When Athens Services opened its mixed waste processing facility in the Los Angeles suburb of Sun Valley, California, in 2014, it was equipped with the most advanced technology available at the time for sorting recyclables, Athens sources say. Designed to process 70 tons of mixed waste per hour, the sorting system included a bag breaker, several types of screens and air and optical sorters to separate paper and plastics grades and aluminum from waste.

In its short history, the plant, part of Athens Services, a hauling and disposal firm located in City of Industry, California, arguably has become one of the most sophisticated mixed waste processing facilities in the country.

As a processor of mixed waste loads from multifamily and commercial enterprises, inbound material isn’t always the cleanest, but the end products could rival that of any single-stream recycling facility, Athens says. This accomplishment earned the company an Excellence Award from the Solid Waste Association of North America, Silver Spring, Maryland, in 2016.


Riel Johnson, the general manager of the Sun Valley facility, says operating a successful mixed waste processing facility really comes down to one word—diligence.

“Every one of our team members needs to be watchful of how the system is running,” he says. “That includes the spotter on the tipping floor selecting the loads to be processed, the operator in charge of loading the system at the right pace with the right material, the sorting team making sure we make high-quality product, the maintenance team constantly maintaining the equipment at peak performance and the forklift operator loading the container so that the material looks good when it arrives at the customer’s door.”

Johnson says volumes have continued to grow as a result of some new contracts and the diligence of his employees. The company also is among the firms that received contracts in LA’s new commercial franchise system.

Athens expects to handle 2 million tons of garbage by the end of 2017. A good portion of that waste will end up in Sun Valley, where customers are given many options, Johnson says.

“The way we are processing waste streams has gained attention on the local and national level,” Johnson says. “We take a consultative approach, learning about opportunities with the potential client and developing solutions that other local haulers cannot provide.”

The added publicity has helped boost business, and so has the Athens Services sales force.

To handle the additional materials, the facility added a shift and hired 50 additional employees. The facility now has 126 employees. “There are a few days a week we are bumping up against our 1,500-ton-per-day permitted limit,” Johnson says.


Rising labor costs and a desire to eliminate repetitive motion jobs that can cause injury has led to Athens’ most recent investment—a Max-AI unit from Bulk Handling Systems (BHS), Eugene, Oregon. Max-AI is designed to use artificial intelligence (AI) that identifies recyclables and other items for recovery. Athens became the first facility to employ this new technology in April.

BHS says Athens was an ideal location for the first installation of Max-AI robotic sorters to complement the screen, air and optical separation technology BHS built that is already in use. Integrating the facility’s existing optical sorters by NRT (National Recovery Technologies), Nashville, Tennessee, Max-AI is designed to provide a fully autonomous polyethylene terephthalate (PET) sorting solution.

“We have installed a robot to perform quality control (QC) on the PET containers after the bottles are sorted out of the waste stream by an optical sorter,” Johnson says. “Eventually, we will install robots as it makes sense at our other QC stations. We have also programmed one of our optical sorters to look for the higher valued polypropylene (PP) resin.”


With China’s new National Sword rules affecting what the largest importer of U.S. recyclables will take in, Johnson says there have been some changes at the facility.

“National Sword is really impacting the plastic world,” Johnson says. “There may be some grades that we will stop making altogether, such as mixed plastic Nos. 3 through 7, film and bulky rigid plastics. National Sword has also forced us to really step up our game in fiber quality,” he adds.

To do that, Johnson says, employees have had to make some changes to how the processing system is run. This has included running the system a bit slower and adding sorters in some cases. He says a lot of training has been given to facility employees, and bales of finished goods have been broken open to measure contamination levels. He says all the education has been internal and has not involved customer outreach. “Because we are a mixed waste processor, there is not a lot of education to give our customers. It all falls back on us,” he says.

In the midst of lower fiber pricing and stricter quality standards, Athens Services has been able to maintain quality. Making only two fiber grades—mixed paper and old corrugated containers (OCC)—has been beneficial in this effort. “This has helped us a little bit because we are mixing a lot of newspaper into the mixed paper, which helps us keep a good quality and a good grade,” Johnson says.

He also noticed an interesting byproduct of using the Max-AI. “When we first installed it, we thought we were really challenging it,” he says. The facility began using the unit on single-stream material; but, as it turned out, the Max-AI unit was up to the challenge of municipal solid waste (MSW).

“There were more PET bottles in the MSW than the single stream,” Johnson says. “Single stream is scavenged harder (since California is a redemption state), and we ended up with a richer material in the MSW.”

Organics is another subset of the waste stream Johnson says Athens is looking at targeting more aggressively. California’s Assembly Bill (AB) 1826 is requiring businesses to recycle their organic waste. He says the company, which already owns a composting facility, is looking into technology, such as anaerobic digestion and mechanical equipment resources, to process organic waste. He adds that the state has strict regulations that only allow for 0.5 percent contamination in compost.

Johnson says Athens also will continue to look at data gathering in Sun Valley. “There will be better data acquisition from the system and the tipping floor so that we can fully measure the facility’s performance and determine if any process changes have improved the recovering of materials from the waste.”

The facility already is using a supervisory control and data acquisition system designed to mine data and track uptime and the causes of day-to-day issues. He says based on the system’s feedback, the facility is running at a 95 percent uptime.

Data gathering also is taking place on the tipping floor. Johnson says Athens’ process improvement manager has developed an app for tablet devices that allows the company to rate loads by cleanliness and dryness. Athens can download information to an Excel spreadsheet and monitor changes in routing. The company can then provide feedback to the hauler.

“You can’t let your eye off the ball because, if you do, you could be out of the game,” Johnson says. “By constantly challenging ourselves, Athens Services has been able to adapt to the constantly changing markets, regulations and technologies affecting this industry.

The author is editor of Waste Today and can be reached at ksmith@gie.net.