Written by What happens to biodegradable in the regular landfill
Some municipalities and provinces banned biodegradable bags along with single-use. Why? Because biodegradable bags and other items don’t break down in landfills?
Many people assume that tossing biodegradable items and bags into the trash means they will naturally decompose in the landfill. Unfortunately, that’s not how modern landfills work. Most landfills can’t support that process.
The Problem: Lack of Oxygen and Moisture
Efficient decomposition needs organic materials, oxygen, moisture, and microbial activity. Landfills are tightly packed and designed to prevent air and water from circulating. This is intentional, slowing decomposition helps reduce leachate (contaminated liquid runoff) and prevents structural collapse.
But it also means biodegradable materials sit there for years, sometimes decades, without breaking down.
What Happens Instead?
When biodegradable waste does break down in a landfill, it happens in an anaerobic (oxygen-free) environment. This leads to methane production, a greenhouse gas that is 25 times more potent than carbon dioxide.
Some modern landfills have systems to capture and use methane for energy, but most do not, meaning it escapes into the atmosphere and contributes to climate change.
Contamination at Recycling
When biodegradable bags mix with regular plastic waste, contamination can occur.
Their presence in the plastic recycling stream can interfere with the recycling process. Since biodegradable materials have different chemical compositions, they can compromise the quality of recycled plastic products, making them weaker or less durable.
This contamination can result in entire batches of recycled plastic being unsuitable for use, leading to increased waste. For proper recycling, it is important to keep biodegradable bags separate from regular plastics and dispose of them in the appropriate composting facilities or bins.
So, What Can You Do?
Reduce waste at the source. Choosing reusable items over disposables is often best.
Be mindful of biodegradable plastics. Many require industrial composting facilities and won’t break down in a backyard compost bin or landfill. Look for compostablecertifications instead.
If a bag must go to a regular landfill, the best choice is a durable, reusable bag. Reusable bags, made from materials like cloth, jute, or recycled plastic, help reduce the overall demand for single-use bags, thereby minimizing waste.
However, if a disposable bag is necessary, a high-density polyethylene (HDPE) bag, such as a typical plastic grocery bag, might be a better option than a biodegradable bag in a landfill setting. This is because HDPE bags, while not ideal, take up less space in a landfill and do not produce methane, a potent greenhouse gas, as they degrade very slowly.