Cow Power and Low Hanging Fruit: Organic Waste is Ripe for Capture

When it comes to solid waste and turning our trash into resources, we are truly starting to move away from the stage of low-hanging fruit. It’s time to go after that low-hanging fruit — organics that is — before it rots on the vine!

That’s the trend across the United States, with the number of anaerobic digesters used to break down manure and even human biosolids growing, and increasingly incorporating other feedstock — food waste and other organics — to increase the methane production. There are currently about two hundred manure based digesters, 1,200 human biosolids digesters, several dozen digesters dedicated to waste streams at food production facilities, and a growing number of ‘centralized’ digesters dedicated to both pre- and post-consumer in municipalities across the US.

Michigan State University

Michigan State University

When feed-stocks are broken down by bacteria-in an oxygen-free (anaerobic) environment; biogas is the result. Biogas typically contains from 60 to 70 percent methane, 30 to 40 percent carbon dioxide and trace amounts of other gases. Methane is the same root energy component in natural gas that we’re all familiar with. But this methane is available as a local, renewable energy source from the rotting organic resources we discard every day.

After expansion of curbside collection of traditional recyclables (bottles, cans, paper, cardboard and plastic) and pressure still increasing to get closer and closer to zero waste (Frederick County’s current goal is to be diverting 60% of the waste stream), more and more cities, counties and even states, such as Massachusetts& Vermont, are banning organic waste generated by the food sector (grocery stores, large restaurants, etc.). This regulatory push is catalyzing the expansion of alternate management strategies (biogas recovery and anaerobic co-digestion systems being at the top) designed to take on more organics combined with manure and wastewater.

Therein lies Frederick County’s opportunity for a transition away from long-hauling the organic portion of our waste—and it could have quite an impact. The most recent federal statistics put food waste at 14.5% (2 percent recovered in 2012); yard trimmings at 13.5% (22.6% recovered) and wood waste at 15.8% (2.8 percent recovered). Frederick County’s solid waste characterization in its plan does not mimicEPA categories – it lists yard waste at 7%, with food scraps mixed among residential and commercial waste. The Residents Guide to Solid Waste Management, however, puts yard waste and food scraps at 30% of the residential waste stream. This nearly one-third of the waste stream identified as organics does fit squarely with EPA numbers, and provides a great opportunity for energy, compost and better management in the county.


We Need to Get Started

Frederick County — and other Maryland jurisdictions — have some solvable problems to tackle before we can jump into organics. Unfortunately, the focus on the Wheelabrator incinerator project for the past few years has set back our progress. But, with focus, we can get back on track. The City of Frederick’s wastewater treatment plant already uses anaerobic digestion to consume its biosolids, though it is not composting them.

Focus: With so much time and energy spent on the quest to prove the efficacy of incinerating trash and generating energy, for the past half-decade Frederick County has left fallow (pun intended) the pursuit of anaerobic digestion of agricultural and food waste.

Dedicating staff resources, political discussion and the Solid Waste Advisory Committee — which has only met a few times a year in recent years — will help to move consensus forward. It is important that citizens are part of this process because even with a green technology, like energy producing-digesters and the composting plants where digestive solids result from the process is composted can be controversial.


A Champion: As one of the East Coast’s largest dairy counties (Stan Fultz, one of the county’s agricultural extension agents, puts the number of dairy cows in the county at 14,200), there is feedstock available — but someone needs to broker the right combination of farms who could participate in a cost-effective system, match them with feasible pilot, and then expanded, food and green-waste generators. Ideal champions would be agricultural community representatives, people who currently work with anaerobic digesters, such as Frederick County and City’s wastewater experts or Morningstar Dairy, and solid waste staff.

Environmental Protection Agency

Environmental Protection Agency

Funding: States like Wisconsin, Massachusetts, Vermont and others with large dairy herds are already successfully incorporating a variety of feed-stocks into on-farm digesters are led largely through matchups of university research and federal grants.

We could be doing the same here if staff in the county and state were assigned to make it happen. Maryland still has a way to go in terms of support for anaerobic digesters that could incorporate other organic wastes, with only small grants from the Chesapeake Bay Clean Power project so far to stimulate investment and projects.

Environmental Protection Agency

Environmental Protection Agency

In Frederick County, we should join our neighbors on the Eastern Shore who are already advocating (and in some cases have started projects) for anaerobic biogas to be a defined part of biomass in the states Renewable Energy Portfolio requirements.

Until we know more specifically the direction in which we would be headed, cost is difficult to estimate. But consider this: as a result of a University of New Hampshire eight-bay aerated static pile system combined with a thermal energy recovery system pilot project, the University is putting together an “off the shelf” system (Smith and Aber 2013) costing less than $1 million and processing between 90 and 400 tons per month.

For comparison, Frederick County’s rough count of its organics, at 30% of the 457,000 tons of waste (2011 figures from Solid Waste Plan) produced by Frederick residents, is 137,000 tons; at an estimate of 150 pounds per cow of manure, total manure tonnage could yield 1,065 tons based on 150 pounds of manure per year per cow, according to an estimate by Chuck Fry, former president of the Frederick County Farm Bureau.

frederickcountyZoning: Also left untended has been an initiative on the current Board of County Commissioners’ to-do list that was innitiated by Hilari Varnadore when she was director of the county’s Office of Sustainability—-zoning amendments to allow on farm systems within the agricultural zone. According to the Frederick County Planning and Zoning Office, the county has been waiting for state action in this arena, but if this is made a priority, the county can move ahead of the state.

Maryland House Bill 1081 (Composting and Anaerobic Digestion Facilities-Yard Waste and Food Residuals) did not pass in the last General Assembly Session, even though it was supported by the Maryland Department of the Environment and US Composting Council. It would have required, after Oct. 1 2015, the separate collection and composting or anaerobic digestion of two or more tons of food residuals per week if a composting facility was within 30 miles. The bill also included zoning and permitting language.

Jobs: Depending upon the type and breadth of composting facility that is selected ultimately, the economic development prospects are encouraging. A study by the Institute for Local Self Reliance on Maryland composting facilities, for every two landfill jobs, there are four incinerator jobs and eight jobs in the compost industry.

carrollcountyIt is heartening to see Carroll County moving in the direction of resource recovery options that don’t involve incineration of useful resources. Frederick County should watch what’s happening with organics recycling in the rest of the country…before re-sinking its resources into more long hauling or landfilling contracts. The fruits and vegetables are ready for the picking!


Institute for Local Self Reliance
Pay Dirt: Composting in Maryland to Reduce Waste, Create Jobs and Protect the Bay

Maryland Biogas Project

Food Waste Bans

Anaerobic Digestion: Questions & Answers from the Massachusetts Office of Energy and Environmental Affairs

Frederick County: The Residents Guide to Solid Waste Management