All should be pleased that Waco Mayor Kyle Deaver and the city of Waco are now analyzing alternative sites for a new city landfill, as time is fast running out for such old-waste technology. A better long-term solution is adopting modern technology that extends the life of landfills through greater recycling and accelerated on-site biologic decomposition.
In fact, we still have time to make the right choice to save taxpayer money and avoid future groundwater pollution.
Solid waste (garbage) is a by-product of industrialization and our consumer society. Only a few generations ago, 90 percent of the U.S. population lived on farms. Solid waste that did not biodegrade on the farm might have consisted of broken glass or pottery. But there were no plastic bags, cardboard or aluminum cans. Most food waste was fed to livestock.
All has changed. Plastic of various kinds and other inert materials can amount to 20 percent of our garbage. The rest can be composted or recycled but often is not. The total volume of waste has changed radically and, on average, Americans generate seven pounds of solid waste per person per day. Almost all Americans dispose of their waste through a government or commercial source.
Various methods of managing solid waste exist. Waste-management techniques vary by country and, in the United States, by state. Methods include incineration, dumping in the ocean, removing all recyclables, processing green waste into compost, requiring merchants to take back all packaging (Germany) and various ways of storing in the earth. The latter is known as landfilling and is often a source of great controversy when a new one is proposed.
Early sanitary landfills evolved from open dumps into wet “bioreactor” or “dry-tomb” technologies. The United States is the only country to choose dry-tomb landfills almost exclusively. The dry-tomb approach generally takes an open area. Technicians create a liner of plastic and impervious compacted clay. Garbage is dumped over that lined area each day, then covered with a few inches of soil or green waste material. The liner is supposed to isolate the untreated garbage from the groundwater. Over the decades of a landfill’s life, technicians collect and manage the leachate (garbage juice) generated by the dry tomb.
Several deficiencies exist with dry-tomb landfills, essentially technology of the 1970s. Think of how far automobiles, telephones and computers have progressed the past 40 years. Sadly, dry-tomb landfills in most of our nation have not progressed generally.
The Environmental Protection Agency has requirements for more robust leachate management and gas collection, but that’s often a Band-aid. In many cases, old landfills are time bombs because eventually liners fail, allowing leachate to seep into groundwater, requiring costly excavation and remediation. Thus, all landfills require decades of environmental monitoring for both water and air emissions. (Flammable methane gas is created as landfills decay, which has caused explosions at poorly managed sites.)
Imagine ongoing costs for decades of collecting and testing leachate water and monitoring gas-collection systems. Also, because it’s a “dry tomb,” the decomposition process and final waste stabilization may be lengthened indefinitely. This all requires tax dollars.
Waco is at a crossroad. The city proposes to spend about a million dollars on initial designs for an expanded (or new) dry-tomb landfill. The current landfill is not sustainable because it creates ongoing costs for post-closure management that stretch into an unknown future. Building more of what exists (instead of developing more sustainable and cheaper options) makes no sense as our community continues to grow. The city should consider and analyze several promising alternatives before making a final decision and committing millions of dollars.
Greater waste diversion (recycling) rather than landfill: This is the low-hanging fruit. A recent study by the city of Austin found 80 percent of all community trash is recyclable or compostable. Waco recycles (or diverts from the landfill) about 20 percent. Some outlying communities that use the landfill do not have curbside recycling pickup. Presumably all their domestic material goes straight into the landfill.
Many apartments have only Dumpsters and no recycling bins available. About half of waste is generated by businesses and many do not have recycling containers on-site. This business waste makes up about one-third of landfill waste. I am not aware of any substantial food-waste composting or recycling, though this generally makes up about 15 percent of total waste.
Too often society looks only at short-term costs, such as the decision to not collect glass for recycling because it is more expensive to collect than it can be sold for. Non-recycled glass goes to the landfill, shortening the landfill’s life, thereby putting us in the position to spend millions for a new landfill. This is an indirect or hidden cost of not recycling. The city should take a hard look at the waste stream to see what can be recycled that is now being landfilled and then evaluate short- and long-term costs and benefits of the recycling. It is actually simple to educate people about recycling, provide bins and create economic incentive via domestic and commercial recycling rates. Diverting waste from the landfill, via recycling and composting, prolongs the landfill’s life and decreases costs now and going forward.
This isn’t rocket science. Communities nationwide have much higher waste-diversion rates than we do, according to a 2013 Heart of Texas study that shows 20 percent recycling/diversion. For instance, statewide Vermont diverts almost half of waste to recycling and composting and plans to reduce landfilling another 25 percent by 2022. Its landfilling is low because recycling and other diversions are high. Austin diverts 42 percent from the landfill and has a plan to achieve zero waste by 2040. The city of Oakland, California, diverts over 50 percent of waste. In Seattle, citizens recycled 57 percent of waste, increasing it by 38 percent since 2003. These increases are a result of aggressive recycling, composting and reuse programs. Examples proliferate nationwide.
Bioreactor and mining: Potentially very cost effective. A traditional dry-tomb landfill discourages wet decomposition, which means the landfill takes decades to stabilize. A wet landfill constructs a bioreactor that accelerates biologic decomposition and uses produced methane to generate electricity. In many cases, bioreactors stabilize waste in five to seven years. This system is not only common in many developed countries but saves substantial amounts of money over the long run. For example, the Yolo County bioreactor near Sacramento can generate 3.8 megawatts daily that is sold to the utility. This revenue has reduced landfill tipping rates while extending the life of the landfill substantially. That’s a win-win.
Another option for the existing Waco landfill: “mining,” where the recyclables are removed and remaining organic material digested in a bioreactor. Remember Austin’s study that 80 percent of garbage is either recyclable or compostable? Presumably this same percentage now lies buried in the Waco landfill. Experience at many bioreactor-mining projects shows that sales of electricity and recyclables often pay for the project with no net costs to citizens. With this mining process, existing landfill life can be extended for many decades — perhaps a century or more. One caveat: EPA permits are required and state regulators must approve the technology. Again, this is not rocket science, but it can be progress.
Waco’s sustainable future: Developing an expanded recycling and diversion program means different and challenging work for city administrators. Designing a bioreactor landfill requires special skills, thought and effort. The EPA and/or the Texas Commission on Environmental Quality may require more documentation and evaluation of operations. Either course won’t be business as usual, but these are not projects requiring reinvention of the wheel. There are at least 30 bioreactors implemented across the country and strong recycling programs in the hundreds. Most developed countries do not use dry-tomb technology because better techniques exist, saving money and avoiding groundwater pollution.
We need to think outside of the box and adopt modern, sustainable technology to make better decisions and extend the life of our landfill. We are so proud of our “green” Chamber of Commerce building. Let’s keep it going and make Waco the sustainability shining star in Texas.
Dave Morrow has worked at landfills, transfer stations and bioreactors. He is a retired professor in civil and environmental engineering from California Polytechnic State University in San Luis Obispo, California.