A recent study by state agency analyzed organic materials recycled since 2011, as well as food waste recovered in 2015. Findings show substantial organics recycling capacity.
The North Carolina Department of Environmental Quality (NC DEQ) released a study in June 2016 analyzing the organic materials recycled since 2011, as well as food waste recovered in 2015. The facility reporting requirement in the North Carolina compost rules and the relationships built over the years with different players in the industry were essential to obtaining the necessary data for both parts of the study, and it shows healthy signs of organics recovery.
North Carolina has a robust network to recover wholesome food through hunger relief organizations and also to reuse excess food by processing it to feed animals, the soil, and the electricity grid. Though the state does not have a food waste disposal ban, it does have a yard trimmings ban in place that has been crucial to expand composting infrastructure. Continued progress in all of these areas has been supported by assistance from state and local governments and by effective action from the private and nonprofit sectors.
Feedstocks, Composting Facilities
The NCDEQ permits a range of organics recycling facilities, however this study focused on a subset of facilities permitted under the same regulatory group (Division of Waste Management’s (DWM) Solid Waste Section). In the latest reporting cycle (fiscal 2014-2015), the facilities consisted of 24 private, 23 public, and 5 college/university operations, which in total, received approximately 640,000 tons of organic material. Yard trimmings accounted for 51 percent of organics processed; food scraps accounted for 7 percent.
Figure 1 shows that North Carolina is using 35 percent (640,276 tons) of its available permitted capacity to process organic material and has available permitted capacity to process an additional 1.2 million tons. This is an approximation based on the available data from the NCDEQ DWM permitted composting facilities. Most recently, NCDEQ DWM has decided to no longer issue facility throughput limits on composting permits; it will only adhere to windrow and curing pile sizes and other dimensional design features to be followed as specified on the permit application. Due to this change, the language of available permitted capacity will shift to unused capacity for the purposes of this study, given that most composting facilities in the past have built their maximum footprints after they have been granted their permits.
Composting facilities across the state typically charge tipping fees for incoming materials. Table 1 summarizes fiscal 2014-15 tipping fees by 9 privately and 11 publicly operated facilities (an average of $26/ton). These values provide a total average and do not reflect the variety of tipping fees throughout the state nor differences in tipping fees based on the type of feedstock.
For comparison purposes, the average North Carolina landfill tipping fees in the same fiscal year were $38/ton at construction and demolition landfills (53 reporting sites) and $41/ton at municipal solid waste landfills (39 reporting sites). Even though the average composting tipping fee is below these two values, collection and transportation costs to composting facilities need to be factored in to account for potentially higher costs due to longer distances to reach the composting sites.
Figure 2. North Carolina’s largest permitted composting facilities
Figure 2 shows the 11 facilities that composted the majority of the material (77% of the total feedstocks reported, equaling 778,412 tons including McGill Delway permitted by NCDEQ Division of Water Resources (DWR) which was added to the list because it is the only composting facility under DWR jurisdiction that accepts a variety of off-site commercial feedstocks). These facilities include 4 public yard trimmings composting operations and 7 are private multifeedstock operations, and show their individual unused capacity as well as any food processed.
Figure 3. High-nitrogen materials received by NCDEQ DWM permitted composting facilities
Figure 3 highlights trends for other materials processed at composting facilities that would be considered high in nitrogen content, such as sludge or biosolids, animal waste, food scraps, grease trap waste and agricultural waste. It shows upwards trends for sludge/biosolids (57% increase since 2010, or 11%/year), grease trap waste (43% increase since 2010, or 9%/year), and agricultural waste (23% increase since 2010, or 4.6%/year). Figure 3 also indicates downwards trends for animal waste (12% decrease since 2010, or 2.4%/year) and upwards trends for food waste in the past 3 years (26% increase since fiscal 2012-13, or 8.7%/year).
It was also found that from a subset of 6 private facilities, 3.7 jobs are generated per 10,000 tons of organic material composted, which is close to the average the Institute for Local Self-Reliance reported in 2013 of 4 jobs per 10,000 tons.