Landfills, Bioreactors and Incinerators Are Garbage Destinations
William Rathje of the Garbage Project said, “Sorting garbage is the ultimate Zen experience of our society . . .”. He believed that separating our refuse would bring us closer to each moment of our existence and strengthen our connection to the earth.
We are embarrassed by our trash so our garbage bags and cans are made from opaque materials. Recycling at any level makes us proud. Containers and bags for cans, bottles and papers headed for recycling centers are usually translucent. One we hide, the other we flaunt.
The garbage we aren�ªt proud to call our own gets taken away by people in noisy, smelly trucks mostly in the wee hours of the morning. Most folks have no interest in knowing where the trash goes and have no idea the effect it has on the environment.
The most common destination for your garbage is a “sanitary landfill”. The first landfill accepted trash outside Fresno, California in 1934. Early ones were gullies, ravines or swamps. Loads of refuse was trucked in, dumped and left for nature to dispose of. There was also trash incineration, where everything was set fire and whatever burned went up smoke, and what didnÃ?ªt burn remained there charred, melted or unchanged. Both methods released toxic sludge to soak in to the ground or flow in to waterways.
The EPA recommended dry tomb landfills in the 1980s. The new landfills would have liners to protect the ground water from the leachate. The garbage liquid would be piped to treatment plants to be neutralized. Methane pipes drew away the gases produced by decomposing trash. Once full the landfill would be capped to prevent rainwater from soaking in.
Leachate is a toxic mixture of the fluids given off by the chemical breakdown of garbage. It can contain battery acids, household chemicals of all kinds, paint, pet waste and medical waste. Tests have shown high levels of cyanide, copper, lead, mercury and other toxic substances. Two thousand-year-old Roman Empire trash dumps are still leaching fluids.
The liner in a dry tomb sanitary landfill is meant to confine the liquids until they can be piped away. Two feet of earth is hard packed with mechanized rollers and a half-inch layer of bentonite clay (Claymax) is laid down. Over that a 60mm gauge plastic sheeting is followed by a 1 inch thick plastic drainage mesh, another layer of Claymax, another plastic sheet, and finally a half-inch thick layer of felt to protect the plastic from piercing. A full landfill is capped with two feet of packed dirt and a duplicate of the bottom liner. Monitoring units are placed to measure levels of gasses and watch for leaks.
This all sounds good but it is far from perfect. Research has shown that most landfills just mummify rather than compost the trash in them. Excuation of sites has revealed biodegradation only at the surface level. Getting rich humus from a landfill years later is a fantasy.
Bioreactors take the sanitary landfill a step further. Leachate is collected, instead of being pumped away, and forced back into the garbage in an attempt to quicken the decomposition process. Fresh water is rinsed through when a specific level of decomp is reached. The toxic liquid is then piped away to be treated.
Two factors make this type of system less than optimal. The obvious is the greatly increased volume of liquid that could be released in the event of a leak. Less obvious, at first, is the fact that most trash is in sealed plastic bags. Without an expensive shredder system to cut open the bags the process bogs down.
Waste To Energy Plants are a modern take on trash incineration. Large pieces of metal are removed by hand, powerful magnets attract smaller chunks of metal and the remaining garbage is burned at extremely high temperatures. In some cases the burned waste powers steam generators producing electricity.
To minimize toxic pollutants getting in to the air, there are scrubbers, precipitators, combustion that lowers carbon dioxide produced, and materials are introduced to neutralize poison chemicals and gasses.
Levels of toxic gasses still get released into the atmosphere. The mega-tons of ash that is a by-product of the process have to be disposed of. Some is used as building material that hasn�ªt been proven completely inert over time.
None of the three major destinations for your garbage are without flaws. They are what we have to work with right now and we, as citizens of Earth need to do our part.
Recycling whatever and whenever you can will undoubtedly help the environment. Plastics, Styrofoam, glass and paper that can be reclaimed and reused will go a long way to reducing the toxins that get in to our ground water and air. Precious natural resources will be saved. Properly disposing of e-waste (electronics) is necessary as this type of waste will only increase exponentially as newer and better electronics are brought to the market.
