Is it really a good idea to make compostable waste go away and never come back? 

Each year, taxpayers collectively spend millions of dollars to burn or bury compostables.  Much like a tribe of ubiquitous Gollums, they just want garbage — the biodegradable and putrefying fraction of the municipal solid waste stream – to go away and never come back. 

The desire to make disagreeable discards disappear into fiery furnaces or burial mounds is understandable.  But is it wise?  Is it fiscally responsible?  Is it really a good idea to make organic waste go away and never come back? 

Nature recycles everything 

Rocks weather and erode, creating sediment. With heat, pressure, and time, that sediment becomes rock again.  Plants and animals feed and drink from the earth, die, and decompose to replenish the soil that will sustain future generations of flora and fauna.  Water drops from the sky as rain, filters down to aquifers, upwells and evaporates back to the clouds to fall once more. 

In a fantasy land, it may be possible to keep using resources without a thought to replenishment.  But in the real world, organic waste – the decaying residuals of once-living things – must be recycled back to the soil to maintain life-critical soil functions.   

Some seem to think the destruction of organics to make energy is more important than rebuilding soil.  But pushing an organic-waste-to-energy agenda by sacrificing the soil makes no sense. Humans managed to survive for millennia without electricity and centralized energy systems.  Without soil’s life-essential contribution to food and clean water, people face extinction in weeks.  

So, which is more important, energy or soil? 

Make energy and rebuild soil?   

Organic waste from developed societies includes all types of vegetation, food, manures … even compostable plastics.  When turned into a quality compost, these once-lost resources can be used by anyone anywhere to replenish depleted soil.   

Happily, making energy and building healthy soil does not have to be an either/or proposition.  It is possible to extract energy from organic waste without destroying the beneficial properties that make it valuable to soil.   The organic waste streams from these processes can then be used as feedstocks in the manufacture of compost products. 

Unhappily, energy production from biomass is one of the most expensive ways to make energy.  Even solar and wind power can be more cost-effective. 

Furthermore, bioenergy technologies based on anaerobic digestion of organics are still too pricey to be practical in many places.  Where they do exist, the waste stream (digestate) is not always put to highest and best use (i.e. composted).  Instead, residuals may be landfilled or relegated to low-dollar-value reuse. 

But one day, as more communities opt to restore natural soil replenishment cycles and energy generation technologies become more efficient, extracting energy from biomass, followed by composting and compost use, can become the system of choice for organic waste management. 

In the meantime … 

The importance of healthy soil 

Where humans live, topsoil has been scraped away or eroded.  Nutrients are used up.  Compaction has destroyed the pore spaces essential to the transport of air, water, and microbes.  Without a regular infusion of new organic matter to correct these deficiencies, soil dies.   

There are lots of processes for generating energy, but there’s only one way to replenish disturbed soils in developed areas – feed them a good, wholesome diet derived from organic waste converted into compost.   

From farms to lawns to sports fields, soils require periodic applications of compost.  There’s no other way to easily and economically provide soil with everything it requires to retain water, nurture vegetation, and create the type of environment soil microbes need to support nutrient uptake, contribute to disease resistance, and degrade pollutants. 

The best news? In many metropolitan areas, efficient, high-rate composting – the type needed to successfully manage big, urban waste streams – costs no more than landfilling or incineration.  Often, recycling at a modern, industrial composting operation can be more affordable than traditional disposal.   

Composting makes organic wastes go away, but they come back as enriching soil amendments.  Biodegradables need to keep recycling, just like they have since the beginning of time. 

Breaking the natural soil cycle by incinerating or burying compostable waste is a bad idea that should go away and never come back.

VIEW THE SLIDESHARE:  Addicted to convenience

How to make compost fast

The desire to make compost fast can be driven by space restrictions, the need for more product, or simple impatience.   It’s a common goal for composters everywhere, from the backyard to industrial facilities.

Unfortunately, wishing will never make it so.  The speediest course from raw feedstock to finished quality compost is a series of steps controlled by the person doing the composting.  Skip or bungle just one, and biodegradation could slow or even grind to a halt.

It doesn’t matter whether you make compost by the tumbler or by the ton.  If you want to make compost fast, follow these steps:

  1. Consider carbon-to-nitrogen (C:N) ratios when mixing every batch.  Base mixes on the C and N percentage of each feedstock, not feedstock volume – it’s not buckets of “brown” to buckets of “green.”   Learn more about calculating C:N ratios.
  2. Get the blend right with uniform particle size, good porosity, no clumps or marbling of feedstocks.  
  3. Maintain a desirable moisture level throughout primary processing.  Don’t expose the composting mass to weather or allow it to dry out.  Add moisture, as needed.   Learn more about composting moisture levels.
  4. Keep air moving through the pile.  This allows microbes to breathe and removes excess heat.  Invest in a temperature probe and adjust air flow to maintain ideal temperatures.       

Master these basics to make compost fast.

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.      

Does composting release CO2?

Carbon dioxide (CO2) emissions from the composting mass are classified as biogenic. This means the same amount of gas is emitted during decomposition whether the organic material is composted or degrades in a natural setting.  Therefore, these emissions are considered carbon-neutral.

Compared to waste management alternatives, it’s the best of the bunch.

Other emissions sources, however, like those from equipment operation,  do add to the size of a composting facility’s environmental footprint.  These are nonbiogenic, a.k.a. anthropogenic, emissions.

This factsheet provides a good topic overview that includes values for helping composting operations with emissions calculations.

 

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. 

LEARN MORE: 

Compost is soil’s superhero

Sure, compost adds nutrients. But that might be this soil amendment’s least important function. 

Quite often, articles will mention compost as a replacement for some or all of the nutrients that might be provided to plants through applications of synthetic (man-made) fertilizers.   

That’s certainly true.  Compost delivers the macronutrients nitrogen, phosphorus, and potassium (NPK), plus a slew of plant-essential micronutrients that are missing from most synthesized fertilizer products.  Compost provides plants with a wholesome, well-rounded meal, not the nutritional equivalent of junk food. 

But what these fertilizer-focused articles rarely mention is the fact that the real value in compost use is not related to feeding plants, but to feeding soil … and soil does require a wholesome diet to function as a true soil and not a dead substrate. 

Compost feeds soil

Providing plant nutrients is just one of many soil functions.  Worms and other creatures that live in healthy soils help to physically break down food sources, then microbes take over to convert that food into plant-available form. 

Both physical and microbial conversion depend on a soil environment that can support those lifeforms.  If the soil is chronically too wet, too dry, too compacted  yada, yada  then it can’t support a healthy soil ecosystem.  That plot of ground may not be soil at all, but lifeless dirt. 

To countermand the impacts of human activity, disturbed soils require regular program of replenishment that includes organic matter and microbes.  Compost provides both.  Compost feeds soil.

Then, when it rains, soil retains that water, reducing runoff.  When runoff is reduced, so is erosion, sedimentation, and water pollution.  Because soil microbial activity also degrades pollutants, any stormwater that does run off is cleaner.  

That same microbial activity can help neutralize some soil-borne diseases, too. 

Improving plant nutrition, aiding in disease control, reducing water pollution, and retaining water are all important soil functions. 

But wait, there’s more. 

Compost as a carbon sink 

The build-up of greenhouse gases in the earth’s atmosphere is cause for concern.  As more greenhouse gases flood the atmosphere, temperatures increase. 

This rise in global temperatures influences many things, erratic and extreme weather being one of the most visible.  Subsequent climate shifts can impact people, crops, and livestock for hundreds of years. 

When used to amend soils, compost sequesters carbon.  This means the soil will act as a carbon “sink,” capturing and holding carbon in stasis – but only as long as the soil remains undisturbed.  When the soil is tilled, that carbon is released. 

Extensive use of compost for perennial crops and other long-term application(grasslands, tree farms, utility easements, etc.) can positively impact atmospheric conditions by reducing greenhouse gases.   

At the same time, the addition of compost rebuilds a topsoil layer that has been eroded or scraped away by farming, development, and other human activity.  Since topsoil loss has been identified as a significant threat to planetary health, second only to population growthits restoration is a global priority.   

At a time when nearly a third of the world’s arable land has become unproductive in just a few decades, compost really can be that superhero swooping in to save topsoil, save water, save the atmosphere, and save the planet. 

Comparing costs per gallon retained 

Soil amendment is one of the least expensive ways to collect and manage stormwater 

Manage water where it falls.” 

This sound advice is the foundation of the Milwaukee Metropolitan Sewerage District’s Regional Green Infrastructure Plana program that identified soil amendment as one of the least expensive ways to manage stormwater.  At 28 cents per gallon, improving soil is second only to native plantings in lowest cost per gallon retained. 

Green roofs?  $4.72 per gallon.  Those fancy-schmancy deep storage tunnels?  $2.42 per gallon.  At $1.59 per gallon, even pretty little rain gardens cost more than five times that of simple soil amendment. 

Milwaukee is not alone in promoting soil amendment as a first line of defense for stormwater management  For example: 

  • Denver and GreenleyColorado, require compost use for new landscaping, as does Leander, Texas. 
  • Some state Departments of Transportation (DOTs) now routinely specify compost.  A few years ago, the Texas DOT said it was the largest single market for compost in the U.S. 

In an urban environment, opportunities for soil amendment abound.  City parks, athletic fields, planters, urban lawns, highway medians and easements, foundation backfill – anywhere there’s soil, there’s opportunity for inexpensive water retention. 

Every 1 percent increase in soil organic matter (SOM) content adds an additional 16,000 gallons of water-holding capacity per acre foot.  A site managed to maintain soil organic matter at only 2 percent can hold all the water of a typical rain event (1 inch or less), which is 27,154 gallons per acre.     

In fact, at 5 percent SOM, the soil can retain the water equivalent of nearly 3-inches of rainfall.  In some regions, this equal95 percent of all storm events. 

Soil amendment may not solve all rainfall issues, especially in downtown areas.  But managing water where it falls can be the most sensible, efficient, environmentally- and economically-prudent strategy for “first line of defense” stormwater management.   

Food waste mandates are only the halfway mark 

Compost use gets organics recycling to the finish line 

Unlike a decade ago, when food waste mandates were few and far between, there is a flurry of activity these days focused on diverting food waste and other residential/commercial biodegradables from landfills and incineration. 

From the U.S. to Italy to northern India, the movement toward more sustainable management of organic waste from households and businesses is real and gaining momentum. 

But while laudable, there’s a big piece missing from some of these programs — mandated compost use.  Just making compost isn’t recycling.  The product must be used – returned to the soil – to be recycled.  That’s what makes the system “sustainable.” 

Landfilling organics isn’t sustainable because they’re buried.  Any thermal or other waste-to-energy (WTE) technology that destroys organics isn’t sustainable, either, no matter how hard technology providers try to paint them as such.  The feedstock – municipal waste – may be considered a sustainable source, but the management system is not. 

A possible exception is biochar, carbon-rich, charcoal waste material produced by pyrolysis that is sometimes used as a soil amendment.  However, not all biochar is right for this type of reuse.  It doesn’t offer as many benefits as compost, and — since the use of biochar is relatively new — there is a lack of research related to its long-term use.  While pure biochar is made from organics, of specific concern is contamination resulting from WTE biochar processes that use unsorted municipal solid waste as feedstock.  

But whether biochar or compost, the truth bears repeating — recycled organics must be used to feed the soil for a sustainable system to exist.  This is the only way to close the recycling loop for organics. 

Going the distance with food waste mandates

Football players don’t move the ball to the 50-yard line and then stand around waiting for the pigskin to get itself into the end zone. 

Establishing a curbside or drop-off program for source-separated organics is a good first step … but it’s only half the distance to the goal.   

The finish line for organics recycling is compost use.  Anything a community can do to encourage that use is important.  But sometimes, it takes more than education and outreach to get the ball rolling. 

When governmental entities write ordinances and project specifications requiring compost use, good things happen.  By creating early markets for quality compost productseveryone from green industry pros to stormwater managers to homeowners can clearly see the benefits of amending soil. 

This demonstration leads to voluntary compost use through the manufacture of quality products and product sales to high-value markets.  Product sales, not giveaway programs, is what will keep composting facilities – public or private – economically sound. 

Any community considering organics recycling needs to think about the end game.  To ignore the ultimate goal is to win the battle, but lose the war for organics recycling.  

READ:  Food waste diversion — it’s time to pursue alternatives that make environmental and economic sense

Making sense of research data

Evaluating organic waste management options and cost comparisons

When personal expertise is lacking, people place their trust in experts to facilitate decisions about everything from home additions to medical care.  Governing boards are no different.  They rely on the knowledge of utility directors, staff engineers, and consultants to help them make informed decisions.

But when presented with an avalanche of numbers – from scientific data to cost and operating projections – how do members of city councils and county commissions know if the information contained in that mountain of reports is accurate and unbiased?  How do they know they’re comparing apples to apples and not apples to oranges?

Placing value on studies specific to waste management can be complex.  One report might compare landfilling, incineration, and anaerobic digestion, but leave composting out of the mix.  Another may include composting, but base assumptions on an antiquated window system and not a modern, high-rate technology.  Research could unearth reports about a costly public project but never discover a more efficient, cost-effective commercial system.

This is not to suggest such errors or omissions are intentional.  Sometimes, it’s simply a case of “you don’t know what you don’t know.”  But when combined with the fact that detailed financial or operational data from private-sector owners is rarely made available in public spaces, one begins to understand the difficulty in obtaining good data on which to base conclusions and recommendations when doing composting cost comparisons.

The takeaway?  Assume all research is flawed in some way.  No one knows everything there is to know about every subject.  But there are a handful of questions that members of city councils and town boards can ask to help clarify reported numbers, level the playing field, and present a more accurate picture of construction and operational realities.

Who paid for the research?

Perhaps the most significant influence on any research project is the entity that foots the bill.  Even university research is funded by someone … and it may not be the university.  Non-profits may fund research, but they rely on the support of donors.  Government agencies can be funders, but governments are run by politicians.  When the private sector funds studies, the results may never see the light of day if unfavorable to the funding entity.  Student work may not be funded, but it’s still student work.

Was the research scientifically sound?

Some “research” may not be new research at all, but assumptions or conclusions based on a literature review that includes outdated or invalid findings.  Investigations may have been conducted in a manner that does not reflect “good science,” including a lack of statistically-representative sampling.  Some findings are more opinion poll than science.  But when sifting through millions of scientific papers for data, researchers won’t always pick up on these types of flaws.

Also know statistics can be presented in a manner that makes differences look more (or less) important than they really are.  (See an example in this SlideShare title:  Apples and oranges: comparing waste management technologies)

How old is the research data?

Unfortunately, it’s all too common to discover a case built on multiple levels of citations that eventually trickle down to data or conclusions that may not reflect present day realities.  Knowing the date and technological sophistication of the original study will help decision-makers evaluate the value/validity of the conclusions and recommendations included in the consultant’s report.

Don’t accept a current date on a citation at face value.  Follow the citation trail to the date and circumstances of the original research.

Is data based on full-scale operations using current technologies?

Was the data based on bench scale, pilot scale, field scale, or full scale?  Conclusions reached during early stages of product or system development can fail to “scale up” successfully.   Investigations based on dinosaur technologies of 20 or 30 years ago exclude advancements and enhancements made in recent years, distorting findings.

For composting specifically, ensure that systems and technologies are apples-to-apples comparisons using the most current data available.  If evaluating high-rate systems, include successful private-sector facilities, too, not just municipal.   Net expense and revenue values per ton processed can vary widely between different types of operations.

Using old data and processing systems for dollar comparisons could greatly skew conclusions when comparing composting to other waste management technologies.

Sometimes, imperfect is the only data available for composting cost comparisons

When conducting research in a field like composting, where meaningful research is scant, at best, the imperfect may be all there is.  Knowing and accepting this reality, proactively seeking out the most accurate information, and evaluating results based on a variety of studies and viewpoints can only help decision-makers make better choices for their respective communities.

Read the article:  Valuing composting as an infrastructure investment

3 questions to ask before choosing a composting system

When evaluating choices for organics diversion, system cost tends to be a major influence in whittling down the available options.  But is capital investment a good indicator of true costs over the decades of composting facility operation?

There are many questions decision-makers need to ask before choosing a composting system.  But judging by the number of lackluster operations in existence, here are 3 biggies that don’t get asked nearly enough:

Co-mingled vs. source-separation — do you want to sell this compost?

At first glance, co-mingling organics with either the total municipal solid waste stream or with other recyclables for central separation (either pre- or post-composting) looks like a no-brainer.  No extra collections or special trucks.  No expensive outreach and education programs.

But co-mingling doesn’t work if the ultimate goal is the production of a salable compost product.  Contamination can be so high, it’s almost impossible to sell the stuff.  Sometimes, farmers won’t even take it for free.

Co-mingled may be acceptable if the objective is to dry organics prior to incineration/WTE, but destroying organic matter does nothing to increase rain infiltration across the region, store carbon, reduce reliance on synthetic chemicals or cut erosion.

But to derive the most benefit from compost use, compost manufacture must result in a high-quality product.  That means source-separation supported by a good education and enforcement program.

Does the management plan include a professional sales effort to maximize the dollar value of the compost?

An inferior compost brings in little to no revenue to offset production costs.  But a quality product, supported by a professional sales effort, can net top dollar.

The first step to getting top dollar value from product sales is to manufacture compost that falls into the premium class – dark, nutrient-rich, even-textured and odor-free.  Every manufacturing dollar spent improving an agricultural-grade product can return additional dollars in compost sales to high-value markets like landscaping, turfgrass management and stormwater management.

Before choosing a composting system, make sure that technology is capable of producing quality compost.

But that manufacturing effort will be wasted if the operation lacks a professional sales program designed and run by experienced marketers and sales pros.  Mounting an effective sales effort requires both premium product and premium people.

Hiring experienced sales pros pays off.  If faced with the choice between someone who knows compost but lacks sales experience and a sales pro with a good track record but no composting background, choose the sales pro to lead the team and put him/her in charge of the compost guru.

Why?  The right pro will be able to learn what s/he needs to structure a program and move product.  The compost person may or may not have what it takes to be successful in sales.   But working for and learning from a seasoned pro will make that compost expert the best salesperson s/he can be, generating maximum revenue for the operation.

Does the analyst’s cost:benefit considerations include the advantages of regional compost use?

Irresponsible soil management practices carry a cost.  Options for highest and best use for compost regionwide should be factors in the cost:benefit evaluation.

Analysists need to ask questions like:

  • If raising soil organic matter eliminates runoff and sedimentation from a typical rain event (1 inch or less), what impact would the use of a quality compost have on the region?
  • How could compost use influence current municipal costs to manage stormwater or treat contaminated drinking water sources?
  • What would be the savings to local farmers if they could cut their fertilizer bills in half?
  • Since compost reduces chemical use and the severity of impact injuries on playing fields, how would this influence things like maintenance budgets, player downtime and medical bills for athletic and recreation venues?

Use of compost in a region can have significant positive impact on costs for stormwater management, synthetic fertilizer and pesticide reduction, water treatment costs and much more.   Costs, cost savings and avoided costs should be discussed and considered when weighing pros and cons for a proposed project.

Decision-makers who look only at trees instead of the forest may be doing their communities a great disservice.  When reviewing analyses and recommendations prepared by staff or consultants, be sure those reports take in the big picture, not just impacts to waste management.