The Driving Power: Behind Waste-To-Energy

Maria Zannes

Is waste-to-energy (WTE) a viable and healthy part of the solid waste industry? Consider the following:

*WTE represents a $10 billion marketplace.

*Nearly 32 million tons of trash are used as fuel to generate the power for 1.2 million homes across the country.

*Currently, more than 40 million people in 32 states dispose of their trash at the 114 waste-to-energy plants nationwide.

*In 1996, more than 101,000 tons of refuse each day was being converted into energy as compared to slightly less than 97,000 tons per day (tpy) in 1995.

Municipal waste combustion (MWC) facilities include three basic technologies: mass burn, refuse-derived fuel (RDF) and modular plants (see chart). In every case, the processes recover the heat value of trash to generate steam for industrial customers or for electricity that is sold to the grid.

Mass burn facilities combust trash in furnaces that produce steam or electricity. Many of these plants have nearby material recovery facilities that separate and recycle trash.

RDF facilities remove recyclable or unburnable materials and shred or process the rest into a uniform fuel. RDF either can power a generating plant on site or it can be burned off site for energy. Modular facilities are similar to mass burn plants, but these smaller plants are prefabricated and can be assembled quickly where they are needed.

WTE Legislation While these facilities are cleaner, more efficient and safer than ever before, challenges remain. This year, the WTE industry will face promulgation and implementation of new emissions rules, congressional action on flow control legislation and restructuring of the nation's electric utility industry.

It's deja vu for an industry that has been working to set Clean Air Act standards for the past seven years. The U.S. Environmental Protection Agency (EPA), Washington, D.C., promulgated maximum achievable technology (MACT) rules in 1995 for existing facilities and new source per- formance standards for new plants, only to see the standards vacated last year by a federal court following a lawsuit brought by two small facilities. EPA appealed, and states are awaiting a final decision in the case.

The U.S. Federal Court of Appeals for the District of Columbia Circuit decided late last year that EPA inappropriately based standards on facilities' aggregate size and instead should have set rules based on unit size. The court ruled that to remedy the situation, all standards must be vacated and EPA must start the rulemaking process again.

EPA appealed, asking the court to change its remedy and keep largely intact the rules for the larger facilities, which impact more than 80 percent of the WTE's national capacity. The appeal now is pending, but EPA has stated that even a new rule might minimally impact the emission standards for large facilities and have no impact on the pollution control required for the larger units including those processing more than 250 tons a day. If the court agrees with EPA, large facilities must comply with MACT standards by 2000.

The compliance timetable will be different if the court maintains its original decision. EPA will need to create new MACT standards for large and small units - a process expected to take a year or more - and thereby delay the compliance schedule by two or three years.

Many modern existing facilities will meet these standards with relatively minor equipment additions. Other facilities will need significant retrofits, such as adding new scrubbers and particulate cleaning equipment. While minor changes may be accomplished soon, some of the more extensive retrofits will have up to three years to be completed after states adopt the federal rules or no later than five years after EPA releases standards.

EPA estimates a household might pay less than a nickel or up to as much as three dollars a month more for disposal at facilities that must add new equipment.

The rules, according to EPA, will yield about 90 percent reduction in mercury emissions, compared to a 1990 EPA source inventory, and 99 percent reduction in dioxin emissions. The WTE industry, taken as a whole, then will represent 3 percent of EPA's U.S. inventory for man-made mercury sources and less than 0.5 percent of all sources.

EPA also issued directives supporting the continued safe management and testing of residue produced in the WTE process. All WTE facilities have been testing ash under these rules for more than two years.

WTE combustion reduces trash volume by 90 percent and consistently results in a non-hazardous ash. Although the residue still weighs one-fourth to one-third as much as the trash processed, it can be used as aggregate material for road building and other construction.

In addition, ash can be an important component of a community's recycling effort, but it is not likely to be the only recycling taking place at WTE facilities. More than 850,000 tons of waste is recycled on-site at WTE plants, including glass, metals, paper, plastic, batteries, yard waste and white goods (see chart).

WTE facilities recycle nearly 740,000 tons of ferrous metal annually after combustion. In addition to on-site recycling, more than 75 percent of these facilities are in communities with off-site recycling programs.

Since 1980, the percentage of trash that is recycled has grown from 10 percent to a national average of 22 percent. Communities with WTE facilities recycle an average of 26 percent of their trash, up one percentage point from last year.

While local governments are considering the more concrete issue of ash use, federal and state governments are grappling with the murky issue of restructuring America's $250 billion electric utility industry.

The scope of the country's renewable energy marketplace - including WTE - may be determined during the next few years as the Congress and the state legislatures debate the current laws governing electricity generation, transmission and distribution.

Renewable energy comprises only 2.1 percent of the electricity generated in America, growing about 1 percent each year. Biomass is a large share of the renewable mix, contributing more than 75 percent to the renewable market or approximately 1.45 percent of total electric generation. WTE is about one quarter of that biomass market.

With such a small portion of the electricity market, you might think that renewable energy will receive only passing interest. However, as Congress begins restructuring the electricity marketplace, a growing number of members are focused in the renewable area.

WTE plays an important part in renewable energy development. Trash is both "sustainable" and "indigenous" - two basic criteria for establishing a renewable energy source. On average, it is more than 80 percent organic material, including paper, wood, food waste and plastic.

Non-combustibles comprise the remaining fraction. While household trash may not be 100 percent organic, each portion of the waste stream combines to make an excellent fuel for energy generation.

For example, the plastics commonly used in packaging can generate twice as much energy as Wyoming coal and almost as much energy as fuel oil, thus helping organic wastes to combust more completely.

Flow Control Electric utility restructurng legislation isn't the only bill impacting WTE facilities that is slated for debate this congressional session. Once again, Congress probably will consider local governments' ability to control trash flow within their borders. The flow control issue remains intertwined with the debate over an individual state's ability to stem the flow of interstate waste.

The Senate passed a broad flow control bill two years ago, but the House of Representatives failed to pass more narrow flow control legislation last year. Interested parties are cautiously optimistic that the Congress will succeed this year with a proposal that protects existing facilities harmed by the 1994 Supreme Court decision ruling flow control unconstitutional.

Some local communities, however, are currently structuring hauling and disposal contracts that direct waste to a specified facility. Last year, the U.S. Supreme Court declined to review a decision by the U.S. Court of Appeals for the Second Circuit holding that a town may require by contract that trash be disposed at a designated facility.

The appeals court ruling in SCC Corp. v. Smithtown struck down a New York town's flow control ordinance while upholding the town's right to enter into contracts with waste haulers as a "market participant," with the same rights, risks and potential damages as any individual who takes part in a particular marketplace.

Smithtown argued in its petition for review that impermissible barriers had not been erected to interstate commerce. Instead, the town claimed it used its police powers to eliminate the private market for solid waste service and provided those services itself through its contractors, as allowed under the commerce clause of the Constitution.

The decision in Smithtown remains a good law, at least in the Second Circuit, which includes New York, Connecticut and Vermont. Such innovative approaches to ensuring proper waste management options are under consideration in a variety of municipalities.

Health And Safety Plant operators also are looking at more innovative approaches to protect their employees' health and safety. The U.S. Occupational Health and Safety Administration (OSHA), Washington, D.C., requires employees to report data related to accidents and other incidents. In this respect, WTE facilities compare favorably to similar waste and sanitary industries.

In 1996, the lost work day rate at WTE facilities was nearly half of the rate for similar industries. Accident rates within the industry also have been decreasing, with an average of 107 accidents resulting in lost work days in 1996 as compared to 169 such accidents in 1994.

In addition, several WTE companies are considering - or already are a member of - the Voluntary Protection Program (VPP) administered by OSHA. VPP awards plants with outstanding worker health and safety programs.

By the year 2000, Americans will generate more than 218 million tons of trash yearly. EPA expects approximately one-third to be recycled or composted, leaving 150 million tons to be managed. A key element of the integrated waste management approach will continue to be waste-to-energy technology.