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Zanker Road Landfill

Zanker EntranceThe Zanker Facilities began operations in 1985 as a Class III landfill and developed into a major full service, resource management, composting/recycling facility and landfill for residents and commercial businesses. The major components of the operations are listed below:

Zanker Materials Recovery Facility

In 1990, Zanker began the extensive permitting process for the Zanker Material Processing Facility, ZMPF, formally known as the Owens Corning Fiberglass Landfill. The ZMPF was fully permitted in December 1998, and officially began operations in June 1999.

ZMPF is divided into several different processing areas, each capable of processing different types of waste streams. These areas include: Demolition Debris Recycling Area, Mixed Construction Demolition Recycling Debris Area, Mixed Debris Recycling Area and the Wood Waste Recycling Area.

Demolition Debris Processing

Since 1988, ZRL has been a leader in processing mixed loads of construction and demolition (C&D) debris with a unique "float tank" and screening system that separates the soil, mixed concrete, and wood components from the mixed debris.

ZMPF designed and constructed a complete Demolition Debris Recycling Facility that can process unsorted demolition debris materials at the rate of 135 tons per hour with a 95% diversion rate. This facility consists of a patented combination of conveyors, screens, magnets and water separation that separates the materials into manageable and marketable products. These products are than directed to other recycling operations on site or shipped directly to end product users.

Concrete Recycling

Concrete RecyclingZRL’s concrete plant was one of the first in the nation to convert concrete debris into aggregate products suitable for foundations and road construction.

The concrete recycling process begins with incoming clean concrete and reinforced concrete. Once the materials are unloaded at the site, non-acceptable materials are hand sorted out and recycled or disposed. Cleaned concrete is then loaded into the primary crusher where it is crushed. After the primary crusher, the material passes under a magnetic belt where steel is removed before moving to a secondary crusher that further reduces the particle size. The material is then screened to remove oversized pieces which are re-circulated back through the crushing circuit. During the entire process, employees and machinery remove non-aggregate materials that would compromise the products value.

Products produced from the recycled concrete includes a 3/4" class II base rock, utility sand, 3/8" pea gravel and a 1/2" and 3/4" drain rock. These materials are sold to contractors and the general public and are available for delivery.

Wood Waste Recycling

Wood Waste RecyclingLandscape contractors, demolition/construction contractors, and private individuals deliver wood waste and brush to the ZRRROL. Incoming loads composed primarily of brush; tree trimmings and wood waste are directed to the wood waste stockpile area for unloading. Wood wastes separated out at the other on-site recycling plants (especially the Construction waste sorting line) are also regularly transferred to the incoming wood waste stockpile.


The wood waste is ultimately ground and then screened to create wood chips and wood fines. The wood chips (anything larger than 3/8-inch) are temporarily stockpiled on site and then hauled off-site and used primarily as co-generation fuel and secondarily as mulch for various landscaping and agricultural purposes. The wood fines (anything smaller than 3/8-inch) are also temporarily stockpiled on site and then hauled off-site and used in landscaping projects or as soil amendment.

The Wood Waste plant consists of an electric Peterson Pacific grinder, an electrically powered trommel screen and a series of electrically powered feed, transfer and stacking conveyors.


Mixed C&D Debris Recycling Area

Sorting SystemZMPF also processes an extensive amount of mixed debris and debris box’s daily through a 240 foot long C&D sorting conveyor system. The system is utilized to remove a variety of materials; up to 16 products from the typical mixed waste stream.

The sorting conveyor system, which includes elevated work-stations, disc-screens and magnets is located above large concrete storage bunkers that hold recovered materials. When the storage bunkers become full, the materials are routed for additional on-site processing, or loaded and hauled to approved recyclers. Other materials such as mattresses, are processed separately into different products.  Residual materials are routed to a landfill for disposal.

The sorting system is capable of sorting 30 to 60 tons per hour with an average 60 to 70% diversion rate. The diversion rate and tons per hour vary depending upon the type of materials sorted.

Gypsum Wallboard Recycling

Gypsum Wall Board RecyclingContractors and private individuals deliver sheetrock to the ZRRROL typically with most of the loads being clean materials. Incoming loads composed primarily of sheetrock are directed to the sheetrock stockpile area for unloading. Sheetrock that is separated out at the other on-site recycling plants is also regularly transferred to the drywall stockpile.

In the recycling process, materials such as wood, metals, and trash are removed on-site leaving the sheetrock in smaller piles. These piles are consolidated in a stockpile where a Caterpillar dozer is used to crush the materials. These materials are loaded into transfer trucks and sent to a sheetrock recycling operation in Monterey.


Yard Trimmings Processing and Composting

Yard TrimmingsYard Trimmings processed at ZRL is primarily residential yard waste received on a contract basis from a variety of communities in the area or self-hauled by residents or businesses.

Once yard trimmings are brought to ZRL and contaminants manually removed, the yard trimmings are then screened to seperate the grass and leaves from the tree trimmings and brush. The grass and leaves are transported to the Z-Best Composting Facility in Gilroy for composting and the trimmings/brush is directed to the wood waste operation for additional processing.

Asphalt Shingle Processing

ZRRROL accepts and processes clean, separated loads of composite asphalt roofing shingles removed from residential buildings. The company sorts and cleans the old shingles and transports them to Oakland where they are processed into dry, granular asphalt that is shipped to other East Bay manufacturers to make “hot mix asphalt” used to build or patch roads throughout the region.

The plant also accepts commercial tier off and tar and gravel roofing. These materials are stockpiles and made into alternative daily cover (ADC).