Palo Alto's convoluted and contentious debate over organic waste trudged toward a hard-won compromise Monday night when city officials adopted a new road map for processing local sewage sludge, food scraps and yard trimmings.

The City Council voted 7-2, with Karen Holman and Greg Schmid dissenting, to approve a four-phase approach recommended by Public Works staff, with sewage sludge designated as the highest priority, followed by food scraps and yard trimmings. In a nod to proponents of a new waste-to-energy plant at Byxbee Park, the vote also explicitly gives preference for compost operations located at the Bayland site that voters "undedicated" in 2011 when they passed Measure E.

The vast majority of the plan has the support of both sides of the city's green debate. Both agree that the city needs to retire its outdated and polluting incinerators and both would like to see food scraps turned into electricity. The glaring point of dispute on Monday was over composting -- mainly, the staff's recommendation that the Measure E site be used and that was added by staff as an "alternative recommendation" at the behest of the measure's supporters.

Even after the council's vote endorsing their wishes, Measure E supporters remained concerned that the city is moving too slowly on implementing voters' vision for local processing of yard trimmings.

Opponents of the measure, a group that includes some of the city's leading conservationists, lobbied for the staff's original recommendation, which also included the four phases but which was less explicit on the composting operation and did not mention the Measure E site.

In addition to approving the four-phase approach brought forward by staff, the council also agreed to scrap all three proposals that the city received from the private sector for treating Palo Alto's organic waste. Though Public Works officials are still preparing to solicit private-sector proposals, the intent now is to have the city own and operate the new waste-to-energy plant.

Phil Bobel, assistant director of Public Works, said staff is confident that the new approach will both give the city more control and save money. A revised cost analysis pegs the cost of the city's proposed four-step "Organics Facilities Plan" at $89.1 million over 20 years. Proposals from the two vendors that wanted to build an anaerobic-digestion plant for the city were $97 million (from the firm Harvest Power) and $107 million (from We Generation). The third vendor, Synagro, had a proposal with an estimated cost of $98.7 million, though it planned to export all three waste streams, a notion that was widely panned as being out of step with the city's desire to keep operations local.

"It would be a good idea to retest the market now," Bobel said Monday. "Now that we have a new end point, the Organics Facilities Plan, we have narrowed down what we're looking at."

Bobel also noted that wet anaerobic digestion is a technology that is widely in use across the country, and in most cases, it is public agencies that are running the operation.

The council's vote directs staff to begin work on a dewatering and truck haul-out facility, an addition to the regional water-treatment plant that would allow the city to retire its sludge-burning incinerators.

The second component of the new approach will focus on building the anaerobic digester, a plant that will process local sewage and convert it into electricity. The third step would create a food-preprocessing facility that would allow Palo Alto to add food into the mix to generate more electricity.

The final step would be to solve the yard-trimmings dilemma that has stumped city officials since 2012, when Palo Alto shut down its landfill at Byxbee Park, putting an end to the local compost operation.

For Councilman Larry Klein, the decision to support the revised staff recommendation, which explicitly cites the Measure E site, was a simple one. The council, he said, needs to respect the will of the voters, 65 percent of whom supported undedicating a 10-acre portion of Byxbee Park (staff now believes only 3.8 acres of the site would actually be needed). The voters, he said, have sent "a very clear message."

"Our discussion here seems to me has to be substantially influenced by the message that our bosses -- the people of Palo Alto -- very explicitly gave to us, by a 65-35 margin," Klein said. "They want the compost facility and they are willing to use up to 10 acres of our park facilities for that to be accomplished."

Holman and Schmid both sided with the conservationist camp, which opposes the use of Byxbee Park for a new waste-treatment plant. Holman pointed out that while Measure E makes the land available for the plant, it does not mandate that such a facility be built. That decision should still be based on factors like financial and environmental benefits, she said. Given that the city has yet to do a full environmental analysis of a local plant, these benefits remain unknown.

Holman and Schmid both advocated going along with the original staff recommendation, which also calls for a four-phase approach but which is fuzzier on the subject of composting yard trimmings. The first recommendation, which was criticized by Measure E proponents, does not mention the undedicated site at all. Holman and Schmid, both of whom had opposed Measure E, argued that the city hadn't yet adequately explored all of its composting options. Schmid said he "enthusiastically supports" pursuing an anaerobic digester for sewage sludge and food scraps, but was more cautious on the subject of yard-scraps composting. Holman agreed and said composting can be addressed later.

"Let's get going with the wastewater, the incinerator – that's a huge polluter. Let's get going now," Holman said. "We can address the composting issue as new technologies emerge and we adopt composting at-home solutions."

The rest of the council, however, sided with the broader group known as the Palo Alto Green Energy (PAGE) Initiative, which spearheaded Measure E with the intent of keeping composting local. Dozens of members of the group attended the meeting and urged the council to move faster in resolving the lingering composting quandary. Walt Hays, one of the leaders of the Measure E group, beseeched the council to get going on constructing the new technology, including a new composting facility.

"To have this whole thing go through and have nothing on the Measure E site would seem like a travesty," Hays said.

Peter Drekmeier, who also led the undedication effort, asked the council to send a "clear signal" that the Measure E site is the city's preferred area for composting.

"This has been a long process," Drekmeier said. "We can only kick the can so many times before it gets really dented."

Enid Pearson, a former councilwoman and a renowned conservationist, took the opposite view and asked the council to eschew politics and to proceed cautiously on composting solutions. Yard trimmings, she said, are a very small part of the overall garbage stream. The council should not rush to commit Measure E land but rather take "the long view."

Her side, however, was outnumbered both in the audience and on the council. Councilman Greg Scharff, who in the past also supported the use of Byxbee Park for a waste-to-energy plant, moved to support the revised staff recommendation, and most of his colleagues opted to join him. The council also endorsed Scharff's proposal directing staff to "expedite the process to the extent possible." The tentative timeline that staff first unveiled on April 29 showed the composting facility opening between 2020 and 2022, far later than many had hoped. Scharff also thanked the audience for its "fervor."

"I think it's really good that there's a healthy debate," Scharff said. "These issues are vetted and thought through, and I actually appreciate that as well.

"I'm proud to be in this community where we're very concerned about these issues."