landfills: Growing Up, Not Out

Marc J. Rogoff and Thomas R. Keith

When you need the space, which way do you go: up or out? That was the question faced by one Florida county landfill.

The problem? Located along Florida's west coast, Charlotte County has experienced growing numbers of retirees moving into its community, increasing the demands on roads, utilities and its Zemel Road Landfill.

Faced with deciding how to provide additional landfill capacity, the county had to determine which was the more cost effective way to add to the facility's life span: vertical or horizontal expansion. The original operating and closure permit limited the site to 98 feet at closure with final grades of 10:1 slopes.

The county, with the help of Tampa, Fla.-based HDR Engineering Inc. conducted an elevation study which concluded that the Florida Department of Environmental Protection (FDEP) would consider a five year landfill permit renewal application, allowing an increased landfill elevation to 130 feet with a 3:1 slope.

Using Zemel's contour data - provided by a construction quality, aerial survey - the consultants compared Zemel's permitted design for Phase I and II with the alternative design, specifically the landfill's remaining volumes at 98 feet versus the proposed elevation of 130 feet. (Three-to-one side slopes and 20-foot-wide terraces were assumed.) In addition, the data was compared against the landfill volumes already effectively used, as noted by the topographic survey.

Based on these results, Zemel's remaining life was estimated with assumptions of per capita waste generation (6.9 pounds per person per day), current county recycling rates (40 percent), assumed compaction density (1,200 pounds per cubic yard) and final top elevation. These assumptions also were used in the county's closure financial responsibility report to the FDEP for 1996.

The report concluded several potential advantages to modifying the landfill's design: * Increased landfill life. Increasing the landfill's elevation to 130 feet at closure would increase Zemel's life span to the year 2020 - 11 years more than the original projections.

* Environmental benefits. Increasing the elevation to 130 feet will not require expanding the landfill's footprint, which, compared to expanding the existing cell, would minimize the stormwater and wetlands impact on an adjacent parcel.

* Construction and capital cost savings. Reconfiguring the existing footprint would require minimal capital construction costs as Zemel would be filled daily as part of the overall design.

Expanding onto an adjacent county owned site, however, would require construction of at least a 100-acre, double lined landfill cell, with costs estimated between $18 million and $22 million. This new cell also would require bond funding with an additional fund reserve account, underwriting costs, payments for municipal bond insurance, etc.

* Develop capital reserve account with additional landfill capacity. The county's existing bond payments for Zemel (slurry wall, leachate treatment plant and injection well) will end in 2011. Debt service is approximately $1 million per year, paid from tipping fees.

So, instead of reducing tipping fees in 2011, the county could deposit the amounts previously paid for debt service into a reserve account collecting interest for eight years, until landfill expansion ultimately would be required.

* Spread landfill closure costs over additional years. The county's budget department typically places additional funds into the landfill's closure account to pay for long-term maintenance, as required by FDEP.

With the new landfill projections, the county could defer payments into this account for several years or spread the needed payments over the 11 additional years.

While not every landfill design study can result in large cost savings, public landfills should evaluate design options which may result in improved economics and enhanced landfill life.

"Thinking out of the box" in Charlotte County resulted in construction cost savings which will be passed along to the county's ratepayers in terms of reduced long term disposal costs and capital expenditures.

Landfilling Hazwastes Declines 3 Percent MINNEAPOLIS - For the second year running, hazardous wastes landfills report a drop in the amount of waste received, according to Minneapolis-based Environmental Information Ltd.'s (EI) annual survey of hazardous waste landfills.

In 1996, the 21 permitted and operating landfills in the United States and Canada took in approximately 2.63 million cubic yards of hazardous wastes - almost 3 percent less than they received in 1995. Prices for both bulk materials and drummed waste decreased accordingly, and operators indicated that they do not expect a firming in the market this year.

With the opening of a new Sub-title C landfill last February by Waste Control Specialist, this already competitive market is experiencing increased competition. All told, 22 facilities are battling for a total waste stream that is unlikely to grow in 1997, the report continues.

"Excess capacity is inherent to the landfill business because of the way such facilities are permitted and constructed," says EI's chief analyst, Cary Perket. "The real issue is that the companies have allowed competitive forces to drive prices below levels that provide shareholders with a reasonable return on investments, even when those investments have been devalued."

The survey results as well as follow -up interviews show that the landfills are being dramatically affected by actions the industry is not taking, such as generating lots of landfillable waste or cleaning up contamination.

The bottom line, according to the report, is that a boost in the number of remediation jobs is the only realistic source of additional landfillable hazardous waste - namely, contaminated soil.

The vast majority of operators indicate that the industry is still holding off on cleanups and several tied their fortunes to developments in the ongoing debate about how to reauthorize the Superfund program, the report reveals.

"The EPA is clearly backing away from stringent cleanup standards," EI's lead researcher Michael Welch says. "No environmental manager wants to be in a position down the road of explaining to corporate why he or she contracted a cleanup that now isn't necessary.

"So, even though prices are low and getting lower for landfilling, it's not surprising that cleanups are on hold pending new, less demanding requirements," he says.

Handling Med Wastes: Regs On the Rise WEST CALDWELL, N.J. - Although a few states regulate sharps disposal in residential areas, household medical wastes generally are not regulated. However, many states, such as New York, Arizona and Wisconsin are considering regulations - particularly sharps disposal - and may adopt new programs to protect solid waste workers.

New York began a pilot program in 1995 to encourage the use of puncture resistant containers for needle disposal. Ultimately, the state's Department of Health hopes to be able to draft legislation for household medical waste disposal.

A similar, voluntary program has existed in Pasco County, Fla., since 1992. Sponsored by seven major healthcare facilities and administered by the county, approximately 14,000 residents can dispose of household-generated sharps in free containers. Since the program began, sanitation workers experiencing needlesticks have been reduced to zero.

Several years ago, a hospital epidemiology publication noted that household waste bacterial counts were considerably higher than those found in hospital wastes. Workers who encounter medical waste should know that many combined factors contribute to disease transmission from the waste to the handler.

Specifically, a viable, disease-causing organism of sufficient strength, quantity and virulence must be present, along with a means of release and a place to enter, such as through breathing, punctured or broken skin.

Unless all of these factors are present, no disease can be transmitted. Training in proper handling techniques should be provided if workers are normally exposed to such hazards.