Waste

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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.
































Solid & Hazardous Waste – Generation and Collection of Solid Waste
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.






Solid & Hazardous Waste – Generation and Collection of Solid Waste
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.)











Solid & Hazardous Waste – Generation and Collection of Solid Waste
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.
Solid & Hazardous Waste – Generation and Collection of Solid Waste
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.



































Solid & Hazardous Waste – Generation and Collection of Solid Waste
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.
Solid & Hazardous Waste – Generation and Collection of Solid Waste
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.)
Solid & Hazardous Waste – Generation and Collection of Solid Waste
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.














Solid & Hazardous Waste -- Composting
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.


Solid & Hazardous Waste -- Composting
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.
Solid & Hazardous Waste -- Composting
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.








Solid & Hazardous Waste -- Composting
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.










Solid & Hazardous Waste -- Composting
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.





Solid & Hazardous Waste -- Composting
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



Solid & Hazardous Waste -- Composting
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.








Solid & Hazardous Waste -- Composting
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.




























Solid & Hazardous Waste -- Composting
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?













Solid & Hazardous Waste -- Composting
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?)














Solid & Hazardous Waste -- Composting
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 8
th
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.

Solid & Hazardous Waste -- Composting
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.















Solid & Hazardous Waste -- 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.
Solid & Hazardous Waste -- Composting
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.
Solid & Hazardous Waste -- Composting
Educator Information 1
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.

Solid & Hazardous Waste -- Composting
Educator Information 2
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
Solid & Hazardous Waste -- Composting
Educator Information 3
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
Solid & Hazardous Waste -- Composting
Educator Information 4
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
Solid & Hazardous Waste -- Composting
Educator Information 5
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).
Solid & Hazardous Waste -- Composting
Educator Information 6
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
Solid & Hazardous Waste -- Composting
Educator Information 7
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
Solid & Hazardous Waste -- Composting
Educator Information 8
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
Solid & Hazardous Waste -- Composting
Educator Information 9
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.

Solid & Hazardous Waste -- Composting
Educator Information 10
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.

















Solid & Hazardous Waste – Household Hazardous Waste
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.

Solid & Hazardous Waste – Household Hazardous Waste
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.


Solid & Hazardous Waste – Household Hazardous Waste
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.






























Solid & Hazardous Waste – Household Hazardous Waste
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.

Solid & Hazardous Waste – Household Hazardous Waste
Educator Information 1
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.



Solid & Hazardous Waste – Household Hazardous Waste
Educator Information 2
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.
Solid & Hazardous Waste – Household Hazardous Waste
Educator Information 3
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.






























Solid & Hazardous Waste – Landfills and Leachate
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
Solid & Hazardous Waste – Landfills and Leachate
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?



Solid & Hazardous Waste – Landfills and Leachate
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.








Solid & Hazardous Waste – Landfills and Leachate
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
Solid & Hazardous Waste – Landfills and Leachate
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.

Solid & Hazardous Waste – Landfills and Leachate
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.
Solid & Hazardous Waste – Landfills and Leachate
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
Solid & Hazardous Waste – Landfills and Leachate
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 to
underlying groundwater
Solid & Hazardous Waste – Landfills and Leachate
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
Cadmiu
m
Probably cancer causing; toxic to developing embryo; affects nervous system,
reproductive and lung/respiratory; kidney damage
Chromiu
m
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
Solid & Hazardous Waste – Landfills and Leachate
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.
Solid & Hazardous Waste – Landfills and Leachate
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.

Solid & Hazardous Waste – Landfills and Leachate
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
Solid & Hazardous Waste – Landfills and Leachate
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?
Solid & Hazardous Waste – Landfills and Leachate
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
Solid & Hazardous Waste – Landfills and Leachate
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 ppt solution = [(.000000010)•(250 ml)]/.000001
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 ppt solution = [(.0000000002)•(250 ml)]/.000000001
unknown volume of ppm solution = 50 ml
(500 drops or measure to nearest mark on beaker then add drops for correct 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 ppt solution = [(.0000000002)•(250 ml)]/.000000001
unknown volume of ppm solution = 50 ml
(500 drops or measure to nearest mark on beaker then add drops for correct 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.

Solid & Hazardous Waste – Landfills and Leachate
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.
Solid & Hazardous Waste – Landfills and Leachate
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.



Solid & Hazardous Waste – Landfills and Leachate
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
bottom of your model.
8. At 5-10 minute intervals, evenly poor ¼ cup water over your landfill model.
9. 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.

Solid & Hazardous Waste – Landfills and Leachate
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
bottom of your model.
6. At 5-10 minute intervals, evenly poor ¼ cup water over your landfill model.
7. 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.


Solid & Hazardous Waste – Landfills and Leachate
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





Solid & Hazardous Waste – Landfills and Leachate
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.


Solid & Hazardous Waste – Landfills and Leachate
Educator Information 1
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.
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.
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).































Solid & Hazardous Waste – Location and Sizing of Landfills
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?

Solid & Hazardous Waste – Location and Sizing of Landfills
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 yd
3

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 yd
3
x (27 ft
3
/yd
3
) = 61,864,763 ft
3

61,864,763 ft
3
/ (800 ft x 40 ft) = 1,933 ft by 800 ft by 40 ft

Solid & Hazardous Waste – Location and Sizing of Landfills
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.


























Solid & Hazardous Waste – Location and Sizing of Landfills
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.
Solid & Hazardous Waste – Location and Sizing of Landfills
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).

Solid & Hazardous Waste – Location and Sizing of Landfills
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
Solid & Hazardous Waste – Location and Sizing of Landfills
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.









Solid & Hazardous Waste – Location and Sizing of 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.
Solid & Hazardous Waste – Location and Sizing of Landfills
Educator Information 1
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.
B.8.6 Explain the ways in which scientific knowledge is useful and also
limited when applied to social issues.
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.
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.

























Solid & Hazardous Waste -- 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
Solid & Hazardous Waste -- Recycling
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.

Solid & Hazardous Waste -- Recycling
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.
Solid & Hazardous Waste -- Recycling
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?









Solid & Hazardous Waste -- 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 10
9
)
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 10
9
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?

Solid & Hazardous Waste -- Recycling
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.





























Solid & Hazardous Waste -- Recycling
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
Solid & Hazardous Waste -- 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 and
use of
Product 2
Virgin Materials
for Product 2
Recycling
Process
Solid & Hazardous Waste -- Recycling
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.

Solid & Hazardous Waste -- Recycling
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.
Solid & Hazardous Waste -- Recycling
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.

Solid & Hazardous Waste -- Recycling
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?
Solid & Hazardous Waste -- Recycling
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.



























Solid & Hazardous Waste -- Recycling
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.

Solid & Hazardous Waste -- Recycling
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.
Solid & Hazardous Waste -- Recycling
Educator Information 1
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.
B.8.6 Explain the ways in which scientific knowledge is useful and
also limited when applied to social issues.
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.
Solid and Hazardous Waste
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.
Solid and Hazardous Waste
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.
Solid and Hazardous Waste
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.
Solid and Hazardous Waste
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.
Solid and Hazardous Waste
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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