Symptoms of leaf and petiole distortion on samples were consistent with chemical injury from a growth regulator-type of herbicide.

November 10, 2016 | General

Composting Roundup

BioCycle November 2016

Boulder, Colorado: ZW Ordinance Requires Organics Separation

When the City of Boulder adopted its Universal Zero Waste (ZW) Ordinance in 2015, residents, business owners and property managers were given one year to become compliant. The new regulation, which aims to minimize waste sent to the landfill and help the community reach its stated sustainability goals, took effect on June 17. A fact sheet distributed by Western Disposal, one of the solid waste companies in the region, outlines a few key components of this ordinance: All properties including residential, commercial and multifamily must subscribe to trash, recycling and composting services for their tenants and occupants. Depending on the lease arrangement, these services must either be provided by the property manager, property owner or the business themselves. In addition, education and signage must be provided to ensure knowledge of recycling and composting. By September 17, all businesses were required to separate recyclables and compostables from the trash by providing properly placed containers and signage inside their business to facilitate collection of these materials. All special events requiring a permit from the city of Boulder must provide both recycling and composting collection. The complete city regulation can be found at

Newport, Virginia: Another Case Of Herbicide-Contaminated Compost

Stonecrop Farm, in the Blue Ridge Mountains of Virginia, specializes in selling certified organic produce to restaurants, health food stores and Blacksburg Farmers Market customers. Earlier this year, the farm lost its first crop of tomatoes apparently to herbicide damage from the compost they used in the planting media. The tomato plants (Lycopersicon esculentum) were examined by the Virginia Tech Plant Disease Clinic. Weed scientists at the university agreed that the symptoms of leaf and petiole distortion on the tomato samples were consistent with chemical injury from a growth regulator-type of herbicide, and the pattern of the problem suggested it was in the compost-based planting media. The Clinic conducted a bioassay using snap beans and noticed the same symptoms.

Symptoms of leaf and petiole distortion on samples were consistent with chemical injury from a growth regulator-type of herbicide.

Symptoms of leaf and petiole distortion on samples were consistent with chemical injury from a growth regulator-type of herbicide.

Stonecrop Farm sent a sample of the compost to an Oregon laboratory for analysis, which reported nondetection for herbicides, including picloram and clopyralid, but did not test for aminopyralid or aminocyclopyrachlor. The laboratory’s limit of detection was 13 parts per billion and these persistent herbicides have been shown to have toxic effects at much lower concentrations. The farm had been purchasing compost from a Virginia-based producer of food scraps compost, but when that composter closed its business in May 2016, Stonecrop switched to an organic farming supplier who sourced an OMRI-approved compost from a South Carolina-based producer who makes compost from horse manure and bedding. The hay fed to horses is suspected of being the primary source of these persistent herbicides as hay farmers use them to control broadleaf weeds in hay fields.
The contaminated compost caught the South Carolina composter by surprise also, as previous compost quality tests run by Penn State University indicated no germination or vigor problems in the compost. As other customers of the composter had reported problems to state regulators, the compost has been delisted from OMRI and the company has switched its business model away from gardeners and farmers to erosion control and turfgrass users. Those applications are unaffected by persistent herbicides.

Burlington, Vermont: Fate Of E. Coli In Compost Amended Soils

Over the past 30 years, pathogenic Escherichia coli (E. coli) have been responsible for several outbreaks of foodborne illness linked to contaminated produce. A study conducted by Anya Cutler, a graduate student at the University of Vermont’s Department of Plant and Soil Science, assessed a variety of abiotic and biotic soil factors that influence the ability of an “invasive” coliform bacterium to survive in compost-amended agricultural soil. The study included both field and laboratory components. In the lab experiment, a mixture of antibiotic-resistant generic E.coli strains was added to sterile and nonsterile extracts of eight different composts and one soil sample from the field sites. E. coli abundance was monitored over a one-week period and composts were analyzed for their nutrient profile. The lab experiment showed that E. coli were able to grow well in sterile compost extracts, without microbial competition for nutrients. Conversely, E. coli populations were only able to survive in non-sterile soil extracts. These results suggest that bacterial organisms adapted for high-nutrient environments may depend on the extracellular enzyme activity of native oligotrophic organisms to acquire sufficient nutrients to survive in soils.
In the field experiment, the same E. coli cocktail was sprayed on plots amended with dairy manure or poultry litter compost made using windrow or vermicomposting methods. Treatments included: 1) Dairy-windrow; 2) Dairy-vermicompost; 3) Poultry-windrow; or 4) No compost. E. coli abundance, soil water potential, soil temperature, extracellular enzyme activity, microbial respiration, phospholipid fatty acid biomarker abundance, and genetic sequencing of the microbial community were measured over a six-month field season. Results of the field experiment showed clear and interdependent effects of soil moisture and nutrient availability on microbial community dynamics and E. coli survival. Data suggested that saturated soils caused a decrease in microbial extracellular enzyme activity, and drying-rewetting cycles can cause respiration bursts, nutrient mineralization, and shifts in community composition. The saturation of soils, which mobilizes nutrients and may result in a decrease in competition from aerobic organisms, correlated directly with increased survival of E. coli. Additionally, amendment with ammonium-rich poultry compost resulted in the maintenance of high levels of E. coli throughout the field season. Despite an increase in microbial biomass from dairy vermicompost amendment, poultry compost was the only compost that had a significant effect on E. coli survival.
The results suggest that nitrogen availability and water potential are strong drivers of E. coli’s survival in soils. Correlations among abiotic factors, community composition, and E. coli survival reveal insights into the complex relationships that occur in disturbed agricultural soil environments. Further research on E. coli‘s response to targeted organisms, abiotic soil properties, and nutrient inputs could have implications for agricultural considerations in food safety and microbial ecology. This thesis research was carried out in support of a graduate degree in the Dept. of Plant and Soil Science at the University of Vermont.

Sacramento, California: Understanding Landfill Diversion Law

SB 1383, signed into law by Gov. Jerry Brown in September, requires the California Air Resources Board (CARB) to approve and begin implementing the comprehensive strategy to reduce emissions of short-lived climate pollutants (SLCPs) to achieve a reduction in methane by 40 percent, hydrofluorocarbon gases by 40 percent, and anthropogenic black carbon by 50 percent below 2013 levels by 2030. With the methane emission reduction goals, the following targets to reduce landfill disposal of organics were adopted, explains the October 2016 edition of the California Compost Coalition (CCC) newsletter: 1) A 50 percent reduction in the level of statewide disposal of organic waste from the 2014 level by 2020; 2) A 75 percent reduction in the level of statewide disposal of organic waste from the 2014 level by 2025. Whereas AB 341 and AB 1826 placed the burden of mandatory organics collection on the generators with some local government planning effort and minimal enforcement, SB 1383 explicitly shares the responsibility with local government and adds fines and penalties, much like AB 939 (the state’s 1989 law that mandated 50% diversion by 2000), but with delayed enforcement.
“AB 1826 mandated a phased in collection where about 2.8 million tons of commercial organics would need to be collected by 2020 coupled with CalRecycle’s Strategic Directive to divert 50 percent of all organics by 2020,” notes the CCC newsletter. “AB 1383 places that directive into law which would amount to 8.9 million tons of all organics needing to be reduced by 2020. SB 1383 has far greater impacts in 2020 because it brings in residential and self-haul organics from policy to law. An effective ban of 90 percent diversion by 2025 as proposed by CARB this year would have required 14.5 million tons of all organics to be reduced by 2025, but with SB 1383 placing the 75 percent reduction amount into law, only 13.3 million tons will need to be reduced by 2025.
Other SB 1383 requirements include: CalRecycle, in consultation with CARB, has to adopt regulations that achieve the specified targets for reducing organic waste in landfills; Authorizes local jurisdictions to charge and collect fees to recover the local jurisdiction’s costs incurred in complying with the regulations; By July 1, 2020, analyze the progress that the waste sector, state government, and local governments have made in achieving the specified targets for reducing organic waste in landfills, such as infrastructure development and markets for products. Depending on the outcome of that analysis, CalRecycle is authorized to amend the regulations to include incentives or additional requirements — including requirements intended to meet the goal that not less than 20 percent of edible food that is currently disposed of is recovered for human consumption by 2025.

Toronto, Ontario: City To Evaluate Compostable Single-Serve Products

In mid-October, the City of Toronto Public Works and Infrastructure Committee requested the General Manager, Solid Waste Management Services to consult with industry experts and the Ministry of the Environment and Climate Change on the implications and impacts of accepting single-serve or single-use products, including coffee pods, in the City’s Waste Diversion Programs. The solid waste department must report its findings back to the Committee in the second quarter of 2017. The report will include, among other items, the following: A review of the anticipated processing operations and requirements for consumer education to distinguish between compostable and noncompostable products; A jurisdictional scan of comparable municipalities with regard to compostable single-serve or single-use products, such as coffee pods; and Options to research, pilot and support new markets for divertible materials under the Unit for Research, Innovation and a Circular Economy, as part of the Long Term Waste Management Strategy.
“We look forward to this collaborative effort based on testing in Toronto’s unique organic waste treatment process which uses anaerobic digestion followed by aerobic composting of the leftover materials,” says John Pigott, CEO of Club Coffee, the producer of PurPod100™, a certified 100 percent compostable pod for coffee, tea and other hot beverages.

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