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Yes, we can build a composting facility for you

Do you want to build a composting facility?  Are you —

  • A private waste management company hauling 35,000 tons or more of biodegradable waste annually and paying more than the U.S. average tipping fee to dispose of that waste at a landfill,  WTE facility, or incinerator?
  • An AD system operator wanting to maximize the market potential of a low-value digestate?
  • A landfill owner hoping to extend the life of the landfill or trying to devise a strategy to meet the growing demand for food waste composting?
  • The utility director of a municipality currently hauling compostable waste to a commercial landfill or incinerator with service contracts expiring within the next few years?
  • A food processor with food waste and other biodegradables like DAF sludge and packaging waste (broken pallets, dirty cardboard, etc.) at multiple plants within 100 miles of a central location?

If the answer to any of these questions is yes, building your own composting facility may offer cost and efficiency savings, as well as long-term pricing stability for the biodegradable fraction of any waste stream,  all while offering a real revenue opportunity from the sale of high-grade compost to plump up the bottom line.

We’re not talking about throwing some clay down in a cow pasture and calling it a composting operation. We’re discussing modern, advanced technology, high-rate facilities that can handle everything from yard waste to biosolids to food waste and biodegradable plastics with aplomb.

And if you’re currently paying high tipping fees or driving long miles to dispose of this material, owning your own composting plant may be just the ticket to price-hike independence and lower costs.

These indoor, industrial operations are weather independent, providing reliable, predictable throughput.  When coupled with a modern process and professional management, they will produce a high-grade compost product with real market value for high-end customers in the golf course, turfgrass, parks and rec, retail lawn and garden, and like industries.

One of the best things about modern, environmentally-secure composting operations is that they take up very little space compared to outdoor windrows.  Ten high-rate facilities can be built within the boundaries of one outdoor windrow operation with the same throughput.   

Because of their biofiltration systems, they can also be sited much closer to population centers than the old-fashioned variety.  Contained, encapsulated processing and aerated processing systems all but eliminate headaches like leachate, off-site odors, and failed tests as management issues. This high level of control also results in a very rapid degradation process, with primary processing completed in a matter of days.

When choosing a composting system vendor, look for a firm with deep experience and a string of financially and technically successful composting operations under its belt.  Companies like McGill (which both operates its own industrial facilities and designs facilities for others) offer a definite advantage over those without these credentials.

Decades of hands-on experience processing some of the most challenging organic waste from municipal, industrial, and agricultural streams will trump a design-only firm with no operating expertise.  

McGill’s design-build options also include operations management and product marketing.   Learn more about McGill’s DBO services here.

What is a composting facility package plant?

In the water/wastewater treatment and composting industries, a package plant typically refers to a small, prefabricated unit dropped on-site, ready to connect to the larger system.  A McGill composting facility package plant is different.

Since McGill doesn’t build small facilities, its “package” is actually a set of blueprints and specifications for an industrial composting plant pre-engineered to meet the specific environmental containment, throughput, and feedstock requirements of the owner.

Actual construction may include prefab and off-the-shelf components, but there is likely iron going up at the site and concrete to pour, too.

While the owner is still responsible for site-specific engineering,  all other aspects – structure, process, operating procedures, etc. — are provided with the package.  Initial crew training and start-up supervision is included, too.

Pre-engineered McGill facilities ensure efficient, economical operations because they are designed by folks who have been successfully building and running trouble-free, 100,000+ TPY commercial plants for nearly 30 years.      

Commercial vs. industrial composting:  are they the same? 

Commercial vs. industrial composting — no, they are not the same, though the terms may be used interchangeably on the web.  But one word has to do with the money trail and the type of organization that owns the facility.  The other is linked to operational scale and/or manufacturing approach. 

A government-owned operation is not commercial, but it could be industrial in scale. It could also be operated like a commercial facility with a similar structure and profitability goals. 

A privately-owned facility would be commercial but might not have any claim to industrial.  A small facility owned by a nonprofit may be neither.   Big, modern compost manufacturing plants may be both. 

What makes a composting operation commercial? 

A “commercial” facility infers ownership by an individual, partnership or corporation, with profits accruing to the benefit of the owners’/shareholders’ bank accounts.  “Commercial” doesn’t have anything to do with the processing method in use, facility design, throughput, technologies, or manufacturing systems. 

Composting operations owned by municipalities, counties, nonprofit organizations and the like are not commercial, because any profits realized go back into communal coffers to subsidize operations or fund other projects related to their respective missions. 

Government-owned plants are “public-sector” operations, while commercial facilities are “private-sector” operations.  Generally, nonprofits or not-for-profit entities are citizen groups and may also be referred to as non-governmental organizations (NGOs). Sometimes, an NGO may be established by individuals representing governments or agencies.  Like public-sector projects, composting facilities owned by NGOs could look very much like a commercial operation, complete with a revenue stream. 

How big is industrial scale? 

“Industrial” is a relative term, most often associated with factories and manufacturing.  In the 21st century, manufacturing infers mass production, big equipment, automation, systems, and uniformity.  Ergo, industrial scale infers a facility size that would require these things to improve efficiencies and revenues. 

When it comes to commercial and industrial composting, how big does the operation have to be to earn the designation of industrial scale?  How big is big? 

Again, it’s a relative term.  When doing research for this post, one of the findings was this article written in the mid-1990s that classified a 100-tons-per-year operation as industrial.   

Compared to the backyard compost pile, 100 tons is a big number.  But the average throughput of a composting operation in the U.S. is now approaching 4,500 tons per year.  There are 194 facilities processing more than 30,000 tons per year, some in the 100,000-plus category.   

It may be time to add one or two more zeros to the “industrial scale” definition of 1996. 

Still, size is only one indicator of an industrial facility.  But other adjectives that might be used to provide clarity are also quite subjective. 

Commercial vs. industrial composting — is “manufacturing” the key? 

The original definition of manufacturing (manu factum in Latin) literally translates to “made by hand.”  Today’s dictionaries typically describe manufacturing as making something manually or using machines.  But for most folks, the word conjures images of big buildings, lots of machinery, and cookie cutter output. 

Yet, no matter the variations in definition, one thing is clear — when applied to the manufacture of goods in the modern era, making something in an industrial setting requires production through a system that typically includes assembly lines, division of labor, a quality control program, and a sales network to move products out into the marketplace. 

Potato, Potahto 

Does it really matter whether a composting facility is commercial or not?  Industrial or not? 

The important thing is for composting operations of every description to make good compost.  How they do it or where the money goes is secondary and may not even be on a customer’s radar. 

A “commercial” facility may still imply private-sector ownership, but if public-sector owners are serious about their responsibilities to taxpayers, they’ll design, operate, and generate revenue from compost sales like the privately-owned. 

Protecting the integrity of the process and quality of the finished compost matters.  Hiring experienced, qualified compost facility operators matters.  Practicing preemption when it comes to the environment and preventing deterioration of the quality of life for the host community matters.  Providing stellar service to both intake and compost sales customers matters. 

These are the indicators of a successful composting operation, whether commercial or not, industrial scale or not.  At the end of the day, professional and profitable are among the most important descriptors for any composting facility. 

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Industrial, high-rate composting:  exploiting the power of microbes

Thirty years ago, beyond the entry sign announcing the location of a composting operation, it wasn’t unusual to see a former cow pasture crowded with long rows of rotting yard waste.

Start-up for these primitive facilities was (and still is) relatively cheap.  A windrow operation is viewed as simple and attracts owners whose primary goal is to get a facility up and running without investing much in capital.

However, in all but the most arid climates, the Great Outdoors is not that great for the microbes responsible for composting’s biodegradation.  Aerobic microbes — the stars of every bona fide composting operation — will only reach peak performance levels if they are protected from the elements, provided with an ample food supply and a bit of water, and live in an environment equivalent to a microbial Goldilocks Zone.

Bring all of these conditions together in one place, and composting doesn’t just happen.  It goes gangbusters.

Today’s industrial composting plants and advanced biodegradation systems are designed to do just that, because the realities of high-volume organics recycling often demand more than the typical windrow can provide.

Science-based recycling systems — exploiting the power of microbes

When serving metropolitan areas, composting operations can be expected to recycle everything from fecal-laden yard waste to industrial by-products — in high volumes. These facilities intake and process hundreds of tons each day.  The larger operations may be processing 100,000 tons or more per year.

Odors emanating from some of these feedstocks can be unpleasant.  The materials can be very wet.  A few will carry chemical residues that require an advanced degradation technology to render them safe for reuse as ingredients in soil amendments.

That’s why more modern plants, those tasked with managing multiple types of organics from large geographic regions, are indoor operations.  Some may still turn under that roof, but others have kicked it up a notch by employing more advanced systems (i.e., aerated static pile or ASP) instead of turning.

While a windrow tends to plod along, controlled aeration accelerates composting, turning stodgy microbes into sleek degradation athletes.  With high stamina and a voracious appetite for all things organic, these Olympians of the microscopic world bring speed, reliability and high performance to an otherwise lackadaisical process.

The industry’s transition from windrow to ASP turbocharged composting, exploiting the power of microbes and giving it the efficiency and predictability required to successfully compete with landfills and incinerators.  But this metamorphosis did not result from genetic manipulation, chemical additives or fairy dust — it was simple biology.

That’s it.  Not engineering.  Not artistry.  Just biology, specifically, exploiting the power of microbes.

Prior to some notable research by scientists beginning in the 1950s, folks may have known how to keep a compost pile chugging, but not why their management efforts worked.  But once researchers figured out the why, they were able to control the process by giving aerobic microbes exactly what they needed to survive and thrive (air, water, food, temperature) in the right amounts and within ideal ranges.

They discovered composting’s Goldilocks Zone.

By the 1990s, this academic exercise had captured the eye of the commercial sector.  With some tweaking to improve efficiency and profitability at scale, a robust, predictable process emerged, one with the ability to cost-effectively recycle high volumes of organics.

But back to those microbes…

After many trials and several errors, industrial composting moved into the waste management mainstream.   But to make biology work as the power behind the progress, both designers and facility operators had to grasp, embrace and deploy a few scientific principles.

At the core was a rudimentary understanding of the two broad categories of biodegradation processes – aerobic and anaerobic.  Each identifier reflects the environment in which the microbes live.

Aerobic organisms require air and water, but like people, they cannot breathe under water.  Conversely, anaerobic microbes are like fish – they’ll die when exposed to air.

Anaerobes live and thrive in much wetter conditions than can be tolerated by aerobes. Both prefer a moderate temperature zone.  Anaerobes will die off at around 150 degrees Fahrenheit (F) or 65.6 degrees Celsius (C).  While aerobes can tolerate more extreme temperatures, the most active phase of aerobic composting takes place between 55 and 155 degrees F (12.8 to 68 C), with a preferred range of about 122-140 degrees F (50 to 60 C).

Anaerobic fermentation generates methane, which can be a good thing if captured and used for heating, cooking and generating electricity.  If not, then it’s a bad thing, a potent greenhouse gas.  When anaerobes are at work, certain compounds are created during intermediate degradation stages that result in unpleasant odors.  That is why some wet, decaying materials carry an offensive stench — the rotting organic matter has “gone anaerobic.”

But an aerobic process neutralizes odors by creating drier conditions, killing odor-causing anaerobes.  Methane is not generated during a well-managed aerobic composting process, and the resulting carbon dioxide emissions are considered carbon-neutral since the gas generation volume is the same as if the materials degraded naturally.

Beneficial bacteria and fungi are among the aerobic microbes that make compost “happen.”  About 2,000 species of bacteria and 50 species of fungi are ably aided in their degradation efforts by a zoo of macro-organisms like beetles and worms.  However, aerobes are the worker bees of the compost pile.  They break down organic matter at the chemical level as opposed to the physical rending of the macros.

Feeding on organic waste, aerobes power the engine that drives moisture from the composting mass, degrades pollutants, and eliminates odors.  The enzymatic action associated with aerobic digestion breaks molecular bonds, releasing by-products (heat, water, carbon dioxide) in the form of steam.  Once these microbes have consumed all available food, they die fat and happy, their microscopic bodies becoming part of the residual mass.

In a controlled composting process, a temperature drop signals a decline in food supplies and a correlating reduction in microbial populations.  Degradation slows, but still continues at the lower temperatures associated with compost curing.

If left to time and nature, organic matter will continue its disintegration until nothing remains.  But long before that happens, biodegradation enters a phase where the residual is relatively stable, while still microbiologically active and chock-full of both macro and micronutrients.  With its soil-like aroma and appearance, the material is pleasant and easy to use – a critical requirement for any product intended for widespread general use — and really, really good for rebuilding depleted topsoil.

This stuff, of course, is compost.

Microbes just keep going and going and…

When talking microbes, conversion of waste to valuable product is only half the job.  Once that compost has been added to soil, the little critters take on even more tasks:

  • DEGRADATION OF POLLUTANTS – microbes break down synthetic compounds to neutralize the impact of things like petroleum products and fertilizers/chemicals that can negatively impact both soil and runoff quality.
  • IMPROVE NUTRIENT UPTAKE – microbes convert nutrients to plant-available form, making more food available to plants and reducing the need for synthetics.
  • IMPROVE DISEASE RESISTANCE — microbial activity is responsible for the plant disease suppression associated with compost use.

The influence of science on facility design

The biggest problem with outdoor operations is not weather, per se, but the fact that weather cannot be controlled.

If a composting mass needs moisture, rainfall can be a welcome addition.  While it’s common for the sides of a compost pile to “crust,” discouraging rain infiltration, piles can be flattened and then concaved on top to capture rainfall for slow infiltration over time.  In this regard, rainfall can be a compost manufacturer’s friend.

But excess rainwater rolling down the crusted sides of a pile will settle into pools of “black liquor” (a.k.a. leachate) at the base.  Leachate and associated runoff contaminate ground and surface waters, attract flies and harbor unpleasant odors.  If the pile gets too wet too soon, pathogens rebloom.  When composting outdoors, a heavy rainfall can set the stage for nuisance complaints and regulatory intervention.

Conversely, maintaining acceptable processing conditions outdoors during dry spells requires sprinkler systems or a hose brigade if the microbes and the process are to be saved.

Add complications like high winds and ice storms to the mix, and the operation of an outdoor facility becomes more about battling Mother Nature than recycling organics.

Having to reprocess ruined piles and windrows adds cost and retards throughput. When hundreds of tons of waste arrive at the gate each day, a stuttering throughput rate can cause massive pile ups that compound and exacerbate the weaknesses of outdoor facilities.

Exploiting the power of microbes means protecting the creatures from the vagaries of weather is a top priority for modern facility designers.  Solutions can range from a shed roof to encapsulation to full facility enclosure.  Each rung on the containment ladder offers an elevated level of environmental control and protection, as well as fewer operational complications.

On that list are the elimination of materials handling woes related to weather delays and the ability to capture inside air and processing off-gases for biofiltration.  Indoor facilities can also make a composting operation more palatable to the locals by providing visual camouflage and sound buffering.

Making biology work for day-to-day operations

Putting a roof over a composting operation may remove many headaches from the manager’s plate, but design is only as effective as the people running the place.  Any composting facility — from the most basic to the most sophisticated — can still run into trouble if mismanaged.

Exploiting the power of microbes requires a multi-faceted strategy.

Feedstocks like food waste and biosolids can be wet and odor-laden when they arrive at a composting facility.  One of the top priorities for modern composting operations is to get these types of materials blended with dry amendment and aerated as soon as possible to kill off anaerobes and encourage the proliferation of aerobes.

But if the blend isn’t right, a batch can be doomed before the admixture ever hits the composting pad or aeration floor.  Wet or dry pockets impact microbial movement throughout the composting mass.  An irregular texture means patchy distribution of target compounds and uneven exposure to the microbes.  Pockets of untouched raw waste can survive an otherwise successful process, leading to regeneration of odors and reblooming of pathogens.

Particle size needs to be consistent to achieve an even degradation rate for all blend ingredients.  Material placed on the composting pad should not be compacted.  Aeration pipes must be free of debris.  Windrows may need more turnings than required by regulations to keep the process humming.

Many items on the list of best management practices (BMPs) are common to all composting operations, from backyard to industrial.  Many items on the DO list relate to the creation and maintenance of an ideal environment for the microbes responsible for biodegradation.  The DON’Ts focus on discouraging of the kind of microbes that cause and perpetuate odors.

But no matter the design or process, people are ultimately responsible for making the science work as it should, keeping those all-important “bugs” happy and ensuring a trouble-free operation.

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Grasping at compostable straws

Biodegradable/compostable straws are still trash if there’s no composting facility to process them

Like “compostable” chip bags and “natural” claims for trashy food, corporate America’s gushing eco-speak lauding the switch from plastic to compostable sippy tubes may really be grasping at straws.   Too often, that greenie glow surrounding biodegradable straws dissipates in a puff of smoke when confronted with the realities of today’s composting infrastructure.

Unless a community segregates its compostable waste and sends it to a modern composting facility, most oh-so-ecologically-correct products are headed for a landfill where they will either generate methane as they biodegrade or break down no better than the plastic they replaced.

And don’t think a landfill gas recovery system makes that disposal any better.  Most of the methane generated during anaerobic landfill decomposition escapes before the cell can be capped and the greenhouse gas collection system installed.

The ability to compost the millions of straws U.S. consumers use every day would definitely be a positive step.  Unfortunately, there are several things that need to happen before that green glow transmutes into something corporeal.

Compostable straws need infrastructure

Let’s consider an example.  One online retailer offers a box of 600 compostable straws weighing 1.8 pounds.  At that weight, America’s daily use of 500 million straws (a contested number, but that really doesn’t matter for this exercise) would fill 833,333 of those boxes for a total of 1.5 million pounds or 750 tons per day for composting.

Distributing those used straws equally among the 4,700 composting facilities in the U.S., the total tonnage would add only 319 pounds of additional material to the daily throughput at each operation – less than half a cubic yard.   So, at least as a “paper” exercise, processing capacity is not an issue.

But here’s the problem:  the vast majority of those facilities can’t accept many of the biodegradable and compostable products being touted in the marketplace because their composting processes aren’t up to the task.  And that includes PLA/bioresin straws.  They can’t break the material down fast enough for the system’s designed throughput rate.  As a result, the partially decomposed “compostable” shows up as contamination in the finished compost.

Additional screenings might get rid of some of that contamination, but extra handling ups the cost and could negatively impact operating expenses and profitability.

The low temperatures of most home composting bins don’t have a prayer of breaking down these types of biodegradable products, either.  Tough-to-degrade materials require modern, high-rate composting technologies to effect rapid biodegradation.

Typically, advanced facilities process indoors and/or in-vessel.  They rely on automated aeration and temperature feedback systems.  This tight environmental control brings the composting mass up to temperature quickly and keeps it in composting’s Goldilocks Zone, eliminating the hot-cold cycling of more primitive composting methods.

Provided all other environmental factors (moisture, C:N ratios, etc.) are right, this level of control accelerates the process by encouraging the proliferation of composting microbes and giving them more actual feeding time within a shorter processing window.

More microbes, plus more feeding time, leads to the rapid breakdown of complex compounds (like the plant-based polymers that make up compostable plastic) without extending the time required for primary processing.

The refuse of any given society reflects that society’s level of sophistication and technological achievement.  If First World consumers and their cities are sincere in the desire to meet zero waste targets, then composting needs to modernize to take on the more complex plant- and animal-based wastes engineered by those advanced populations.

If not, then consumers will need to assign many “biodegradable” and “compostable” labels to the realm of irrelevance.   Without a strategy to separate biodegradables from other trash and a composting facility that can process the tough stuff, it really isn’t compostable in that community.

Collection infrastructure

Composting co-mingled trash, then attempting to screen out contaminants at the end of the process, has proved to be unworkable.  At best, contamination in the finished product is simply too high to give the resulting compost any market value.  At its worst, the contaminated compost is peppered with glass shards, unsafe for use as anything but boiler fuel or landfill cover.

Therefore, walking hand-in-hand with advanced composting is the need for a collection system that separates biodegradable material from wastes that would contaminate the stream – before that material arrives at the composting facility.

Fortunately, several opportunities exist between zero collection and 100 percent collection for urban organics:

  • Waste streams from food and fiber production, processing, and manufacturing, where generators discharge clean, organic waste by the roll-off box or tractor-trailer load, represent the low-hanging fruit for composting. With waste capture systems already in place, rerouting those truckloads to composting instead of disposal is the only effort required.  Indoor composting operations equipped with biofiltration systems can be sited closer to populated areas than landfills, targeting sites near heavy industry and other locations with appropriate zoning and access routes.
  • In the absence of mandates, third-party collection has proven to be a successful strategy for mid-size food waste generators like universities, restaurants, and grocery stores who fill carts and bins instead of tractor-trailer rigs. These collection companies then transport to a local composting facility.   Eco-driven start-ups have also pioneered voluntary food waste collection at the residential level in areas where composting facilities exist, but city composting mandates do not.
  • School systems, apartment complexes, shopping malls, business parks – any owner/management entity with the authority to implement and enforce policies for a group can initiate a source-separation strategy for biodegradables and compostables. Some collectives may generate enough volume for their own in-vessel composting unit or direct service by a traditional hauler.  Others will need to contract with a company providing cart/bin collection service or plan to self-haul to the composting operation.  For generators intending to self-haul, know that minimum load requirements may apply, as well as policies related to the hauling vehicle, driver licensing and safety equipment. (See an example of the McGill policy here.)  Reach out to the intended composting facility early in the planning process.
  • Commercial and residential curbside collection represents the greatest challenge to the recycling of biodegradable materials. While central authorities for schools, business complexes, and the like may need to educate a handful to a few thousand waste generation units, cities may need to develop outreach and enforcement programs impacting millions of people.  But it can and has been done.  The difference between those who have and those who have not is lack of intention, not missing infrastructure, tight budgets or any of the other “reasons” used to excuse complacency.

Regulations

Composting can become a reality without a capital investment on the part of the host community.  Just set the stage and invite the players.

The bigger companies in the composting industry, those with proven technologies and track records, will look favorably on building, owning, and financing new facilities when appropriate sites are offered and diversion mandates promise high volumes through their gates.

Laws and policy mandates are the catalysts that build both composting and collection infrastructure.  While progress can be made in their absence, forward motion is much faster and tacking most favorable when propelled by regulations.

Finally, if composting options for paper straws or compostable cups or any other biodegradable waste is needed in the region, call someone – a councilman, county commissioner, state legislator, or congressional aide.  Ask like-minded friends and colleagues to do the same.  Get the issue on the local radar.  Make composting happen.