Last year there were four award winners. This year the judges picked five. Clearly the competition is becoming fierce.

By John Trotti

Gold Award
Silver Award (Tie)
Bronze Award (Tie)

Introducing last year’s SWANA’s Landfill Excellence Award Winners, we noted that the bar has been raised each year and "competition is stiffening." Well, we sure did we call that shot, and this year we had two ties, proving just how intense the competition has become. So while you join MSW Management in applauding this year’s winners, make your plans now to enter and win one of SWANA’s 2002 Landfill Excellence Awards. This time, however, the competition will be getting downright fierce.

Gold Award

Southeastern Public Service Authority

Since 1977, the Southeastern Public Service Authority (SPSA) has been developing and operating an integrated solid waste management system to serve the residents and businesses of eight communities in southeastern Virginia: Chesapeake, Franklin, Isle of Wight, Norfolk, Portsmouth, Southampton, Suffolk, and Virginia Beach. Together they encompass an area of 2,000 mi.² and are home to approximately 1 million residents who generate more than 1 million tpy of solid waste. More than 400 SPSA employees are responsible for the daily management of the region’s solid waste, while SPSA Board of Directors, composed of a member and alternate representative from each community, oversees system development. The board’s mission is to develop SPSA into "an independent, innovative, regional organization that aggressively provides comprehensive, cost-effective, solid waste management in an environmentally sound manner, incorporating state-of-the-art methods and technology and educating the public on responsible waste management." This mission reflects the philosophy behind the establishment of SPSA: to collectively manage the region’s waste utilizing a variety of methods to reduce reliance on landfilling. Today the programs and operations presented in this article are evidence of this philosophy and of SPSA’s continued commitment to provide the region with innovative, integrated waste management. SPSA’s integrated solid waste management operations include waste-to-energy, a landfill, a transfer station, household hazardous waste (HHW) collection, recycling, and community education.

Regional Landfill

Aerial photo of Regional Landfill

Regional Landfill is located in the city of Suffolk, at a site central to both the eastern and western communities of the service area.

The site encompasses more than 300 ac. and serves as the location for additional SPSA operations, including yardwaste composting, HHW and used-oil collection, tire shredding, ferrous-metal processing, transfer vehicle maintenance, and landfill gas (LFG) recovery and reuse. The synthetically lined landfill received its first ton of solid waste in l985, and today approximately 44% of the waste managed by SPSA is disposed of at the landfill. This nonprocessible waste is spread, compacted, and covered with a 6-in. layer of soil at the end of each day. Groundwater is regularly monitored through the landfill groundwater monitoring. Facilities include:

• a ferrous-metals processing plant,
• a Virginia Recycling Corporation tire processing plant,
• a ZAPCO LFG-to-energy plant,
• a Soilex soil remediation facility,
• an administration/maintenance building,
• a yardwaste composting facility,
• an HHW collection facility,
• a vehicle and equipment wash facility,
• a leachate pond and pump station,
• a citizens’ waste drop-off area,
• a scale house.

Approximately 150 ac. of the landfill site are used for actual disposal of solid waste. SPSA recently constructed a 43-ac. landfill cell known as Cell V, which exceeds federal and state regulatory design requirements, and began accepting waste in May 2000. Cells I through IV of the landfill also remain in operation. The existing landfill is expected to have 10-12 years of disposal capacity. SPSA also plans to construct an additional disposal cell, Cell VI, on the existing landfill site, which will likewise add another 10-12 years of active life to the landfill. In anticipation of the area’s disposal needs beyond that point, SPSA is proposing to expand the landfill onto a portion of a 525-ac. parcel adjacent to the existing landfill. The proposed expansion area, Cell VII, occupies 69 ac. in the southernmost third of the site, between the gas pipeline easement and US Route 13/58/460.

Design and Construction

Employees at the opening of Regional Landfill's Cell V

Cells I through IV. Regional Landfill has been a state-of-the-art facility since the Virginia Department of Health issued its initial permit in September 1983. Although this permit preceded the promulgation of the federal Subtitle D regulations and the resulting changes to the state requirements, the facility design included a clay and synthetic liner system with leachate collection piping. The Cell IV construction package included a leachate pretreatment system consisting of a holding lagoon for equalization, an aeration lagoon, and a pumping station/force main for conveying the pretreatment leachate to the Hampton Roads Sanitation District for final disposal. To minimize turbidity in groundwater sampling, SPSA uses QED Well Wizards.

Cell V. SPSA began planning the Cell V expansion in 1993. In 1997, all permits had been obtained, but SPSA decided to consider a revision to the Cell V design to an inward gradient system for both economical and environmental reasons. The landfill economics are improved by gaining additional airspace through significant excavation prior to liner placement. SPSA has been able to directly compare the economics of the conventional Cell V design to the inward gradient design. In 1997, bids were received for construction of the conventional design, with a low bid of $8.6 million. The conventional design included 2.1 million tons of waste capacity. Therefore, the liner system cost was $4.05/ton of capacity constructed. The inward gradient design was bid in 1998 and was awarded for a construction cost of only $8.9 million, an increase of only 3.5%. However, the design affords 3.7 million tons of capacity, an increase of 76%. This calculates to a liner system cost of only $2.38/ton of constructed capacity. Viewed incrementally, Cell V afforded 1.6 million tons of waste disposal capacity for only $300,000, equating to only $0.20/ton of capacity gained. In addition, 1.5 million yd.³ of soil was gained from the excavation. Based on historical costs to truck in cover soils, the soil is worth more than $10 million to SPSA.

Innovation and Creativity

In addition to the innovations of Cell V described in Section 2, SPSA’s Regional Landfill is host to a number of unique solid waste management facilities and practices.

Pipe installation for Cell V construction

Soil Remediation. In 1999, SPSA opened a 15,000-ft.² soil remediation and treatment facility at Regional Landfill. The facility, operated by Soilex Corporation, specializes in treatment and recycling of petroleum-contaminated material. The site receives the majority of the region’s waste materials from oil spills and other emergency response actions. Once treated, the material is used for landfill cover, offsetting the cost of transporting material from off-site.

Yardwaste Composting. Yardwaste recycling facilities are located at Regional Landfill. Leaves, grass clippings, and tree trimmings are converted into mulch or composted to produce approximately 80,000 yd.³ of 100% recycled material each year. Mulch and compost are sold to landscapers, nurseries, and residents for use in gardening and lawn care under the trade name Nature’s Blend.

Drop-Off Center. A drop-off recycling program was initiated in 1991 for residents not receiving curbside service. Today there are more than 35 drop-off sites located throughout the communities SPSA serves, one of which is at Regional Landfill. Residents may bring recyclables such as newspaper, cardboard, phone books, glass bottles and jars, aluminum cans and foil, steel cans, and household dry-cell batteries. Most drop-off sites are available for residents’ use 24 hours a day.

Ferrous-Metal Processing Plant. The ferrous-metal processing plant cleans and presses into nuggets the ferrous metal extracted from the wastestreams at the refuse-derived fuel plant and the power plant. Each month, the plant processes approximately 1,000 tons of material for sale to steel mills. The ferrous-metal processing plant opened in October 1989–only the second facility of its kind in operation in the country. A private contractor operates the facility for SPSA.

Tire Shredder. The tire shredder processes approximately 200,000 tires each year received from residents as well as commercial and municipal haulers. Automobile tires are shredded to create fuel for use at the power plant, and truck tires are collected to serve as raw material in the manufacturing of solid-rubber industrial equipment tires. As with the ferrous-metal processing plant, the tire shredder is located at Regional Landfill and operated by a private contractor.

LFG/Power Generation. In 1995, SPSA’s landfilled waste became an energy resource to residents of the Tidewater Region. Zahren Alternative Power Corporation (ZAPCO) constructed and operates the nearly $5 million facility, which produces electricity through use of four generator sets (3.2 MW) for sale to Virginia Power. The plant produces enough electricity to power more than 6,000 homes. Broadening its operation, ZAPCO is currently constructing an LFG line to a local industry to provide an additional fuel source for their boilers.

Silver Award (Tie)

Integrated Solid Waste Management Facility

In 1989, despite much involvement with an adjoining county government in a joint venture to site a landfill, the City of Bristol, VA (population 18,000), was rapidly running out of airspace in its existing landfill and faced imminent closure.

Immediately adjacent to the city’s existing landfill lay the abandoned Vulcan Materials Company limestone quarry. The quarry, with canyonlike dimensions, had recently closed in 1988. Vulcan previously investigated the possibility of using the quarry as a regional landfill and went so far as to initiate a preliminary feasibility/marketing study, but the prospect of successfully permitting a landfill through the Virginia Department of Waste Management seemed remote.

Three salient points emerged that led the city back to the Vulcan quarry: (1) the belief that Subtitle D regulations would render small jurisdiction ownership and management of individual landfills prohibitively expensive, opening the door for larger regional facilities; (2) the same regulations were primarily performance-based, thus allowing greater engineering flexibility needed for a landfill development in a rock quarry; and (3) redirecting the jurisdiction’s MSW effort from disposal to transfer with the associated costs and uncertainties was deemed unacceptable.

A feasibility study conducted by STS Consultants Ltd. indicated that the quarry landfill was technically viable, and construction began in September 1996. Funding for the landfill construction and start-up operations was provided by a combination of general fund reserves, user tipping fees, and two general obligation bonds. A $3.5 million development grant was also secured from the Tennessee Valley Authority.

Design and Construction

Overall the quarry had dimensions approximately 2,100 ft. long on its north/south axis, 800 ft. wide, and nearly 350 ft. deep, yielding a preexcavated airspace nominally valued at $8 million to $16 million as compared to conventional landfill excavation costs. The quarry was configured as a figure eight with the north and south end separated by a narrowed neck. A development plan for both ends of the quarry provided for the north end to be developed first, followed by the south end. This development scheme provided for unequal phases with nearly three times the volume in the south end versus the north end and a total capacity of 8 million yd.³ This airspace capacity at current filling rates would serve the region’s landfill needs for about 35 years.

With a preliminary development scheme in mind, an economic model projected a cost of operations and capital amortization ranging from $12 to $16.50/ton, depending on several operating assumptions. These break-even cost projections assumed that the capital costs could be amortized over the full life of the facility.

Early planning determined the quarry to be feasible if (1) it was initially operated as a balefill; (2) the required regulation variances were granted during the permitting process; and (3) a follow-up geotechnical analysis revealed the slope stability concerns were manageable. Baling was considered important so that the MSW was prestressed in advance before disposal to minimize stress, strain, and settlement because of downdrag forces on sidewall liner system.

MSW is delivered to the 20,000-ft.² tipping floor at the transfer station where it is screened, sorted, and blended for smooth baler operation and maximum bale density. In-situ baled waste densities average nearly 1,600 lb./yd.³, with fill depths ranging from 50 to 100 ft.

The leachate management system consists of collection piping, a wet-well sump, and a 325-ft.-deep access shaft. About 3.1 million gal. of leachate was managed and treated in 2000, and currently the leachate quality meets all of the pretreatment standards required by the sewer utility. Scrap tires, which are shredded and recycled on-site, are used as fill in the upper portion of the leachate collection blanket drain. The lower part of the leachate collection blanket consists of a 6-in.-thick sand blanket overlain by 1 ft. of noncalcareous aggregate.

The LFG management system consists of a horizontal gas collection/vent system installed during the bale placement activities. These gas collection legs are connected to a header to vent gas and minimize gas-pressure development. The headers and drop-pipe risers are monitored for LFG constituent concentrations and pressure.

As the lowest dewatering point within several miles, the quarry serves as a groundwater sink for the region. Upgradient groundwater monitoring wells are located around the quarry rim. These wells determine the natural background groundwater quality. Each of these drain legs is designed to be permanently saturated below the base liner. The backpressure in each drain leg may also be varied by adjusting the weir levels in the access shaft sump on an as-needed basis to control groundwater flows below the baseliner system.

The baling/transfer station is designed for material handling efficiency and consists of a two-level baling and tipping floor. A horizontal conveyor moves the MSW refuse from a conveyor pit on the upper tipping floor to the baling hopper below and is compacted in a two-stage baler. Bale loading, cleanup, and maintenance occur on the lower baling floor, where bales are loaded with forklifts and then transported via rolloff truck to the disposal location in the quarry landfill. The bales are then unloaded and placed in blocklike walls/wall faces and later covered with an alternative daily cover (ADC).

The facility currently serves a four-state region consisting of regional communities and solid waste management districts, as well as private haulers mostly within a 100-mi. radius. Bristol has managed both the operations and marketing of the quarry landfill and has increased the daily MSW receipts to average more than 600 tpd in a three-year period since start-up. MSW growth has been almost 200% alone in the last two years. Even greater growth has been experienced with nonbaleable wastes. The city currently offers an advertised $25.50/ton MSW tipping fee. Volume discounts are offered under service bids or negotiated contracts for larger-volume and longer-duration contracts. The quarry landfill currently ranks as the local low-cost provider.

Annual quarry landfill revenue currently approaches $4 million per year, which covers the $1.75 million annual cost of operations. Modest revenue is also earned in other operations. The city maintains financial assurance in the amount of $4.3 million for estimated closure costs and $3.4 million for the estimated postclosure care costs under the terms of the quarry landfill permit.

Innovation and Creativity

The sidewall liner system was created out of a laminated sandwich of geosynthetics consisting of a 16-oz. needle-punch geotextile overlain with a 60-mil, single-sided, textured HDPE geomembrane overlain by a double-sided, trilinear geocomposite drain. These three geosynthetics act together to create a barrier system to control water flow on both the front and back sides of the geomembrane, to cushion both sides of the geomembrane from damage, and to provide a preferred friction slip-surface between the geomembrane and the buffer/structural fill placed inboard of the composite drainage layer, if necessary. The sidewall liner also acts as a rockfall mitigation system.

Tajiguas Landfill

Tajiguas Landfill is the only landfill serving the south coast of Santa Barbara County, CA, which in 2000 had a population of approximately 262,200. Typically, 700-800 tpd are delivered to the site by an average of 75 vehicles, primarily commercial, as Tajiguas does not accept self-hauls except from immediate neighbors.

Santa Barbara County's recycling logo (above) and solid waste staff (below)

The landfill is situated in a small, confined, south-facing coastal canyon 26 mi. west of the city of Santa Barbara. In its present (January 2001) configuration, the landfill has nine 40-ft.-high, generally south-facing benches that abut the east side of the canyon and partially abut the west side of the canyon. South of the fill area, a cutoff trench extending into bedrock intercepts subsurface water flow and some piped discharge so there is no offsite subsurface water discharge.

Through the early 1990s, waste cells were routinely constructed behind earthen berms measuring between 15 and 50 ft. thick. The area method of disposal was used, requiring refuse-hauling vehicles to travel on a landfill access road over previously buried refuse to the disposal area. Ridges were constructed on the top deck in an east-westerly direction, dividing the top-deck drainage pattern into two parts. As additional waste lifts were placed, a slope was built onto the interim surface to promote drainage. By the mid-1990s, imminent expansion beyond previous waste areas as defined in 1989 required that a liner be installed along the east side of the landfill on the eastern canyon wall.

In 1999, a new configuration was designed to take advantage of a considerable amount of permitted airspace volume of the outside faces of the landfill. A permit was obtained to excavate parts of the thick soil retaining berms of the lower benches (built in the 1960s) and to emplace new refuse fill at a steeper angle (2:1 vs. 3:1). This phase of construction was referred to as the Benchfill Plan that began in November 1999 and is projected to provide approximately six years of additional landfill permitted airspace.

To prevent the generation of leachate, stormwater is diverted around the active landfill via a 48-in.-diameter subsurface culvert that drains the lower in-channel basin and generally follows the western perimeter of the landfill. Runoff is transmitted via a concrete drainage outlet structure south of the toe of the landfill, leading to a natural water course just east of the entrance road. From here it travels about a mile, in part under the freeway, and is discharged into the ocean.

In California the average tipping fee in 2000 was $39.62 and the highest was $85, according to a survey published in 2001 by the California Integrated Waste Management Board. Tajiguas’s integrated tip fee of $48 helps fund programs critical to increasing the longevity of landfill.

Vehicles check in at the scale house, where they are weighed on a computerized scale using Compu-Weigh and Weigh Station software. The vehicles are spot-checked for hazardous materials by scale-house personnel, and records of the daily wastestream from private haulers and county-operated transfer trucks are compiled daily. In addition to screening for hazardous materials, checkers try to identify valuable recyclable loads that can be redirected to the South Coast Transfer Station for recycling.

At the end of each operating day, if the newly placed waste layer is not yet to grade, it is covered with 6 in. of clean soil from the soil borrow area or an ADC. The cell is constructed, and cover is placed to promote positive drainage in the area. The next working day, the process is repeated. Approved ADCs at Tajiguas Landfill include greenwaste, foam, and tarps. The use of an ADC can save from 125 to 150 yd.³ of airspace a day. The use of a tarp ADC has been found to conserve the greatest amount of airspace and therefore is used more often.

Typical waste cell dimensions are approximately 17 ft. high, 125 ft. wide and 20 ft. deep. As often as possible, the county surveyor’s office helps establish the line where waste cells start and finish using a global positioning system unit. Waste cell density is tracked via aerial topographic photos taken approximately every six months and then calculated against how much airspace is available.

Immediate dust control at the site consists of the daily spraying of water by water truck(s) on roads and in active working areas. Preventative control measures include applying soil stabilizer such as Soil Sement, a liquid binder that hardens the soil surface, forming a crust, making it resistant to wind erosion for months at a time; hydroseeding on bare slope areas to bind soil and reduce blowing dust areas; applying wood-chip mulch (generated at the landfill) on borrow areas not in use for the season; removing loose earth from haul roads and restricting travel on unpaved roads; and capping frequently used haul roads with asphalt.

Cell construction is planned and sequenced to minimize exposure to prevailing winds during winter and summer and to orient, when possible, the working face to shelter waste unloading areas from winds blowing north-south. During severe wind events, there is a contingency plan for redirecting waste bound for the landfill to the transfer station. Standby operations personnel are available to staff the landfill on Sundays or holidays if large flows of stormwater runoff occur. Other controls include minimization of the working-face size, immediate and increased compaction of waste, and placement of earth berms around the active area.

Three leachate collection and removal systems operate at Tajiguas. The first system is a subsurface collection trench located in the narrowest part of the canyon downstream of the landfill. The second system is part of a composite liner located on the eastern side of the landfill. The liner and leachate collection system consists of a 60-mil-thick plastic liner membrane, a geosynthetic clay layer (GCL), and associated collection and drainage piping. The third system consists of three horizontal wells–each 200 ft. long–constructed at a level between the toe of the landfill mass and the first bench. Liquid collected from these wells is drained by gravity to a 4,300-gal., aboveground, double-contained storage tank located near the wellheads.

A GCL system covers an area of approximately 300,000 ft.² along the eastern slope of the canyon. The GCL was installed over the subgrade and was in turn overlain by a flexible membrane liner (FML) made of high-density polyethylene (HDPE). On slope areas, the FML is textured on one side, with the textured side placed down and in contact with the GCL to prevent slippage. The FML on slope areas is further overlain by 16-oz. nonwoven geotextile material, which in turn is overlain with scrim reinforced protective plastic in areas not covered with the protective cover/operations layer. On relatively flat-bottom areas, the HDPE membrane is textured on both sides and is overlain by a 12-in.-thick gravel layer, an 8-oz. nonwoven geotextile, and a 24-in.-thick operations layer composed of onsite screened material with a maximum 1-in.-diameter particle size.

The Tajiguas LFG-to-energy project, a partnership between the Santa Barbara County Department of Public Works and NEO Inc., resulted in the installation in 1998 of the active LFG collection and disposal system at the Tajiguas Landfill. Designed to reduce surface emissions of LFG while concurrently meeting regulatory requirements of EPA’s New Source Performance Standards, the LFG system at Tajiguas consists of a network of vertical LFG extraction wells, laterals and headers that convey the LFG to the cogeneration plant and flare.

Bronze Award (Tie)

Brea Olinda Alpha Landfill

Olinda Alpha Landfill (OAL) is a Class III Sanitary Landfill located in Orange County, CA, adjacent to the city of Brea. It is located on a 562-ac. county-owned property, of which 420 ac. are used for waste disposal. OAL accepts only nonhazardous MSW. The service area of the landfill includes the cities of Anaheim, Brea, Fullerton, Garden Grove, La Habra, Orange, Placentia, Yorba Linda, and several unincorporated Orange County communities that deliver solid waste for disposal under long-term contracts for $22/ton disposed.

Three privately owned transfer/MRFs process solid waste for the cities and deliver residual waste and waste self-hauled to their facilities to Olinda under the contract rate. Approximately 12% of the waste disposed is delivered by self-haul to the landfill at a disposal rate equivalent to $27/ton. In addition to Orange County waste, OAL also accepts imported waste from surrounding communities in Los Angeles, Riverside, and San Bernardino Counties.

The landfill is operated by the county’s Integrated Waste Management Department (IWMD). OAL is the fourth-largest landfill in California based on a total annual 1999 disposal of 1.9 million tons. The landfill’s daily maximum permitted disposal capacity is 8,000 tons. The site receives approximately 6,300 tpd. The ultimate site capacity is 123.1 million yd.³

Operational since 1960, the landfill is composed of two canyons, Olinda and Olinda Alpha, which were initially separately permitted landfills. Excavation of the central ridge dividing the canyons was completed in October 2000 as part of a 1992 plan to provide necessary disposal capacity. By agreement between the County and City of Brea, OAL is scheduled to close in 2013; however, at the present fill rate and using best management practices, it is estimated that the active life could be extended to 2017 without additional major construction. With additional construction, engineers estimate that the landfill could be active until 2021.

What is unique about OAL is how the vertical expansion of the landfill was accomplished. First, the location of the two landfills side by side lent itself to the strategy of combining the canyons. Second, an innovative engineering design was created, providing an alternative solution that fulfilled the standards of the prescriptive requirements of federal Subtitle D regulations. The design also included an advanced oxidation process to treat impaired groundwater.

Other implemented projects include a gas-to-energy facility and the use of processed green material as ADC to overcome the site’s soil shortage.

A state-of-the-art groundwater extraction and treatment system was installed at OAL in 1996, consisting of 27 groundwater monitoring wells and 22 extraction groundwater wells equipped with an air-operated pump. The units are situated in extraction areas at the southeastern, southwestern, and western toes. Volatile organic compounds (VOC)—impacted groundwater extracted by the system is routed to a central collection tank prior to treatment by an advanced oxidation process referred to as Ultraviolet Light (UV)/Ozone.

The UV/Ozone treatment system processes 1,095,000 gal./yr., reducing influent VOC concentrations to less than the drinking-water primary maximum contaminant levels. The treatment involves adding ozone to the influent water and subsequently exposing the mixture to ultraviolet light within the treatment unit. The process converts the VOC into benign compounds of carbon dioxide and water. A final polishing unit, consisting of two activated carbon canisters, ensures that the final effluent meets the cleanup standards. The final effluent is stored in a treated water storage tank and ultimately used on the active portions of the landfill for dust control.

The current LFG collection system includes 164 vertical gas extraction wells, 82 horizontal gas extraction wells, and 29 horizontal migration control wells. Subsurface migration is monitored using 15 multidepth monitoring probes around the landfill boundary. An integral part of operating an LFG collection system is condensate management. At OAL, approximately 2,000 gal./day of condensate is disposed by injection into an operating flare. This method is efficient and cost-effective, as large storage capacity is not required.

Since 1984, the County of Orange, in partnership with private enterprise, has been converting LFG to electrical energy for sale to the local electric utility company. The LFGTE consists of three internal combustion engine/generator sets capable of delivering 6 mW, consuming about 2,000 scfm of LFG. Revenues derived from the sale of energy are used to offset the cost of installing and maintaining the LFG collection/disposal system. The gas-to-energy plant is supplemented by two 4,200-scfm enclosed ground flares for LFG disposal.

Since 1997, OAL has been effectively using processed green material (PGM) for erosion control and as ADC. PGM consists of yardwastes that are dried, crushed, shredded, and sorted. A demonstration project was conducted to determine if PGM used as ADC could meet regulatory and operational standards. This testing demonstrated that the plots covered with PGM performed better in minimizing rainwater contact with refuse than the plot covered with onsite soil. The data demonstrated that the PGM met the standards of soil cover in all areas.

During the extensive 1998 El Niño storms, in which the site received more than 35 in. of rainfall within 58 days, PGM-covered slopes showed no evidence of erosion. These slopes performed better than the slopes covered with traditional erosion control materials. ADC use has also enhanced landfill capacity, and its cover-to-refuse ratio has improved from 3:1 to 5:1.

Between 1993-94 and 2001-02, $49.7 million will have been invested in capital improvements at OAL. Completion of the construction project and the filling of that area with trash have already generated approximately $25 million in revenue. The excavated area is expected to generate approximately $49 million in revenue from trash fill. In addition, rephasing of trash fill sequencing and expedited completion of related projects are anticipated to save nearly $61.2 million between fiscal years 1998-99 and 2008-09 because offsite soils for daily cover will not be required.

Annual operational costs are estimated at $12.8 million. Starting in fiscal year 2001-02, the site is expected to generate approximately $41-million-per-year gross revenue through the scheduled closure date of December 31, 2013.

Innovative Practices

ADC. The master plan determined that the available soil for cover on-site is only sufficient through 2003; however, the extensive use of PGM and modified fill phasing plans significantly reduced site soil usage. This unique aspect has given the total refuse-to-soil usage an increase from 3:1 to 5:1 or better. It is now calculated that sufficient soil cover will be available through 2009 and possibly through closure in 2013. The use of PGM also provided excellent erosion control, reduced site maintenance on all PGM-covered slopes, and helped minimize LFG emissions.

Ultraviolet/Ozone Treatment System. The UV/Ozone Treatment System is a groundwater extraction and treatment system installed at OAL in 1996. The VOC-impacted groundwater is transferred to the Ultraviolet/Ozone unit to reduce the concentration of VOCs in the groundwater to levels acceptable to regulatory agencies. Once treated, the water is stored in a treated water storage tank and used on active portions of the landfill for dust control.

Alternative Liner for the Central Ridge. In 1997, IWMD requested and obtained an approval for an alternative liner to the prescriptive requirements of the California Regional Water Quality Board—Santa Ana Region. OAL demonstrated that the alternative liner provided equivalent groundwater protection as the prescriptive composite liner system. The Central Ridge Groundwater Protection System was subsequently constructed to satisfy this requirement. This resulted in a cost savings of approximately $3.5 million.

Caterpillar Computer Aided Earthmoving System (CAES). OAL is currently conducting a pilot project testing new technologies provided by the CAES in order to improve landfill operations. The project is designed to demonstrate the benefits that will be achieved, including controlling and reducing soil cover usage, better compaction, safer operation practices, and potential additional airspace, which will result in significant cost savings.

Crapo Hill Sanitary Landfill

Crapo Hill Sanitary Landfill (CHSL) is owned and operated by the Greater New Bedford Regional Refuse Management District. Located in Dartmouth, MA, CHSL accepts solid waste only from district member communities, the City of New Bedford, and the Town of Dartmouth. The 150-ac. facility is part of a broader system of integrated solid waste management services furnished to the member communities by the district. The current permit allows the landfill to accept 115,000 tpy. On average, the landfill accepts 425 tpd.

In early 1993, the CHSL site was completely undeveloped and comprised mostly woodland. Therefore, the initial phase of development had to include the construction of the supporting infrastructure and the initial landfill disposal cell, the Phase I area. The district borrowed $12 million via municipal bonds for the initial development and to get the project started. Construction was completed on January 1, 1995.

Approximately 50 ac. were used for the construction of the site entrance and access road, maintenance facility, scale, Phase I landfill, and stormwater control basin. Construction of the site access road necessitated filling 4,600 ft.² of wetland. To mitigate this impact, retaining walls were constructed along the edges of the roadway and culverts were installed to allow continued water flow in the wetlands. A replacement wetland area was constructed to compensate for wetland area lost because of the roadway.

The composite lined cell of approximately 20 ac. and leachate storage provided the initial five to seven years of disposal capacity. Leachate storage facilities included four underground tanks with a combined storage capacity of 60,000 gal. A drainage swale was constructed around the entire perimeter of the Phase I landfill to convey runoff to a stormwater retention basin with a storage capacity of 25 ac.-ft. In 1999, the district installed an LFG collection system with 11 vertical extraction wells, four horizontal collectors, and an open gas flare. In 2000, the average gas flow managed at the flare was 600 scfm.

In 2000, the district received a permit for the construction of the first two cells of the Phase 2 landfill. While full development will extend over a period of 17-20 years, Cells 1 and 2 will be constructed in 2001, providing approximately 1 million yd.³ of landfill volume, or five years’ capacity. Concurrently a duplex leachate pump station was constructed, allowing direct discharge of leachate into the city of New Bedford’s municipal sewerage system. This allowed the removal of the four existing underground leachate storage tanks. At the same time the district constructed a 100,000-gal. aboveground leachate storage tank fabricated of glass-fused-to-steel panels that will be used to store peak leachate flows and allow discharges to the municipal sewer during off-peak hours, if necessary.

The district employs a variety of measures to segregate and collect contact runoff. As a first defense, the landfill area in the vicinity of the active face is graded and sloped to prevent contact runoff from flowing off the landfill into the perimeter runoff management system. Flow diversion berms and swales are employed to prevent contact runoff from exiting the active landfill area and to prevent noncontact runoff from entering the active landfill area. These controls are implemented as a regular part of daily landfill operations.

Noncontact runoff is managed using conventional stormwater management methods. For example, noncontact runoff from landfill areas with intermediate or final cover systems is managed by onslope flow diversions and lined channels, which discharge to a swale at the toe of the landfill. This runoff is then conveyed through a series of swales and culverts to the Meadow Retention Area with a capacity of 25 ac.-ft. The system is designed to handle a 100-year storm.

CHSL implements a comprehensive waste-control and inspection program to monitor for the inappropriate disposal of recyclables and to prevent the disposal of other wastes prohibited from disposal. The program includes:

• a waste inspection to assess conformance with state prohibitions against the disposal of certain wastes,
• a hazardous-waste exclusion policy and waste inspection,
• an identification of asbestos-containing materials,
• a review and analysis of special wastes.

Waste prohibited from disposal in Massachusetts includes lead batteries, yardwaste, unshredded tires, white goods, aluminum, other metal and glass containers, single polymer plastics, recyclable paper (includes cardboard), and cathode-ray tubes. In addition, the state prohibits disposal of hazardous waste, liquid waste, sludges, asbestos-containing materials, and infectious waste.

Once a vehicle containing waste arrives at the facility, it is directed to the scale house where the attendant ascertains the source of the waste and identifies the waste hauler. At this time, the attendant has the opportunity to question the hauler and the option to request that the load be uncovered for viewing from a platform. In addition, each vehicle passing over the scale is scanned by a radiation detector to screen for radioactive material. A radiation monitor is mounted on the scale house. Randomly identified waste loads are subject to a comprehensive viewing and inspection of waste near the active face. This level of inspection includes dumping and spreading of the waste load so its contents can be viewed. Typically the waste is spread with a compactor and tracked to open bags in the load. Upon completion of each random inspection, a log is prepared, indicating the name of the waste hauler, the source of the waste, the general nature of the waste, and any waste prohibited from disposal. If a vehicle fails the inspection, a letter is sent to the hauler, providing the results of the inspection and type of infraction. Each month the facility chooses six vehicle loads for comprehensive inspection.

The equipment operators are also trained to recognize unacceptable waste as they spread and compact the incoming loads. All are familiar with telltale signs, which might indicate the presence of unacceptable waste, including asbestos-containing material.

Special wastes, which require specific handling or are regulated as such by the state environmental agency, are subject to a higher level of scrutiny and review. Based on the nature of the waste and its source, chemical identification tests are performed and reviewed by the district’s consultant.

Each year the district commissions a topographic survey of the landfill to determine landfill surface elevations, assess compliance with the state’s landfill slope requirements, and calculate in-place waste density. In 1999, the district achieved an in-place waste density of 1,400 lb./yd.³ In 2000, CHSL managed 116,210 tons of solid waste.

In an effort to preserve landfill capacity and reduce reliance on the use of natural soils, the district uses a variety of ADC materials extending operating life while reducing operating costs. In 1995, CHSL undertook a demonstration project for the use of Posi-Shell, composed of shredded recycled plastic, paper fibers, and kiln dust that form a slurry sprayed onto the surface of the waste. Once applied to the waste, the slurry cures to a shell-like consistency, which is resistant to water and discourages scavenging by gulls and other vectors. The district also utilizes other types of ADC available within the local waste management market, including automobile-shredder residue, fines from construction waste processing, and petroleum-contaminated soil.

The estimated operations budget for fiscal year 2002 is $4.1 million. This includes debt service but excludes capital project expenses. A summary of CHSL operations costs is tabulated below.

Innovative Technologies

In addition to the district’s aggressive ADC strategies, odor management is a major concern. When odors were becoming an issue with neighbors, the installation of passive vent flares in certain "hot spots" on the landfill provided rapid relief for odors caused by venting LFG. These vent flares, manufactured by Landfill Technologies Inc., are self-igniting, solar-powered LFG combustors that can destroy up to 50 scfm of LFG at any methane concentration that can support combustion. Low levels of positive pressure generated by LFG are enough to move the gas through the flare structure, and the solar-powered igniter provides a spark every few seconds to ignite the gas.

CHSL utilizes vent flares for odor and gas control on the leachate collection system cleanouts and manholes, at the leachate lift station wet well, and connected to stone-filled gas collection trenches on the landfill and around its perimeter where the potential of drawing air into the landfill precludes the use of the active gas system. The vent flares are easily installed and moved when necessary to address potential odors at specific locations. CHSL has purchased 50 vent flares for such use. When the active gas extraction system was installed in early 1999, a 2,000-scfm open flare manufactured by Organics Ltd. of Great Britain was provided to destroy collected gases.

John Trotti is the editor of MSW Management.