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Diverting organic waste from landfills provides significant emissions benefits in addition to preserving landfill capacity and creating value-added energy and compost products. Dry anaerobic digestion (AD) is particularly attractive for managing the organic fraction of municipal solid waste because of its high-solids composition and minimal water requirements. This study utilizes empirical data from operational facilities in California in order to explore the key drivers of dry AD facility profitability, impacts of market forces, and the efficacy of policy incentives. The study finds that dry AD facilities can achieve meaningful economies of scale with organic waste intake amounts larger than 75,000 tonnes per year. Materials handling costs, including the disposal of inorganic residuals from contaminated waste streams and post-digester mass (digestate) management, are both the largest and the most uncertain facility costs. Facilities that utilize the biogas for vehicle fueling and earn associated fuel credits collect revenues that are 4-6x greater than those of facilities generating and selling electricity and 10-12x greater than facilities selling natural gas at market prices. The results suggest important facility design elements and enabling policies to support an increased scale of organic waste handling infrastructure.

Municipal organic waste (MOW) contributes to greenhouse gas (GHG) emissions leading to global climate change. Incentives that encourage consumers to adopt MOW disposal strategies that minimize environmental impacts are needed. Policymakers must ensure that incentive programs align with environmental objectives and are economically competitive. The MOW disposal infrastructure in the city of Milwaukee, WI, was evaluated using a coordinated market model capturing the inherent value of environmental indicators (estimated with partial life cycle assessment methods) in the context of the city’s MOW supply chain. Tax programs are identified that incentivize consumers to reduce emissions through MOW disposal patterns. Results indicate that the existing MOW management infrastructure in Milwaukee incentivizes residents to minimize MOW GHG emissions by sending MOW to composting and digestion sites that have lower tipping fees and are located closer to the city (have lower transport costs). Therefore, limitations associated with MOW collection likely decrease alternative landfill disposal options. GHG reduction policy prioritizes anaerobic digestion systems for MOW disposal, but the outcome can be altered depending upon the tipping fees and transport distances. Composting and digestion hold few opportunities for reducing ammonia emissions from landfills, but there is a need to expand ammonia emissions measurements from landfill systems to improve model predictions as ammonia losses can redeposit, resulting in environmental issues and indirect formation of N₂O.

The opportunity cost concept refers to quantifying the opportunities lost upon choosing one investment option over a more economical alternative. The present study applies the concept to the process of choosing the best investment option for managing municipal solid waste. In a case study in Brazil, the options on the table are bulk collection and tipping versus reverse logistics with selective collection and sale of recovered components. The use of relative monetary values renders the results general and applicable in other scenarios. The bulk tipping option represents the reference cost of 100. The research postulates a linear relation between the opportunity cost of bulk tipping (y) and the efficiency of reverse logistics operations (x). Zero efficiency means bulk collection and tipping of all waste. Full efficiency means capture of all recyclable items, which in the case study amount to 80% of waste. Various intermediate points confirm the relationship that takes the form y=0.968x. The result shows that opportunity cost is dynamic in as much as changes of technologies and administrative procedures move it along that line. It also illustrates to municipal administrations the immediate economic effect of implementation and stepwise improvement of reverse logistics.

Managing waste is a crucial challenge for modern societies. The UK government has established ambitious targets in terms of landfill diversion for household waste. Household Waste Recycling Centres represent key facilities for achieving these targets. However, Local Authority budgets are under severe strain due to reductions in central government transfers. As such, local councils often need to perform reconfigurations of the recycling centres networks, by reducing the number of sites or their opening hours while still offering adequate service levels. Central to being able to do this, is understanding the spatial patterns of access to such centres. Therefore, this paper develops a spatial interaction model aimed at examining and exploring users’ behaviour and preferences when choosing recycling centres. Specifically, an origin-constrained gravity model is developed; through a careful estimation of its attractiveness parameters, the model is capable of describing demand flows from Sheffield City Council districts to Household Waste Recycling Facilities. The results are compared to actual data obtained through a users’ survey from an English Local Authority. The high level of correlation between the results provided by the model and actual users’ preferences indicates that the model can be a valuable tool in describing users’ behaviour in accessing the service. Based on this, the model can be employed in order to estimate the impacts of modifications to the network configuration on users, performing scenario analyses and providing useful suggestions to planners.

This study presents solid waste management planning in an urban green area, Bangkok, Thailand based on the material flow analysis (MFA) and life cycle assessment (LCA). Global warming potential (GWP) of four scenarios for handling solid waste generated in Chulalongkorn University Centenary Park, 2018 was assessed concerning the different ratios of waste recycling, composting, incineration, and landfilling. The results show that alternative systems proposed will result in lower GWP than the existing waste management strategy. The MFA results reveal that the final weights of solid waste ending up in a landfill are 98.8, 101.9, 68.2, and 44.8 t yr− 1 for scenarios 1, 2, 3, and 4, respectively. Increased rates of landfill diversion by increased recycling, composting, and incineration decreased the quantity of solid waste disposed to the landfill and improved the environmental profile of the park waste management system. The LCA results found landfilling to be the dominant source of greenhouse gas (GHG) burdens, while waste recycling was found to result in the reduction of GHG. The results highlight that the use of MFA and LCA as a combined tool to evaluate the environmental performance of solid waste management systems provides valuable information for policy and decision-makers.

Solid waste management (SWM) is a key function of local government and is critical to protecting human health and the environment. Development of effective SWM strategies should consider comprehensive SWM process choices and policy implications on system-level cost and environmental performance. This analysis evaluated cost and select environmental implications of SWM policies for Wake County, North Carolina using a life-cycle approach. A county-specific data set and scenarios were developed to evaluate alternatives for residential municipal SWM, which included combinations of a mixed waste material recovery facility (MRF), anaerobic digestion, and waste-to-energy combustion in addition to existing SWM infrastructure (composting, landfilling, single stream recycling). Multiple landfill diversion and budget levels were considered for each scenario. At maximum diversion, the greenhouse gas (GHG) mitigation costs ranged from 30 to 900 $/MTCO2e; the lower values were when a mixed waste MRF was used, and the h...

Proponents of material recycling typically point to two environmental benefits: disposal (landfill/incinerator) reduction and primary production displacement. However, in this paper we mathematically demonstrate that, without displacement, recycling can delay but not prevent any existing end‐of‐life material from reaching final disposal. The only way to reduce the amount of material ultimately landfilled or incinerated is to produce less in the first place; material that is not made needs not be disposed. Recycling has the potential to reduce the amount of material reaching end of life solely by reducing primary production. Therefore, the “dual benefits” of recycling are in fact one, and the environmental benefit of material recycling rests in its potential to displace primary production. However, displacement of primary production from increased recycling is driven by market forces and is not guaranteed. Improperly assuming all recycled material avoids disposal underestimates the environmental impacts of the product system. We show that the potential magnitude of this error is substantial, though for inert recyclables it is lower than the error introduced by improperly assuming all recycled material displaces primary material production. We argue that life cycle assessment end‐of‐life models need to be updated so as not to overstate the benefits of recycling. Furthermore, scholars and policy makers should focus on finding and implementing ways to increase the displacement potential of recyclable materials rather than focusing on disposal diversion targets.

High-density polyethylene is an important polymer for a variety of industrial applications. The pressure for landfill diversion strategies have increased with consumer awareness of traditional end-of-life practices. It is critical to understand the influence of post-consumer recycled polymer (PCR) content on properties and consumer safety as converters blend PCR with virgin resin to increase sustainability. The ability to empirically quantify the PCR content is vital for compliance with minimum content laws. This work determined ∼380% increase in UVA absorption, increased carbonyl and terminal vinyl functional groups, a 50% reduction of fluorescence properties, a reduction of the polymer crystal quality, and a ∼4 °C increase in the degradation temperature. The extractables content of all PCR blends complied with the Code of Federal Regulations for direct food contact applications. Trends between the measured properties and PCR content identified potential certification markers for empirical quantification of PCR content and single-measurement quality control metrics.

In this article, we analyze the Minnesota Electronics Recycling Act to explore the benefits and potential drawbacks of a market-based Extended Producer Responsibility (EPR) implementation with operational flexibility for manufacturers. Based on publicly available reports and stakeholder interviews we find that the Minnesota Act attains two key goals of market-based EPR (i.e., higher cost efficiencies and substantial landfill diversion); however, this may come at the expense of selective collection and recycling, an increased burden on local governments, and an uneven competitive landscape for some stakeholders. We observe that such concerns arise because of flexibility provisions afforded to manufacturers that allow them to operationalize their EPR compliance with a cost efficiency focus. Thus, we conclude that a critical operational perspective is necessary for anticipating environmental and economic implications of different flexibility provisions associated with market-based EPR policy implementations.

Separate household food waste collection for anaerobic digestion is one method used in the sustainable management of biodegradable municipal solid waste (MSW). Recycling of food waste contributes to the UK’s reuse, recycling and composting targets and can help local authorities boost plateauing rates whilst encouraging landfill diversion. This study explored the reasons for differences in the provision of food waste collections, using two comparable local authorities, one with a collection in Wales (Cardiff), and the other absent of such service in England (Southampton). A PESTLE analysis investigated the political, economic, social, technological, legal and environmental impacts of separate food waste collections. The greenhouse gas impacts of the collection and treatment systems of MSW in both cities were estimated for 2012/13. Results showed significant policy and legislative differences between devolved governments, that separate food waste collections can save local authorities significant sums of money and substantially reduce greenhouse gas impacts. A survey of one hundred respondents in each city aimed to understand attitudes and behaviours towards recycling, food waste segregation, cooking and purchasing habits. The number of frequent recyclers and levels of satisfaction were higher in the authority which provided a separate food waste collection. In the area which lacked a separate collection service, over three-quarters of respondents would participate in such a scheme if it were available.

When assessing the environmental and human health impact of a municipal food waste (FW) management system waste managers typically rely on the principles of the waste hierarchy; using metrics such as the mass or rate of waste that is 'prepared for recycling,' 'recovered for energy,' or 'sent to landfill.' These metrics measure the collection and sorting efficiency of a waste system but are incapable of determining the efficiency of a system to turn waste into a valuable resource. In this study a life cycle approach was employed using a system boundary that includes the entire waste service provision from collection to safe end-use or disposal. A life cycle inventory of seven waste management systems was calculated, including the first service wide inventory of FW management through kitchen in-sink disposal (food waste disposer). Results describe the mass, energy and water balance of each system along with key emissions profile. It was demonstrated that the energy balance can differ significantly from its' energy generation, exemplified by mechanical biological treatment, which was the best system for generating energy from waste but only 5th best for net-energy generation. Furthermore, the energy balance of kitchen in-sink disposal was shown to be reduced because 31% of volatile solids were lost in pre-treatment. The study also confirmed that higher FW landfill diversion rates were critical for reducing many harmful emissions to air and water. Although, mass-balance analysis showed that the alternative end-use of the FW material may still contain high impact pollutants.

Annually, millions of tonnes of leftover edible foods are sent to landfill. Not only does this harm the environment by increasing the release of greenhouse gases which contribute to climate change, but it poses a question of ethics given that nearly 16 million households are food insecure in the US, and hundreds of millions of people around the globe. The purpose of this study was to document the amount of food diverted from landfill in the pilot year of a convention food rescue program and to determine the amount of greenhouse gas (GHG) emissions avoided by the diversion of such food. In the pilot year of the convention food rescue program 24,703 kg of food were diverted. It is estimated that 108 metric tonnes of GHG emmisions were avoided as a result, while 45,383 meals for food insecure individuals were produced. These findings have significant implications for public and environmental health, as GHG emissions have a destructive effect on the earth&rsquo, s atmosphere and rescued food can be redistributed to food insecure individuals.

The selection of an appropriate technology for waste management in a way that enhances sustainability is a complex problem requiring information from multiple disciplines. This decision is made more complex for large, diverse organizations for which individual sites or components have different requirements and capacities for waste management. For U.S. Army installations, sustainable waste management is a major obstacle for resource constrained and overburdened installation personnel. The Army has prioritized landfill diversion at installations; there is a significant push for each installation to develop and implement waste management plans that follow high-level goals set by U.S. Army Installation Management Command (IMCOM). The main objective of this study is to demonstrate an excel-based dashboard tool incorporating Multi-Criteria Decision Analysis (MCDA) for site-specific waste management technology selection. The dashboard uses the preferences of an installation and a series of weighted metrics to evaluate technologies. With this information the dashboard can rank the technologies to identify those that simultaneously meet IMCOM's objectives and are appropriate for specific sites' capabilities and resources. Fourteen different technology makes and models were compared in this version of the decision model including dehydrators, pulpers, garbage disposals, containerized in-vessel composting, windrow composting, forced-air static composting, and containerized anaerobic digestion. MCDA provides for transparent comparison of technologies for all sites, and the dashboard visualizes the level of appropriateness of each technology for each site. The approach developed here adds value in that it utilizes the priorities of the organization and identifies the best performing waste management technology given the specific capacity and capabilities of an individual site.

The city of Makkah in the Kingdom of Saudi Arabia (KSA) hosts millions of Muslim worshippers every year. As a consequence, the municipal solid waste (MSW) quantities become enormous. City landfills receive about 2.4 thousand tons of MSW every day, whilst during the months of fasting (Ramadan) and Pilgrimage (Hajj), these quantities become 3.1 and 4.6 thousand tons per day respectively. Currently, there is no waste-based biorefinery or waste-to-energy (WTE) facility existing in KSA to treat different fractions of MSW as a source of renewable energy production and a solution to landfill waste problems. Therefore, the waste-based biorefinery, if developed in Makkah city, including WTE technologies such as anaerobic digestion (AD), transesterification, pyrolysis and refuse derived fuel (RDF) can be able to treat around 87.8% of the total MSW. The remaining 12.2% of MSW fraction can be recycled. The waste-based biorefinery, along with the recycling approach, can generate savings of about 87.6 million Saudi Arabian Riyal (SAR) from carbon credits. Similarly, a total net revenue of 758 million SAR can be generated from landfill diversion (530.4 million SAR) and electricity generation (288.5 million SAR). Moreover, 1.95 million barrels of oil and 11.2 million MCF of natural gas can be saved with a cost savings of 485.5 million SAR. Collectively, the waste-based biorefinery and recycling can reduce the global warming potential (GWP) of 1.15 million Mt.CO2 eq.

Purpose – The purpose of this paper is to review and update Devens eco-industrial park sustainability indicators and benchmark progress made since 2000 in the seven key areas of its sustainability vision. Design/methodology/approach – The authors examined publicly available data for Devens, Massachusetts, and obtained additional data from Devens Enterprise Commission and a survey of 29 local organizations. Findings – Of the 43 indicators adopted by Devens eco-industrial park in 2012, 29 demonstrate progress, seven show lack of progress, six point to a potential progress, and for one no information was available in 2000 to evaluate progress. Most progress has been made in the areas of transportation, business and economic sustainability, governance and natural resources. Research limitations/implications – For some proposed indicators no data were available to evaluate progress (e.g. waste generation, recycling, compositing, and landfill diversion) yet these are among the key measures for an eco-industrial park. Practical implications – Proposed framework, indicators and lessons learned are of value for researchers and practitioners at other eco-industrial parks (EIPs) interested in benchmarking progress toward sustainable local development. Social implications – The case provides insights on integrating sustainability in local economic development. Originality/value – The study is paving the way toward development of a standardized set of sustainability indicators for EIPs in the USA.

This study presents a preliminary assessment of biodiesel production from waste sources available in the Kingdom of Saudi Arabia (KSA) for energy generation and solution for waste disposal issues. A case study was developed under three different scenarios: (S1) KSA population only in 2017, (S2) KSA population and pilgrims in 2017, and (S3) KSA population and pilgrims by 2030 using the fat fraction of the municipal solid waste. It was estimated that S1, S2, and S3 scenarios could produce around 1.08, 1.10 and 1.41 million tons of biodiesel with the energy potential of 43423, 43949 and 56493 TJ respectively. Furthermore, annual savings of US $55.89, 56.56 and 72.71 million can be generated from landfill diversion of food waste and added to the country's economy. However, there are challenges in commercialization of waste to biodiesel facilities in KSA, including waste collection and separation, impurities, reactor design and biodiesel quality.

Diverting organics from landfills to compost piles is generally recognized as a means to reduce greenhouse gas emissions. This article provides a detailed review of the Climate Action Reserve (CAR) and the U.S. EPA Waste Reduction Model (WARM) protocols on landfill diversion and composting for food scraps and yard waste. The primary benefits associated with diversion are methane avoidance. The equations used to quantify methane avoidance include first-order decay rate constants for different feedstocks to predict how quickly organics will decay. The total methane generation potential of the different feedstocks is also included. The equations include estimates of gas collection efficiencies in landfills. The decay rate constants have been determined from laboratory incubations and may not be representative of decomposition within a landfill. Estimates of gas capture efficiency have been improved and more closely reflect actual landfill conditions. Gas capture efficiency will vary based on landfill...

In the United States of America (U.S.) almost all of the food waste generated is ends up in landfills. Centralized systems of composting have been effective at diverting large volumes of food waste. However, they require considerable capital investments and face operational challenges. As solid waste planning practices vary across national geographies, this study primarily focuses on the application of decentralized composting within the U.S. This study advocates decentralized composting for its anticipated benefits of outreach, landfill diversion, and cost savings. Using Chicago as a case study, the recovery potential and challenges of using a portion of public parks for community composting are explored. Community characteristics are incorporated in the numerical and spatial analysis of food waste generation and capture potential. This study also conducts a preliminary cost and greenhouse gas (GHG) emissions impact analysis, comparing the proposed community composting to current food waste processing systems. The results demonstrate the viability of decentralized composting to divert substantial volumes of food waste, as a complementary strategy to other landfill diversion programs. Policy recommendations are provided to facilitate the implementation and increase the efficiency of decentralized composting programs.

High annual volumes of television and computer waste presents a challenge to Australian communities,resulting in the development of Extended Producer Responsibility (EPR) legislation. This study aims to establish, through the use of public interest theory, whether EPR legislation in Australia was in the public interest. Using a regulatory analysis, the results show that during the first 3 years of the scheme, over 130 liable parties joined co-regulatory arrangements each year to fund upstream recycling services for television and computer waste. In program terms, the scheme has been highly successful recycling over 130,000 tonnes of metals, leaded and non-leaded glass, plastics and other materials while limiting landfill transfers to approximately 6900 tonnes, all at a cost of A$50e60million per annum to producers. The scheme has also seen a range of upstream recycling partnerships established between the co-regulated administrators and formal technical and social enterprise waste management organizations. However, while the upstream material recovery rate is steady at approximately 95%, the results suggests that exporting waste for downstream processing will continue in the future. Analysis also points to substantial funding for ‘over target’ collections,downstream recycling infrastructure and landfill diversion strategies as critical for averting severe environmental impacts from e-Waste dumping. The study concludes by suggesting that while the successes of EPR scheme are in the public interest, its potential deficiencies could limit such benefits and therefore need to be addressed. Notably, the scheme could be enhanced through the application of improved recycling target methodologies, including the estimation and forecasting of domestic Waste Electrical and Electronic Equipment (WEEE) stock levels. Refereed/Peer-reviewed

New regulations and targets limiting the disposal of food waste have been recently enacted in numerous jurisdictions. This analysis evaluated selected environmental implications of food waste management policies using life-cycle assessment. Scenarios were developed to evaluate management alternatives applicable to the waste discarded at facilities where food waste is a large component of the waste (e.g., restaurants, grocery stores, and food processors). Options considered include anaerobic digestion (AD), aerobic composting, waste-to-energy combustion (WTE), and landfilling, and multiple performance levels were considered for each option. The global warming impact ranged from approximately -350 to -45 kg CO2e Mg(-1) of waste for scenarios using AD, -190 to 62 kg CO2e Mg(-1) for those using composting, -350 to -28 kg CO2e Mg(-1) when all waste was managed by WTE, and -260 to 260 kg CO2e Mg(-1) when all waste was landfilled. Landfill diversion was found to reduce emissions, and diverting food waste from WTE generally increased emissions. The analysis further found that when a 20 year GWP was used instead of a 100 year GWP, every scenario including WTE was preferable to every scenario including landfill. Jurisdictions seeking to enact food waste disposal regulations should consider regional factors and material properties before duplicating existing statutes.

With the escalated increase in municipal solid waste (MSW) generation in Malaysia reaching a shocking 38,000 ton/day in 2017, a sustainable waste management system is much desired. Nationwide, there are 176 landfills but only 8 are sanitary landfill with the rest are open dumpsites. In the campus of University of Malaya, UM Zero Waste Campaign (UM ZWC) was introduced in 2011 to start a long-term campaign to achieve an integrated and sustainable waste management model and ultimately a zero-waste campus. Since year 2015, UM ZWC is fully funded by Sustainability Science Research Cluster of UM (Susci) as one of the living labs of UM as well as by JPPHB under the RMK-11 budget. UM ZWC operating projects including in house composting center, food waste segregation scheme, research composting emission and waste characterization, anaerobic digestion (AD), used clothes collection program, wood waste separate collection, e-waste collection and drop-off recycling collection were initiated under the campaign. Since the inception of the project in 2011 until December 2017, almost over 620 tons of solid waste has been diverted from disposal in landfill with composting, AD, recycling, re-use and energy recovery. A roadmap of UM ZWC was drawn up in 2013, with a goal to achieve 60% landfill diversion by year 2040. In the next 5-10 years, UM ZWC plays a vital role to formalize the recycling collection in UM and further increase the organic waste recycling with green waste shredding and composting. Besides environmental benefits (pollution prevention and carbon emission reduction), UM ZWC brings various benefits such as academic research opportunities for UM, contribute in UM LCCF (Low carbon city framework) target and serve as platform to improve students soft skills and entrepreneur skill. Multi stakeholders participation, support form top management and industrial collaboration are the key factors that are able to drive the development of a sustainable waste management model in UM campus.

International audience; With the goal to move society toward less reliance on fossil fuels and the mitigation of climate change, there is increasing interest and investment in the bioenergy sector. However, current bioenergy growth patterns may, in the long term, only be met through an expansion of global arable land at the expense of natural ecosystems and in competition with the food sector. Increasing thermal energy recovery from solid waste reduces dependence on fossil- and biobased energy production while enhancing landfill diversion. Using inventory data from pilot processes, this work assesses the cradle-to-gate environmental burdens of plasma gasification as a route capable of transforming construction and demolition (C&D) derived biomass (CDDB) and forest residues into electricity. Results indicate that the environmental burdens associated with CDDB and forest residue gasification may be similar to conventional electricity generation. Land occupation is lowest when CDDB is used. Environmental impacts are to a large extent due to coal cogasified, coke used as gasifier bed material, and fuel oil cocombusted in the steam boiler. However, uncertainties associated with preliminary system designs may be large, particularly the heat loss associated with pilot scale data resulting in overall low efficiencies of energy conversion to electricity; a sensitivity analysis assesses these uncertainties in further detail.

Waste generation and waste disposal are issues that are becoming increasingly prominent in the environmental arena both from a policy perspective and in the context of delinking analysis. Waste generation is still increasing proportionally with income, and economic and environmental costs associated to landfilling are also increasing. This paper provides a comprehensive analysis of waste generation, incineration, recycling and landfill dynamics based on panel data for the EU25, to assess the effects of different drivers (economic, structural, policy) and the eventual differences between western and eastern EU countries. We show that for waste generation there is still no Waste Kuznets Curve (WKC) trend, although elasticity to income drivers appear lower than in the past. Landfill and other policy effects do not seem to provide backward incentives for waste prevention. Regarding landfill and incineration, the two trends, as expected, are respectively decreasing and increasing, with policy providing a strong driver. It demonstrates the effectiveness of policy even in this early stage of policy implementation. This is essential for an ex post evaluation of existing landfill and incineration directives. Eastern countries appear to perform generally quite well, thus benefiting from their EU membership and related policies in terms of environmental performances. We may conclude that although absolute delinking is far from being achieved for waste generation, there are first positive signals in favour of an increasing relative delinking for waste generation and average robust landfill diversion, and various evidence of a significant role of the EU waste policies implemented in the late 1990s and early 2000s on landfill diversion. Waste prevention is nevertheless the next necessary target of waste regulatory efforts.

International audience; Worldwide, health and environmental considerations encourage landfill diversion of the organic fraction (OW) of municipal solid wastes, through alternative such as home composting. Of poor sanitation, and trace element and toxic hydrocarbon content (PAH) documentation, this study compared against a laboratory composter (LR), the performance (temperature regime and compost quality) of four 300 to 400 L home composting systems (HC), namely the Plastic (P) and Wood (W) Bins, the Rotary Drum (RD) and the Ground Pile (GP). All were batch loaded with the same food waste (FW) and yard trimmings (YT) mixture for uniform testing. The P and GP performed best in terms of temperature regime, followed by W and LR, while all demonstrated similar dry and organic matter and chemical oxygen demand except for RD with a higher dry matter because of poor aeration. All composts respected regulatory pathogen/parasite counts, trace element and PAH levels