The city is in the midst of a multi-year effort to figure out what to do with its food scraps, yard trimmings and biosolid waste. As officials weigh the pros and cons of shipping waste elsewhere or building a plant to convert the waste into energy, they are preparing to solicit proposals that will help them refine their cost estimates for both.
The question of what to do with local compost took on a sense of urgency last year, when the city shut down its Byxbee Park landfill — a 126-acre sprawl near the Baylands that had housed the city's composting operation.
The idea of building a plant gained a burst of momentum in November 2011, when voters overwhelmingly passed Measure E. The measure, which was placed on the ballot by a coalition of local environmentalists, authorizes the city to use 10 acres of previously dedicated parkland for an anaerobic digester — an enclosed plant in which micro-organisms break down yard trimmings and food waste and turn them into either electricity or natural gas. Opponents of the measure — a group that includes some of the city's most prominent conservationists — have vociferously argued that Byxbee Park is no place for a waste facility and have urged the city to export the waste and turn the former landfill site into a public park, as had long been planned.
While Measure E answered the main question in the compost debate — where a plant could be built — many other questions remain. These include: Does it make economic sense to construct a local plant? Which technology should the city adopt? To what extent should the city be involved in operating the facility?
The request for proposals, which the city plans to send out to potential vendors in February, could offer some much-needed answers. At a public meeting Wednesday night, Public Works staff and consultants shared their plan and received input from residents about the criteria the city's request should contain.
Jim Binder of the consulting firm Alternative Resources, Inc., said the proposals on both options will be due by next July. The department's action plan calls for the City Council to make the key decisions about the future of organic-waste disposal in February 2014.
"We're hoping to get firm pricing in response to both of those alternatives," Binder said. "That information will be used as part of the economic analysis that goes before the council so that they can make a decision in February (2014) what direction you want the city to go in."
As part of the process, the city will also allow vendors to propose technologies other than anaerobic digesters — including plasma gasification, which converts organic waste into synthetic gas through a high-temperature "electric arc." Clean-energy proponents such as former Mayor Peter Drekmeier and environmental attorney Walt Hays have also expressed enthusiasm about a "wet" anaerobic digester, which would accept biosolid waste in addition to food scraps and yard trimmings.
Phil Bobel, assistant director at Public Works, stressed that the city is trying something very rare in seeking a technology that will take care of all three types of waste: food scraps, yard trimmings and biosolids.
"It's uncharted ground," Bobel said.
While the technology question is complex enough in itself, the city is also wrestling with the question of what to do about the recently closed landfill. The original plan was to cap the landfill once it reaches its capacity — a requirement of state law — and add the land to Byxbee Park. That plan was tossed aside once Measure E passed.
"Because of consideration of putting energy composting there, it raises the question: Should we cap it now or should we wait and do something different while we decide what we're doing with the energy-composting facility?" Bobel said.
Ron Arp, who manages the city's environmental-control programs, said the city had planned to cap the landfill this year but received permission from the three agencies overseeing landfill operations — Cal Recycle, Santa Clara County and the Regional Water Quality Control Board — to delay the capping by a year. It is now scheduled to occur in 2013.
So far, the city had capped and reopened about 75 acres of Byxbee Park, while the other 51 remain uncapped, Arp said.
"We didn't want to jump right into capping while there's a plan for a possible facility out there," he said.
The council is scheduled to discuss the city's progress on composting options in December.