People in waste management cringe when they hear landfills called dumps. Around eight million metric tons of plastic enters the ocean each year, and much of this leaked out of dumps in the developing world. Past blogs have talked of dumps and their inadequacies. This blog is about the modern landfill. I took a tour of my local landfill recently to found out why they are better.
Andrea Bolitho works with the Solid Waste Management Department in Brevard County, Florida. She loaded our group into the Recycle Van and headed to the top of the landfill. At 185′ above sea level, it is the highest point in the county. The landfill is huge, but only one small section, the working face, receives trash each day. We watched a convoy of garbage trucks climb the hill, empty their loads and head back down. A compactor, a huge, heavy contraption with spiked wheels, drove back and forth over the garbage.
This garbage, about 2000 tons per day, is covered each evening with a layer of dirt and mulch. The mulch originates as yard waste, which is collected separately then ground up. The dirt is purchased. Covering the garbage each evening is expensive but critical. This keeps garbage in.
Birds were everywhere. Gulls, crows, ibis, pigeons and occasionally a pair of eagles fly between garbage trucks searching for food. Andrea tells us the birds don’t show up on Sunday when the landfill is closed.
Modern landfills are closed, sealed systems. Air and water don’t penetrate, so decomposition occurs very slowly. You can dig down into time in a landfill and find fifteen-year-old newspapers that are still legible. Garbage breaks down anaerobically, producing methane. Methane explodes easily and is a potent greenhouse gas. In this modern landfill there are wells that remove methane and pipe it to a facility that converts methane to energy. Methane from this landfill powers 6,000 homes.
There are wells scattered around the landfill which constantly check for the presence of leachate in groundwater. Leachate is the nasty liquid that leaks out of landfills. The landfill has slurry wall surrounding it and a clay liner underneath that contains the leachate. There has never been a leachate leak from the landfill. Leachate seeps down to the bottom of the landfill where it is sucked out and piped to a large tank. Leachate from the tank is sent to a wastewater treatment plant, cleaned and ends up in reuse water for lawns.
Yard waste isn’t the only thing kept out of the landfill. Recyclables, including paper, glass, some plastics and metal, are picked up separately. These are brought to a facility where they are sorted, baled and sold. Tires are shredded for mulch or incinerated. They float to the surface when buried in landfills. Concrete is set aside, then crushed and used as road base material. Appliances are collected curbside and brought to the landfill. Coolants are removed from refrigerators to keep them from escaping into the atmosphere and poking holes in the ozone layer. Metal from appliances is recycled.
This landfill has been in operation since the 1960’s. It has space for around two more years of garbage. Construction of a new landfill adjacent to the current one is underway. Dirt has been excavated, plastic liners installed, plumbing for leachate is being put in. This new landfill will be even better than the current one, and much better than the open dumps of developing countries. Modern landfills hold plastic and other garbage in, they prevent groundwater pollution, air pollution and global warming through release of methane, and they’re safer. Modern landfills give us time, and we need time to learn how to use plastic wisely. Until we figure things out, you can help keep plastic out of the ocean by using the BlueTube at your beach. Grab a bag on your way to the beach, pick up trash, throw it away. Send that plastic trash to the landfill where it will stay. That’s much better than ending up than the ocean.