landfills: Choosing an Alternative Liner System Proves Difficult

Robert Hauser Jr.

Demonstrating that an alternative liner system is effective and meets regulatory requirements can be tricky.

During Subtitle D's development, the U.S. Environmental Protection Agency (EPA) analyzed liner systems' performances and the protection they offer under various scenarios.

From this evaluation, EPA established a "composite liner" system: a 24-inch natural soil layer with a maximum permeability of 1 x 10-7 cm/ sec. overlaid by a geomembrane and leachate collection system.

Although Subtitle D allows alternative liner system use if it demonstrates "equivalent or better" performance, the agency gave limited guidance on how to make such measurements. An equivalency demonstration usually relies on modeling the proposed system.

The challenges, however, often are to identify the assumptions and the performance criteria to be measured.

In the meantime, manufacturers have developed various new products with specific properties to meet different conditions while the solid waste industry has gained a greater understanding of liner systems' performance under varying conditions. Thus, with the correct product and applied knowledge, landfill managers can address unique site conditions. And often, these options can be more cost effective than using the traditional composite liner.

For example, in regions where low permeability clay soils are not readily available, alternative liner systems that use various combinations of geosynthetic clay liners, geomembrane and higher-permeability soils can be used to avoid importing clay or amending local soils. Although many states will allow using alternative liners of demonstrated equivalency, the difficulty is in determining what will be accepted and how to perform these demonstrations.

A few states, such as Florida and Delaware, have included alternative liner systems in their regulations. Some states mandate a specific process or they will review equivalency individually. Still others are evaluating how to perform the demonstrations.

While using and permitting alternative liner systems can provide both environmental and economic benefits, solid waste professionals, associations and regulatory agencies, including EPA, first must agree on how to measure equivalency.

This should be based on clear performance criteria and key assumptions that must be used in the analysis (with flexibility to meet various conditions in different states).

Fiscal Browning-Ferris Industries Inc., Houston, has reported a consolidated net income of $85,223,000 for the first quarter of fiscal 1998, ended December 31, 1997.

Internet Sites Eaton Corp., Clemmons, N.C. has launched a new web site for its Trucking Information Services division: http://fleetadvisor.eaton.com/ BRT Recycling Technologies' web site is: www.brtrecyclingtechnologie.de

The U.S. Environmental Protection agency's new Pay-As-You-Throw web site is: www.epa.gov/payt

Merger Frontier Manufacturing Co., Northridge, Calif., and Industrial Machining Corp., Woodburn, Ore., have merged.

HOUSTON - Safety Vision Inc. and Omni Industries have announced that they are combining forces to create one rear vision distribution company.

Once strong competitors, Safety Vision and Omni will join formally on April 6, 1998 when they move into a new 15,000-square-foot facility.

The company will keep the "Safety Vision" name. The new address for both companies is 6650 Roxburgh Dr., Ste. 100, Houston, Texas 77041-5208. While each company will retain their previous toll-free numbers (800-850-4355 for Omni and 800-880-8855 for Safety Vision), Safety Vision's new numbers are: (713) 896-6600 (phone) and (713) 896-6640 (fax).