Keeping the foodservice equipment marketplace up to date with the latest menu and concept trends.


How to Specify Composting Equipment

The world of waste management is vast and complex. With more landfill diversion options from which to choose, foodservice operators can sometimes be at a loss as to where to start.

Should you go with straight up composting/recycling bins and a waste hauling service? Do you install an onsite dehydrator and/or pulper to reduce trash and potentially create soil amendments? Or, do you take things one step further and install your own AD system to compost yourself?

When trying to identify a solution, no one size fits all. That’s where foodservice consultants can step in to help. Though waste management equipment and supply (E&S) specification may not have been in the scope of a foodservice consultant’s or designer’s work in years past, it’s increasingly becoming part of the overall project package as more operators know they need to examine this part of their business for environmental, cost-saving and even legal reasons depending on state and local legislation.

Christine Lenches-Hinkel, president of 301 Organics, an environmental consultancy, believes foodservice consultants can help operators select and specify the right equipment for efficient waste management. “We recognize the importance and benefits of using new technologies when it comes to waste management, but we stay impartial and focus on making the best recommendations for that specific operator,” she says.

Start by conducting a thorough, unbiased evaluation before choosing the best composting or other waste management plan, Lenches-Hinkel says, because choosing the wrong system, or not having the resources or preparation to handle the new system, could lead to thousands of investment dollars wasted.

Compost Bins

Implementing a third bin to collect post-consumer compost can be one of the least costly and time-heavy investments, but that all depends on local infrastructure and if there is a hauler willing to pick up the bins.

Assuming there is a willing waste hauler, signage plays an important role in the success of this initiative. Consumers can still get confused about what trash goes into which bin, Lenches-Hinkel says. “Don’t use words — use clear images to show what you want in which container,” she adds.

A solid PR and marketing campaign can help educate customers as well. Lenches-Hinkel says she’s had students get involved in designing custom sorting stations, worked with student green teams to educate patrons about composting on-site, helped organize other community partnerships and facilitate green messaging to get the word out about new composting systems. “We want patrons to be looking for the composting bins and want to separate trash themselves — that is the behavioral changes we’re looking for,” she says.

Lenches-Hinkel has also done countless studies and observations of people around trash cans to determine flow and where to best position the receptacles throughout a space. In most cases, she prefers to strategically cluster near ingress, egress and pinch points.

Lenches-Hinkel also recommends investing in waste measuring and tracking systems rather than relying solely on the waste hauler for feedback to better denote patterns of overproduction and excess waste.


Dehydrators — often used in conjunction with pulpers to first mash food waste into a condensed material — extract water and liquid from the waste, transforming it into a light and fluffy material that contributes less density to landfills and can cut overall waste hauling costs.

When using this equipment, though, operators run the risk of rehydration depending on how they store the material and the length of time the waste sits before someone hauls it away, Lenches-Hinkel says.

Food Waste Liquefiers

Food waste liquefiers operate with electricity, require a drain connection into the waste water sewer system, and are intended for installation in commercial or industrial settings. Operators must separate food waste from other forms of waste before placing items into this equipment, which typically sits near the food preparation area.

Food waste liquefiers typically break down food waste using a shredder or grinder as a first step, and a secondary step may use biological agents such as microorganisms and/or enzymes as additives. These units may require a continuous addition of fresh/potable water. The fresh water helps clean the system and replenishes the water lost through the discharge into the wastewater sewer system.

Food waste material breaks down in an aerobic environment that may include mechanical turning or agitation of the slurry. The unit then discharges the residual food waste slurry into the wastewater system. It’s important to note that food waste that has been liquefied is not the same thing as graywater, which is typically clear in color and comes from the drainage of bathtubs, showers, bathroom washbasins, clothes washing machines and laundry tubs. Liquefied food waste must undergo further treatment at a waste water treatment facility in order to be reused.

It is possible for liquefied food waste to be used as feedstock for an aerobic digester if it undergoes further treatment. In this case, there would have to be a waste hauler willing and able to pick up the stored liquid. This can get messy and complicated, however, for operators having to store the liquid separately rather than flush it down the drain.

While liquefiers do divert food waste from landfills, there’s still the concern that liquefied waste could impact water quality and lead to cumulative problems and complications over time. “In my opinion, it’s just a distraction from the landfill — you’re still overloading another facility, and in this case the waste water treatment facility,” Lenches-Hinkel says. “You want to think about the downstream impacts of these systems, not just the upstream ones.”

It’s also important to note that use of a food waste liquefier does not ensure compliance with the requirements of AB 1826, California’s Mandatory Commercial Organics law. In California, liquefiers may contribute toward compliance only when coupled with composting or anaerobic digestion.


For some operators, simply having a hauler take away compost or running food waste down a drain is not enough; they want to go the extra step of cutting down on the greenhouse gasses created in the hauling of the waste, and/or they want a more closed-loop system in which the waste can be reused.

Biodigesters are machines that mimic human digestion by breaking down food waste using microorganisms and enzymes in an oxygen-free environment to produce a renewable energy called biogas (methane and carbon dioxide) and other material that can serve as fertilizer. This is the process of anaerobic digestion.

While commonplace in agricultural communities, biodigesters are still few and far and between in the restaurant and foodservice industry because of their cost, space requirements and lack of availability in that market.

However, forward-thinking universities and other larger-scale facilities “who are committed to using the output product and want to integrate it into existing operations,” might benefit from investing in an on-site biodigester, Lenches-Hinkel says. “Schools or other institutions that want to use the product for landscaping or on-site gardens would benefit the most from this system, however the commitment and communication has to be there.”

In-Vessel Composting Systems

In-vessel composting generally consists of metal or plastic tanks in which air is injected under pressure to break down organic material using aerobic decomposition. The resulting product can be used as a soil amendment.

Several school districts, universities and even some hotels use these systems, as well as breweries and food manufacturing facilities, according to Lenches-Hinkel. Still, they’re a bit of an investment, both on the financial level and on the operational level.

Composting systems like these can lead to offensive odors if not properly controlled. They require a precise carbon to nitrogen ration as well as ventilation. More advanced systems are able to capture the energy output by switching to anaerobic digestion.

Some of these systems can be large in size, so they do well in larger facilities. However, there are smaller models coming into the market, says Lenches-Hinkel.

It’s important for operators to understand their intent with these systems. Do they want to create a product meant to enrich the health of our soil? Or do they want to create more energy for use? Some environmentalists are divided on composting systems because they believe we should be cutting down on energy production — in conjunction with using other renewable resources like solar and wind energy — rather than creating additional energy. Others view the energy output from a composting machine to be just another form of renewal energy that doesn’t come from the grid.

“This is why we run assessments for our clients when trying to decide which system to use,” says Lenches-Hinkel. All of her clients, she adds, have different views, needs, resources and priorities and the best fit for one might not be the best fit for another.