste disposal that hasn't been answered by this experiment.



Educator Information Title: Landfills and Leachate Grade Level: Core Activity 7-8 + Expanded Activity 9-11 Content Areas: Mathematics, Science Performance Standards:

A.8.6 Use models and explanations to predict actions and events in the natural world.

B.8.6 Explain the ways in which scientific knowledge is useful and also limited when applied to social issues.


G.12.5 Choose a specific problem in our society, identify alternative scientific or technological solutions to that problem and argue its merits.

Overall Objective: To understand how a landfill is designed to protect the

environment while providing for waste management needs. Leachate will be introduced and investigated through the landfill model experiment and parts per million/billion/trillion are presented.

Solid & Hazardous Waste – Location and Sizing of Landfills

Activity One 1

Activity One THE LOCATION AND SIZING OF LANDFILLS

Purpose: To provide an understanding of the relationships between municipal waste generation and landfill capacity.

Materials: The Location and Sizing of Landfills Problems and Activities

worksheet.

Methods: Students should complete the worksheet exercises (an answer key is provided).


Activity One 2

The location and sizing of landfills Problems and Activities Each person in the state of Wisconsin generates approximately 3.1 pounds of municipal solid waste each day. Of this amount, approximately 19 percent of the waste is recycled in Wisconsin. Studies have shown that the maximum amount of waste which could be realistically recycled or otherwise diverted from the landfill is 25 percent. For a community/service area of 200,000 people, determine: 1. The amount of municipal solid waste generated each year, in pounds.

2. The amount of municipal solid waste generated each year, in tons.

3. The amount of municipal solid waste currently recycled each year, to the nearest pound.

4. The amount of municipal solid waste currently recycled each year, to the nearest ton.

5. The maximum amount of municipal solid waste which could realistically be diverted from the landfill, to the nearest pound.

6. The maximum amount of municipal solid waste which could realistically be diverted from the landfill, to the nearest ton.

7. Using the current rate of recycling calculate the amount of municipal solid waste sent to a landfill over a 15-year period, to the nearest pound.

8. If a landfill has a density of 1,200 pounds per cubic yard what would be the volume required to hold 15-years worth of municipal solid waste to the nearest cubic yard?

9. If the landfill is 1,000 feet wide and 65 feet deep what would be the final dimensions of the landfill described in question 8 to the nearest foot?


Activity One 3

The location and sizing of landfills Problems and Activities - Answer Key 1. The amount of municipal solid waste generated each year, in pounds.

3.1 lbs/person/day x 200,000 persons x 365 days/year = 226,300,000 lbs/year

2. The amount of municipal solid waste generated each year, in tons. 226,300,000 lbs/year x (1 ton/2,000 lb) = 113,150 tons/year

3. The amount of municipal solid waste currently recycled each year, in pounds. 226,300,000 lbs/year x 0.19 = 42,997,000 lbs/year

4. The amount of municipal solid waste currently recycled each year 113,150 tons/year x 0.19 = 21,499 tons/year

5. The maximum amount of municipal solid waste which could realistically be diverted from the landfill, in pounds. 226,300,000 x 0.25 = 56,575,000 pounds/year

6. The maximum amount of municipal solid waste which could realistically be diverted from the landfill, in tons. 113,150 tons/year x 0.25 = 28,288 tons/year

7. Using the current rate of recycling calculate the amount of municipal solid waste sent to a landfill over a 15-year period, in tons. 226,300,000 - 42,997,000 = 183,303,000 lbs/year 183,303,000 x 15 = 2,749,545,000 lbs = 1,374,773 tons

8. If a landfill has a density of 1,200 pounds per cubic yard what would be the volume required to hold 15-years worth of municipal solid waste? 2,749,545,000 lb x (1 yd3/1,200 lb) = 2,291,288 yd3

9. If the landfill is 800 feet wide and 40 feet deep what would be the final dimensions of the landfill described in question 8? 2,291,288 yd3 x (27 ft3/yd3) = 61,864,763 ft3 61,864,763 ft3 / (800 ft x 40 ft) = 1,933 ft by 800 ft by 40 ft


Activity Two 1

Activity Two Purpose: Background reading for information about how landfills are

located when taking into account environmental and social concerns.

Materials: The Location and Sizing of Landfills handout and Problems and Activities that follow.

Students will need access to an area map that shows sufficient detail of natural and man-made features. A USGS Quad that shows both rural features and some fringe of municipal development would serve well for this exercise.

Method: Each student should read the informational handout and complete the Problems and Activities individually or in groups. The expanded activity requires that students apply the information included in this activity to a situation presented in Activity One, problem 9.


Activity Two 2

The location and sizing of landfills Landfill Location Although our society continues to make great strides in reducing the amount of waste that we generate, there is still a large fraction of the waste stream that cannot be reused or recycled. This waste must ultimately be placed into a landfill. Realizing that landfills are a necessary part of our daily life, we need to be sure that we locate landfills in areas where they will not cause a negative impact upon the environment or people. To help ensure that landfills will not negatively impact the environment or people, both state and federal government agencies have developed setback distances from various types of land uses and natural features to provide additional protection beyond the engineered design of the landfill. The following discussion identifies some of the setback restrictions for landfill siting and the primary reasons for not constructing landfills within the setback area. Federal Siting Requirements The Federal siting requirements are developed by the United States Environmental Protection Agency (EPA). It is the responsibility of the EPA to develop regulations that protect human health and the environment from potential sources of contamination of the air, soil, and water. The siting regulations developed by EPA provide a minimum set of protective measures for all landfills in the United States. A. Distance from Airports Any landfill proposed to be located within 10,000 feet of an airport served by jet-engined aircraft, or 5,000 feet of an airport service by piston-engined (propeller) aircraft, must demonstrate that the landfill will not create a bird hazard to aviation safety. Additionally, any landfill proposed to be located within 5 miles of any airport must notify the Federal Aviation Administration (FAA) of the intent to site the landfill. Landfills are a popular gathering and feeding source for birds, especially gulls which are notorious scavengers. The reasons for this attraction include the availability of food to the birds and large open areas of land. The large open areas of land allow the birds to loaf without fear of predators and also contribute to the development of thermals. A thermal refers to the upward movement of air warmed by the earth. The birds will fly into these thermals and soar to heights of 1,000 to 2,000 feet, similar to the way a glider soars. While soaring on thermals, birds can place themselves into the same airspace used by aircraft on takeoff or landing at an airport. It is during takeoff and landing, while the plane is gathering power to get up in the air or decreasing power during landing, that the plane is most susceptible to damage. If the plane were to be struck, especially in the engine, during takeoff or landing, it could lead to a plane crash. Therefore, to avoid this potential for birds from landfills occupying the same airspace as airplanes on takeoff and landing, the 10,000-foot/5,000-foot setback distance was developed. B. Floodplain The term floodplain means the lowland and relatively flat areas adjoining inland and coastal waters, including flood-prone areas of offshore islands, that are inundated by the 100-year flood. In simple terms, this means the land which would be covered by runoff from a storm which had a certain amount of rainfall.


Activity Two 3

In a 100-year storm, a very large amount of rainfall lands in a very short period of time. This causes rivers, streams, lakes and ponds to spill over their normal banks and flood the low lying or relatively flat land surrounding them. If a landfill were located within the area which would be covered by such a flood, several things might result. The first problem which might occur is that the flood might carry garbage from the landfill away. This is called a "washout", and results in the floodwater being contaminated by the garbage from the landfill. The second thing that may happen is that a large amount of floodwater would be trapped in the landfill. This would saturate the garbage, creating large quantities of water called leachate inside of the landfill which would have to be removed and treated at a wastewater treatment plant. This could also cause the garbage inside the landfill to become unstable and susceptible to a sort of landslide. To avoid these types of problems, landfills cannot be located within a floodplain. C. Wetlands Wetlands provide several vital functions, including stormwater detention, sediment removal, and habitat for many different types of wildlife. These areas have the ability to reduce the amount of runoff, which comes from precipitation. This in turn reduces the amount of erosion caused by stormwater runoff. By slowing down the runoff and providing storage area, wetlands also provide a way for surface water to infiltrate back into the groundwater system. The plants found in wetlands also trap sediments, preventing them from going into surface waters such as rivers, streams, and lakes. Wetland plants also utilize nutrients found in these trapped sediments, which would otherwise be discharged into surface waters. Lastly, wetlands provide habitat to a wide range of plants and animals, contributing toward a more diverse ecosystem. Because of the benefits that wetlands provide, and due to their connection to the groundwater system, landfills should not be located within wetland areas. D. Faults Landfills cannot be located within 200 feet of any faults which have had displacement within Holocene time. A fault is a fracture or area of fractures in the earth. Displacement means the movement of one side of a fault relative to the other side in any direction. Holocene time refers to the most recent epoch of the Quaternary period, extending from the end of the Pleistocene Epoch to the present (approximately the last 11,000 years). The reason for not locating landfills near faults is basic. If the fault has moved recently, it may move again. Movement of the fault could cause the ground in which the landfill is constructed to move, creating ruptures or tears in the protective liner in the bottom of the landfill. This would provide a pathway for waste within the landfill to contaminate the underlying soil and groundwater. E. Seismic Impact Zones Landfills cannot be located within seismic impact zones unless the liners, leachate collection systems and surface water control systems are designed to resist the maximum anticipated horizontal acceleration in the earth expected at the site. A seismic impact zone is an area with a 10 percent or greater chance of experiencing a horizontal acceleration of 0.1 times the gravitational pull of the Earth (0.01 g) in a 250-year period. These areas are mapped by the United States Geological Survey (USGS).


Activity Two 4

Again, the reason for not locating landfills within seismic impact areas is basic. Seismic impact areas, or areas affected by earthquakes, have the ability for sudden earth movements which could damage or destroy the protective features of the landfill, such as the base liner or the leachate collection system. This would present a situation where waste or leachate from within the landfill could escape and potentially contaminate surface water or groundwater. F. Unstable areas Landfills cannot be located in unstable areas unless the landfill design demonstrates that the structural components (liner, leachate collection system, etc.) will not be disrupted. Unstable areas include areas which are susceptible to mass movement, such as landslides or avalanches, areas which have poor underlying soils, such as swamps, or other features such as Karst terrain. Karst terrain means areas which developed as the result of the dissolving of the underlying soluble bedrock. Karst terrain features include sinking streams, sinkholes, large underground spring or caves formed by water flowing underground, which dissolved the bedrock. As was the case with faults and seismic impact zones, the primary reason for not locating landfills in unstable areas is that if the protective layers were damaged by the unstable area, waste or leachate could escape the landfill and cause contamination. State Requirements In addition to the federal requirements developed by EPA, each state may have its own requirements developed by a state regulatory agency. In Wisconsin, the regulatory agency is the Department of Natural Resources (DNR). The DNR has all of the same siting restrictions as EPA as well as several which are their own. The DNR siting restrictions take into account more than just the environmental effects of a landfill, they also address the social aspects of a landfill. A few of the more important siting restrictions are addressed below. A. Distance to Navigable Surface Waters No landfill may be located within 1,000 feet of a navigable lake, pond, or flowage nor within 300 feet of navigable streams. There are two primary reasons for this setback restriction. The first is an environmental concern. The setback distance provides a separation between the landfill and surface water body in the event that there is a release from the landfill. Secondly, many surface water bodies are often used as recreation areas. The setback restriction provides a buffer area between the surface area and landfill to reduce the possibility of blowing paper and litter or odors from the landfill from affecting those using the surface water. B. Distance to Primary Highways and Public Parks No landfill may be located within 1,000 feet of a primary federal highway or public park boundary unless the landfill is screened by natural objects, plantings, fencing or other appropriate means so that it cannot be seen from the highway or park. The reason for this setback restriction is purely social. Landfills by their nature can be rather unsightly in the area where waste is being actively placed. The setback restriction, or need for berms and plantings, is in place to be sure that persons driving on the highway, or enjoying a public park, do not have to view waste being placed in the landfill. C. Distance to Private Wells No landfill may be placed within 1,200 feet of a public or private water supply well. This restriction is in place to ensure that drinking water supply from wells is not threatened by any potential releases from the landfill. This restriction may be removed by DNR if the landfill


Activity Two 5

operator produces information relative to soils at and around the landfill site and details of the well construction which show that the water supply would not be jeopardized by the landfill. Summary Regulations for siting landfills are prepared by both federal agencies, such as EPA, and state agencies, such as DNR. The reasons for including siting regulations include protection of the environment as well as our enjoyment of the land. The siting of landfills requires a comprehensive knowledge of several fields of physical science, including geology and engineering, as well as a strong background in social sciences to ensure that our health, the environment, and our enjoyment of our surroundings can coexist with our need for waste disposal through landfill usage. Sizing of Landfills The Wisconsin Department of Natural Resources (DNR) regulates the size of landfills in Wisconsin. This state agency also regulates the siting and operation of landfills to ensure that the health and safety of the public and the environment are protected. The regulations on landfill size are both environmental and social in the origins. Currently, Wisconsin landfills are designed to handle waste generated within the service area over a period of not less than 10, nor more than 15 years. Also, the community in which a landfill is to be located must be involved in negotiations with the landfill owner to ensure that the landfill owner addresses the community's concerns. During the planning stages of landfill development, the proposed landfill owner must demonstrate that the landfill is needed in an area. This needs assessment takes into account the effects of other waste management strategies, such as recycling, the size of the service area, and whether or not other landfills exist in the service area which could receive the waste. The needs assessment ensures that only the landfill space that is really needed is developed and encourages wise land use. By making landfills fall between the 10 to 15 year life expectancy, certain benefits are realized. The minimum life span helps to keep landfills large enough to be economically viable. This also makes sure that the community has a chance to bring up any concerns that they may have before another landfill can be sited in the community. Yet another reason for having a maximum life span of a landfill is to provide an easy mechanism for incorporating advances in landfill technology during the design of new landfills.


Activity Two 6

The location and sizing of landfills Problems and Activities - Landfill Siting Activity Using a USGS map provided by your instructor, locate and describe federal and/or state siting restriction features and log them below. Indicate the required setback distance from each of the restricted areas on the map. Also, identify areas in which landfills could be located and those in which landfills could not be located. Feature

(Township/Range/Section) Setback Distance

(if applicable) Locate Landfill

(Yes/No)

Example: T30N, R4E, Sec. 12 Burton Reservoir

1,200 feet (public water supply) Yes, if setback is observed

Expanded Activity: Determine whether or not there is sufficient space on your map to site the landfill described in question 9 of the problems in Activity One.



Educator Information Title: Location and Sizing of Landfills

Grade Level: Grades 9-11

Content Areas: Mathematics, Science

Performance Standards: A.8.6 Use models and explanations to predict actions and events in the

natural world.



G.12.5 Choose a specific problem in our society, identify alternative scientific or technological solutions to that problem and argue its merits.

Overall Objective: To understand the concepts related to landfill location and

construction and how they are applied to minimize impact upon the environment while providing for society’s waste management needs.

Solid & Hazardous Waste -- Recycling

Activity One 1

Activity One: Reading Activity – Automobile Recycling Purpose: Background information about automobile recycling and the

economics of recycling Materials: Automobile Recycling article and Reading Response Worksheet Method: Students should read the article and complete the worksheet

exercises. An expanded activity involves the student investigating the ability of

certain automobile parts to be recycled. Advanced exercises involve the consumption of energy for

automobile recycling.


Activity One 2

Automobile Recycling (adapted from Graedel and Allenby, Industrial Ecology and the Automobile) The recycling of an automobile occurs in several stages, each stage having its own actors (see Fig. 1). It begins when a vehicle is considered to be no longer suitable for service. The vehicle is transported to a dismantler, who removes components for which markets exist, such as:

usable body panels lead-acid battery wheels and tires radiator alternator Sometimes the lead-acid battery can be returned to a used-parts market, but usually it is sold to a lead processor, who extracts the lead and sells it to a battery manufacturer. A similar process occurs with the catalytic converter and with electronic components. The recent development of automotive electronics has resulted in limited recycling of electronic components, sometimes for the components themselves, sometimes for the precious metals they contain. The platinum group metals in catalytic converters are quite valuable. Thirty to thirty-five percent of all platinum is used in manufacturing catalytic converters. Some components of old automobiles can be reused directly and are immediately sold to spare-parts dealers: wheels, motors for power windows or seats, and radiators. Tires that are still road-worthy are reused; otherwise, they are recycled or incinerated. Others are reusable after reconditioning: alternators, air conditioners, and even entire engines. This is particularly important in cases where the engines and other components are no longer being manufactured, so recovered and reconditioned parts are the only effective way to keep older vehicles in service. After all readily usable or recyclable parts are recovered, the remaining vehicle (the hulk) is then sold to the shredder operator. The shredding operation is accomplished by large machinery that chops the hulk into small pieces

Fig 1: The Automobile Recycling

Car

Recovered Components

Steel

Shredder Residue

Aluminum Scrap

Zinc Scrap

Copper Scrap

Nonferrous Separator

Dismantler Hulk Shredder


Activity One 3

about 4 inches (10 cm) or so in length and a couple of pounds (1 kg) or so in weight. These pieces are then sent through a variety of operations that produce three output streams: Ferrous fraction: iron, carbon steel, stainless steel Non-ferrous fraction: aluminum, zinc, copper

Automotive shredder residue (ASR): Polymers (plastics) contaminated with metals, oil, or grease

Each of the three output streams goes to a further actor in the recycling sequence: Ferrous fraction → Steel Mill Non-ferrous fraction → Separator (where the different metals are separated for resale) ASR → Landfill In some countries, and in some cases, the ASR is processed and incinerated for energy recovery. Thus, depending on how far one wants to follow separated metals and resold parts, automobile recycling is a linked activity of between a dozen and two dozen independent participants, each with different roles, different technologies, and different mixes of automotive and non-automotive business. The automobile recycling system is very efficient at recovering vehicles at the end of their useful lives and reusing at least some of their parts and materials. About 95% of all vehicles are eventually involved in this process, compared with an estimated 63% of aluminum cans, 30% of paper products, 20% of glass, and less than 10% of plastics. A product that is recyclable may or may not be recycled. The distinction here is important: Recyclability refers to a product possessing properties such that it is technically possible

to recycle it. Recycling is the actual process of recovering materials, components, or other resources –

such as energy – from a recyclable product. Recycling has a strong dependence upon technology, but since it does not occur unless profits can be made by participants, it is also an economic activity. The automobile recycling process can be shut down at any step in the flow of materials if either the technology or the economics is unsatisfactory. For example, shredder operators sell scrap steel to steel mills, which recycle it. In the 1960s, most steel mills were of the open-hearth variety, which could produce steel with 40 – 45% scrap in the mix. In the 1970s, many steel makers switched to a new and more efficient technology, the basic oxygen furnace, which could only use 20 – 25% scrap. The result was a lowering in demand for scrap steel and a rapid accumulation of junked automobiles that were no longer economically attractive to recycle. The situation changed again in the 1980s as another new steel making technology, the electric arc furnace, became more popular. This new process could produce high-quality steel from mixes of 80% scrap or greater. Suddenly, the recycling of automobiles became much more economically advantageous. As you can see, the automobile-recycling infrastructure is complex and often is dependent upon forces not always directly related to automobile manufacturing and use.


Activity One 4

Reading Response Matching: place the number associated with a term below in the blank next to the appropriate definition. 1. lead 6. non-ferrous fraction 2. recyclability 7. separator 3. recycling 8. hulk 4. automotive shredder residue 9. dismantler 5. ferrous fraction 10. platinum _____ This is made up of polymers (plastics) contaminated with oils, grease and

metals. _____ A metal recovered from automotive batteries. _____ The remaining vehicle after processing by a dismantler. _____ The shredder output sold to steel mills. _____ Removes used automobile parts for which markets exist. _____ The shredder output that contains metals such as aluminum, copper and

zinc. _____ The properties of an item that make it technically possible to recycle. _____ A valuable metal recovered from catalytic converters. _____ The process that recovers non-ferrous metals from shredder output. _____ The actual process of recovering materials, components, or other

resources. True or False T F The ferrous fraction of the shredder output is sent to a landfill. T F The electric arc furnace made it possible to recover higher

percentages of steel scrap. T F Recycling is both a technical and economic activity. T F Polymers (plastics) contaminated with oil are sold to steel mills.


Activity One 5

T F Only 25% of all vehicles are eventually involved in the recycling

process. T F Lead is a highly-valued metal recovered from catalytic converters. T F A product that is recyclable may or may not be recycled.

Expanded Activity Look closely at the dashboard of an automobile and respond to the questions below: How many different types of materials are used in construction?

What problems can you anticipate in recovering materials?

What could be changed in the design of this part of a vehicle to encourage more efficient recycling?


Activity One 6

Advanced Exercises The average 1990’s automobile contains 65 kilograms (kg) of aluminum. Mining and processing bauxite into aluminum takes about 270,000,000,000 (270 x 109) Joules of energy (a Joule is a standard unit of energy) per metric ton (1,000 kg). Recycling aluminum has an energy cost of about 17 x 109 Joules per metric ton. 1. What is the energy cost of producing 1,000 automobiles from aluminum

processed from bauxite? 2. What is the energy cost of producing 1,000 automobiles from recycled

aluminum? 3. What is the energy cost of producing the estimated 15,000,000 automobiles

each year in North America from bauxite ore? From recycled aluminum?


Activity Two 1

Activity Two Reading Activity – Recycling Consumer Products Purpose: Background information about recycling and the economics of

recycling Materials: Recycling Consumer Products article and Reading Response

worksheet Method: Students should read the article and complete the worksheet

exercises. An expanded activity involves the student investigating the

recyclability of a manufactured consumer product.


Activity Two 2

Recycling Consumer Products (adapted from Graedel and Allenby, Design for Recycling) A 1991 Carnegie Mellon University research project on personal computer disposal estimated that by 2005, approximately 150 million obsolete PCs – none with readily recoverable materials – would be landfilled. The required landfill volume would be more than 8 million cubic meters and the total cost of disposing of these computers would be around $400 million. This is just one consumer item; similar statistics can be produced for things like washing machines, refrigerators, and automotive plastics. One thing all of these items have in common: They were not designed for recycling. What happens after a product’s useful life? Can it be reconditioned to be used again? Can it be taken apart in order to recover usable components or materials? Or is it too costly to pursue these options in either labor, materials, or energy?

In order to plan for the end of a product’s life, let’s first look at how products are recycled. The first way, closed-loop recycling (Fig. 1), involves reuse of the materials to make the same product over again. A typical example would be reusing the aluminum from aluminum cans to make new aluminum cans.

As Fig. 1 shows, in all recycling processes, not all material can be successfully recycled. A certain percentage is returned to the materials to be used in production, but a certain percentage is also going to be considered unusable, either before the recycling process or afterwards. Open-loop recycling (Fig. 2) reuses materials to produce a different product. An example of this would be to recycle office paper into brown paper bags.

Recycling Process

Virgin Materials

Production and Use

Collection for Disposal

Disposal Fig. 1 Closed-loop recycling


Activity Two 3

Fig. 2: Open-loop Recycling Whether closed-loop or open-loop recycling is used will depend on the materials and products involved. It generally takes less energy and labor to perform closed-loop recycling, but not all materials can be reused in the same process over and over again. Let’s look at the recycling of some common materials to illustrate this point. Recycling Paper Paper is made from a resource (trees) that can regenerate itself within a few decades. A significant fraction of paper products – around 30% -- is recycled. Paper recycling is a highly developed system consisting of several stages. At each stage, the fibers in the paper become shorter and less durable, restricting the range of acceptable uses. Generally speaking, paper fibers are recycled into lower and lower grades of paper. The normal cycle is from white bond to colored bond to newspaper to grocery bags to toilet paper. Recycling Plastics Given careful attention to design and materials selection, many of the plastics in industrial use can be recycled. This is particularly true of thermoplastics, which can be ground, melted, and reformulated with relative efficiency. Thermoplastics include the following, which are listed along with their recycling properties:

Production and use of

Product 1

Disposal of Product 1

Virgin Materials for Product 1

Disposal of Product 2

Production anduse of

Product 2

Virgin Materials for Product 2

Recycling Process


Activity Two 4

Polyethylene Terephthalate (PET) SPI Code #1 Properties: Toughness, clarity, low permeability. Applications: Soda bottles, vegetable oil bottles, liquor bottles, tennis ball containers, peanut

butter jars. Recycling Markets: Soda bottles*, carpet backing, carpets, fiberfill, strapping, non-food

bottles and containers, surfboards, sailboat hulls. * Requires FDA “non-objection” letter.

High Density Polyethylene (HDPE) SPI Code #2

Properties: Stiffness, low cost, ease of forming, resistance to breakage. Applications:

Blow-molded: Milk and water jugs (unpigmented); bleach, detergent, motor oil (colored). Injection-molded: Yogurt cups, butter tubs, bread trays, buckets, pails.

Recycling Markets: Detergent bottles, trash cans, soda bottle base cups, drainage pipe, animal pens, drums/pails, matting, milk bottle carriers, pallets.

Polyvinyl Chloride (PVC) SPI Code #3

Properties: One of the most versatile of all plastics because of high blending capability. Good clarity and chemical resistance.

Applications: Vinyl siding, water pipe, machine parts, wall coverings; Some bottles such as window cleaner, harsh household chemicals and some water bottles.

Recycling Markets: Drainage pipe, fencing, handrails, house siding, sewers/drains. Low Density Polyethylene (LDPE) SPI Code #4

Properties: Clear, inert, processing ease, moisture barrier. Applications: Film, some blow-molded bottles. Recycling Markets: Film for bags.

Polypropylene (PP) SPI Code #5

Properties: Low specific gravity, good resistance to chemicals and fatigue. Applications: Screw-on caps, snap-top lids, yogurt and margarine tubs, and syrup, ketchup

and salad dressing bottles. Recycling Markets: Auto battery case, bird feeders, furniture, pails, golf equipment, carpets,

recycling containers, industrial fibers. Polystyrene (PS) SPI Code #6

Properties: Clarity, ability to foam, ease of processing. Applications:

PS Solid: Eating utensils, yogurt and cottage cheese containers, salad containers, meat trays, clear drink cups and lids. PS Foam: Food containers, packaging, building and construction.

Recycling Markets: Insulation board, license plate frames, reusable trays. Other Resins/Multi-Layer Plastics SPI Code #7

Properties: ?? Applications: Mixed plastic bottles (many PP with ethyl vinyl alcohol content) and plastic

film, i.e. grocery bags, dry cleaning bags, stretch wrap and shrink wrap. Recycling Markets: Landscape timber, animal pens, road posts, pallets, marine pilings,

picnic tables.


Activity Two 5

The utility of recycling these materials is a function of their purity, which implies that the use of paint, flame retardants, and other additives should be minimized or avoided if at all possible. Having plastics of many different colors in a product limits recycling options, as well. Many product applications also require plastics to become coated with oils or grease while in use. Again, this type of contamination complicates recycling. Thermosets are plastics with far more complex chemical compositions. These are much more difficult to recycle as re-melting can change many of their physical properties. This group includes polyesters, silicones, phenolics, and epoxides, and they have many industrial and consumer product applications. Even if a recycler knows and understands all the relevant information needed to successfully recycle a particular plastic, it is often difficult to tell one plastic from another. The SPI codes listed with the thermoplastics on the previous page are becoming common markings on many plastic products internationally. However, when more than one type of plastic is used in a product, disassembly is a necessary step before recycling. Disassembly of plastic products – as well as other materials – prior to recycling can be an expensive and labor-intensive task if it is not planned as part of a product’s life cycle. Design for Disassembly There are two general methods of disassembly:

Reverse Disassembly: Removal of screws, other fasteners, or just unsnapping snap-fit parts. Irreversible Disassembly: Cutting or breaking into pieces.

Neither of these methods is preferable to the other. The point is to reduce a part into pieces that can be readily recycled. Parts that are assembled with special tools or have been coated with paint, oil, or grease often create problems in disassembly. Designers of products can greatly reduce the “end-of-life cost” of a product (that is, the cost of disassembly for recycling or even disposal) by making sure that the product can be disassembled in as few steps as is possible. Designing for disassembly means that manufacturers need to clearly identify that materials used in a product. This can be done by labeling parts with standardized identification markings, such as the SPI codes for plastics. Does Recycling Always Make Sense? It is not automatically sensible to recycle all products. There are often trade-offs and the decisions of whether or not to recycle and how to recycle should be made after thoroughly analyzing the situation. In particular, performing recycling should not result in greater environmental impact than not performing recycling. The costs associated with transporting material frequently make the recycling process too expensive. If parts have to be collected from many sites – as is often the case – transportation costs can rapidly mount and soon outweigh any benefit derived from recovering the material. Any recycling analysis must consider the full range of impacts, including the value of the recovered materials, the alternatives methods of recycling, or the option of not recycling at all. Not recycling may seem wrong, but unless it can be shown that that the economic and environmental cost of recovering a material does not exceed the benefits derived from recycling, it may be best solution until markets improve or the technology changes. Manufacturers can assist in improving the viability of recycling by making products from parts that have established markets for recovered materials, and by considering disassembly in their design.


Activity Two 6

Reading Response Matching: place the number associated with a term below in the blank next to the appropriate definition.

1. closed-loop recycling 6. thermoplastics 2. open-loop recycling 7. PET 3. thermosets 8. SPI Code 4. end-of-life cost 9. reverse disassembly 5. HDPE 10. irreversible disassembly

_____ A thermoplastic used in soda bottles that can be recycled into carpets and carpet backing. _____ Recovering and reusing materials to produce a different product. _____ These can be ground, melted, and recycled with relative ease. _____ Taking a product apart by removing screws or other fasteners. _____ The cost of disassembly for recycling or disposal. _____ A thermoplastic used in detergent bottles that is often recycled into detergent bottles. _____ Recycling a material to make the same product again. _____ A standard marking to identify plastics. _____ These plastics are technically far more difficult to recycle. _____ Taking a product apart by cutting or breaking it. True or False T F Identifying materials is an important part of recycling. T F Transportation costs rarely have any impact on recycling. T F It is always a good idea to recycle any material. T F Paper fibers are recycled into lower and lower grades of paper. T F In closed-loop recycling, no material is considered unusable at any time in the

process. T F Having plastics of many different colors in a product limits recycling options. T F Reverse disassembly is always preferred over irreversible disassembly.


Activity Two 7

Expanded Activity Choose a fairly complicated consumer item, such as a bicycle, a microwave oven, a personal computer, or a refrigerator and perform a Design for Recycling Analysis on it using the following questions (Your responses should be based upon what is easily observable. Do not disassemble the product!) :

• How many different types of materials can you identify in the product?

• Are the materials marked or labeled in any way to assist with identification?

• Are dissimilar materials fitted together in ways that will be difficult to disassemble? (for example, threaded metal inserts in plastics)

• Are plastic parts painted or otherwise coated?

• Has the product been assembled with fasteners such as screws, clips, or hook-and-loop attachments rather than with chemical bonds or welds?


Activity Three 1

Activity Three Recycling Tires Purpose: An overview of the current state of tire recycling in the United

States along with some of the technical and economic hurdles encountered in the process.

Materials: Reading What to Do with Old Tires? and Reading Response worksheet

Method: Students should read the article and complete the worksheet exercises. Form small groups to do the Group Discussion exercise and compare the results of each group’s conclusions.


Activity Three 2

What to Do with Old Tires? (Sources: Graedel, T.E. and B.R. Allenby. Design for Environment. Prentice-Hall.

1996. Katers, John D. and Mary G. Kohrell. Waste Tire Market Update. Solid and Hazardous Waste Education Center (SHWEC) Issue Paper. 2000)

Old tires are good objects of focus to learn about disposal and reuse. The numbers are staggering – the United States alone throws away 250 million tires every year. For decades these tires were dumped in landfills and other less suitable places, but limited landfill capacity and a feeling that there must be better alternatives are gradually changing that approach. Retreading tires is useful in lengthening service life, but this process merely delays the inevitable. Data compiled by tire manufacturers in Spring, 2000 indicated that even if tire manufacturers could incorporate 10 percent recycled rubber in new tires, this would only consume about 27 million old tires each year, leaving a very large balance to be managed in some other way. Research into increasing the amount of recycled rubber in tires is ongoing, but it may be years before it has an impact on the marketplace. Whole used tires are often exported. By some estimations, about five percent of the total volume of discarded tires – about 15 million units per year – are shipped to overseas markets. Scrap tires are often used in agricultural applications. They are used to weigh down covers on haystacks, over silage, or for other purposes where an easily handled weight is needed. Tires can be used as feeding stations or to protect fence posts or other structures from damage from livestock. They are also used in erosion control and other land retention purposes. It is estimated that about 2.5 million scrap tires are used in agriculture each year in the U.S. Upon eventual disposal, a fraction of today’s old tires are sent to modern facilities that shred and separate them into three flow streams:

• Small tire chunks • Steel shards • Crumb rubber

The steel is easily recycled. The crumb rubber is burned for energy (each tire contains the equivalent of more than 8 liters of recoverable petroleum). The chunks see a variety of uses:

• Running tracks • Rubber boots • Rubberized asphalt, etc.

The main challenge in recycling tires lies in separating the chunks from the steel and the crumb. This is most frequently done with mechanical shredders. More innovative techniques are being used and tested, such as freezing the tires with liquid nitrogen prior to grinding them, which makes them break apart more efficiently. Tire recycling technology is improving, but it is not keeping up with the overwhelming supply of old tires. The reason is primarily economic. Recycling of tires only occurs when it is profitable and, unfortunately, energy, transportation, and labor costs of recycling tires often far outweigh any economic benefit that will be realized from the process.


Activity Three 3

Currently, tires are not designed with recycling in mind, nor do the laws in many states help with this process. Legislation often prohibits the burning of tires in incinerators, even though the petroleum from which tires is made is an approved fuel. If those laws can be altered to allow for safe burning for energy recovery, it may provide the economic incentive to design tires that burn more efficiently while releasing little pollution. Perhaps if the economic incentives for reuse of a tire’s components could be improved – recycling deposits have been proposed in some areas – tires could be made that could be more easily separated into its recyclable components. Solving the old tire problem will take a cooperative effort by the recycling industry, tire designers, economists and even politicians. Reading Response True or False T F Tire recycling is usually a very profitable business. T F Crumb rubber can be burned for energy. T F Scrap tires always have to be shredded in order to be reused. T F It is currently possible for tire manufacturers to reuse all of the

recycled rubber from old tires. T F Chunks of tire rubber may be recycled as an asphalt component. T F There are many agricultural applications for used tires. T F Recycling old tires is strictly an economic issue and not a political

problem. Group Discussion Think of all of the materials that go into making a tire. List some design changes that could increase recyclability.



Educator Information Title: Recycling Grade Level: Middle School / High School Content Areas: Mathematics, Science Performance Standards:

A.8.1 Develop an understanding of science themes by using the themes to frame questions about science-related issues and problems.


H.8.2 Present a scientific solution to a problem involving the earth and space, life and environment, or physical sciences and participate at a consensus-building discussion to arrive at a group decision.

H.8.3 Understand the consequences of decisions affecting personal health and safety.

A.12.1 Apply the underlying themes of science to develop defensible visions of the future.

H.12.1 Using science themes, and knowledge of earth and space, life and environment, and physical science, analyze the costs, risks, benefits, and consequences of a proposal concerning resource management in the community and determine the potential impact of the proposal on life in the community and the region.

H.12.2 Evaluate proposed policy recommendations (local, state, and/or national) in science and technology for validity, evidence, reasoning, and implications, both short and long term.

H.12.3 Show how policy decisions in science depend on many factors, including social values, ethics, beliefs, time-frames, and considerations of science and technology.

H.12.4 Advocate a solution or combination of solutions to a problem in science or technology.

Solid and Hazardous Waste

Glossary 1

Glossary 20-60-20 Rule There is often a small sector of residents (20%) who will

begin backyard composting initially just because they know that it is a beneficial activity for them and for the environment. Sixty percent of the population needs to be reached by either word of mouth, advertising, or through hands-on workshops before they begin composting. The remaining 20% of the population will not participate no matter how much education they receive.

Anaerobic Decomposition occurring in the absence of oxygen. An oxygen level of greater than 5% is needed otherwise anaerobic conditions can occur. This will result in the generation of malodorous compounds, which can be detected by the human nose as a pungent odor.

Aquifer A geological formation, group of formations, or portion of a formation capable of yielding significant quantities of groundwater to springs or wells.

Carcinogenic A substance, which can cause cancer.

Cells A confined portion of the landfill site in which refuse is spread and compacted in thin layers; several layers may be compacted on top of one another to a maximum depth of about 10 feet (3 meters).

Closed-Loop Recycling Involves reuse of the materials from disassembled products to make the same product over again.


Glossary 2

Composting The controlled decomposition of organic matter by microorganisms into a humus-like product (see below for humus). Composting is a natural process to stabilize biologically decomposable organic material.

Conductivity Ability to conduct electricity; indirect measurement of dissolved ions.

Crumb Rubber By-product of tire recycling. It is often burned for energy recovery.

Hazardous Wastes Industrial and hospital waste is considered hazardous as they may contain toxic substances. Certain types of household waste are also hazardous. Hazardous wastes could be highly toxic to humans, animals, and plants; are corrosive, highly inflammable, or explosive; and react when exposed to certain things e.g. gases.

Humus Essentially the same as compost, it is produced from the carbon content of organic material while water and carbon dioxide dissipate into the atmosphere. The forest floor is a natural compost system that creates humus by decomposing leaf and other material, thereby recycling nutrients and conditioning the soil.

Inorganic Compounds not based on hydrogen and carbon structures.


Glossary 3

Irreversible Disassembly Products that are not easily separated into components, so they are taken apart by cutting or breaking into pieces.

Landfill (Sanitary Landfill) A specially engineered site for disposing of solid waste on land, constructed so that it will reduce hazard to public health and safety. Some qualities include an impermeable lower layer to block the movement of leachate into ground water, a leachate collection system, gravel layers permitting the control of methane, and daily covering of garbage with soil.

Leachate Highly contaminated liquid that is the result of runoff that infiltrates the refuse cells and comes in contact with decomposing garbage.

Macroorganisms Large organisms (as compared to microorganisms), like earthworms, isopods, or millipedes that also aid in the composting process.

Microorganisms Organisms too small to be seen without a microscope or magnifying glass, like bacteria or fungi, which occur naturally in the soil or old compost.

Municipal Solid Waste Municipal solid waste consists of household waste, construction and demolition debris, sanitation residue, and waste from streets. This garbage is generated mainly from residential and commercial complexes.


Glossary 4

Open-Loop Recycling The reuse of materials from disassembled products to make a different product.

Organic Referring to or derived from living organisms. In chemistry, any compound containing carbon.

Percolate To ooze or trickle through a permeable substance. Groundwater may percolate into the bottom of an unlined landfill.

pH A measurement of the acidity or alkalinity of a solution.

Protective Liner Layer of compacted clay or impermeable materials such as plastic at the bottom of a landfill to prevent ground water contamination.

Recyclability Refers to a product possessing properties such that it is technically possible to recycle it.


Glossary 5

Recycle The process of collecting materials from the waste stream and separating them by type and recovering materials, components, or other resources, such as energy. Recyclables could also be remade into new products or reusing the materials as new products.

Reduce To lessen in extent, amount, number or other quantity

Reuse Extending the life of a product by finding an additional use for it without significantly altering its composition. This new use may or may not be related to the product’s original purpose.

Reverse Disassembly Products that can be taken apart by reversing the assembly process, such as by the removal of screws, other fasteners, or just unsnapping snap-fit parts.

Solid Waste Material that has been discarded because it has worn out, is used up, or is no longer needed, such as packaging, newspapers and used writing paper, and broken appliances.

Thermoplastics Common consumer or industrial plastics, which can be ground, melted, and reformulated for recycling with relative efficiency.


Glossary 6

Thermosets Plastics with far more complex chemical compositions. These are much more difficult to recycle as re-melting can change many of their physical properties.

Total Dissolved Solids Measurement of dissolved materials in solution.

Volatile Organic Compound Organic compounds which evaporate quickly. They are most times toxic or carcinogenic.

Working Face Portion of a landfill cell that is currently exposed and available for trash disposal.

Yard Trimmings Grass, leaves, and tree and brush material. These can make up a significant part of total municipal waste with large seasonal variations in volume and characteristics.

Yard Waste Solid waste generated as a result of activities such as gardening, lawn mowing or leaf collecting.

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