Coming into focus

In 2007, the city of San Jose, California, had a vision for its future that included economic growth, environmental sustainability and an enhanced quality of life for its community. Nearly seven years later, the Green Vision is becoming reality with the help of the city’s integrated waste division and its partners in waste collection, processing and energy recovery.

The Green Vision, adopted by San Jose City Council in 2007, outlined 10 goals the city is to meet by 2022. The Green Vision was developed to “transform San Jose into the world center of clean technology innovation, promote cutting-edge sustainable practices and demonstrate that the goals of economic growth, environmental stewardship and fiscal responsibility are inextricably linked,” according to the city’s website, www.sanjose.gov.

Stephanie Molloy, the supervising environmental services specialist in integrated waste management for the city of San Jose’s Environmental Services Department, says waste collection and processing fits into four of these goals:

• create 25,000 clean tech jobs (Goal 1);
• receive 100 percent of the city’s electrical power from clean renewable sources (Goal 3);
• divert 100 percent waste from landfill and convert waste into energy (Goal 5); and
• ensure that 100 percent of public fleet vehicles run on alternative fuels (Goal 8).

Down to business

To achieve the aggressive waste diversion goals set forth in the Green Vision, the city of San Jose determined it needed to overhaul commercial waste collection.

“Before the commercial system redesign, there were variations in the availability and quality of commercial services,” describes Molloy. She says more than 20 providers were servicing San Jose’s commercial sector. While it was easy for the larger businesses to secure garbage and recycling services at a lower rate, smaller businesses had a more difficult time obtaining adequate services, she says. The separate providers also did not coordinate their services which also caused traffic issues.

“The variations in the level of recycling services resulted in a low overall commercial sector diversion rate, which was at that stage approximately only 22 percent,” Molloy says.

The lack of guaranteed tonnage also prevented waste management companies from investing significantly in high-tech waste processing facilities in San Jose, according to Molloy.

In 2008, a waste characterization study was conducted in which the findings came as no surprise. “It identified a potential for almost a 79 percent commercial solid waste to be diverted through recycling and composting.” Molloy says. “The study found a large opportunity to improve recycling and the processing of organics.” She adds, the study is why initially San Jose targeted the commercial sector.

The city government issued a five-year notice to nonexclusive franchise haulers that commercial contracts would be expiring and the collection system was going to be overhauled.

In 2012 the city released two requests for proposals (RFPs). The first RFP was for the overall collection of commercial waste, processing of all nonorganics and preprocessing of organics. The second RFP was for the processing and management of organic waste. Both of these RFPs included bringing infrastructure into the city limits for processing the material. “This not only aligned with our Green Vision goals of diverting waste from landfill and powering from renewable sources, but Goal No. 1 was to create 25,000 clean-tech jobs,” Molloy explains.
 

Facility development

Republic Services, based in Phoenix, was awarded the contract for collection and recycling, and local company Zero Waste Energy Development Co. (ZWEDC) was awarded the organics processing contract.

“These RFPs contained contracts that were pretty much unheard of up until that point,” says Molloy. “The terms include a guaranteed tonnage stream and the length of the agreement was 15 years.”

Carl Mennie, division manager for Republic Services of Santa Clara County, California, says Republic’s proposal included a plan to process all material being collected from commercial businesses, meaning no material would go directly to a landfill. The material recovery facility (MRF) was built in an existing building that was already permitted for the tonnage capacity.

Republic’s fleet of collection trucks run on compressed natural gas (CNG) and service about 8,000 commercial accounts in San Jose.

The MRF, Newby Island Resource Recovery Park (NIRRP) opened in summer 2012. It was designed by Bulk Handling Systems (BHS), Eugene, Oregon, to sort wet waste, dry waste and traditional recyclables and is considered one of the largest facilities of its kind in the world.

“The scale is where it really becomes noteworthy,” says Mennie, who says the facility processes about 300 tons per day of commercial material. “There are probably some other smaller wet/dry pilot programs, but no one has gone through doing something the size of the city of San Jose in that manner.”

In 2013, 205,312 tons of material were processed at NIRRP as part of the commercial program. About 36 percent of those tons, or 74,860 was the organic fraction which was provided to ZWEDC. In just one year, the city has been able to triple its commercial recycling rate more than 70 percent with the two new facilities and new collection system.

“It’s been quite a process from design to startup to what you do in year two. It is very much a team effort,” explains Mennie. “There was a significant partnership that Republic built with BHS. It’s an ongoing process in looking at where material is ending up in that system and where can we make our next tweak to get a little more recovery out of the system.”

ZWEDC comprises two companies which have a long history of servicing San Jose: GreenWaste Recovery and Zanker Road Resource Management. GreenWaste provided yard waste collection and processing services since 1991 for part of the city’s residents. The yard waste was processed at Zanker Road’s ZBest composting facility.

“Over time we expanded our contract with the city of San Jose and began being the exclusive yard waste provider,” says Emily Hanson, ZWEDC director of business development. “We have continued to expand our relationship with the city.”

In 2008, GreenWaste Recovery constructed a MRF to process 100 percent of the city’s multifamily waste. “At that point we had all of the clean green yard waste, and we had all the multifamily garbage coming to our MRF and all of the wet garbage we were composting at ZBest Composting as well.”

Hanson says the owners of Zanker and GreenWaste decided to “kick it up a notch.” They began looking at different technologies for higher and best use philosophy with the organics the companies were managing. They decided to build a facility that employed dry-fermentation anaerobic digestion (AD) technology because according to Hanson, it had “the fewest moving parts.”

GreenWaste and Zanker came together to form ZWEDC as a 50/50 joint venture. In late 2008, ZWEDC began working with the city of San Jose to develop a triangle of land located between two of its facilities, which was used as a city-owned landfill.

ZWEDC approached the city about developing the site, establishing a long-term lease and having a partnership with the city. “We were able to do that noncompetitive because we were offering no-gift of public funds,” explains Hanson.

ZWEDC invested $12 million to bring the land to “leasable condition” on the city’s behalf. ZWEDC has a 30-year lease with the city for the land. The parcel of land is divided into three separate areas. The first parcel is in exchange for the $12 million. The city will receive a per ton fee as rent when the facility expands into the other two areas. Hanson says ZWEDC had to obtain more than 40 different permits for the project.

Hanson says ZWEDC had to obtain more than 40 permits for this project.

The city of San Jose’s Green Vision, Hanson says, “really laid the policy directive path for all the city departments to be able to step up and bring green technology and innovation to the city and a more sustainable future for the city. Working hand-in-hand with them and being part of that, this was sort of the next step in public-private partnership.”

The first phase of the ZWEDC dry-fermentation anaerobic digestion began operations in November 2013, making it one of the first and largest facilities in the country that is using this technology. The company’s fully enclosed facility includes 16 anaerobic digesters and four in-vessel composting tunnels. Zero Waste Energy, Lafayette, California, was selected as the technology and equipment provider.

In addition to organic materials from NIRRP, ZWEDC accepts direct-haul organics which is part of Republic’s Clean Commercial Organics program.

ZWEDC defines materials suited for AD as “organic materials that generate methane when anaerobically digested to create biogas as an approved product without negatively impacting digester performance.”

Organics suited for the dry-fermentation AD process are loaded into tunnels and deprived of oxygen for 21 days to induce biogas production, according to ZWEDC. After the digestion process is complete, the remaining material is moved into in-vessel compost tunnels for five days to facilitate the composting process. Acid scrubbers remove the majority of the ammonia, particulates and compounds.

The biogas extracted from the digestion tunnels are routed to two combined heat and power (CHP) generators to produce electricity and heat with a total generation capacity of 1.6 megawatts. The recovered heat supplies all of the thermal demands of the digesters and compost tunnels in the facility, according to Hanson. Two piping chambers provide process piping, controls and instrumentation to the digesters. Materials that aren’t suitable for the AD process are either used to make compost or are sold to a cogeneration fuel plant for use as fuel.

With a capacity for 90,000 tons of material, ZWEDC is considered the largest facility of its kind in North America. ZWEDC plans to expand its facility in phase II, which is expected to be complete in 2018. By that time GreenWaste will be processing all single-family waste at its mixed waste processing MRF. Hanson says, the company uses a three-stream system of recyclables, garbage and yard waste. She says this helps keep the yard waste clean for composting.
 

Positive partnerships

Republic and ZWEDC long-term contracts are with the city of San Jose, not with each other, but both are working together to achieve the best results for recovery. Glass contamination thresholds of 0.25 percent, which acceptable for ZWEDC’s digesters, have been difficult for NIRRP to achieve.

“We’ve had to work out agreements on what we are going to do with that additional glass contamination. We have a stop-gap agreement in place as we figure out how best to address that and figure out the cost of cleaning out some of the material.”

Overall Mennie says, “It is a pretty cooperative and collaborative relationship. I think when you go through a new program of this size and scope, unique to San Jose, not all issues could have been contemplated when you draft the agreements between parties. There’s been a lot of things that have come up through the process and we’ve just had to work those issues out.”

He adds that it has been a cooperative process. “Essentially each party has been willing to come to the table and discuss issues that have come up to discuss solutions that work to keep the program moving forward,” he says.

“The city is proud of these partnerships that we have that allow us to work toward achieving our Green Vision goals,” says Molloy. “Our mission and goals are very similar. Using the waste as much as possible as a resource, diverting as much as possible from the landfills and creating those jobs within the city of San Jose.

“One of our goals in the environmental arena is to lead by example and to pursue innovative technologies and strategies, and the city of San Jose Integrated Waste Management Division we feel has taken an innovative approach to developing public-private partnerships that help provide these world-class services and help us meet our city’s goals, and these are beneficial to all of our stakeholders,” Molloy says.

The author is a managing editor with the Recycling Today Media Group and can be reached via email at ksmith@gie.net. A version of this article first appeared in the September/October 2014 issue of Renewable Energy from Waste, a sister magazine of Recycling Today.