Sample Consumption and Waste Audit
The aim of the waste audit is to measure the weight and types of waste produced by your school in one day. It is an integral part of a school waste reduction campaign. Waste is collected, sorted and weighed by students, teachers and other helpers. The data collected will help you measure the effectiveness of your campaign. The audit should be carried out prior to the implementation of a school action plan to reduce waste and again afterward, in order to measure the reduction levels achieved. Please feel free to add or edit questions so that it makes sense for your school and local community.
- Investigate categories of school waste.
- Learn sampling techniques to monitor waste volume.
- Record and analyze waste data.
- Mathematics, Science, Citizenship
Eco-Schools USA Pathways
- Consumption and Waste, Energy, Global Dimensions
- Bagged trash
- Old trash cans or bins (eight for each group)
- 10-20 large trash bags
- Spring balances or scales
- Ground sheets
- Clipboards with copies of the Waste Audit
- Rubber gloves (one pair for each participant)
- Identify an 'average' school day on which you will audit your school's waste (not during special events, the end of term, or when groups are out of school). Let all staff know when the audit will take place.
- Carry out a risk assessment for the activity.
- You may want to send a letter home to parents to inform them about the activity, to ask them to provide clothing, and possibly to request adult volunteers.
- Ask the site manager to save one day's waste (both trash and recycling) from the entire school, including non-teaching areas such as bathrooms, staff rooms, offices and the exterior.
- Ask the site manager to look through the bags to remove sharp objects and label each bag with the area of the school it came from, such as classroom number, cafeteria, or playground. Ensure that bags of food waste are clearly labelled and kept separate. Store all bags of waste safely overnight.
- Explain health and safety issues to the students. Gloves must be worn before touching any waste, and students should call an adult if they see any sharp objects.
- Weigh all bags containing food waste, log the results in pounds on the recording sheet and dispose of the waste in the usual manner.
- Divide a class into three to four groups. Each group should have a ground sheet, a recording sheet and pencil, and a set of spring balances or scales. Each student should wear protective rubber gloves.
- Each group should empty the contents of one bag of waste at a time onto the ground sheet and sort it into the different types of waste shown on the recording sheet.
- Groups should have a separate carrier bag for each waste type. They will sort the waste into these bags, weigh them and log the results on the recording sheet.
- Once the contents of the carrier bags in each group have been weighed and recorded, empty them into larger bin bags and re-use the carrier bag.
- When all bags have been sorted and the data has been recorded, dispose of the waste and recyclables in the usual manner.
- The next time the group meets, calculate the daily, weekly and annual waste totals for the whole school. Multiply daily totals by five for the weekly results, and the weekly totals by 38 weeks (the average number of weeks per year spent at school). Work out the percentage of different types of waste produced.
- Compare waste data from different areas around your school and identify waste 'hot-spots.'
- Discuss your findings. What are the most common types of waste? Is anything currently being thrown away that is recyclable? Which type of waste would make the biggest difference if recycled?
- Use the information from your waste audit to plan or improve your recycling scheme as outlined in the Action plan activity.
- Instead of sorting the waste, you could attach recording sheets to each bin on the evening before the audit. Get everyone to tally what they throw in the bin. This avoids the need for sorting the waste by hand and is particularly suitable for smaller schools. The tallies can be used to estimate the relative proportions of materials in each area.
- While sorting the waste, ask students to note the most common waste items. How could you reduce this type of waste?
- Present your findings to the rest of the school through an assembly or newsletter.
- Repeat your audit after you have set up a waste reduction scheme. This will show if your recycling system and action plan is effective. It will also identify areas which require further work.
This activity and action plan is adapted from the Sonoma County Waste Management Agency.