Both the Environmental Protection Agency and the Congressional Office of Technology Assessment have noted that when properly designed and operated, waste incinerators can be both safe and effective. For that reason, incineration is part of both federal agencies' waste management recommendations. However, unlike landfills, which bury waste, incinerators – called "Waste-to-Energy" or "Resource Recovery" systems by waste management professionals – have the capacity to turn waste into electricity – a marketable product. Indeed, burning waste to generate energy may be the ultimate form of recycling: energy is used in producing the products which become elements in municipal solid waste, and burning that energy under controlled conditions generates new energy.
Provided the right mix of waste is provided, and under controlled high temperature conditions, most of the incinerators which are currently in operation can reduce the volume of waste which enters the incinerator by 75-90 percent. Most existing or planned U.S. incinerators are either "mass burn" systems that burn mixed, unprocessed MSW or "refuse-derived fuel" systems, which first mechanically process solid waste to produce a more homogenous fue1. 
Many of those who favor source reduction and recycling over landfilling cite Europe and Japan as prime examples of successful recycling and argue that the United States should imitate both countries. At the same time, many of these individuals dislike incineration on the grounds that incineration is both expensive and environmentally risky.
What is often overlooked in the argument for recycling and against incineration is the fact that in both Japan and Europe, a substantial proportion of MSW is disposed of through waste-to-energy incinerators. 
In Japan, over 1,900 cities – almost two-thirds of all municipalities – have waste incinerators of one type or the other. About one-fifth of all Japanese incinerators are mass burn. Nearly two-thirds of Japan's post-recycling municipal solid waste is burned. 
The majority of European facilities are mass burn, waste-to-energy facilities. Sweden and Denmark combust more than half of their post-recycling solid waste and West Germany about one-third after recycling. 
The safety issue surrounding waste-to-energy facilities centers on toxic particles in either released stack gases, or in the residual ash. In Sweden in the early 1980s, questions were raised about the health risks associated with mass burn combusters. Two families of toxic chemicals were believed to be emitted from municipal incinerators: polychlorinated dioxins (PCDD) and polychlorinated furans (PCDF). In response, the Swedish Board of Environment placed a moratorium on new municipal combusters and began an intense study of the issue.
After a thorough review of the scientific evidence in Sweden and other European countries, Swedish environmental authorities concluded that PCDDs and PCDFs, while present in residual gases and ash, were present at levels were well below acceptable minimums. Therefore, on the grounds that this method of waste disposal posed no health risk, incinerators were released from moratorium. 
Floyd Hasselriss, Diplomate of The American Society of Environmental Engineers, has studied incineration as an option for managing MSW and concludes, "worldwide research on emissions from combustion has produced a consensus that with good design, operation, and monitoring, municipal refuse combustors can reduce potentially toxic organic compounds to extremely low levels which do not represent a health risk. The residues of burning, which represent about 20% by weight of the MSW, can be partially recovered for beneficial use, reducing landfill requirements to as little as 5% to 10% of the original MSW weight." 
Given the advances which have been made in waste combustion technology, and in light of the fact that, properly designed, waste-to-energy incinerators pose no health hazard, EPA and OTA concluded that this part of the waste management hierarchy should be able to handle as much as 20 percent of MSW by 1992. 
Waste-to-energy incinerators already handle 63% of waste in Connecticut; 57% in Maine; 48% in Massachusetts; and 43% in Delaware. In Michigan, only 4% of MSW is disposed of in this manner. 
But incinerators are not cheap. With construction costs running as high as $500 million, the economic advantages of simultaneously disposing of garbage while generating electricity are not compelling. While the Public Utility Regulatory Policies Act of 1978 requires public utilities to purchase electricity from such facilities at a price equal to the utility's "avoided cost" (what it would cost the utility to generate this energy), waste-to-energy plants' costs are higher than the price utilities would have to pay to produce their own energy. 
Moreover, with the high start-up costs associated with large (1,000 and more tons per day) conventional waste-to-energy plants, the only way economies-of-scale can be achieved – i.e., overhead costs can be spread over extended periods of operation – is if sustained flows of MSW are presented to the plant. A city which has built, or invited a private firm to build, a conventional large waste-to-energy plant at the same time it has implemented a recycling program will discover that the two may not be complimentary. They may be competitive. A corrugated box or a plastic bottle – plastic has high BTU value – can be either burned or recycled, but not both.
As is true for landfills vis-a-vis recycling and recycling vis-a-vis landfills, failure to consider the costs of alternative waste disposal options before committing to a conventional large incinerator could be financially disastrous. Case in point: EPA officials are now seeking public response on proposed regulations forcing all cities that incinerate garbage to achieve a 25% recycling rate. A resource recovery – i.e., waste-to-energy – plant needs fuel to produce steam and electricity. Recycling deprives the plant of some fuel. The two may be incompatible and the public needs to take account of this problem.
Detroit's huge waste-to-energy plant now faces the prospect of future "fuel" shortages. Consequently its operating costs are expected to rise. With rising operating costs, incinerator "tipping" fees are expected to rise. Per ton disposal fees at Detroit's incinerator were originally calculated to be $38.20 per ton, rising to $53. The city's engineering consultants are now warning that costs could more than double to in excess of $120 per ton under certain circumstances.  That is a figure well above what anyone currently expects to be the cost of landfilling anytime in the future in Michigan.
Question: Is it necessary to spend upwards of $500 million to build an incinerator of the type which the City of Detroit, and several other large cities, operate? Detroit's incinerator, like that of many large cities which are using this method of waste disposal, was designed to burn as much as 2,000 tons per day. With that design, and with such high start-up costs, it virtually has to have that amount every day to realize the economies-of-scale required to keep its per ton costs as low as possible while simultaneously recovering construction and operating costs.
What about smaller waste-to-energy incinerators? Are they possible?
Morbark Industries of Winn, Michigan, has developed and tested what its people call a "Waste Gasifier." Starting with a shredder unit which combines common household garbage, construction debris and wood, it shreds these materials and passes them along on a conveyer to a metering bin which accepts the blend of wood chips and garbage. At this stage any oversized material is reduced to proper size and then augered to a primary combustion gasifier. The gasifier takes the garbage and wood chip blend and converts the fuel to a hot gas at a temperature range of 1,200 degrees achieved by controlling internal air flow. The material then passes through a cyclone scrubber where more air is injected and a super heat level between 3,000 and 3,300 degrees is achieved. The circular flow inside the cyclone at these high temperatures (more than twice the temperatures achieved in the large Detroit incinerator) insures that all fly ash material is completely gasified before entering the boiler. The super heat in the boiler produces high temperature steam. Any unburned ash and char is removed and recycled back to the beginning of the process to be used as primary first-stage fuel.
The Morbark gasifier is small and inexpensive. After glass, metal, and batteries have been removed – all of which are better candidates for secondary materials markets than is the case for many other elements in typical MSW, it is capable of safely handling up to 200 tons of waste a day – including grass and leaves which, properly mixed with wood chips, will burn easily. [Hillsdale County, Michigan, generates less than half that amount of waste a day. Isabella County, Michigan, which includes Winn and Mount Pleasant, along with the large student population at Central Michigan University, produces no more than 100 tons of MSW per day.]
With the ash and char which remains from Morbark's gasifier recycled into primary fuel supplement waste reduction, the system is capable of reducing the volume of waste by as much as 98.5% – compared to, at best, no more than 90% for large conventional waste-to-energy incinerators.
The cost? While conventional incinerators may cost $500 million, Morbark' Gasifier is expected to sell for around $1 million. With costs this low, energy production from MSW need not be economically inefficient in competition with recycling and landfilling. For many, if not most, Michigan cities and counties, the Morbark gasifier could handle virtually all waste. For larger cities, several such gasifiers could be used at strategic points around the city to take 100 to 200 tons per day. Located at the edge of cities in or near industrial areas, with minimal garbage transportation costs, waste could be received and gasified, and energy – up to 10 megawatts according to Morbark officials – could be created.