The Zanker Road Landfill, Rethink, Reinvent, Renew
You may not think of landfills as harbingers of a “green” future, but if you check the web site of the Zanker Road Landfill or, even better, visit the landfill sites on Zanker Road in San Jose you will think differently.
Historically, landfills have been the repositories of rubbish, defined as waste, refuse or litter of no value. But about ten years ago as municipal dumps filled up, the importance of finding ways to re-use the debris from construction and demolition grew rapidly and rubbish began to acquire commodity status and a bigger market.
Today, Zanker Road Resource Management, Ltd., which was formed in 1985 to operate the Zanker Road Landfill (ZRL), receives up to 2,600 tons of materials per day from around the Bay Area.
In 1999, after completing a nine-year permitting process, the Zanker Materials Processing Facility began operations. The ZMPF is divided into several processing areas devoted to different kinds of waste: demolition debris, mixed debris, and wood waste. The Facility, which can process unsorted demolition debris at the rate of 135 tons per hour, separates the materials into manageable and marketable products. These products are then directed to other on-site recycling operations or shipped directly to end product users.
The 240-foot-long Conveyor Sorting System, which includes elevated work stations for employees, disc-screens, and magnets, is located above large concrete storage bunkers that hold recovered materials. The sorting system is capable of sorting 30 to 40 tons per hour; it removes a variety of materials and creates up to 16 products from a typical mixed waste stream.
During the sorting process the mixed construction and demolition debris is removed from the soil, and the residue is loaded into a tank of water. Wood floats to the surface where it is collected and dried. Metals and rubble drop to the bottom of the tank where magnets remove the metal.
Using heavy equipment, the wood is loaded into a grinder. The shredded wood is then screened and separated into wood chips and fines similar to sawdust. The site of this operation is shown above.
The accumulated wood chips are either sent to markets as fuel for electric generation facilities or colored and sold as landscape mulch, shown below. The fines are sold as soil amendments and blended with other products on site to produce top soil. All products are sold to landscapers, contractors or the general pubic.