Capping Out: How To Make It Work And Save

April 1, 1997

7 Min Read
Capping Out: How To Make It Work And Save

Marcia Papin

When groundwater contamination was discovered after only three years of operation at the Enoree Landfill, Greenville County, S.C., citizen confidence in its government's ability to operate the site plunged. In response, county staff determined to turn things around.

The county's sanitary landfill operation began its evolution in the early 1990s. Phase I of its Enoree Landfill was opened (as a trench-type fill) with a clay liner that had a permeability of 10-7 centimeters per second (cm/sec). The county implemented a comprehensive solid waste management plan which required that Enoree's remaining phases comply with Subtitle D regulations.

While the permitting process for the Subtitle D facility was underway, landfilling continued. Unfortunately, groundwater contamination was detected, and continued operation as well as permitting of additional phases became questionable.

As a result, the county devised a plan that provided for the continued disposal of its waste and the closure of Enoree Landfill's Phase I within six months.

Since Enoree was closing before construction was complete on its next phase, commercial waste (and its revenue) was diverted to a privately owned facility in the next county. Without revenue to fuel its operating budget for 12 to 18 months (while closure activities took place), the county faced a tight budget.

In addition to diverting its commercial waste, the county's domestic waste was rerouted to the Greenville City Landfill. Since upgrades - including a 4,585 linear foot, all-weather access road and 532 feet of storm water pipe - were needed, the county was faced with yet another expense. Materials for this project exceeded $75,000 (actual staff and equipment costs to the county were never calculated).

Trained personnel also were needed for Phase II construction when Enoree's permit finally was issued. Both the new administration and the regulatory community agreed that a clay cap with a permeability of 10-7 cm/ sec would reduce infiltration.

Lacking enough native soil capable to achieve this permeability, a geosynthetic clay liner (GCL) was chosen. Estimated costs for installing this cap over 26 acres was $1,000,000.

After considering these factors, the county decided to use its own staff to perform the closure, saving an estimated $500,000.

Their first step was to correct the landfill slopes' overfilling. Approximately 50,000 cubic yards of waste had to be removed to turn 2:1 slopes into 3:1 slopes. Immediate erosion control measures had to be implemented as well. With the help of Greenville County's Soil and Erosion Control staff, a schedule for temporary seeding and terracing was developed. With preliminary estimate for the GCL at 900 rolls, an ambitious schedule of installing and covering 50 rolls/ day, five days per week had to be met.

The staff designed special tools to unload and deploy the GCL. A carpet pole was designed that attached to a rubber tire loader and was used to unload the GCL from the standard tractor trailer containers. Most of the rolls could not be reached from the back of the truck, so a cable rigging system was created to pull GCL rolls from inside the trailer to within reach of the carpet pole. The material was installed with two track loaders equipped with spreader bars.

Seven full-time heavy equipment operators were needed - some of whom were used to run equipment during the material's unloading and deployment. Since the process was labor intensive, temporary summer help was hired to unload the GCL rolls, place them onto the spreader bars and lay down the fabric. All remaining staff hauled and spread approximately 2,700 cubic yards (cy) of soil cover each day.

A strict delivery schedule also was developed. The staff insisted on morning deliveries only (7:30 a.m. and 10 a.m.). This allowed the earth moving crew time to unload the materials, while the fabric crews layed it down ahead of them. Material was delivered continuously during the project because of limited storage area.

Work followed a pattern: A plan was developed and the materials and tools were ordered. The site was stabilized to minimize erosion, while grading began to establish positive drainage and minimum cover requirements. All slopes were regraded to achieve acceptable slope stability, and a grid survey was performed to establish base line elevations. All disturbed soil was seeded, and a gravel area was constructed for the GCL's storage and deployment.

Installation of 1,140,000 square feet of GCL and cover soils began, and permanent erosion control structures were created. All areas received permanent seeding.

Finally, a grid survey was performed to establish finished elevations and cover thicknesses. Permanent settlement plates then were installed and surveyed.

The project was completed ahead of schedule - in five and one-half months - at a total cost of $764,707. Eighteen months after the project began, the landfill's first 12-acre Subtitle D cell was constructed; it has been operating for one year. The county's staff provided the bulk excavation for the construction of this cell, moving more than 200,000 cubic yards.

County staff also performed the bulk excavation and fill (185,000 cy) for a second cell at $1.47/cy. The settlement plates were resurveyed; the maximum settlement was 0.36 feet (see chart on page 6). Reseeding slopes where soil quality is poor has been routine, and there has been no evidence of vegetative stress along the cap's seams.

It was Greenville County's decision to use GCL as opposed to native soil, however, the state decided on the 10-7 soil cap. Although the cap has reduced infiltration, it is important to note that the material within the landfill will continue to leach for some time to come (even if it had a cap that included 60 mil HDPE). The cover material's benefits may not be conclusive until sampling data has been collected for several years.

Acquisitions Geo-Synthetics, Inc., Waukesha, Wis., a distributor/installer of geomembranes and geotextiles for environmental and construction applications, has purchased United Linings from Ace Asphalt in Phoenix. Annual sales from this new location are projected to be $6 million. Covington, Ky.-based Waste Reduction Technologies, which has exclusive rights to a process developed at the University of Alabama for reducing the bulk of solid waste, is being acquired by DynaMotive Technologies, Vancouver, Canada. The agreement was facilitated by Chase Manhattan Bank.

Ford And Freightliner - The Real Deal PORTLAND, ORE. - With its pending purchase of Ford's heavy truck business, Freightliner Corp., Portland, Ore., stands ready to claim nearly 40 percent of the Class 8 market.

If the deal is finalized and approved by the government, Freightliner will own technology, tooling and assembly equipment for Ford's HN80 truck line - including the Louisville and Aeromax. "The product line acquired from Ford will not carry the Ford name," Jim Hebe, Freightliner's President and CEO, told World Wastes. "We will rename it in the near future."

According to Hebe, Freightliner intends to sell the trucks through separate sales, marketing and dealer organizations. "Only current Ford dealers will sell and service the products we acquire," he said.

Although the production facility for the HN80 products has yet to be selected, the company intends to start production by the end of the first quarter 1998. Hebe is remaining closed-mouthed about the product strategy, preferring to wait until Justice approval is received.

Following the sale, Ford dealers will continue to service the truck line and will retain warranty responsibility for the vehicles that it manufactured prior to the sale's completion.

According to Ford, employees will be accommodated within the company, but working for Freight-liner is not prohibited. "We would certainly value the experience and knowledge of the Ford employees and will definitely consider hose employees who are interested in working for us," Hebe said.

Though both companies are keeping the deal's specifics under wraps, industry analysts are estimating a $200 million price tag for Ford's Heavy Duty Truck line

The transaction will effectively end Ford's heavy truck market involvement in Canada, Mexico, Australia and the United States.

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