Does composting need a puppetmaster?

For far too long, composting was relegated to a position on the fringe of waste management, despite the fact that 70% of the world’s wastes are compostable. Composters, quite literally, had to wait for someone else to feed them the leftovers.

A major chunk of composting’s potential feedstocks (yard waste, food waste, sludges, etc.) are “owned” by the municipalities in which those wastes are generated.  Traditionally, government has taken the lead in providing waste services of all types, from collection to final disposition.

Unfortunately, that ownership has made composting an ipso facto puppet dancing to the tune of others.  And that song is not a merry jig.  According to the American Bar Association, waste flow control is #2 on its list of the Top 5 most litigious MSW topics.

Numbers tell a sorry tale

There are about 89,000 local governments in the U.S.  But a November 2020 article in BioCycle estimated only 4,500 to 5,000 composting facilities serving those populations – less than 6%.  A mere 326 of 19,000 towns (less than 2%) offer curbside collection of food waste.

Granted, more than half of those are small governments managing jurisdictions of fewer than 50,000 people – our very rough estimate of the population base needed to support an industrial composting operation for urban organics.  

But that still leaves a sizable number of cities, counties, and towns that have the potential to generate the minimum volume of composting feedstocks required for commercial viability.  That support would come from municipal, commercial, institutional, and industrial generators.

Sadly, too many of those who control those wastes seem to be in no hurry to divert the bulk of that stream to a municipally- or privately-owned composting facility, even when it could be the most cost-effective management choice.  

Clearly, the prevailing paradigm needs to shift if composting is to become the management choice for all Urban organics.

Enter new models for resource recovery

Over the past 30 years, composting has matured to become an efficient, economical, dependable, and profitable technology for recycling the full gamut of urban organics. 

A big, 100,000 tons/year indoor plant can go from groundbreaking to start-up in 12 to 18 months, and when equipped with an efficient biofilter, can be sited closer to both waste generators and end use markets than windrow operations.  Its footprint is only 1/10 the size of that windrow operation, too.

When designed and managed with preemption as a priority, a composting facility generates no waste stream of its own, and the resulting compost is a much-needed product for restoring function to depleted urban soils. 

Compost use also sequesters carbon when soils will remain undisturbed for long periods of time, adding to its long list of benefits.

When a community can have all of this – privately funded by experienced commercial companies with no taxpayer investment – why do city and county governments hesitate to put out the welcome mat for composting? 

In recent years, the emergence of small businesses and community non-profits willing to cut the strings and do an end run around the municipal “middleman” has demonstrated new models for resource recovery.  

In the UK,  a bio-ware manufacturer, recyclables/food waste collection company, and composter are teaming up to create a service model outside of a municipal system. (READ:

In the U.S., door-to-door collection companies are picking up household and commercial organics and transporting the material to their own composting facilities and/or other established composting operations (of all sizes and descriptions) in the region.

Even companies who serve municipalities (like McGill) also work directly with high-volume generators in the corporate/industrial sector, bypassing the city or county collection system entirely.

While municipal composting programs can get tossed around and fumbled like a political football, collection services by independents providing direct service to the waste generator may offer more stability.

For municipalities struggling to set up composting programs on their own dime, the expansion of composting infrastructure via private-sector services and financing might be fostered and supported by local governments in several ways:

Exclude compostables from flow control.  Flow control is a contentious and much-litigated device used by governments to force all trash generated within its jurisdiction to be managed by a specific facility or facilities.  

At its worst, the practice protects the investment of a private waste contractor – typically a transfer station, landfill, incinerator, etc. – and eliminates any possibility of competition for the life of a project that can have an amortization period of 50 years.

This may be good for the private contractor investing many millions of dollars in the development of a facility.  But taxpayers can end up paying more over those decades when competitors (like composters) are barred from offering alternate services during the contract term.

Sometimes, specific streams are excluded from flow control ordinances.  If organics are included in those exclusions, then the door is open for independents to move in and offer direct services to organic waste generators of every size.

If not, this lock forces a community to use the contract disposal option even when composting might be the least expensive service.

Identify and advertise appropriate composting sites.  The best location for an industrial composting facility serving an urban area is not a farm field or landfill located 100 miles outside of the city.

It makes no sense from either an economic or environmental perspective to shuttle feedstocks out to the country only to truck the finished compost back to the city.  This strategy adds unnecessary cost to both composting services and products. 

So, when both intake and compost use markets are urban, that is where the composting facility needs to be, too.  But composting facilities of any significant size belong in areas zoned for heavy industrial use, not business parks or other locations with too much exposure to the general public.

Over the years, poor location choices may have had as much (or more) to do with facility closures as bad design or management.

While building industrial structures is usually cost-prohibitive on a closed out landfill, an old “dump” located within or near the city limits might be suitable for an operation utilizing tarps or other less permanent containment – with optional biofiltration, of course.

City managers and decision-makers know their jurisdictions better than anyone.  By identifying appropriate sites, acquiring and designating those sites for composting, and advertising/offering those locations to commercial composters, a local government can secure high-quality composting services for its city without a hefty capital investment or related management/operating costs.

Metro areas also benefit when multiple sites and/or companies serve the region, building redundancy into the composting infrastructure.

Mandate compost use.  As demand for compost rises, compost manufacturers will be able to hold steady or even lower tipping fees for composting services.  

One of the most effective mechanisms for increasing demand is for governments to mandate compost use for all new public and private construction projects, major residential landscaping rehabs, DOT construction and maintenance, and all publicly-owned parks, recreation areas, and other greenspaces.  

Typically, this is achieved through stormwater management and grounds maintenance programs.  As compost is one of the lowest cost stormwater capture solutions per gallon retained (native plants are a few pennies cheaper), it only makes sense to begin the restructuring of any stormwater program by mandating compost use whenever and wherever soil disturbance or maintenance takes place.

Working toward the win-win

The ultimate goal is to create a robust market for compost products, one that will generate an even stronger demand for the organic waste that feeds compost manufacturing processes.  

When this happens, manufacturers may be able to greatly reduce (or even eliminate) tipping fees for yard waste, food waste, sludges, and other urban organics received from local governments.

It’s a scenario where both small businesses and taxpayers win.  Isn’t that outcome worth the loss of a few strings?

Can I sell my backyard compost?

From time to time, a backyard composting enthusiast poses the question: Can I sell my backyard compost?  Unfortunately, the answer is complicated.  Switching from the backyard to the commercial world is like shifting the preparation of a plate of spaghetti from a home kitchen to a 120-seat Italian restaurant – even if you only want to sell one or two plates.

Rising interest in food waste diversion causes entrepreneurial spirits to think about starting a composting facility.  That’s great news and deserves encouragement. There is plenty of room at the table for composting operations of every size, including the backyard variety. 

Some pulling up a chair will come with little to no experience running a business, composting at scale, or managing wastes of any description.  On one hand, that is a good thing for the composting industry as a whole.  Fresh ideas and a non-jaded outlook (mixed with a dollop of desperation, naïveté, and plain dumb luck) drive progress.

But the budding entrepreneur must accept the fact that when money changes hands, the small-scale/backyard composter crosses over into the commercial composting world, one that is tightly regulated.

Fortunately, many states have exemptions or lighter “regs” for low-volume projects.  But that’s not the same as no regulation.   To find out more about regulations in your state, here is a list, compiled by the U.S. Composting Council.

If you are thinking about a for-profit or non-profit composting-related business, or even a public project, taking the time to do a little research before the planning process begins is the smartest and most economical first step any new business endeavor can take.

Can I sell my backyard compost?

There are many factors to consider before answering that all-important question.  Some are related to rules and regulations.  Others have to do with running a business.

Knowing the answers to questions like these can make the difference between success or failure:

  • If considering a door-to-door food waste collection and composting service,  what are similar companies charging in cities like yours?  What is the average size of their customer base?  What percent of the households that meet the identified customer profile (age, income, etc.) use the service?  How does your community compare and will you have the possibility of gaining enough customers to make your business profitable?  How are they marketing the service to potential customers? Talk to the local recycling coordinator.  Is s/he aware of any similar companies operating or considering start-up in your locale?
  • If you plan to intake waste from other household or businesses, most privately-owned composting facilities rely on tipping fees to support compost production, not compost sales.  Do you know the average tipping fee in your region?  Who are your biggest competitors for composting feedstocks?  What other competing companies or technologies are thinking about moving into your market?  A chat with your city or county business development specialist could be insightful.
  • What are the high, low, and average wholesale and retail prices for a cubic yard of compost in your targeted service area?  What about bagged products?  Will customers expect auxiliary services like delivery or spreading?  
  • Have you read all of the regulations, zoning ordinances, and building codes that will impact your operation?  Check in with the local planning department and correlating state agencies to determine if there are any changes in the works.  
  • Do you know where the high growth areas are in your region?  There is nothing worse for a composter than to open a remote facility only to find the land around it being gobbled up by housing developments a few years later.
  • Your annual reports to the state, including names of customers and volumes processed, as well as copies of your permit and any related violations, will probably be made available to the general public online or on request.  As a result, potential anchor accounts — large corporations, municipalities and commercial entities — may wait a few years before doing business with you.  They want to know the way you operate, the dependability of your service, and your efforts to protect the environment and local community are above reproach and will not negatively damage their own reputations by association.  Obviously, this can have a major impact during the initial years of operation.
  • First-time business owners may underestimate expenses and overestimate revenues.  Talk to people who actually operate composting facilities before developing financial projections.  Look for tradeshows, conferences, and other networking opportunities that will allow you to meet and learn from folks who have spent time in the trenches.
  • If you do plan to open a facility of any significant size, there are only a handful of engineering firms and technology providers with extensive experience in designing successful composting facilities.  Choose a designer with a resume that includes multiple, long-term composting operations with no technology/design-related problems.  

As with any business start-up, be prepared for long days and short nights.  The owner of a successful composting operation must not only know how to make good compost, but also keep the books, hire and manage employees, promote the business, and keep customers, regulators, and neighbors happy.

Until the business grows to the point where it can support others in managerial positions, the full weight of those jobs is carried on the shoulders of the owner.

More time will be spent on matters unrelated to compost production than on making compost.  Knowing how to make good compost will not be enough.  Before taking the plunge, be sure you have the drive, stamina, and desire to devote such a large portion of your day to shepherding a new business.

Minecraft composters – a sign of things to come?

Did you know there is a composter block in the popular videogame, Minecraft?  Minecraft composters have been available for a couple of years, though the unit is something of a Rumpelstiltskin model.  While the composter doesn’t spin organics into gold, it does turn food waste (no meat) and green waste into bone meal.  Quite a trick.

Gamers build the thing with wood planks and fences.  Each composter provides a job for one farmer.

Games designed to teach children and adults how to sort materials for recycling/composting have been around for a while.  But when a pop culture megastar like Minecraft (the best-selling videogame of all time with about 126 million active players worldwide) embraces composting, organics recycling has arrived.

There’s even a bit of 2021 forum chatter from gamers pushing for the inclusion of fish, meat, and rotting flesh as permitted compostables.

Questions about the origins of the rotting flesh aside, this seems to indicate a big swath of the general public knows composting is capable of recycling much more than yard waste and veggies.

But one has to wonder how much longer it’s going to be before the communities those players call home turn fantasy into reality.

There are no real barriers to composting, just excuses

It’s not unusual for an article to focus on “barriers” to large-scale composting projects.  Lack of infrastructure typically tops the list.

But when composting has proven itself to be an economical, efficient, and reliable technology for recycling urban organics, perhaps the time has come to admit the real barrier to universal composting is the human factor.

When any number of experienced, commercial firms stand ready to build, finance, and operate big, industrial composting operations in exchange for a suitable site, lack of infrastructure is not the barrier.  

Lack of publicly-funded investment capital is not the barrier.

Lack of curbside collection is not the barrier.  Yes, source-separation and collection is certainly an issue to be addressed.  But it’s not a barrier when cities around the world have figured it out.

Too often, these are simply excuses to justify inaction on the part of community leaders.

Time to get off your duff?

Composting in Cyberland provides a window into public awareness.  But the general public doesn’t enact change on a municipal, state, or national scale.  Their elected officials do that.

To convince 100 households in a borough to compost is laudable.  But to convince the elected representative of that borough to embrace composting can set the stage for a citywide program creating tens of thousands of composting households.

Decision-makers may be the vehicles of change.  But the energy and drivers behind transformation come from their constituents.

Want an elected official to support composting sooner rather than later?  Pick up the phone, visit their office, or send a letter from the heart using your words, not those of somebody else.

A phone call is better than an email.  A handwritten letter carries more weight than typed.  In the eyes of an elected official, a single letter is said to represent the views of 100 constituents.  Posting to social media may not outshine traditional communication, but it does provide opportunity for public awareness and dialogue.

There are also a couple of practices most professional advocates tend to agree on: (1) don’t waste your time trying to influence a politician if you’re not a constituent – even signatures from non-constituents on petitions may be disregarded – and (2) do not send a form letter/email. Use the form as a guide only … and restrict your correspondence to one page.

Include relevant facts and figures.  “Greenie” statements without science and hard numbers to back them up are a waste of space.  Show.  Don’t tell.

The time to act is now

In the months following an election, there are a lot of new folks settling into offices at all levels of government.

For the most recent race, there were thousands of incumbents who either opted out of the elections or lost their seats.  Taking those chairs are thousands of enthusiastic, fresh faces representing new opportunities to move composting to the next level.  Old pros are learning to navigate shifting currents of public opinion.

So, whether you are an experienced composting advocate or have never reached out to a public official, now is the right time to make sure organics recycling is on their radar.

INTERESTING FACTOID:  According to Merriam-Webster, the word “duff” can also be used to describe the partially decayed organic matter on the forest floor.  Synchronicity or kismet?

Find a composting facility – then what?

As frustrating as it may be, even if you can find a composting facility near you, its presence may not guarantee your ability to recycle even the most common household organics.  Facilities that accept compostable resins are rarer still, and it might be best to buy recyclable plastics, instead.  

In the world of waste-related search terms, this one – “find a composting facility near me” (or some variant thereof) — is not unusual. People are actively searching for ways to recycle food waste, compostable serviceware and packaging, and other organics.  

Unfortunately, the fact that a composting facility may be operating near you does not guarantee your ability to recycle all organics via composting.

For individual households, composting options for food waste beyond the backyard may still be limited.  According to industry resources, more than half of the composting facilities in the US only accept yard waste.

Of those operations equipped to handle more challenging materials – like food waste – some will be large operations like McGill that specialize in services to high-volume generators only.

Other composting operations may be able to compost the actual food, but not the compostable plates on which it was served.

Relatively new to the industry are a growing number of entrepreneurs offering door-to-door food waste collection outside of the municipal disposal system.  Some transport the food to larger composting facilities; some will operate their own food composting systems.  But this is very much an emerging service, mostly in larger metropolitan areas.

Wish-cycling won’t make it so

Wish-cycling describes the practice of tossing anything designed to be recycled into the recycling bin, hoping someone on down the line will figure out where it is supposed to go.

Sadly, this isn’t the way recycling (including composting) works.  Until the day when scanners and robots take over sorting lines, households and businesses must pay attention to separation guidelines.

There is no such thing as a universal recycling mandate.  Every jurisdiction will have its own list of what can or cannot be diverted from the landfill or incinerator.

That list can depend on many factors.  Distance from the recycling facility, current prices for and availability of recycled feedstocks or recycling services, and other considerations influence the recycling options for any given community.

How do you find a composting facility?

Before grabbing that package of compostable cups on the grocer’s shelves, find out what is and is not compostable in your community.   

A call to City Hall or a quick web search will usually do the trick.  There are also a couple of sites maintained by national entities that can help you with that search:

Once you have determined what can and cannot be recycled/composted in your town, make a copy of the list and tack it up somewhere near your sorting and recycling bin area so there will be no excuses for convenient memory lapses.

Avoid cross-contaminating recycling/composting streams

More and more restaurants and groceries are separating their food waste from landfill-bound trash and diverting it to composting.

Do seek them out and spend your dollars with businesses with good waste habits.

But when dining or shopping at these establishments, don’t screw up all that good work by being careless with your own trash separation choices.

Clearing a tray by dumping everything into the food waste bin – including that aluminum soda can and plastic fork – contaminates the entire container. 

One aluminum can might not seem like much. It’s big and bright and can easily be spotted and snatched out of the pile some time before, during, or after processing … right?

Wrong.  When a truckload of similarly contaminated bins gets to the composting facility, that entire load could be rejected and sent to the landfill.    Feedstock contamination is a major problem for composting facilities.  It can damage equipment, diminish the value and reuse potential of the finished product, and impact worker safety. 

Tossing a compostable bottle in with the traditional plastics can cause big problems for those recyclers, too.  In fact, a single compostable item can ruin an entire processing batch of conventional resins.

Bottom-line:  Pay attention to the symbols and sort accordingly.

Buy goods that can be recycled in your community

Plastic waste has become something of a planetary nightmare.  But it’s the plastic that doesn’t get recycled that’s causing the biggest problems.

Here’s the truth:  It can make more recycling sense to buy a plastic cup that can be recycled in your community than a compostable one that cannot, because that compostable will only end up in the landfill.

To put an end to your household’s wish-cycling, shop smart.  Take that recyclables list to the grocery store and check recycling symbols before dropping a package into your cart.  If it can’t be recycled, choose a different product.  If your favorite fast food restaurant or coffee shop doesn’t serve their beverages in a cup that can be composted or recycled in your community, go somewhere else – and tell them why.

By practicing good buying and recycling habits, every household can do its part to reduce waste.  Just compost what you can and recycle the rest.


Whatever happened to aiming for the best waste management option? 

If it’s easier to do, then it’s the thing to do.  If the job can be done faster by cutting corners, go for it.  If it’s the cheapest option, buy two.  Somewhere along the path of societal evolution, easiest-fastest-cheapest has become synonymous with best.  This linguistic transmogrification is so pervasive, society no longer takes notice of its shortsighted slide down a spiraling path toward all things inferior.

When did easiest-fastest-cheapest become synonyms for best? When did we stop aiming for the best waste management choices and settle for inferior? 

There are good, affordable options out there that can strengthen/support recycling mandates and result in better waste management systems.  But progress toward zero waste is s-l-o-w and too many communities are still stuck in their comfortable ruts.

Progressive leadership looks to the future, ever-steering its constituency toward that proverbial “brighter tomorrow.”  For waste management, that horizon does not include landfills or incinerators. But it does include high-rate industrial composting … if public and private facility owners aim for the best and not the cheapest.

What are the best options for biodegradable wastes, the best organics collection strategies, the best composting technologies, the best facility designs, the best uses for compost products – who asks these questions before plunging head first into a development project?

Or, if someone asks the questions, do they really mean what’s the cheapest technology, design, and collection strategy? 

As for the resulting compost product, is the real objective to put it to highest and best use or to get rid of the stuff as easy and as fast as possible?

‘Best use’ is hard to achieve with an inferior product

Stormwater management, erosion control, carbon sequestration, turfgrass management, landscaping – these rank among the best uses for compost products.

They represent markets that place high dollar value on stable, quality soil amendments with no odor, high organic matter content, macro and micro nutrients, and other characteristics linked to a high-performance product that can be safely used by anyone, anywhere, at any time.

Poor quality compost cannot meet this minimum standard.  For the most part, its sale and distribution is restricted to low-dollar markets like farming and landfill cover.

The catch here is that, when managing mixed organic wastes, it usually requires a combination of the best facility designs, composting technologies, and management protocols to produce a really good compost product.

To achieve top quality, keep product moving out the gate, and ensure the highest possible revenue stream, a facility owner must match those aspirations with a high-quality manufacturing process and competent management that includes a professional sales effort.

Shortsighted strategies won’t meet long-term goals

Many communities are waking up to the fact that their long-range plan needs to include a viable strategy for organic waste management that keeps biodegradable materials – especially, food waste – out of landfills and incinerators.

Composting certainly fits the bill, and it’s often possible to modify an existing yard waste windrow permit to include other organics.

But what happens a few years down the road when that one load of food waste per week turns into a load per day, and then two loads per day, and then 10 loads per day?

When the entire city is source-separating organics curbside, and the vast majority of those garbage trucks are headed for that crowded, outdoor windrow composting facility, what happens then? 

Historically, facility owners (public and private) can struggle through years of banned feedstocks, failed lab reports, public complaints, unsellable product, fines, and/or legal fees before finally facing the facts. Their antiquated composting system simply isn’t up to the challenge of today’s urban waste streams … and their bargain basement facility wasn’t such a bargain after all. 

Successful high-volume processing of urban streams that include highly putrescible materials and biodegradable plastics requires tight environmental control and a high-rate composting process. 

If a facility owner wants to process in the least amount of space, taking the least amount of time, using the most reliable, predictable process, then that owner is going to convert that lesser system to the best system for mixed urban organics.  A covered and/or encapsulated aerated static pile (ASP) system, preferably with computerized control/monitoring and biofiltration, meets those expectations.

But how much might that region or business have saved/earned by investing in an expandable, high-rate facility in the beginning?  Remember, we’re not just talking composting, but all the dollars saved associated with compost use, too.

While Nero fiddled, Rome burned

Fiddling about while the city buries itself under a mountain of garbage is not an example of good governance.  In the private sector, failing to invest in upgrades and new technologies sets a company up for obsolescence.

Both depict outcomes resulting from failure to act when the time is right.

Unlike even 10 or 15 years ago, when most people were clueless about the many benefits of organics recycling on a municipal/industrial scale, today’s taxpayers are aware of composting as a waste management strategy.

Large volume waste generators in the private sector have been using commercial composting services for decades for one reason only – it’s more cost-effective than landfills.  As a bonus, it also gives corporations green points to use in their marketing messages.

Is it right for governing boards to continue to expect taxpayers to pay more simply because those who made the decision failed to be proactive in their decision-making?

No single option will be right for every community.  But giving serious consideration to organics recycling is always the right thing to do.

Starting at the top and working down is a lot easier than trying to claw one’s way up from the bottom.  So, aim for the best solution first, even if it’s not the easiest, fastest, or cheapest option.  

Then, use easy-er, fast-er, cheap-er tweaks to mold that system into the perfect waste management approach, customized to meet the unique needs and expectations of each community or business. 

True sustainability requires a system, not marketing-speak

Sticking a bird’s head on a spider does not transform that organism into a creature capable of flight.  Adding energy generation to incinerators and landfills doesn’t make them sustainable systems for organic waste management, either. 

“Sustainable” is one of those words that has been co-opted by Madison Avenue, slapped on everything from dog food to baby toys, and flung about willy-nilly like insults on nighttime reality TV.

It seems every product, process, and entity with even the smallest claim to the word uses it, because “sustainable” has finally caught the attention of the general public.

But the term, when applied to waste management choices, may be just as misleading as the words “natural” and “organic” on supermarket shelves.  What’s behind the label can still be the environmental equivalent of junk food. 

Admittedly,  people have become so adept at generating waste that the world has a never-ending supply have the stuff.  Ergo, any disposal or recycling technology could legitimately claim its feedstocks are sustainably sourced – even landfills without methane capture and plain, old incinerators.  

But that doesn’t make the total system sustainable or economically prudent or environmentally sound.

If pears are grown in compost in South America, shipped to Asia for processing, and transported back across an ocean to the U.S. for distribution and consumption, are those pears a sustainable choice?  

Using compost is better than not using compost.  But, c’mon, folks.  Did that pear earn the right to call itself sustainable?

Of course not.  Neither do disposal options that burn or bury compostables … even if they do result in energy generation.

Currently, only technologies that recycle or divert organics for use as a soil amendment (in farming, landscaping, turfgrass management, etc.) can claim true sustainability.  They close a loop, and when properly managed, do no environmental harm in the process.  

It remains to be seen whether some of the emerging re-uses for organic waste like building highways and formulating cleaning products will help or hurt the effort to recycle biodegradables back to the soil. 

Making new products from waste can be a swell idea.  But if those products can’t find their way to recycling at end-of-life, if the reclamation process renders them too toxic or otherwise inappropriate for composting, or if that reclamation generates a waste stream that cannot be efficiently returned to the soil, these types of reuse projects will likely – albeit indirectly – contribute to further soil depletion, more polluted runoff, increasing stormwater problems, and atmospheric carbon overload.

When government decision-makers are asked to evaluate new systems for organic waste management, marketing-speak has no place in a serious discussion.  One or two sustainable components does not make a sustainable system.

True sustainability cannot be conferred by feedstock source alone.   For organics, returning nutrients, organic matter, carbon, and beneficial microbes to the soil in an efficient, cost-effective manner makes composting and compost use a true sustainability choice – no marketing-speak required.

Lab test lingo:  How much is 1 PPM?

Test results — compost analytical reports included — often convey constituent concentrations in parts per million (ppm) or milligrams per liter (mg/L).  Both state the fraction of the tested substance found per one million units of gas, liquid, or solid.

But what does that really mean?  Is 1 PPM a drop in the bucket or a thimble of water in an ocean?

Such infinitesimal amounts can be difficult to visualize, but here are a few examples found on the web that may help:



Sometimes, even smaller concentrations may be reported as parts per billion or micrograms per liter (μg/L).  When you see this term, correlate to:

Know the limits

One of the best analogies is 1 ppm equals one large mouthful in a lifetime of eating.  But it must be said:  just a small bite of the wrong thing can be one bite too many.

That’s why it’s important to always correlate reported concentrations  with the limits deemed safe by regulators and other jurisdictional entities.  Typically, for easy comparison, these ceilings will be reported in an adjacent column on the lab report.

Estimating organic waste volumes for composting 

Imagine you’re the facilities manager for a large commercial building or institution, staring at a row of overflowing carts or roll-off boxes sidled up to the wall in the alley or back parking lot. 

They’re filled with crumpled paper, reams of old reports, food leftovers, used coffee pods, an avalanche of plastic bottles and aluminum cans, and pizza boxes with paper napkins stuck to the remnants of a variety of cheese toppings.    

You know all of those discards can be recycled and/or used as compost feedstocks.  Since most of that waste is compostable, diverting the organics from the landfill to composting could save money.   

The problem is, few composting operations will accept mixed waste loads.  The resulting compost is just too contaminated to use and winds up in the landfill anyway.  And if you want to develop an on-site composting project, knowing the volume/weight of compostables influences everything from sizing to siting to process selection. 

Source-separation – removing recyclables and compostables from the disposal stream at your location – is not as difficult as it sounds.  A good education program supported by a healthy dollop of (re)enforcement usually does the trick.   But before investing time, money, and brainpower in the project, you know the decision-makers will want to talk dollars and sense.  They’ll want assurances that the economics work.   

The first step is to determine how many pounds or tons of compostables are being generated each year.  Then, you can begin the planning process and start to gather cost estimates. 

Routes available for developing estimates all come with advantages and disadvantages, mostly related to things like people-power, total generation volumes and required degree of accuracy.  A web search will offer lots of ideas.  Here, we look at 3 broad categories: 

Route 1 – Develop estimates based on published norms and averages 

The easiest, fastest, and cheapest method to estimate compostable volumes is to glean “typicals” and “averages” from the web.   

The U.S. EPA says about 61% of the total MSW stream is made up of food, paper and cardboard, wood, and yard trimmings.  If your commercial or institutional stream is similar, this method could work for you.  Couple this percentage with known weight capacities of the specific receptacle in use, and the result is a baseline number you can use to calculate weekly or annual tonnage.   

Simply convert those gallons or cubic yards to pounds (based on container weight limits), divide by 2,000 to get tons, then multiply that number by .61 or 61%.  This is the estimated weight of all compostables. 

There are also sources that will provide weights based on generation rate per defined unit.  Example: 41 pounds MSW per week per household or 200 pounds per week for each fast food restaurant employee.  Again, convert pounds to tons and multiply that number by .61 for a rough estimate of compostable tonnage. 

Want to count bins or carts?  Contact your waste hauler for specific container sizes/weights or use a more generic number like 180 pounds for a 96gallon cart (from one online resource). 

Just focusing on food waste?  A cubic yard of food waste weighs about .5 tons. 

This method of estimating volumes for composting is probably best for low volume generators, because the total volume and weight of any “error” will be relatively small.  For everyone else, use this type of generic data for rough estimates only. 

You can find charts to help with weight estimates in our SlideShare title:  Estimating volumes of food waste and other organics for composting. 

Route 2  the DIY waste audit 

This method relies on statistically representative random sampling to develop a picture of the total waste stream.  There are several sample size calculators available online to help you get it right, and they come in handy for evaluating validity of other types of surveys, too. 

The following examples were calculated using the SurveyMonkey tool: 

Let’s say you counted a total of 40 trash cans in your office building.  Using a confidence level of 95% and a 5% margin of error, the calculator suggests a sample size of 37 trash cans. 

If you have a larger building with 400 trash cans, using the same confidence level and margin of error, the sample size is 197. 

Trying to pin down the generation volume of a city of 40,000?  The sample size is 381. 

Once you know how many units you need, identify a representative subset for sampling.  A human can do this, but to be totally unbiased in the choice of trash cans, let a computer randomize the list.  Using the 40-can building as an examplecreate a list of all trash can locations in a spreadsheet.  Then randomize the list Randomizing is easy … this site is just one of many with step-by-step instructions.   

Once the list is randomized, use locations 1-37 for your audit: 

  • Assemble supplies (gloves, aprons, scales, etc.) and identify helpers. 
  • Pull all 37 trash cans at the same time on the same day and move to your audit location. 
  • Provide training to any helpers who might not be able to distinguish compostable from non-compostable.
  • Separate can contents into those two piles.  If conducting a full waste stream audit, further subdivide the non-compostables into glass, metal, plastic, etc. 
  • Weigh the compostables pile and divide by 37 (sample size) to get an average weight per can.  Multiply that average by 40 cans (total building) for a daily average.  Multiply the daily average by the number of workdays per year to arrive at an annual weight and divide by 2,000 to convert pounds to tons. 
  • If you’re just doing compostables, you’re done.  Otherwise do the same calculations for each waste group you wish to audit. 

Advantages of this method are improved accuracy and the fact that audits can make good group projects.  But the audit is only as accurate as the volunteers, and auditor safety (masks, gloves, etc.) must be a top priority.  

Also consider, as an alternative to the internal DIY, the resources of a local university where a researcher, class or student may be looking for a project.  Some private companies and governmental entities also offer free audits.  Just make sure they understand the focus is compostables, not just the more traditional recyclables like plastic and glass. 

Route 3 – professional waste audits 

Sometimes, only a professional audit will do.  This will include sizeable and/or toxic waste streams where the expense of professional expertise is warranted.  Typically, these will be engineering firms and other specialists with experience in waste management. 

Professionals can charge by the hour or by the contract.  If taking this route, choose a reputable firm and make sure there is a clear set of deliverables, as well as a timeline, spelled out in the Scope of Work agreement. 

As might be expected, this option can require a healthy budget.  But on the plus side, using professionals can be more accurate than any other when estimating volumes for composting.  If composting costs less than landfilling in your region, the audit may well be a money-saver in the long-term. 


Good compost starts with a good recipe 

Whether making a small batch or a big one, following basic instructions will get composting done right. 

While baking relies on an external heat source to trigger a myriad of chemical reactions, and composting generates heat as a result of biological activity, both processes have a great deal in common – including the end result. 

Whether baking cupcakes or making compost, a quality product starts with quality ingredients added in the right amount, at the right time, and in the right order.   

Mess up even one step of the process, and the end product may never be right. 


Adding a pinch of sugar and 2 cups of salt to a cake recipe (instead of the other way around) could become an inedible disappointment.   

Composting is no different.   

For the process to work as it should, the carbon to nitrogen ratio must be right (25-30:1 by total C and N content, not “brown and green” feedstock volumes) and moisture levels must be in the zone (40-60% by weight). 


In baking, improper or incomplete mixing of ingredients can result in gooey or dry pockets within the finished treat.  Batches must be thoroughly blended to distribute ingredients evenly throughout the mixture. 

Goof up a compost blend, and the same thing happens.  Wet or dry pocketsmarbling, and other mixing mishaps mean microbes will not have equal exposure to target compounds, air, or moisture.   

This can create zones of uncomposted materials in an otherwise completed batch, failed laboratory tests, smelly finished product, etc.   

When blending, focus on achieving uniformity in moisture distribution, texture, and porosity. 


Convection ovens, equipped with fans that move heated air during the baking process, have become a favored appliance for bakers who once struggled to achieve even baking in older, conventional models. 

But the latest and greatest in kitchen gadgets are no help if temperature settings are wrong.  Heat levels must still be correct to bake a cake or casserole to the center without drying or burning the edges. 

For composting, that zone is 113-160 degrees for initial composting and 70-113 degrees for curing.  The time it takes to complete each processing stage depends on the level of control applied … which is where those fans come to the fore. 

It is possible to compost (and do it well) without an automated aeration system – it just takes more time and trouble.  But it’s not possible to compost without any aeration.  

In nature, it doesn’t matter how long a pile of yard waste or a dead squirrel takes to decompose.  Sometimes, it can take years for nature to work its recycling magic. 

But most composting operations don’t have the luxury of unlimited time.  Speed and effectiveness of the process impacts everything from acreage requirements to the cost of operations.  Managing air flow through the composting mass must be a top priority for any municipal or commercial composting facility that needs to meet both throughput and budget targets. 

Here’s why: 

Remember that 70-160-degree temperature range?  Two types of composting microbes live and work within those zones.  Mesophiles are most active at the lower temps, while thermophiles dominate the higher levels where microbial activity and the resulting biodegradation is quite robust. 

Air flow is the primary mechanism for temperature control within the composting mass.  If temps are allowed to exceed 160 degrees F, thermophiles die off, the entire process crashes, and heat (generated by biological activity) must rebuild to productive levels. 

Every “crash” slows the process.  It’s like opening the oven door every five minutes to check the rise of a souffle — does more harm than good. 

But by using fans to move air through the composting mass, temperatures can be controlled.  More air cools the pile; less air allows warming.  By using sensors linked to microprocessors to automatically adjust those fans to meet specific time/temperature goals, a composting batch can meet regulatory requirements for pathogen kill in a matter of days instead of weeks or months.   

Of course, a manual probe will work, as well, if the budget allows for a person to walk around all day monitoring pile temperatures and making the necessary fan adjustments. 


Food is rarely at its best when consumed straight from the oven.  Most dishes require a cooling/resting period prior to consumption, allowing sauces to thicken, juices to be absorbed and starch retrogradation to “happen.   

Compost, while it can be used fresh once PFRP/VAR requirements are met, is best when allowed to cooltoo. 

This is compost’s curing phase, when temperatures drop into the lower, slower zones preferred by the mesophilic organisms that will finish off the last of the food and bring the composting mass to a stabilized state. 

Farmers may prefer an immature compost because it can offer a slightly higher nutrient value than a more mature product.  But fair warning:  Use a compost before it’s fully cured only when destined for agriculture or other application away from sensitive noses.  Otherwise, wait until the pile offers only the sweet smell of rich, fertile soil before distribution.   

Depending on the initial feedstocks and technology used, the curing phase can last anywhere from a few weeks to several months.  Technologies used during curing can range from controlled aeration to occasional turning of a windrow to static pile. 

What is composting and how does it work? 

Composting is the managed degradation of plant and animal matter under aerobic (with air) conditions.  The process mimics natural decay in a controlled environment to speed up the breakdown of these organics. Composting results in a safe and easy-to-use soil amendment — compost.

Insects and bacteria are examples of the types of creatures that feed on discards like food waste and leaves during composting.  The larger animals tend to use mechanical methods, while the microscopic rely on chemicals to degrade these materials.

This feeding activity reduces complex compounds into simple molecules that are benign and odor free. Compost is used to build and replenish soils, closing the recycling loop for organic matter.  

The only byproducts of composting are CO2 and water;  the process produces no waste requiring disposal.  The CO2 is considered “carbon neutral” since its release during composting is the same as if decomposed by nature.

Most municipal, commercial, and non-profit composting facilities rely on microbes to do the bulk of the organic decomposition.  There are mancomposting methods in use, although outdoor windrows are among the most common.  Earthworms are the primary agents of decomposition in the controlled process known as vermicomposting. 

However, some other processes that have the word “composting” attached to their name in the vernacular may not be true composting processes.

Bokashi composting, for example, is an anaerobic (without air) fermentation process. Anaerobic composting is another misnomer.  Because neither is aerobic, neither is true composting.   Both can biodegrade organics, however.  Unfortunately, anaerobic decomposition may generate unpleasant odors since anaerobes produce mercaptan during biodegradation. (Mercaptan is added to odorless natural gas to give the gas its distinctive rotten egg smell.)   

Composting digestate, the by-product of energy extraction using anaerobic digestion, increases both the market value and uses for this waste material if managed for quality compost production.  

While neglected composting piles have been known to “go anaerobic,” too, a well-managed composting process — one that keeps the piles aerated — will not generate unpleasant odors.  Any odors present in the incoming feedstocks will be quickly neutralized, too.