Waste Audits: What They Are, Why They Matter, and How to Conduct One
In an era of growing sustainability commitments, many organizations are turning to waste audits as a practical tool to manage waste and improve recycling. A waste audit involves sorting through an organization’s trash, weighing and categorizing all the different materials, and measuring how much of each category is present. By examining a representative sample of waste (often a week’s worth), auditors can determine exactly what types of waste (e.g. paper, plastics, glass, metals, organics, etc.) are being thrown away and in what quantities. This process provides hard data on waste generation and recycling rates, helping businesses pinpoint opportunities to cut waste, boost recycling, and save money.
What Materials Are Measured in a Waste Audit?
A waste audit accounts for all major waste categories that a business or facility generates. Typically, the discarded materials are separated into categories such as paper, cardboard, plastics, glass, metal, and organic waste (food scraps and yard debris). Specialized streams like construction and demolition (C&D) debris, textiles, or electronic waste may also be included if they are part of the facility’s waste stream. Auditors will also look at contamination – for example, how much trash is mixed into the recycling bins or how many recyclables end up in the trash – as this highlights problems in waste sorting. Each category of material is carefully weighed and recorded. The volume and weight of each category can then be compared against the total waste to calculate what percentage is made up by each material.
Common waste audit categories include: paper (office paper, newspaper, cardboard), plastics (bottles, packaging film, others), glass bottles and jars, metal cans (aluminum, steel), organics (food waste, compostable paper), and residual trash that cannot be recycled. For instance, an audit might reveal that 40% of a company’s waste by weight is organics, 25% is paper, 15% plastics, 10% glass/metal, and the rest is true landfill waste. By identifying these components, the organization can see which waste streams are most significant.
Figure 2: Example pie chart of a waste audit breakdown
Interestingly, waste audits often uncover that a large portion of what’s thrown out could have been diverted through recycling or composting. For example, a municipal waste characterization study in Nashville found that food scraps were the single largest component at 15.4% of landfilled waste, followed by construction/demolition materials (12.2%) and compostable paper (9.3%). In total, about 30% of the material sent to landfill was actually recoverable (recyclable paper, plastic, glass or metal) according to that study. These insights show why audits matter – they identify huge opportunities to recover valuable materials and reduce the trash going to landfill.
How Is a Waste Audit Conducted?
A waste audit is a structured process, usually carried out over the course of a week, that provides a snapshot of an organization’s waste stream. The key steps include:
Planning & Sampling: A representative sample of waste is collected from across departments. Bags or containers are labeled so auditors know the source, and safety measures are put in place.
Sorting: The waste is laid out and divided into categories (paper, plastics, metals, glass, organics, textiles, C&D debris, etc.). Auditors also flag contamination, such as recyclables in the trash or trash in recycling.
Weighing & Recording: Each category is weighed and logged. This data is used to calculate the diversion rate — the percentage of total waste that is recycled or composted instead of landfilled.
Analysis & Recommendations: Results are analyzed to identify trends (e.g., how much of the trash was actually recyclable, or where food waste dominates). From this, auditors recommend actions such as adding recycling bins, starting a compost program, improving signage, or switching to reusables.
Implementation & Follow-Up: Businesses then act on recommendations — updating contracts, training staff, or adjusting bin placement. A follow-up audit (after 6–12 months) tracks progress and identifies new opportunities.
As the U.S. EPA explains, waste audits are a systematic way to quantify waste composition and provide the foundation for effective waste reduction programs (EPA) — in short, you can’t manage what you don’t measure.
Why Do Businesses Conduct Waste Audits?
Waste audits take effort, but the payoff is significant. They help organizations:
Save Money: Identifying recyclables or compostables in the trash reduces disposal costs and sometimes even creates revenue streams (e.g., selling cardboard or scrap metal).
Boost Diversion Rates: Audits reveal how much waste could have been recycled or composted, helping businesses set clear targets and optimize bin systems.
Stay Compliant: Many cities require recycling or food waste diversion. Audits ensure businesses meet local laws and avoid fines.
Advance Sustainability Goals: Reducing landfill waste cuts greenhouse gas emissions and conserves natural resources (EPA). Audits provide the data to track progress toward “zero waste” or climate goals.
Strengthen Image & Engagement: Sharing audit results in sustainability reports demonstrates accountability, while employees and customers respond positively to visible commitments to waste reduction.
Measure & Improve: The audit provides a baseline to track progress. Without data, goals are guesswork — with audits, companies can benchmark, re-measure, and steadily improve.
Waste audits deliver financial, environmental, and reputational benefits, making them a smart step for any organization.
Best Practices for Better Waste Management
A waste audit often reveals simple ways to improve. Some proven practices include:
Clear Sorting Systems: Place recycling, compost, and trash bins side-by-side, with consistent colors across the facility.
Strong Signage: Use clear labels and pictures on bins so people know exactly what goes where.
Employee Engagement: Provide regular education, reminders, and recognition to keep staff motivated and reduce contamination.
Waste Prevention: Focus on reducing at the source — go paperless when possible, encourage reusables, and donate items rather than discarding them.
Targeted Programs: Expand recycling or add composting if your audit shows large amounts of paper, cardboard, or food waste still going to landfill.
These practices not only reduce waste but also save money and help build a culture of sustainability.
From Audit to Action: Leveraging Expertise
A successful waste audit is not just a report to file away – it’s a springboard for action. The insights gained should feed directly into the company’s sustainability strategy and daily operations. Many businesses form “green teams” or sustainability committees to carry out audit recommendations and monitor progress. Setting specific waste reduction goals (with timelines and responsibilities) will turn audit data into tangible results.
Ultimately, conducting a waste audit is an eye-opening experience for any organization. It shines a light on what we throw away and often reveals that “trash” isn’t just trash – it’s missed opportunity. By understanding their waste through audits, businesses can reduce costs, improve compliance, boost sustainability, and make a positive environmental impact. Whether done internally or with professional help, waste audits empower organizations to move from awareness to action, creating a more efficient operation and a greener community. A waste audit is the first step in turning waste from a problem into a resource – a smart move for the planet and the bottom line.