By Leanna Sweha
The Davis organics collection program has been around for almost two years. Brown-top bins are now a part of the weekly garbage routine.
The city is conducting both an organics disposal study and a solid waste rate study to decide what rate increases will be needed to pay for the organics program.
On top of that, council next week will decide whether to approve Recology’s purchase of Davis Waste Removal (DWR), the city’s franchise waste hauler.
With Recology, how might the equation change for organics disposal options?
DWR currently hauls organics to the county landfill. From there, organics get repacked and trucked to Napa Recycling and Waste Services. (Organics were hauled to Zamora until November, 2017).
The goal of the city organics disposal study is to determine “the most environmentally and economically preferred destination for delivering organic material for processing.”
Before Recology entered the picture, the study was looking at two disposal options:
- Davis builds an anaerobic digestion and/or compost facility at its waste water treatment plant or at the Old Davis Landfill.
- Davis sends organics to an expanded anaerobic digestion facility at the Yolo County Central Landfill.
If Recology buys DWR, there is this third option:
- Recology trucks organics to its Vacaville composting facility, Jepson Prairie Organics, located about 25 miles from Davis.
So, what are the likely economic and environmental costs and benefits of these options?
If Recology takes organics to its Jepson site, it would incur no tipping fees, and it can turn the waste into commercial compost products. It does that now with over 100,000 tons of organics annually from the Bay Area.
On the other hand, Recology would pay county tipping fees to take organics to an expanded digester at the county landfill. Recology won’t be able to turn these organics into commercial compost products. Instead, the organics would be turned into biogas. Currently, the county combusts gas produced from its digester to make electricity, which it sells to PG&E. The county is seeking state permits to expand the facility to accommodate increased organics volume.
A new Davis site would charge no tipping fees. It would likely clean up the biogas produced for use as truck fuel and market the solid compost products.
So, the third option would decrease Recology’s costs relative to the first and second. The city would incur the highest costs under the first option by building a digester.
Looking at environmental issues, there would be higher vehicle emissions if Recology hauls organics to its more distant Jepson site versus to an expanded county digester or new Davis site. (The highest vehicle emissions would result if organics continue to be hauled to Napa.)
Anaerobic digestion and composting qualify as recycling under state law, and both methods reduce greenhouse gas and other emissions relative to landfilling. However, controlled anaerobic digestion results in less air and water pollution than straight composting.
The current franchise agreement, which Recology will step into if it buys DWR, doesn’t dictate where organics must be delivered.
However, expect the franchise agreement to be amended to give the city the right to tell Recology where to haul organics. It’s included as a “point of importance” to all the parties in DWR’s revised waiver request letter and as an “additional term” in the city’s February 20 wavier resolution. In other words, council’s decision to approve the sale of DWR to Recology rides in part on the city having this right.
The city began organics collection in 2016 as a one-year pilot program to achieve state landfill diversion and recycling mandates. Solid waste reserve funds were drawn down to pay for the pilot, which was deemed a success. Now that reserve funds are depleted, service rates must increase to cover program costs.
The organics disposal study is being conducted by Clements Environmental and should be complete soon.
Leanna Sweha has been a Davis resident for over 20 years. She is an attorney specializing in natural resources and environmental law, with a background in biological research. She has worked for the California Legislature, the California Resources Agency, and the UC Davis Office of Research.