Field Trips

Trash Talk

Grade Level:
Middle School: Sixth Grade through Eighth Grade
Subject:
Math,Science
Common Core Standards:
6.L.1, 6.L.2, 6.L.3, 7.L.1, 7.L.2.b, 7.L.3
State Standards:
Science: VA – LS.1; MS-ESS3-3; HS-LS2-4
English-Language Arts: MD - SL1.c
Mathematics: VA - DS.12

Feature Description - Lesson Overview

This is a self-facilitated field trip at the Chesapeake and Ohio Canal National Historical Park. In this program, students will learn about biodegradation and decomposition and consider how these processes factor into the impacts human waste production and littering have on the environment. Students will pick up trash in the C&O Canal NHP as an act of service while practicing data collection by recording the types of trash they collect. Students will use the data they collect to better understand the kinds of litter they removed from the park in the context of biodegradation rates and their local recycling program policies. This 60 to 120-minute program is designed to be appropriate for grade 6-12 students and done in all seasons. Word or PDF versions of this lesson plan can be requested by emailing cocanaleducation@nps.gov.

Essential Questions

  • What types of trash are present in the C&O Canal NHP?

  • What happens to manmade materials left in a natural environment? 

  • What roles do decomposition and biodegradation play in waste management? 

Learning Objectives

Students will be able to...

  • Collect and dispose of litter safely

  • Create a data collection sheet and use it to collect data

  • Explain the roles decomposition and degredation play in waste management

  • Familiarize themselves with the policies of their local recycling program

Thinking Skills

  • Critical Thinking

  • Compare and Contrast 

  • Analysis - Evaluate and Synthesize information and data

  • Data Collection

Background Information

  • This is a fully self-guided field trip and will be planned and led by school staff and not NPS park staff.  

  • This field trip can be completed at any location within the Chesapeake and Ohio Canal NHP.  We recommend several sites, such as Fletcher’s Cove, Monocacy Aqueduct, Williamsport, or Spring Gap for this field trip, or another site which you prefer. 

  • If you choose the Great Falls Tavern area of the park in Potomac, MD there is an entrance fee. This is the only entrance fee for locations in the park. There are academic fee waivers available. To learn more about this process or to get the application, e-mail cocanaleducation@nps.gov.  

  • All necessary background and content can be found in the pre-field trip activity and the instructions for the trash collection activity. 

Vocabulary

  • Biodegradable - the ability to be broken down especially into innocuous products by the action of living things (such as microorganisms)

  • Decomposition - the act of breaking up into constituent parts by or as if by a chemical process

  • Litter - trash, wastepaper, or garbage laying scattered about

  • Microorganism - an organism (such as a bacterium or protozoan) of microscopic or ultramicroscopic size

Materials

  • Notebook OR paper and clipboard for data collection sheet

  • Writing utensils

  • Gloves (recommended; check for latex allergies)

  • Trash bags (1 per student or 1 per group + extras if bags get full)

  • Hand sanitizer

  • (Optional) trash grabbers

  • Post-Field Trip Activity Materials:

    • Calculator

    • Scratch paper and writing utensil

    • OR Electronic devices with Excel or other spreadsheet application (optional)

Procedure

Lesson Hook/Introduction (5 min)

Welcome students to the Chesapeake and Ohio Canal National Historical Park! Explain where this part of the park is in relation to where the students have come from (miles away, direction, etc.) and explain that this is just a part of the 184.5-mile-long canal that runs along the Potomac River.  

Discussion (10 min)

Explain to students that the C&O Canal NHP is a trash free park.  This means that the park encourages all visitors to practice Leave No Trace principles, and there are not trash cans in the park for visitors to deposit trash.  Visitors are expected to take trash home with them.  Ask students to get into the groups they were in for the pre-field trip activity and brainstorm ways trash could get into a park like the C&O Canal despite being trash free. Have students share their answers. Possible answers include: park visitors bring trash in and leave it in the park on purpose or by accident; trash from people stays at lockhouses and campgrounds can be improperly disposed of; when trash is collected it flies out of trucks and gets into waterways or is carried by wind and can end up in the park; animals like raccoons can access and spread unsecured trash into the environment; flooding can carry trash into the park.  

Activity: Collect trash and data (45-60 min)

  • Have students get out the data collection sheet and explain how students will be collecting data. Will one person do all the recording, or will they take turns? 

  • Distribute a trash bag to every group or individual along with any other trash collecting materials to groups including gloves and trash grabbers. 

  • Go over procedures with students: 

    • The C&O Canal National Historical Park is a place that is protected to preserve the history, the ecosystems, and the recreation opportunities of the canal. As stewards of a park, we are an important part of this process.  Today we are doing our part by helping to clean up trash we find in the park to leave the park better than we found it for future visitors. 

    • Set the boundaries for how far you want students to go along the towpath or established hiking trail for the area you are visiting.  Remind students of the Leave No Trace principles, which includes staying on the trail. Give students the time you want them to report back and the location for them to return to.  We recommend each group have a chaperone with them.  This will help keep the small groups together safely.  Give students 30-60 minutes to collect trash and gather their data. Throughout your exploration, you will pick up any trash you see, record the quantity and type of trash it is on your data sheet, and place the trash in your trash bag.  

    • There are important safety considerations to keep in mind while you’re collecting trash because your safety is the most important thing. Remember, no piece of trash is worth getting hurt. First, avoid collecting any trash that requires climbing or a risk of falling. If you can see the trash, you can record it on your data sheet without collecting it. The same principle applies for sharp or hazardous trash like broken glass or needles. Never attempt to pick up anything sharp and risk getting cut. You may record it on your data sheet without touching it. Be aware of metal debris that might have sharp edges or be rusted after sitting in water from a flood.  If you find oversized trash, for example a barrel, do not attempt to remove the item.  Report large trash items to the park staff for safe removal of these items. Make sure you drink water, especially on warm days, to prevent dehydration during your collection. On the towpath, be careful and aware of other people using the towpath to avoid collisions. Avoid reaching into unknown plants with hands, especially without gloves, to prevent exposure to poison ivy which is found in the park, and to avoid contact with snakes or biting insects or animals. 

    • There will not be somewhere for you to dispose of your bags at the park.  Tie off your trash bags and take them with you out of the park. Dispose of them according to your school procedures for trash, such as in the school’s dumpster. Encourage students to use hand sanitizer at the end of the field trip and then wash their hands well with soap and water once you have completed the disposal of your trash if you have a park comfort station near your location. Remind students to keep their data sheets to use in the post-field trip activity.  

    • Thank you for helping to be stewards of the Chesapeake and Ohio Canal NHP and assisting with cleaning up a section of the park! 

Lesson Conclusions (10 min)

If time permits, before getting back on the bus and returning to school, have the students reflect with the following questions:

  • How much trash did your group collect? Was it more than you expected?

  • Were there any types of trash that surprised you? Something you were not expecting to find or that was in higher quantities that you expected?

  • Was there anything challenging about the data collection process? Is there anything you would have done differently if you did this again?

  • Why is the work we did important to the park? The environment of the canal ecosystem?

Park Connections

This lesson and its activities connect to the themes and mission of the Chesapeake and Ohio Canal National Historical Park by exploring the ways in which the park has been changed and has adapted to human trash production. Students learn how people interact with the canal by creating litter and how the natural environment adapts through biodegradation. Students also learn about and experience the canal as a place of refuge and work to preserve this by collecting trash and removing it from the park.  

Pre-Field Trip Activity

During the field trip and post-field trip activity, students will be collecting their own data by categorizing and quantifying the litter they pick up and then analyzing the data. In order to prepare for the activities, students will need some important background information and will need to design their data collection sheets to bring on the field trip. 

Procedure

  • Start by going over important topics:

    • What happens to litter that ends up in environments it doesn’t belong in? Does it ever go away? Answer: It depends on the material of the litter, but most will not readily go away naturally. Once exposed to microorganisms like bacteria, litter may decompose. Decomposition is the act of breaking something up into constituent parts by or as if by a chemical process. In this context, we are talking about biological decomposition which is when microorganisms like bacteria and protozoa break materials down. We can see how long it would take different kinds of litter to biodegrade (be broken down by microorganisms) in this chart that uses U.S. Forest Service data:

      Trash Type Time to Biodegrade
      Apple core/Orange peel 2 – 4 weeks
      Newspaper 2 – 4 weeks
      Paper towel 2 – 4 weeks
      Plain cardboard (unwaxed) 3 months 
      Cotton cloth 3 – 6 months
      Rope 1 year 
      Cigarette 1 – 5 years
      Milk Carton (waxed) 5 years
      Disposable diaper 10 – 20 years
      Steel can 80 – 100 years
      Aluminum can 200 – 400 years
      Resealable plastic bag 300 years
      6-pack plastic rings 400 years 
      Plastic bottle 450 years
      Monofilament fishing line 600 years
      Glass bottle Thousands to millions of years 
      Styrofoam Unknown/never

    • What are good data collection techniques? Answers: Consistency and standardization of methods; record conditions when data is collected; decide how to collect data before starting field work (not during); leave extra space in records for notes or additional data 

  • Next, break students into groups that they will be in on their field trip. Group size will depend on the size of the class, but generally groups with 3-6 students will be appropriate for this field trip. 

  • Once in groups, ask students to make one data collection sheet per group. This can be in someone’s notebook or on a separate piece of paper. They will document the amounts of different kinds of trash they pick up on the field trip on this sheet. You may want to remind students to include comprehensive categories and consider leaving room for other types of trash they didn’t predict they would find. Put the table of biodegradation rates on the board to remind students of different categories of litter.  

  • Make sure students choose who will be responsible to bring the data sheet on the field trip.  

Example Data Collection Sheet:

Type of trash 

Quantity    

(room for additional columns)   

Newspaper 

 

 

6-pack plastic rings 

 

 

Ziploc bag 

 

 

Cigarette 

 

 

Glass bottle 

 

 

Fishing line 

 

 

Aluminum can 

 

 

Apple core/orange peel 

 

 

Rope 

 

 

Additional observations: 

 

 

Post-Field Trip Activity: Analyze the Trash

Now that students have data on the trash they collected in the park, it is time to analyze that data and think critically about it!    

In this activity, we will be looking at local recycling practices in your county and using that to determine how much of the trash collected was recyclable where you live. Then, using the biodegradation chart given in the pre-field trip activity, we will determine the average biodegradation rate of the litter each group collected. If students have access to laptops or computers, it may be helpful to organize their data in an Excel sheet or other spreadsheet and use the computer for calculations instead of a calculator. Note that to find averages and use the functions on these applications, the data would need to be in a long format – there would need to be one row for every piece of trash not one row for every type of trash. See the Procedure (with computers) for detailed instructions.  

Procedure (without computers)

  1. Make sure your datasheet is easily readable. If you used tally marks, make sure you have totaled the amount of each kind of trash so you have numbers readily available. If you need to formally add new categories, do that now. An example datasheet is found below. 

  2. Add a column to your data sheet called “Recyclable”. In this column you will put “yes” or “no” based on if that item can be recycled in your county. The teacher should look up the county’s recycling standards and put them on the board viewed by all students or printed out and distributed to students so that students can determine if each trash category is recyclable.  

  3. Now, determine what percentage of the trash collected in your group was recyclable. To do this you need to account for the number of items in each category and their ability to be recycled. Determine a value for how many items are “yes” recyclable or “no” not recyclable. Divide each of those numbers by the total number of items of trash and multiply by 100. That will be the percentage that is or isn’t recyclable in the trash you collected.

    1.  Simplified example: collected 5 aluminum cans (yes), 2 fishing lines (no), 3 plain cardboard boxes (yes) -> 8 recyclable items, 2 non-recyclable items, 10 items total -> 8/10 x 100 = 80% recyclable; 2/10 x 100 = 20% not recyclable 

  4. After calculating the recyclability of your trash, let’s calculate how long your trash would have taken to decompose if it was left in the park. Add another column to your dataset called “Biodegrade time”. Use the following chart to add a time for each trash category. Notice that we have eliminated ranges and given one time for the sake of these calculations. Remember that calculations require working in the same units. Consider using days as the standard unit. 1 week = 7 days, 1 month = 30 days, 1 year = 365 days.  

  5. Now, determine the average time it would take for all the trash you collected to biodegrade. Multiply each trash category count by the biodegrade time. Add these values together and then divide by the total number of pieces of trash. This will give you the average time to biodegrade in days. Convert this into a more familiar unit like weeks, months or years. 

    1.  Simplified example: collected 5 aluminum cans (300 years), 2 fishing lines (600 years), 3 plain cardboard boxes (3 months) -> (5 x [300 x 365]) + (2 x [600 x 365]) + (3 x [3 x 30]) = 985,770, 10 items total -> 985,770/10 = 98,577 days; 98,577/365 days = 270.07 years; remainder calculations: 98,577 – (365 x 270) = 27 days – (3 weeks x 7day/week) = 3 weeks and 6 days remainder -> average time to biodegrade = 270 years 3 weeks and 6 days 

  6. (Optional) Come together as a class and determine these values for all of the trash collected by the class. The calculation process is the same. All you need is the total number of trash items collected, the total number of recyclable and non-recyclable items collected, and the total time to biodegrade for all the trash (add the value in days each group already calculated). Compare the class totals to your group totals.

    Trash Type Time to Biodegrade
    Apple core/Orange peel 3 weeks 
    Newspaper 3 weeks
    Paper towel 3 weeks 
    Plain cardboard (unwaxed) 3 months
    Cotton cloth 4.5 months 
    Rope 1 year 
    Cigarette 3 years 
    Milk Carton (waxed) 5 years 
    Disposable diaper 15 years 
    Steel can 90 years
    Aluminum can 300 years 
    Resealable plastic bag 300 years 
    6-pack plastic rings 400 years 
    Plastic bottle 450 years 
    Monofilament fishing line 600 years 
    Glass bottle 500,000 years
    Styrofoam Unknown/never
    Exclude from all calculations.


 

Simplified Example Data Sheet:

Trash Quantity   Recyclable   Biodegrade time
(days)
Aluminum can
 		 IIIII 5 yes 109500
Fishing line
 		 II 2 no 219000
Plain cardboard box
 		 III 3 yes 90









Procedure (with computers)

  1. Digitize your handwritten datasheet into Excel or another spreadsheet application. Each piece of trash should have its own row. In row 1, write a header for column A called trash. Then for each trash type you collected, record the type using _ instead of spaces and drag at the bottom right corner to repeat the cell however many times you collected that type of trash. An example of a finished sheet can be found below these instructions.  

  2. Add a column to your data sheet called “recyclable”. In this column you will put “yes” or “no” based on if that item can be recycled in your county. Look up the county’s recycling standards and determine if each trash category is recyclable. You can drag the bottom right corner down again instead of typing yes or no repeatedly. It is very important you do not capitalize and that you spell correctly for calculations later.  

  3. Now, determine what percentage of the trash collected in your group was recyclable. To do this you need a cell that has the total number of rows (pieces of trash) collected. Place a label next to this cell called total_count. The formula for this calculation is = COUNTA() and then you select all the rows starting at row 2. Next, determine a value for how many items are “yes” recyclable or “no” not recyclable. The formula for this is = COUNTIF(range, value). The range is all of the recyclable column and the value is “yes” or “no” (type the quotation marks). In another cell below the table, perform the function, = (yes_count/total_count) * 100. That will be the percentage that is recyclable in the trash you collected. Do the same thing with the no_count.  

  4. After calculating the recyclability of your trash, let’s calculate how long your trash would have taken to decompose if it was left in the park. Add another column to your dataset called “biodegrade_time”. Use the chart above to add a time for each trash category. Notice that we have eliminated ranges and given one time for the sake of these calculations. Remember that calculations require working in the same units. Consider using days as the standard unit. 1 week = 7 days, 1 month = 30 days, 1 year = 365 days. You can perform calculations in the cells of your spreadsheet by starting with an = and using * for multiplication. 

  5. Now, determine the average time it would take for all the trash you collected to biodegrade. Below the biodegrade_time column, in an unused cell, calculate the average by using the =AVERAGE() function and selecting all of the biodegrade times. This will give you the average time to biodegrade in days. Convert this into a more familiar unit like weeks, months or years. 

    1. Example of conversion calculations: 98,577/365 days = 270.07 years; remainder calculations: 98,577 – (365 x 270) = 27 days – (3 weeks x 7day/week) = 3 weeks and 6 days remainder -> average time to biodegrade = 270 years 3 weeks and 6 days 

  6. (Optional) Come together as a class and determine these values for all of the trash collected by the class. The calculation process is the same. All you need is the total number of trash items collected, the total number of recyclable and non-recyclable items collected, and the total time to biodegrade for all the trash (add the value in days each group already calculated). Compare the class totals to your group totals. 

Example spreadsheet: 

trash recyclable   biodegrade_time  
aluminum_can yes 109500
aluminum_can yes 109500
aluminum_can yes 109500
aluminum_can yes 109500
aluminum_can yes 109500
fishing_line no 219000
fishing_line no 219000
plain_cardboard   yes 90
plain_cardboard yes 90
plain_cardboard yes 90
  AVERAGE= 98577
total_count 10  
yes_count 8  
no_count 2  
yes percent 80  
no percent 20  

Post-Field Trip Resources

We would love to hear from you and be notified about the clean-up your class(es) did! E-mail us at cocanaleducation@nps.gov telling us any statistics you have on your trip (how many students participated, where you went, how much trash you collected, etc.). Thank you for helping keep our park clean!    

Tags: human waste trash clean-up trash biodegradable materials stewardship data analysis self-guided

Last updated: March 3, 2026