I’ve written here several times about composting, the high-minded effort to turn waste into re-usable mulch. When it comes to setting up large-scale composting operations, these efforts tend to follow a familiar sad sequence. The initial proposal assures the public that the facility will be run according to the latest best practices and result in minimal odor, if any. Once the operation gets underway, nearby residents start to notice objectionable smells. The facility may deny being the source; there may be a back-and-forth as the town tries to document the stink and locate its origin. The facility may own up to being the source, and offer assurances that the smell is a mere hiccup that will disappear once the operation is fully optimized. When the smell and local objections continue, the town hires consultants who recommend installing some sort of odor remediation system. The result: the entire project comes in heavily over budget and leaves a lot of ill will in its wake.
A common feature of these episodes is a failure to take potential odor issues seriously from the very start of the project. Why does this happen? I think it’s because proponents of large-scale composting don’t anticipate issues of scale.
Home composting enthusiasts maintain little heaps of banana peels, apple cores, and lawn clippings in their backyards. These produce a small amount of innocuous odor. So what’s the problem in just adding everyone’s little heap to a town compost pile?
The problem is that the amount of biomass in a commercial or municipal composting facility is exponentially larger than a backyard heap, and that the resulting odor production will also be exponentially larger. Massive odor generation is a certainty—it’s an operational issue that ought to be dealt with in detail at the preliminary engineering stage. It is not enough for planners and proponents to blithely claim that proper “turning over” and aeration of the pile will minimize odor.
Now comes a story out of Longmont, Colorado, roughly 35 miles south of FirstNerve headquarters. Three residents have filed a lawsuit against a proposed composting facility—one that hasn’t even been built. Among other things, the lawsuit anticipates loss of property values should the facility-to-be emit “noxious odors.” Is this simply a case of NIMBYism or is there something more to it?
What is at issue is a proposal by Boulder County to build the facility on ~40 acres of land that was purchased, with voter approval, as preserved open space with a perpetual conservation easement. By law, the county’s open space “can be used solely for passive recreation, agriculture or environmental preservation purposes.” But that’s no problem for the three county commissioners. By using an obscure real estate doctrine and a recent land purchase they claim to have extinguished the conservation easement, giving themselves the ability to build a compost facility on the land. The commissioners pushed their plan through with a minimum of public notice.
The 235-page plan is a classic instance of blithe disregard for potential odor issues. It mentions odor only four times:
(1) In the architect’s narrative under “Buildings”, it states that waste will be delivered to a 17,590 square foot “tipping building”: “This building is a fully enclosed, fully contained component of the operation that will minimize odors, provide visual screening, and prevent any leaching of feedstock liquids into the surrounding soil.”
(2) In the “Operations” section under “Odor control”: “The CASP [“covered aerated static pile”] bunkers have been shown to reduce odors by 90-95% over conventional open pile windrow systems.”
(3) In the “Proposed Conditions” section under “landscaping: “Newly landscaped areas are strategically located for visual screening and to reduce sound and odor impacts of the facility.”
(4) And on page 12: “The existing site border of trees creates a natural setback from the road and would provide visual and odor screening.”
The idea that a line of trees and other landscaping features will reduce and screen odors is laughable. The tipping building may indeed contain odors—as long as the doors are never opened. And once the dumped waste is moved out of the building for composting, the odor issue pops right back up. Finally, even assuming that the claim about CASP bunkers is correct, that residual 5 to 10% of odors may still reach obnoxious levels, especially since the county intends to process “125 million pounds of animal manure, sewage sludge and food waste per year.”
Yes, that’s right: this is not just a food waste compost pile. It includes massive amounts of animal manure and sewage sludge (i.e., human manure).
The city of Boulder gives Berkeley, California a run for its money when it comes to progressive politics. Boulder County has a “Zero Waste Action Plan” that aims for a goal of zero waste by 2025. The three county commissioners (all Democrats) seem hell-bent on getting there, even if it means overriding the declared intent of county residents. Will three residents be able to stop the onrushing tide of sludge? Stay tuned. You can track their battle here.
UPDATE March 22, 2021
The Boulder County commissioners caved and will no longer consider placing a composting facility on the open space in question. The county has filed motions to dismiss lawsuits by neighboring property owners. Story here.
6 comments:
Request the facility be changed to an Anaerobic Digester which can operate odor free.
I don't see "Anaerobic Digester" as an option for these facilities in the US. The latest info I can find shows:
265 Total Projects
-108 Aerated Static Pile
(Windrow on in-slab aeration system)
-83 Windrow
-46 In-vessel
-9 Not specified (unable to determine type)
-8 Aerated Windrow
-4 Static Pile
-4 Enclosed Aerated Static Pile
(engineered tarp enclosure with aeration)
-1 Vermicomposting
From: https://www.sourcewatch.org/images/9/9d/Sludge_Compost_Facilities,_NEBRA_report_2010.pdf
https://www.sandiegouniontribune.com/communities/north-county/escondido/story/2020-12-26/your-next-green-move-recycling-that-kitchen-waste
This looks like a wonderful option for green bin food scraps and yard waste. I'm not sure if it works or is legal or EPA approved with biosolids, feedlot waste and roadkill. Boulder County is proposing a facility that process all of it. Class III items. Not the same process required.
Sir, this is a viable, legal and responsible option.
Feedstocks for Anaerobic Digestion
Most easily biodegradable biomass materials are acceptable as feedstocks for anaerobic digestion. Common feedstocks include livestock manure, food-processing waste, and sewage sludge. The energy production potential of feedstocks varies depending on the type, level of processing/pretreatment and concentration of biodegradable material. Listed below are feedstocks that can be commonly used in anaerobic digesters:
Livestock manures
Waste feed
Food-processing wastes
Slaughterhouse wastes
Farm mortality
Corn silage (energy crop)
Ethanol stillage
Glycerine as the product from biodiesel production
Milkhouse wash water
Fresh produce wastes
Industrial wastes
Food cafeteria wastes
Sewage sludge
Excellent! Thank You so much for finding this information.
This option definitely needs to be presented to Boulder County, no matter where they end up putting this plant.
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