Sustainability: The Challenge of Waste

The subject of waste is the last installment of this three-part series on sustainability and the big environmental challenges. Earlier articles discussed the other two big environmental issues: energy (and global warming) and water.

“I hate waste. I have to pay for it with the product and then I have to pay to get rid of it.” This is a paraphrased quote from Lee Scott, the chairman of WalMart, from some years ago. He was talking about the excess packaging used to ship product to them and their need to then get rid of it. This is one of the aspects of the waste “problem” as it relates to sustainability.

The term “waste” actually defines the problem. It can be said to be something that is not wanted or needed, has no economic value and requires disposal by some means. It could be by incineration (with the resulting ash) or burial or other means of destruction. It is an oxymoron in industrial processes since waste means loss. In an ideal world, all processes would be efficient and there would be no waste.

Waste is a problem not just for industry and commerce, but for all of us. It is an artifact of human existence as demonstrated by archaeology. One of the more infamous sites for waste disposal is the Fresh Kills landfill adjacent to Staten Island in New York. It is one of the largest in the world and received wastes from 1948 until 2001, when it was closed to create a park (this is still progressing). It is visible from space with the naked eye and is thought to contain more than 150 million tons of trash.

New Yorkers generate more than 36,000 tons of trash daily. Most of this now is trucked to nearby states for disposal. Landfills always have been the easiest and least costly choice for ultimate disposal, since rural land was cheap when compared to other options such as incineration.

This outlook rapidly is changing. It is abundantly clear that we cannot continue to just bury our trash.

The most current municipal solid waste statistics from EPA show a slight dip in the generation of total waste over the period between 2007 and 2008 (254 million tons to 249.6 million tons). This is almost double from what it was in 1970. The good news is that recycling has increased from 6.6 percent to 33.2 percent since 1970. The statistics are similar for Europe but with a much slower rise in waste generation and more recycling. It also is estimated that between 55 percent and 65 percent of waste comes from consumers. However, it is clear that there is pressure from many quarters on business to take a leading role in waste minimization and resource recovery.

David Korten, an economist and former Harvard Business School Profession, said:

“To achieve true sustainability, we must reduce our ‘garbage index’ — that which we permanently throw away into the environment that will not be naturally recycled for reuse — to near zero. Productive activities must be organized as closed systems. Minerals and other nonbiodegradable resources, once taken from the ground, must become a part of society's permanent capital stock and be recycled in perpetuity. Organic materials may be disposed into the natural ecosystems, but only in ways that assure that they are absorbed back into the natural production system.”

WASTE TO ENERGY

Waste-to-energy is not a new concept. In fact, it was the subject of my dissertation (“The Resource Recovery of Municipal Solid Wastes”) a few decades ago. It has been much more successful in Europe than in the United States, primarily due to siting issues with waste recovery incinerators. It just is being developed in most of the rest of the world.

The basic concept is that wastes are burned in a water wall incinerator, creating steam that is supplied to others or used to generate electricity. If the waste is energy positive (provides more energy than is used for burning it), the waste could be considered as “used” as a fuel and thus would not be waste. If it takes more energy to burn it than is provided, then credit for recycling would not be appropriate. This applies to all wastes including hazardous waste.

To be absolutely, technically correct, one would have to subtract any residual ash created by the burned waste unless that ash in turn is used for another purpose, such as in cement or road construction. This use of waste actually has resulted in a very interesting business artifact.

The cement industry requires a huge amount of energy in its production of cement. Increases in fuel costs are very detrimental to the economics of producing cement. Since kiln temperatures of approximately 1500°C are required to produce the main constituent of Portland Cement (Alite, which is Tricalcium Silicate), it is ideal for the destruction of a large number of flammable and hazardous wastes including tires. Today, especially in Europe, most kilns make as much money from hazardous waste destruction as they do producing cement.

One further can stretch this principle to many other means of creating value from waste, which means it no longer is a waste. Waste sludge from wastewater treatment can be anerobically digested to create methane gas that can be used as a fuel. In fact, almost any organic waste can be anerobically digested to produce methane. Collection of methane gas from landfills is common today, but probably would not qualify specifically as waste recovery to the waste generator since it is quite inefficient and impossible to quantify.

CREATING THE MARKET

In my previous position, we established a zero landfill goal as well as the goal for complete “valorization” of waste. Valorization is a French term that is equivalent to creating value. Said another way, the intent was to have all waste recycled, reused in its original form or destroyed with value provided in that destruction (e.g., waste to energy). In order to achieve this laudable goal, markets had to be created in some areas. This especially is true in some countries where there is a lack of resource recovery infrastructure.

We had a factory in South America that had gotten to the point of achieving about a 95 percent valorization or recovery rate, but just could not figure out a way to get to the 100 percent mark. The last 5 percent was waste from the factory cafeteria. They worked with the local authorities and helped create a new company employing local disadvantaged persons in a small composting operation. The compost created from the cafeteria food wastes initially was used on the factory grounds. Within 2 years, several other companies had joined in the effort and today it is a thriving small business serving a large number of local firms and supplying the entire area with compost. The bottom line is that sometimes you will need to search for creative approaches and establish the market.

ZERO WASTE AND ZERO LANDFILL

The principles of waste management commonly are referred to as the Three Rs (reduce, reuse, recycle). The concept is preventing waste, reusing what is left so that there is no waste or recycling if it cannot be used in the original form. Recycling is less advantageous than reuse, since it usually requires some additional processing (e.g., paper waste to a new paper product) and potentially additional waste. There also are the options discussed earlier (resource recovery though waste-to-energy, etc.).

The latest buzz words are “zero waste” and “zero landfill.” These terms are not exactly equivalent, since zero waste implies no waste and zero landfill implies waste that goes through other resource recovery techniques. Nevertheless, these both are laudable targets for companies.

In closing, we have reviewed the three big environmental issues in sustainability. Energy (and global warming), water and waste are the key focus areas, but other environmental issues such as atmospheric emissions (sulfur dioxide, nitrogen dioxides, hydrogen chloride, particulates, etc.), wastewater quality, persistent chemicals, preservation of biodiversity and many other environmental key performance indicators also are important in the overall environmental footprint of companies.

Interest in sustainability clearly has grown in the public, NGOs, financial analysts, governments and companies competing for business. It has been a trend over the last decade that likely will intensify. If it is not already on your agenda, I predict it will be.


Zack Mansdorf, Ph.D., CIH, CSP, QEP, is a consultant in sustainability and EHS. He is a former senior vice president, L'Oreal, and a past president of the American Industrial Hygiene Association. He can be reached at mansdorf@tiac.net.

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