Updated: Thu, Feb 24, 2011, 6:59 am
Uploaded: Thu, Feb 24, 2011, 12:40 am
Palo Alto wrestles with composting dilemma
Environmentalists get an early look at the potential costs of a local anaerobic-digestion plant
The battle between Palo Alto's environmentalists over the future of local composting resumed Wednesday night when both sides of the debate packed into a meeting to learn more about the costs of building a local waste-to-energy plant.
What they learned was that when it comes to new waste-processing technologies, there are no cheap or simple options.
A standing-room-only crowd of about 60 people met at the Lucie Stern Community Center Wednesday to get an early peek at the feasibility study for a local anaerobic-digestion plant -- a proposal that continues to both inspire and outrage Palo Alto's green leaders. The plant would process local yard trimmings, food scraps and sewage and convert these materials into methane, which could then be used as natural gas or converted to electricity.
The study, which Public Works staff and consultant James Binder from the firm Alternative Resources, Inc., presented Wednesday, indicates that top composting technology comes with a hefty price tag. If Palo Alto were to build an anaerobic-digestion plant, it would have to pay more to dispose of each ton of organic waste than if it shipped this waste to other facilities in the region.
The draft study that staff and the consultant presented Wednesday considers four different potential uses for a local anaerobic-digestion plant. In each scenario, the city would use dry anaerobic digestion for yard trimmings and food waste. The only variable is what the city does with biosolids. In each case, the cost of processing waste in an anaerobic-digestion plant amounts to more than $100 per ton (in two scenarios, close to $200 per ton).
Shipping local yard trimmings and food waste to facilities in Gilroy and San Jose would cost about $70 per ton, the study shows, though this figure doesn't consider factors such as the rising cost of gasoline. This option also assumes that Palo Alto would continue to incinerate its sewage sludge -- a practice that many local environmentalists want to see come to an end.
Binder told the Weekly that the capital costs for a local anaerobic-digestion plant could range between $25 million to about $100 million, depending on the type of technology the city chooses and the plant's capacity.
"There is quite a variation of costs for the different types of technologies," Binder said at the meeting.
So far, anaerobic digestion has been used primarily in Europe, with countries such as Germany, Italy and Spain taking the lead in the emerging field. Each country uses the technology in a different way and for a different objective, Binder said.
The European companies also tend to have different priorities than Palo Alto when it comes to waste management. Their main objective, Binder said, is to reduce the volume of material heading to the landfill. They don't particularly care about the compost product, he said.
In Palo Alto, by contrast, composting is a top concern. The city's current composting facility is located at a landfill at Byxbee Park. The landfill is scheduled to close next year, at which time the site is slated to convert to parkland. A large coalition of environmentalists, led by former Mayor Peter Drekmeier, is calling for the city to build a new anaerobic-digestion plant at a 9-acre site in the landfill, next to the Regional Water Quality Control Plant, so that the city could take care of its own waste and retire the incinerators.
Other environmentalists, including former Vice Mayor Emily Renzel and former Councilwoman Enid Pearson, counter that Byxbee Park should revert to public parkland when the landfill closes. If that happens, Palo Alto's food waste and yard trimmings would then be shipped to a composting facility in Gilroy.
The City Council is similarly split about the proposed plant. In April, the council voted 5-4 to conduct the feasibility study. The council also voted 5-4 to have staff evaluate regional opportunities for waste management.
To make the Byxbee Park land available for a new waste-to-energy plant, city voters would need to "undedicate" the dedicated parkland site. Drekmeier's coalition has already received the required number of signatures to place the issue on the November ballot.
Tom Jordan, a land-use attorney who opposes a new plant at Byxbee Park, argued Wednesday that the Baylands site is actually owned by the state, rather than the city, and that Palo Alto can't build a waste facility on land it doesn't own. Last week, Jordan, Renzel and Pearson filed a petition with the State Lands Commission asking the agency to enforce its ownership of the land.
"The city does not own the land and does not have permission to build on the land," Jordan said at the meeting.
Assistant Public Works Director Phil Bobel said the city and the state have long disagreed over who owns the Baylands. Palo Alto and the State Lands Commission have an agreement that allows the city to lease the land at no cost. The lease also requires Palo Alto to modify its lease with the state if it wants to build something in the Baylands.
Bobel also noted that the city already has several different agreements with the state relating to waste-management facilities in the Baylands, including the landfill and the wastewater plant.
Renzel pointed out that the preliminary report didn't consider what it would cost to redesign Byxbee Park if the city were to build the new plant. The study also does not consider the costs of mitigating the plant's impacts or building a green roof on the facility, she wrote in a letter. All these factors could add to the price tag of building a local facility.
But supporters of the plant suggested that the figures in the preliminary study may in fact exaggerate the cost differences between building a plant in Palo Alto and shipping organic waste elsewhere. The study adds a 30 percent "contingency cost" to the options involving a local anaerobic digestion facility, but does not add such costs to the alternatives involving exportation of waste. Walt Hays, who is supporting a local plant, said the city should add contingency costs to the latter alternatives because of uncertainties over how much exporting waste would ultimately cost.
Drekmeier submitted a letter that also voiced concerns about the study's addition of contingency costs to the Palo Alto options but not to the San Jose one. He also wrote that the study doesn't consider the cost of continuing to incinerate biosolids. If Palo Alto stays on the current path, it would have to bear the costs of retrofitting its incinerators and of bringing them in compliance with new air-quality regulations.
"This makes the cost of continuing to incinerate biosolids artificially low," Drekmeier wrote.
The City Council is scheduled to review the draft feasibility study in late March. The final study is scheduled to be released in the fall.
Posted by Cedric de La Beaujardiere
a resident of Barron Park
on Feb 26, 2011 at 4:35 am
Cedric de La Beaujardiere is a registered user.
There are several points in the article and comments which I can correct or clarify.
The best news is that, over a 20-year period, public-financing of the local Dry Anaerobic Digestion (AD) will actually save the city and its rate payers millions of dollars compared to sending our wastes "away". People (including myself) get hung-up on the year-one costs and fail to notice the year-twenty and total 20-year costs. A 30-year horizon will likely show even greater over-all savings for the local option. The study's Preliminary Cost Analysis Summary (Web Link) indicates the following:
YEAR-ONE YEAR-TWENTY 20-YEAR TOTAL PROJECT/FINANCING OPTION
$ 68/ton $118/ton $71 million Truck food & yard to Gilroy, Incinerate sewage
$112/ton $106/ton $91 million Dry AD: private financing/private operation
$ 81/ton $ 81/ton $67 million Dry AD: public financing/private operation
$ 62/ton $ 65/ton $52 million Dry AD: City receives 30% in grants worth $12M
This shows that, over a 20 year period, the public financing of local Dry Anaerobic Digestion is $4 million more affordable than sending our wastes away. With a 30% grant, we save the rate-payers $19 million, which comes out to about $1 million a year in savings through handling our wastes locally.
What's more, there are several factors which will drive up the costs of incineration/remote disposal which the draft study has not yet taken into account. These include long-term maintenance of the incinerator, increasing fuel costs for transportation, and unreliability of the cost estimate for GreenWaste's as yet unbuilt facility. While a 30% contingency has been applied to local dry AD, no contingency was added to the San Jose's Dry AD rough quote of $85/ton for food-waste.
The article auther wrote "So far, anaerobic digestion has been used primarily in Europe". In fact, Wet AD is currently used throughout the world, including in the United States and California. It is only Dry AD which is new to the U.S.
The vendors and consultants are hesitant to commit to a price estimate/feasibility of using Dry AD for sewage, but I think they are over-cautious: Wet AD is used extensively for sewage, and Dry AD uses similar principles, and at least one company is interested in doing a pilot project to test and study the best way to process our sewage in a Dry AD.
In case Dry AD really is somehow not compatible with sewage, we've also asked the city/consultant to examine doing Wet AD for biosolids and food, and composting the digestate with our yard waste. Digesting biosolids with food produces more net energy than doing each of those separately, and while the compost product may not be as valuable the difference in energy value will likely make up much more than the difference. Wet AD is a very well known technology, so this might turn out to be a better plan than using Dry AD.
"To make the Byxbee Park land available for a new waste-to-energy plant, city voters would need to "undedicate" the dedicated parkland site."
More specifically, only 10 out of 126 acres of former landfill would need to be undedicated, which is what the petition seeks. There are 1,940-acres of Palo Alto Baylands. If, like one College Terrace resident, you prefer your area estimates in American football fields instead of acres: the proposed 10-acre site covers 7.7 football fields, including ~5 football fields worth of building, out of 97 football fields worth of Byxbee Park on former landfill. It's really not that big when you look at in in context, it's less than half the sewage treatment plant.
@same College Terrace resident, who wrote "And I learned that NO digestion faciltiy in existence does anything with their digested waste other than dump it onto their old-fashioned landfill..."
Actually, the consultant was saying that Europeans typically don't bother composting the digestate from the dry AD facilities, but just landfill it. Many US digestion facilities make compost from their digestate. Others send it to a landfill. The sale value of compost is small compared to the energy value, so most places don't bother. Making use of the 10-acre site, Palo Alto could make both energy and compost, while saving money too.
While the waste-management techniques studied all cost something, they have different costs, and when you look at the total 20-year cost, public financing of local Dry AD saves the rate-payers between $4 million (w/out grants) and $19 million (with 30% grant).
The Preliminary Green House Gas analysis shows that the local Dry AD option reduces our emissions by between 13,000 and 15,000 Metric Tons of CO2-equivalents per year. So in addition to being a net money savings, we also significantly reduce our GHG emissions.
@svatoid's "Didn't we have some kind of Green ribbon Panel that was supposed to study this and come up with conclusions/recommendations? What happened with that?"
I was on that Council-appointed 9-member Blue Ribbon Composting Task Force, and served as one of two Co-Chairs for that group. The current process is a direct result of our unanimous recommendations, which were to pursue Dry Anaerobic Digestion for our yard, food, and sewage wastes at a location adjacent to the sewage-treatment plant. Council directed the Compost Task Force to consider the use of parkland as a last resort, so we recommended that an empty-field in the airport site be used (we were informed that the site could not be used by the airport, and that all previous attempts by the airport to use the site had been rejected). Understandably, the airport community freaked out and raised arguably legitimate concerns. After considering all this, the Council realized the landfill/parkland was the only other viable location in Palo Alto.
@svatoid's criticisms of Peter:
I advise against casting aspersions when one doesn't know the facts. I've known Peter for a dozen years, and throughout that time he has successfully supported himself through his hard work, dedication, and smarts. Just like the rest of us, he gets up everyday to go to work and make ends meet. But rather than contenting himself with just getting by or amassing vast personal wealth, he has successfully applied himself towards socially and ecologically beneficial service. We are lucky in Palo Alto to have people like Peter who care and act not just for themselves but for the rest of us and the planet as well.
Yes, debt financing was included in the Dry AD project costs.
@Stan, who seems to think the AD-produced methane is not a workable energy source:
Actually, Dr. Cannara was referring to landfill gas being unsuitable to scrubbing/pumping any significant distance, not to the methane produced by digesters. In fact the draft study indicates that if the landfill gas were fed to the Dry AD's turbine, it would save the city/ratepayers an additional $1 million over 20 years.
@Lee who mentions the rent issue:
The land rent issue is a red herring brought up by opponents to this use of the landfill/byxbee park, to try to kill the project by asserting that the landfill land must be rented from the city at high rates. In truth, the initiative to make 10 acres next to the sewage-treatment plant allows for no other use of the land than for an organic waste-to-energy facility, and commercial use of the land would not be permitted. Any rent that could be charged would be at the City Council's discretion, and any rent money raised would go from ratepayers to the city. When this project can save the city and its residents millions of dollars w/in a 20-year window, it would be fiscally irresponsible for the Council to choose to force the project to pay such a high rent that the project became infeasible.
@Lois, who thinks Green Waste's Dry AD facility in SJ will save us:
GreenWaste's total facility capacity will be either 150,000 or 270,000 tons per year (tpy), and they will only take food-waste, of which Palo Alto generates 20,000 tons per year. Palo Alto is 3% of the county's population, but would take up 7% to 13% of the regional San Jose facilty's capacity, way more than our fair share. It is not even certain that the SJ facility would have room left for our food-waste, once they take up San Jose's food. The yard waste would still go 53 miles to southern Gilroy, and sewage would still be incinerated in Palo Alto. If we could send them all three of our organic waste streams, at 62,000 tpy we'd use up 23% to 43% of the plant's capacity.
The only regionally, locally, and fiscally responsible way to go is to to reduce our waste and generate local renewable energy from the rest.
Sorry for the long post, but it's a complicated issue, and simple sound bytes just don't serve us well...