In its latest bid to curb landfill-bound waste, Palo Alto is preparing to effectively ban contractors from demolishing entire buildings starting in July 2020.
Instead, workers will now be required to systematically disassemble structures, with the goal of reusing or recycling the bulk of the material on the site. Based on experiences in Portland, Oregon, which has a similar law in place, staff believes that up to 95% of the construction debris can be salvaged — either reused or recycled — through "deconstruction."
Much like the city's recent bans on plastic straws and single-use plastic utensils, the newly adopted "deconstruction" ordinance aims to help the city meet its goal of diverting 95% of local waste from landfills by 2030. But while the straw and bag bans have generated substantially more public discussion because of the ubiquitous nature of the objects being regulated, the deconstruction ordinance is expected to have a far greater impact on the city's "zero waste" goal.
Construction and demolition materials represent more than 40% of Palo Alto debris that gets disposed in landfills, according to an estimate from the city's Public Works Department. As such, it represents a prime opportunity for diversion and recovery, staff told the City Council at the June 10 meeting, shortly before the council voted unanimously to adopt the new ordinance.
Paula Borges, the city's zero-waste manager, called construction and demolition debris "one of the largest landfill contribution materials," comprising about 19,000 tons of waste annually.
"It is therefore essential that we focus on reducing the source of this landfill material in order to meet the city's goals," Borges told the council.
To do that, the city is preparing to fundamentally change how contractors take down old buildings. Under the old model, excavators smash and knock down the structure, reducing its materials into rubble that gets placed in containers and shipped to a waste-sorting facility. The operation takes a few days and a crew of two to three people, according to staff, and costs between $8 and $12 per square foot to complete.
The new model calls for buildings to be systematically disassembled, typically in the reverse order in which they were constructed. Based on two recent pilot projects, deconstruction work using this method would take about 10 to 15 days to complete and require a crew of four to eight people, with the cost ranging from $22 to $34 per square foot.
Under the old model, demolition debris is placed in containers designated "as mixed waste." In the new one, a contractor fills out a "salvage survey" listing all materials that can be reused and then source-separates the debris accordingly in blue and green containers. The city's hauler, GreenWaste of Palo Alto, would then deliver these materials to city-approved recovery stations.
Staff estimates that the deconstruction-collection program will cost the city about $243,000 in one-time expenses and $567,000 in annual ongoing expenses. In addition, the city plans to spend about $118,000 in one-time expenses for consulting services related to outreach and education.
Even so, city staff believes the environmental benefits outweigh the rising costs. Public Works staff pointed to Portland, where up to 25% of materials in residential buildings were deemed reusable and up to 70% recyclable, for a total recovery rate of 95%. Mixed construction-and-demolition debris, by contrast, typically nets recovery rates between 71% and 80%.
The new deconstruction ordinance is expected to help the city divert 7,930 tons of waste annually (by contrast, the disposable-foodware ordinance that the council adopted at the same meeting would divert 290 tons). The deconstruction ordinance is also expected to reduce the city's greenhouse-gas emissions by 22,300 metric tons annually (for the foodware ordinance, the number is 470 tons).
Assistant Public Works Director Phil Bobel noted that deconstruction allows for a "hierarchy of uses," with reuse at the very top, followed by recycling and composting. A report from staff includes a list of items that can be salvaged and reused during deconstruction, including appliances, cabinets, lumber, windows, doors, electric and plumbing fixtures and hardwood floors.
Tiles, blocks and bricks can at times be reused, if recovered in entirety. In cases where the block or brick is damaged or misshaped, a reuse facility can hammer it down and turn it into "base rock," which can then be used as the underlayment to roadways and other construction projects, Bobel said.
Wood can also be sold and reused if it's in good shape. Otherwise, it can be shredded and become compost. Even old sheetrock can be made useful if it's separated on-site from other debris, Bobel said. It can be ground down into gypsum, which would be used as a soil supplement.
Prior to the council's adoption of the new ordinance, Public Works staff experimented with deconstruction at a city-owned property: a 2,500-square-foot building in the wetlands formerly owned by International Telephone and Telegraph. The city bought the property in 2016 and demolished the building earlier this month. Borges said the deconstruction generated about 184 tons of material, about 4% of which was set aside for reuse (this was mostly old lumber, including redwood). Another 93% was source-separated on-site and recycled, with only 3% disposed of as garbage, she said.
Staff had also solicited input from contractors and held two workshops on the proposed ordinance. These were offered to about 1,200 contractors, developers and architects who regularly work in Palo Alto, according to a staff report. Many were reportedly concerned about the city's initial proposal to apply the ordinance to all projects valued at over $25,000 and about the need to educate contractors about proper materials sorting.
Based on the feedback, the city will initially apply the ordinance for total demolitions of commercial and residential projects starting on July 1, 2020. The ordinance is expected to affect about 114 projects, according to staff.
The ordinance will attain a broader reach in January 2022, when it becomes applicable to all projects valued at $100,000 or more, and in January 2023, when the threshold is lowered to $50,000.
While Borges said some stakeholders said they were concerned about the high costs of complying with the new ordinance, Drew Maran, founder of the local construction company Drew Maran Construction and director at the nonprofit The ReUse People, said he completely supports the new ordinance.
The idea of reusing materials in demolished projects is "way, way beyond its time," Maran said.
"We really need to do it. Recycling a two-by-four just simply makes it mulch for gardens and landscapes. Reusing it as a two-by-four in buildings makes sure that we don't cut down a whole lot more trees," Maran said.
But Ed Dunn, a longtime employee at San Francisco Community Recyclers, said he and others in the recycling community are concerned about a "serious lack of relevant stakeholder input" with the ordinance. He questioned whether there would actually be a market for the salvaged material.
"You've seen pictures of a deconstruction project underway," Dunn told the council after the staff presentation. "You have not seen pictures of people buying that stuff and that's a crucial thing. Who will take the stuff, take it back to their house and reuse it as is?"
Councilman Greg Tanaka also questioned whether the materials recovered during deconstruction will ultimately find new uses.
"I know from my own home renovation, it's really hard," Tanaka said. "Even when you make a huge effort to try to reuse it, it's really hard to do it because it's not the right size."
Ultimately, he joined five of his colleagues (Councilman Tom DuBois was absent) in approving the ordinance. Councilwoman Alison Cormack acknowledged that the ordinance comes with "significant costs," both to the city and to the residents and businesses undertaking deconstruction. Even so, she said the new requirement is "absolutely worth doing."
"I do think it's appropriate. It's a huge opportunity," Cormack said.