Incremental growth

For more than 30 years, San Jose, California-based Zanker Recycling has worked to prove itself as a large player in the construction and demolition (C&D) recycling space. Beginning operations with the development of the Zanker Road Landfill in 1985, Zanker has grown to provide full-service waste processing services for more than 300,000 residents and commercial businesses in Northern California.

Zanker’s first venture into the C&D recycling space was the development of a demolition debris recycling facility in 1988. Since then, the company has expanded into other verticals, including concrete recycling, wood recycling, asphalt shingle recycling, drywall recycling and mixed C&D debris processing. Zanker manages these operations at two sites in San Jose, Site 1 and 2.

In addition to the company’s C&D recycling operations, it also boasts multiple sister companies under the Zanker Road Resource Management LLC umbrella. These sites—Z-Best Composting, Florin Perkins and ZeroWaste Energy Development Co.—encompass the composting, zero waste and waste transfer spaces.

Increased diversion

Over the past few years, Zanker Recycling has implemented large and small upgrades at both of its C&D recycling facilities.

In late 2018, the company installed an artificial intelligence- (AI-) powered robotic sorting system from Denver-based Plexus Recycling Technologies, the North American distributor of Helsinki-based ZenRobotics, at Site 2. The technology, called ZRR2 AI Robots, uses ZenRobotics’ automated sorting system to more effectively process and sort incoming mixed C&D materials while achieving high diversion rates.

The system, which has been online since July 2019, operates more than 20 hours per day with total production targeted at 155,000 tons per year.

“Because of our increasing tonnages and decreasing diversion rates at our facility, we decided to construct an entire new sorting operation that included robots instead of utilizing an existing operation,” Michael Gross, director of sustainability for Zanker, told Construction & Demolition Recycling for a previous article. “AI is bringing reliability to our industry by increasing not only our diversion rates but also the cleanliness of our commodities. AI is here to stay and quickly becoming the new norm.”

Following this installation, Zanker has since shifted gears to focus on smaller improvements at its facilities.

“The past three years, there hasn’t been complete major upgrades or new revamps, but there have been very small steps in furthering our diversion rates at our various plants … meaning that we’ve added little things here and there to make [our] operations better,” says Jerame Renteria, marketing manager for Zanker.

An example of these smaller upgrades includes the installation of onboard scales on wheel loaders used at Zanker’s recently added demolition recycling plant.

“Instead of our front loaders driving all the way to our scale house, which is on the other side of [Site 1], we now have the scales and the weights on the loader, so we can weigh it and know how much material was removed from our demo plant,” Renteria says.

He continues, “With this upgrade, we have increased our efficiency in regard to knowing how much material was translated from our demo line that is now going to enter into our source-separated process.”

By not having to reweigh material, Renteria says Zanker has been able to increase diversion rates by producing end market materials at a higher rate.

In addition to the wheel loader scales, Zanker also installed a new screen at the demo plant in 2021 to better separate process fines from larger debris. With the fines screen, Zanker can now separate processing fines down to a 1/4-inch, thus creating a higher quality product for use in the agriculture industry.

“If we’re creating process fines, we increase our diversion rate and have a market for that material to get sent out to California agriculture. The benefits of doing that are also reducing our … landfill costs. So, it’s good for the bottom line because we increased our diversion rate, and we increased material that’s going to an end market,” Renteria says.

Zanker also began using Tesla batteries at Site 1 in 2018 to store electricity during peak operating hours. He says, “That was probably one of the biggest advancements we’ve made at the site that can help us with our utility bills and overall [energy] consumption.”

At its concrete recycling operation, also at Site 1, Zanker added a telescoping radial stacker to move crushed material more efficiently to various locations on-site. Prior to this advancement, Renteria says personnel would move material with wheel loaders.

“Moving a big pile of concrete with a front loader is a very grueling task. It took a lot of man-hours and a lot of resources to do that,” he says. “Now, we’re able to deposit the material in one location and then simply adjust the stacker 20 feet to the right, and we’re able to make a new pile there instead of using the machinery and all the resources we had to before. It’s a lot safer, and our footprint is much lower.”

Prioritizing safety

Most recently, Zanker decided to install a fire prevention and monitoring system from West Bloomfield, Michigan-based Fire Rover. The system will be installed in most of the company’s facilities in the coming months.

“In the past, we’ve had [other] heat sensors notify us that there’s a fire and, when that happens, the fire department [has to] come out, our security needs to notify us and one of our representatives who has administrative rights has to come to the site to determine that we’re good to go before we can open [the facility] back up,” Renteria says. “With Fire Rover, we’re looking to eliminate the possibility of a fire breaking out so there’s no damage to materials and we don’t have to worry about material combusting.”

He says safety is the main priority for Zanker when it comes to past and planned upgrades.

“With a lot of the advancements we make, whether they’re a process line or [a] procedural change, our goal is to make sure that no one gets injured and that we’re able to process material at a fast rate,” he says. “Having a safe workplace with the technology that we use allows us to avoid any type of damages or harm that could possibly happen. When you’re in this industry, you have a lot of machinery and heavy material, and somebody can get hurt pretty easily … That’s why we’ve always been a firm believer in innovation.”

The author is the assistant editor of Construction & Demolition Recycling and can be contacted at hrischar@gie.net.