Hardly a community exists in America to-day that does not separate some of its waste stream for re-cycling or some other beneficial reuse. Of those separated items, one category - special wastes - has grown by leaps and bounds in recent years. Managing these wastes efficiently is a task that agencies such as the Lancaster County, Pa., Solid Waste Management Authority (LCSWMA) have taken to heart.
What makes special wastes special? They must be segregated due to:
* unique handling requirements due to potential health, safety or environmental concerns;
* opportunities to create energy or save resources;
* a generator's security re-quirements for disposing of items such as confidential documents or controlled substances; and
* regulatory requirements.
Some materials will fit into more than one category. For example, household hazardous wastes (HHW) are considered special not only for safety reasons, but also because of some states' regulations. The Pennsylvania Department of Environ-mental Protection, for ex-ample, requires all operators of resource recovery facilities (RRF) to have a HHW program.
Handle With Care Due to their inherent risks, many materials in today's waste stream require unique handling. Concerns may include fire or reactivity hazards, as well as worker safety.
In Pennsylvania, as with many states that do not regulate their household wastes, residents are allowed to dispose of virtually anything. As a result, many haulers' collection crews are exposed to risky materials ranging from poisons and chemistry sets to medical wastes in-cluding sharps, co-lostomy bags and blood-soaked bandages.
Sharps mainly used syringes - are a large part of the residential medical waste stream. Sharps typically are disposed in coffee cans with the plastic lids taped down, or in plastic laundry detergent containers with screw-on lids. While this is better than throwing the sharps into the trash, it doesn't eliminate health risks to haulers. LCSWMA now provides residents with red, five-gallon medical waste buckets for a nominal fee, which includes disposal.
For other types of special wastes, the prime concern is their potential environmental risk. Used tires, for example, often are dumped illegally - becoming an eyesore and an environmental threat. Tire fires tend to burn for days, leaching petrochemical residues into the soil and water, while emitting various compounds into the air.
In addition, tire piles often are breeding grounds for insects including mosquitoes, which may carry life-threatening diseases such as encephalitis. Fortunately, tires can be recycled and their components can be reused in applications ranging from playground equipment to auto bumpers.
Aim For Reuse Special wastes can be valuable for their high BTU content and are an excellent source for fueling resource recovery facilities. While municipal solid waste (MSW) typically produces approximately 5,000 BTUs per pound, some special wastes such as oily debris or paint filters may run as high as 12,000 to 13,000 BTUs per pound.
On the other end of the spectrum, however, some filter cake sludge wastes have much lower BTUs and may reduce furnace temperatures. Before processing special wastes at a waste-to-energy (WTE) plant, a clear knowledge of each component's BTU content is essential.
If the targeted special waste stream's average BTU content is greater than the facility's waste stream design value, the plant's processing capability may be affected. Meanwhile, other plant systems may experience greater wear and tear due to the special wastes' "hotter" fuel value.
In Lancaster's case, high-BTU fuels have increased boiler exit temperatures, resulting in above-average use of the dry scrubber/lime slurry system. This, in turn, has boosted fly-ash generation and has increased wear on the residue handling system. For these reasons, LCSWMA and its plant operator, Ogden Martin Systems of Lancaster (OMSL), work closely together when reviewing and accepting materials for incineration.
Before a special waste is accepted, it undergoes a scrutinizing review beginning with the authority's Special Waste Division. The waste generators first must submit Ma-terial Safety Data Sheets (MSDS) and/or chemical analyses for each material. The authority staff reviews this information along with the required Departmental Form for Residual Wastes and the Ogden Martin Systems (OMS) Material Characterization Form (MCF). Ac-ceptance is contingent upon whether the material contains constituents that could negatively affect the facility's emissions or its ash characteristics.
If the special waste passes this review, the waste profile is sent to the OMS corporate office for a multi-phase review that includes environmental, health and safety, and facility permit evaluations. If a material meets Ogden's and the authority's standards, the information is sent to the Pennsylvania Department of Environmental Protection (DEP) for approval. Only after the DEP has issued approval is the material accepted.
Some special wastes' tipping fees may be higher than regular MSW, due to the inspection, processing or handling required. The material's physical factors, including moisture content, density and size, as well as its ability to be blended or processed, also affect the fee.
In 1995, approximately 23 percent of the authority's tipping fee revenues was generated from special wastes (see graph on page 73). Of the 454,800 tons of MSW brought into the authority's system, 120,600 tons (or 123,200 tons with recyclables) were special wastes. Ap-proximately half of the special wastes were landfilled and the re-maining 45 percent were processed at the RRF (see graph on page 73). Due to the authority's increased efforts in 1996, tipping fee revenue from special wastes are expected to rise to 27.6 percent - equal to an anticipated 180,000 tons of special wastes.
With volumes like these, disposal security is essential. Consequently, the Lancaster RRF has implemented a rigid compliance program to en-sure proper disposal of all special wastes.
The program involves a three-level compliance check. At Level One, wastes are visually inspected and checked against a waste description list. Level Two entails comparing the materials received to those listed on the bill of lading or manifest. Files on LCSWMA, OMSL and DEP ap-provals also are checked at Level Two.
Finally, at Level Three, the delivered waste is compared to a sample on file to cross-check the waste's color, texture, odor and physical state. Level Three wastes generally consist of process residues such as sludges, resins, filter media and oily debris.
If, at any level, wastes do not match the pre-existing description, the material may be tested further or rejected. Such diligent load-checking helps to assure generators that their materials, including items such as controlled substances, confidential documents and materials from the Drug Enforcement Agency, will be properly handled.
Regulatory Mandates Over the past several years, many states have adopted special-waste management regulations. In 1988, for example, Pennsylvania enacted Act 101, which designates certain items for recycling or special handling. Included were various recyclables, HHW, household batteries, lead-acid batteries, leaves and used motor oil.
Recyclables. At the residential level, recyclables - primarily glass bottles and food containers, aluminum and bimetal cans and newspapers - have been segregated for more than five years in Lancaster County. Businesses throughout the county also are required to recycle a portion of their wastes. The combined residential and commercial waste recycling goal was set at 25 percent by 1997. Lancaster County met this goal in 1994.
HHW. This category includes household cleaners, paints, pool chemicals, pesticides, gasoline, etc. These items may harm human health, the environment and processing equipment. Segregating HHW also protects a solid waste facility. For example, a RRF's emissions are reduced when jars half-full of liquid mercury are prevented from entering the hopper.
Segregating liquid HHW also helps protect landfills without state-of-the-art leachate treatment plants. Finally, the regulations protect collection vehicles because certain types of HHW may react with non-HHW materials, causing fires or hazardous fumes to escape and endanger collection workers and equipment.
Batteries. Like many states, Pennsylvania has banned automotive lead-acid batteries from the regular MSW stream due to their high lead content, which generally ranges from 85 percent to 90 percent of the total battery weight. The batteries' sulfuric acid also is corrosive and hazardous, requiring careful handling to avoid injury. Fortunately, spent batteries often can be reconditioned or recycled.
While not heavy in lead like automotive batteries, household batteries (alkaline, nickel-cadmium and buttoncells) do contain heavy metals such as mercury, silver, zinc, nickel and cadmium. Keeping these metals out of RRFs should be a priority for MSW managers because, although these batteries are small in size, they are plentiful in the waste stream.
For more than five years, the Lancaster County Solid Waste Management Authority has collected household batteries at the curb. Weekly, at least one 55-gallon drum of household batteries, weighing between 500 and 600 pounds, is brought to the HHW facility and separated. Mercuric and silver oxide buttoncells and nickel-cadmium batteries are sent for recycling. Alkaline and carbon-zinc batteries are placed in five-gallon buckets, sealed and disposed at the LCSWMA Frey Farm Landfill.
Leaves and Wood Waste. Under Act 101, leaves are banned from all Pennsylvania landfills. During the fall, residents either must home-compost their leaves or, in municipalities with designated pickup days, place them at the curb.
Although wood waste reduction is not mandated in Act 101, LCSWMA has taken this special waste and made it a resource. For the past several years, the authority has shredded treated and untreated wood, including railroad ties, telephone poles and wood construction debris, and sent it to the RRF.
White Goods. Due to their recyclable metal value, refrigerators, washers, dryers and other white goods have been handled separately by the authority for several years. In more recent years, however, white goods with capacitors containing polychlorinated biphenols (PCB), as well as refrigerants laden with chlorofluorocarbons (CFC), have been further segregated to ensure proper removal and handling.
As these programs demonstrate, Lancaster County now manages its formerly generic garbage as diversified, individual waste streams - whether it is in response to regulatory requirements, demands of the ever-changing marketplace, innovations in beneficial reuse opportunities or special material handling needs. As a result, the authority also benefits from the additional revenue generated by its special waste program.
While no one knows how U.S. special waste management will change in the future, one thing is certain: There's no such thing as "just garbage" anymore.
Many special wastes may provide beneficial reuse opportunities that were inconceivable just a few years ago. For example, precious landfill space doesn't have to be squandered on foundry sands, vinyl flooring chips, tire chips and certain types of ash. Rather, these materials can serve as a protective layer on a new landfill cell's cover stone.
The Protective Cover Enhancement Layer (PCEL) project at the Frey Farm Landfill was initiated in March 1994 by the Lancaster County, Pa., Solid Waste Management Authority (LCSWMA). This project aims to reuse waste materials.
To attract the materials, the authority offered local generators a reduced tipping fee. The increased waste volumes, in turn, helped reduce costs for buying additional base cover material for the landfill's new cell liner. Typically - and at a significantly higher cost than PCEL - additional stone would be placed over the existing 18 inches of stone that directly covers the liner system.
Thus far, the project has used more than 40,000 tons of material, spread over six acres, at depths of three to five feet. The PCEL project was approved by the Pennsylvania Department of Environmental Protection and, because it provides savings for both the generators and LCSWMA, represents an innovative way to reuse waste materials.
In a recently initiated pilot program, the Lancaster RRF has begun accepting certain sludge wastes for incineration. Sludge generators range from manufacturers to wastewater treatment plants; their wastes currently are undergoing the approval and acceptance stages.
Within the next few years, an anticipated 15,000 tons of sludge per year will be accepted, mixed with MSW and burned in the Lancaster RRF. In addition, the authority may accept certain types of waste through direct liquid injection. Finally, the authority will likely consider accepting de-listed Subtitle C materials at its RRF.
Another focus is to expand the authority's supplemental waste program. Currently, LCSWMA offers local generators state-of-the-art, environmentally compliant, secured disposal for a long list of materials, including telephone poles, carpet scraps, pharmaceutical wastes, sludge-type wastes, oily debris and resin residue.
To expand the system, the authority recently contracted with the Lancaster Enviroservices Corp. (LESCO) to provide sales and marketing services and to solicit special wastes generated outside the county. While the authority and LESCO have both re-directed numerous special waste streams to the Lancaster RRF facilities, many more have yet to be tapped.