Preempting composting disasters: mitigating impacts from urban sprawl, changing regulations and other nightmares
View the SlideShare: Preemption — the future of composting
Even the most advanced composting operations are not immune from unforeseen disasters. It’s difficult to develop a preemptive strategy for extreme weather, for example, other than to draw up a disaster plan and hope it never needs to be executed. But preempting composting disasters — at least, the most common — is possible.
These are the lesser catastrophes that, if left to the whims of fate, can cripple an operation just as effectively as a direct hurricane hit.
Odors, leachate and unsalable product can be disastrous, but they’re not unexpected or unpredictable. All can be linked to bad planning, poorly-designed facilities and careless process management.
Great heaps of decaying organic matter are going to smell unless someone takes proactive measures to make sure they don’t. Those piles are going to ooze “black liquor” unless someone aggressively works to eliminate the possibility.
That makes these lesser disasters preventable through preemptive design and management practices.
Preempting composting disasters — urban encroachment. Talk to any facility owner who woke one morning to find his or her composting operation floating in a sea of irate suburbanites. Urban encroachment is a real threat to composting operations of every size, and it never matters that the composting facility was there first.
While nearly impossible to prevent, the disastrous conversion of nearby fields and pastures into housing developments can often be predicted through long-term planning combined with preemptive strategies in siting and design. Population and growth projections, as well as long-range land use and zoning maps, provide clues as to the sanity of siting or expanding on any parcel. They also foretell the wisdom of choosing outdoor over indoor facilities or windrow over forced aeration composting.
These types of prognostication tools are readily available online and can provide invaluable guidance for a small investment in time.
When shopping for sites, zero in on parcels with plenty of buffer potential. Generous use of woodlands and vegetated berms between the facility and the host community can make the difference between a contentious relationship or a symbiotic one, especially when neighbors are not accustomed to living near a heavy industrial environment.
For existing windrow operations, transitioning now to faster, more efficient composting technologies can free-up valuable acreage for conversion to wooded buffer zones while allowing for future expansion. By the time suburbia creeps up to the gate, the facility can be cloaked in trees and thick undergrowth.
Strategic placement of buffers will be influenced by sight lines from the road, property boundaries and prevailing winds. Understand the role tree height, windbreak angle and density play in the redirection of wind and dispersal of odors. Design windbreaks and buffers accordingly.
Preempting composting disasters — tighter regulations. If one looks back at the changes imposed on the landfill, incineration and wastewater treatment industries over the decades, it’s not too far-fetched to expect a similar evolution for composting.
Breaking into mainstream waste management in the 1990s, composting has seen regulation and policy overhauls in a number of states in recent years as the technology is asked to take on an ever-increasing percentage of the total municipal solid waste stream.
Outside of the regulatory arena, expectations of the marketplace can also drive composting operations to voluntarily set higher standards.
Like urban sprawl, there are clues as to the challenges and expectations composting may face in the next phase of its evolution.
Mandates, practices and consumer preferences in the European Union, as well as trailblazer states like California, seem to set waves in motion that eventually hit the U.S. mainstream. The impact might not shake an operation for a decade or more. They might take the form of regulations or market trends. But either way, that influence can change the way composting facilities of all sizes and methods do business.
Keeping an eye on the horizon will help composters prepare for those waves, be they gentle ripples or tsunamis.
Preempting composting disasters — odor containment and neutralization. In most cases, the same measures taken to preempt odors will also solve issues like leachate generation and poor compost quality. They’re all of a piece.
Odors form when feedstocks and composting piles are too wet, encouraging the proliferation of odor-causing, anaerobic organisms. Leachate results when excess moisture drains to the base of piles and flows from standing pools of “black liquor.” Poor compost quality, including rebloom of pathogens, can be linked to wet piles, as well.
A composting facility of any size or type, anywhere other than the middle of expansive acreage or very favorable climates, is best served by preemptive design and management practices that wrest moisture control away from Mother Nature.
This control extends from feedstock storage and blending to processing and curing. If finished product is to be stored for any length of time, preemption principles can be applied here, too.
The goal is to place moisture management in the hands of the facility operator, not the weatherman. Typically, this takes the form of some type of cover. Indoor operations solve the problem with a roof and siding, but shed roofs, tarps and bags can work just as well – they just require more labor, equipment and management. But in the absence of full indoor operations, there’s no practical way to extract and filter the odors generated throughout the operation.
In addition to indoor work zones, odor mitigation measures will include:
- Covered off-loading, and when sited within close proximity to neighbors, indoor off-loading. Air from raw feedstock storage areas will be treated/filtered.
- Expedited blending of high-moisture feedstocks, meeting all targets for C:N ratios, moisture, porosity and homogeneity.
- Contained, high-rate processes to quickly reduce anaerobic populations and create environments favorable to aerobic microorganisms. These measures can be combined with computerized process control to automate monitoring and datalogging for regulatory compliance.
- Immediate and generous use of dry compost to absorb any seepage from the composting mass during the initial stages of processing. This absorbent should be replaced, as needed, with the used material returned to the head of the plant for reprocessing.
- Air extraction systems and biofiltration to neutralize odors from processing bays and other indoor work zones prior to venting.