Palo Alto Weekly
News - July 1, 2011
New study, same arguments in Palo Alto's compost debate
Latest analyses brings new data but no new answers to city's green dilemma
by Gennady Sheyner
Palo Alto's heated debate over the future of local composting re-ignited Monday night, with both supporters and opponents of a new facility pointing to a newly released analysis to support their position.
The analysis, performed by consulting firm Alternative Resources, Inc., evaluates the costs and environmental impacts of building a new anaerobic digestion facility, which would process local food waste, yard trimmings and possibly sewage sludge. It also considers the costs of exporting local food waste and yard trimmings to San Jose and Gilroy after Palo Alto's landfill closes on July 28.
But while the 37-page report weighs a wide range of factors, including different financing methods, contingency fees and carbon adders, it does not answer the central question of whether it would be cheaper to build a new waste-to-energy plant in Byxbee Park or to ship waste elsewhere.
"The Alternatives studied to date are close enough in costs that it does not appear warranted to eliminate any of them from further consideration at this time," Phil Bobel, the city's environmental compliance manager, wrote in a staff report.
The draft report suggests that a waste-to-energy facility could be economically feasible in Palo Alto, but only if a series of uncertain assumptions prove true. The report found that building a local plant would be cheaper than exporting if the plant is publicly owned, if the project receives a lucrative bank loan and a grant covering 15 percent of construction costs, and if a "carbon adder" is considered in the calculations. This scenario would also assume that the city wouldn't charge rent for the Baylands site — an assumption that critics of the proposed facility say should be reconsidered.
Because of the uncertainty of these assumption and the relatively close cost comparisons, staff determined that both the local and the export options are feasible. The council voted 8-0 to direct staff to finalize the study by October.
While the study brought forth new information about the costs of various compost options, it did little to sway the two sides in the debate. One group, led by former Mayor Peter Drekmeier, is lobbying for the city to build the new facility at Byxbee Park, a proposal that would require voters to "undedicate" a 10-acre portion of park land. Drekmeier's group has already gathered enough signatures to place the issue on the November ballot.
Drekmeier noted at the council meeting that the new projections show that the city would save about $30 million over 20 years if it were to build the new facility. The savings would only increase over time, once the plant is fully financed, he said.
But opponents questioned the numbers and challenged the assumptions behind these calculations. Former council members Emily Renzel and Enid Pearson both spoke out against the new plant, saying that city has no business putting a waste facility on public parkland.
Renzel characterized the latest analysis as a "confusing mix of statistics" that began with data from "self-interested technology vendors and massaged in-house with inflation rates varying from 0 percent on rent to 5 percent on the fictional carbon adder."
Pearson said there were 44 landfills around the bay in 1961. All but the Palo Alto one have since been closed. She asked the council not to pursue a new waste facility at Byxbee Park.
The council will resume the conversation in the fall, once the voters have their say on the undedication of parkland. If residents agree to make the site available, staff will come back to the council with other options, including proposals for further analyses.
Staff Writer Gennady Sheyner can be emailed at firstname.lastname@example.org.
Posted by Cedric de La Beaujardiere,
a resident of Barron Park
on Jun 29, 2011 at 12:09 am
Cedric de La Beaujardiere is a registered user.
I think we can all agree that sewage incineration is out: it will be is outrageously expensive to rebuild it, and emits a lot of green house gas. Both opponents and proponents of the initiative agree on this.
For the sewage, of the options evaluated in the study, that leaves either Dry or Wet Anaerobic Digestion (AD). (These correspond to cases 1a for Dry AD, and 1b, 1c, 2a & 3a for Wet AD.)
For the yard and food wastes, the study considered processing them in Dry AD (Case 1a), or sending yard to southern Gilroy for Composting (2a & 3a), and/or sending food to a Dry AD in San Jose (2a).
For reasons of cost competitiveness, I have focused on options 1a, 2a & 3a. The opponents to this initiative like 2a or 3a, because these would handle the sewage at the water treatment plant, keep this 8% of the landfill/park intact, and send the rest of our wastes "away".
The study considered three scenarios which affect costs, which are summarized on page 1 of Web Link
Under these Scenarios (Sc 1, 2, 3), these cases were estimated to have the following total 20-year costs:
20-year NPV (Millions $):
Case..... Sc 1..... Sc 2..... Sc 3 .... Description
1a............ 60........ 73......... 96 ...... local Dry AD for all our organics
2a............ 94........ 96......... 81 ...... Wet AD for sewage, Food sent to San Jose Dry AD, Yard sent to Gilroy for Composting
3a............ 89........ 91......... 77 ...... Wet AD for sewage, Food and Yard sent to Gilroy for Composting
In Scenario 1, Cases 2a, 3a cost 50% more than Case 1a.
In Scenario 2, Cases 2a, 3a cost 28% more than Case 1a.
In Scenario 3, Cases 2a, 3a cost 18% less than Case 1a.
Note that Scenario 3 has $908,000/year in rent for the Case 1a Dry AD on the landfill/Byxbee park site, inflating its cost by $11M over 20 years. It's not $18M because inflation means that the fixed-cost of rent deflates over time ($1 is worth more today than in 20 years), so when you add up all the future costs and bring them to their Net Present Value (NPV), it comes to $11M in today's dollars... Scenario 3 Case 1a would be $85M without rent.
I asked myself, why is it that cases 2a and 3a cost so much more than 1a, given that they're all doing forms of AD, and so I calculated how much of their costs come from exporting the food and yard wastes. I obtained the following results:
20-year NPV (Millions $) of exporting food and yard wastes (and percentage of total cost):
Case...... Scenario 1..... Scenario 2...... Scenario 3
2a............ 44 (47%)........ 44 (46%)......... 35 (43%)
3a............ 39 (44%)........ 39 (43%)......... 30 (39%)
Sending our wastes "away" will cost us tens of millions of dollars. While processing them locally will also have costs, the affordability of Case 1a hints that keeping our compost local may be more affordable, plus it retains a local source of compost, and a place where residents could dump their green waste after a big yard cleanup. This is why, if the citizens vote to make the land available, I encourage the City and Staff to study a combination of Wet AD for sewage at the existing treatment plant, and composting the digestate from the AD and other organics at the landfill site.
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