TECHNICAL MEMO Bio-Logic Environmental Systems Responsible Waste & Resource Management 18 Erin Drive, Dartmouth, NS, B2W 2B8, (902)

TECHNICAL MEMO Bio-Logic Environmental Systems Responsible Waste & Resource Management 18 Erin Drive, Dartmouth, NS, B2W 2B8, (902) November 17, 2011 Knick Knack Nook Re-Use It Store Society 1063
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TECHNICAL MEMO Bio-Logic Environmental Systems Responsible Waste & Resource Management 18 Erin Drive, Dartmouth, NS, B2W 2B8, (902) November 17, 2011 Knick Knack Nook Re-Use It Store Society 1063 Mt Gardner Bowen Island, BC V0N 1G0 Subject: Bowen Island Organic Waste Management Assessment Executive Summary The impending ban of organics in the garbage stream throughout Metro Vancouver by the end of 2012 has created a need among municipalities to deal with two fundamental questions: i) how will the separation, transport and disposal be achieved and at what cost, and ii) is it viable to manage (some of) these municipal organic wastes within the Municipality? Layered on top of the waste diversion imperative is an initiative to better control air emissions in the sea-to-sky air corridor through an agreement to which Bowen Island is a signatory. The following report provides comment on existing waste management practices on Bowen Island as well as a path towards addressing the two fundamental questions above. A municipal source-separated organics collection program can be achieved with minimal incremental cost through the expansion of the existing seasonal yard trimmings collection program to a weekly basis and the reduction of garbage service to a biweekly or even monthly basis with the option of residents delivering their garbage to the existing transfer station at the BIRD during operating hours. Like the present method of containing green waste, the choice of a green/food waste container could be left to the residents discretion with certain minimum standards in addition to the option of purchasing a container supported through the Municipality. In terms of processing organic waste, backyard composting should continue to be supported and could be enhanced through a portable, mobile wood chipping service for residential green Bio-Logic Environmental Systems 1 Bowen Island Organics Assessment waste. The method by which much of the municipal organic waste is managed will depend upon a combination of economic and environmental interests. Options include: i) the status quo in which all source-separated organic wastes are transported off the island to be processed elsewhere, and ii) an organic waste management facility on the island managing all of the organic waste. Historically, significant quantities of woody, green waste and land clearing waste have been collected and in some cases incinerated through an open burn permitting process by the private sector. The increasing cost of these permits coupled with the desire to improve the protection of the regional airshed will encourage the private sector to consider alternative processes which produce marketable products and/or capture the energy released from the decomposition process. Any of these alternative organic management processes considered should be capable of integrating the municipal organic waste from Bowen Island into the feedstock, which would provide the required balance of carbon, nitrogen and moisture. Blending the current woody waste stream that is currently captured by the private sector with municipal food waste would generate revenue through tip fees and allow the private sector to recoup much of the additional investment required to manage both streams in a more environmentally responsible manner. In order to determine the best economic/environmental choice to handle the Municipality s organic wastes, interested private stakeholders should be invited to respond to a Request for Proposals (RFP) from the Municipality in two stages a preliminary submission to determine if the method of management is viable, environmentally responsible and cost-effective compared to the alternative of moving waste off-island, followed by a detailed engineering design with refined costs. Throughout the process, the Municipality should provide opportunities to consolidate concepts and build partnerships to minimize the economic and environmental impact and build upon the private waste management services currently collecting and managing a significant amount of green waste and land clearing waste. In terms of the Sea-to-Sky clean air initiative, the Municipality should move to reduce/eliminate the practice of open burning for the sole purpose of waste disposal/reduction. Wood waste provides a valuable resource as a compost amendment, or can be managed independently to produce a marketable product without significant cost. Private industry should be encouraged to develop alternatives to incineration that includes the incorporation of the Municipality s yard trimmings and food waste into the management of the woody waste currently collected. In summary, a preliminary assessment of managing Bowen Island s organic wastes recommends a management policy consisting of weekly collection of all organic waste and managing these wastes on the island through a centralized compost facility or equivalent (assuming economic Bio-Logic Environmental Systems 2 Bowen Island Organics Assessment justification), supported by an active portable chipping service and backyard compost program. A number of policy issues remain to be publically discussed including: the use of clear garbage bags, choice of taxation to cover costs, garbage collection schedule, organics containers, and the abolition of open burning for the purposes of waste reduction. Managing organic waste on the island and utilizing wood waste in a more productive manner would place Bowen Island at the forefront of environmental stewardship throughout the region and set the precedent for other municipal units to follow. 1.0 Preamble At the behest of interested stakeholders 1 on Bowen Island, a site visit was completed on August 9, 2011 in order to assess issues associated with organic waste management and provide recommendations to the stakeholders (and ultimately the municipal government) regarding a future direction in light of Metro Vancouver s impending organic waste diversion policy. The visit included stops at: i) the recently upgraded wastewater treatment facility, ii) the Bowen Island Recycling Depot (BIRD) & facility operated by Bowen Waste Services, iii) J & E Backhoe Ltd.'s quarry on Buchanan Rd, iv) Twin Island Excavation s quarry on Radar Hill, and v) the municipally run site on Salal Road. Following the site visits, a number of stakeholders met at the municipal office during which discussion ensued on the day s findings and the future direction of organic waste management on Bowen Island. In addition to the site visits, two documents were reviewed including: i) the Sea-to-Sky Air Quality Management Planning for Bowen Island Municipality, Wood Waste Management Baseline and Options Report, Scroggins Consulting, EABB Planning Services, Timmenga & Associates Inc., (June 16, 2010 draft), and ii) Bowen Island Organic Resource Recovery Report, ReSource-Full Habitats, July 25, In general, both these documents captured most of the essential elements regarding the issue of open burning and the use of organic waste. The following overview provides comment and direction in this regard and is an attempt to consolidate the previous reports into an action plan that provides a clear direction in the future management of organic waste on Bowen Island. 1 Knick Knack Nook Re-Use It Store Society, Whitehead Environmental Consultants Ltd., Maureen Whitney, Twin Island Excavating Ltd., Tom Roocroft Excavating Inc., J&E Backhoe Ltd. Bio-Logic Environmental Systems 3 Bowen Island Organics Assessment 2.0 Current Conditions & Future Policy At present, the residents of Bowen Island take part in a number of waste management practices including: i) the sorting and weekly collection of leaf & yard waste (April 15-Oct 15) which respects the regional ban on landfilling leaf & yard waste, ii) the source-separation of recyclables and their subsequent personal delivery to the BIRD, iii) the weekly curbside collection and disposal of garbage including food waste in receptacles affixed with a waste management decal, and iv) the intermittent collection and partial separation of construction and demolition waste through private enterprise. Waste management costs are offset in part through the annual purchase of $82 decals for garbage collection (one decal per container) and through the municipal tax base. Presently, some wood waste and all non-wood waste is ferried to the North Shore Transfer Station on the mainland via 40-foot containers and is either delivered to a materials recovery facility (recyclables) or to the landfill (garbage and organics) where the leaf and yard waste is composted in open windrows. The upgraded wastewater treatment facility on Bowen Island produces a de-watered (15 18% solids) wastewater sludge that is also a potential amendment to the compost process; the sludge is currently disposed of off-island. Some of the clean construction and demolition wood waste is extracted before the balance is disposed of offisland. Significant quantities of woody land-clearing debris including stumps are consolidated and, from time-to-time, burned through a permitting process. Future regional plans include the removal of all food and soiled paper from landfills by the end of 2012 with all wood banned as of Bowen Island is also a signatory to the Air Quality Management Bylaw No and its attendant Fees Regulation Bylaw No and therefore has committed to working towards a reduction in open burning as well. The purpose of the following report is to address the primary organic fraction (food and green waste) of the waste stream in terms of alternative management methods that are both environmentally and economically responsible by reducing air emissions in the Sea-to-Sky airshed, taking ownership of organic waste, and encouraging additional business activity on Bowen Island while maintaining costs at or below existing thresholds. The overall intention is to build capacity on the island by retaining and managing more organic waste on-island and support local businesses that are capable of processing the waste. The approach is simply to first consider redirecting the potential stream of green and food waste into an on-island system at a cost that is no more than what is currently incurred to transport and dispose of the material off-island; further improvements to the collection system and the integration of Bio-Logic Environmental Systems 4 Bowen Island Organics Assessment additional feedstocks such as clean wood, paper fiber and biosolids should then be built on the initial program as capacity and experience is developed. 3.0 Composting Basics A review of composting basics is in order as it provides one of the more likely organic waste management processes for consideration. There are three fundamental management issues associated with successful composting which are depicted in Figure 1 and described below. 3.1 Food Food for a compost pile is defined in terms of greens (wet, with a higher nitrogen content that decomposes quickly) and browns (dryer, with a lower nitrogen content that decomposes more slowly). Greens are generally the waste from kitchens in addition to grass clippings and freshly cut plants. Figure 1 The Three Fundamental Elements of Composting Browns are generally fallen leaves, straw, sawdust and wood. The compost pile works best if the greens and browns are mixed with slightly more browns than greens (Figure 1). Since most browns (leaves) are only available in the fall and the greens from the kitchen are produced year-round, dried leaves (or equivalent browns such as chipped wood) should be stock-piled and stored under cover. As the greens are added to the pile, they can then be matched with readily stored browns. Since larger items break down more slowly, it is advised to shred the coarse material to increase the surface area. Too many greens lead to a smelly, wet pile; too many browns will lengthen the decomposition process. For the purposes of discussion in this document, three organic waste streams will be defined: i) food waste from either residential or commercial sources, ii) green waste which includes leaf & yard waste, trimmings, and branches, and iii) wood waste including land clearing wood waste and stumps. Bio-Logic Environmental Systems 5 Bowen Island Organics Assessment In general, two streams (food waste and green waste) will be addressed; although wood waste can arguably be included with green waste, in some cases, concentrations of wood waste are high enough on the island that they can constitute an independent waste stream of their own. The incorporation of boxboard and other paper fibers, clean drywall and clean construction wood waste could also be included in the organic waste stream; these materials would also obviously require source-separation, or separation on-site as the material is delivered. 3.2 Water The main source of moisture is either from fresh green material (which is often over 70% water) or from rainfall. Compost piles should be maintained at a moisture content of 45 60% water which is confirmed through the squeeze test in which a handful of the material is squeezed hard if a few drops of water fall from the material, sufficient water is present. Too much water produces a smelly, wet pile, while too little water slows the decomposition process. Figure 1 depicts the moisture as a thin dark film surrounding each organic particle, for it is within this water film that the microbes carry out their decomposition of organic waste. In general, compost facilities run their process too wet, and as a consequence, fill up the pore spaces between particles; this can produce significant quantities of leachate as well as unnecessary odours the two key challenges in operating a compost facility. 3.3 Air Composting is an aerobic process in which billions of microbes that live in a thin film of water on the surface of organic waste utilize the available oxygen to consume the readily available organic matter. Due to the voracious appetite of the microbes in the early stages of decomposition, the oxygen naturally available is often quickly used up. Consequently, the oxygen must be replenished which is often accomplished through forced aeration. The supply of air to the water film greatly depends on available passageways, for if there is too much moisture present, the passageways become blocked and the organisms are effectively suffocated. One of the most effective operating practices that allows the replenishment of air is turning the material frequently, for it is not uncommon to find that the oxygen content in active compost piles can drop from 21% (ambient conditions) to below 10% in as little as one hour or less; most composting facilities suffer from a lack of sufficient mixing. In summary, inattention to the three key elements of composting create most of the problems that arise from compost processes too much wet, green matter will quickly fill up the pore spaces creating an anaerobic environment that produces foul odours, offensive leachate and a product that is far from marketable. Bio-Logic Environmental Systems 6 Bowen Island Organics Assessment 4.0 Management System Options The most effective means to deal with domestic organic waste is at home. Clearly, backyard composting should continue to be promoted as a means to manage most residential organic waste, as it is by far the most effective means to reduce collection, management and disposal costs. The inclusion of food waste in backyard composting does present issues with respect to pest/rodent control and should be addressed through a rejuvenated educational program that also includes the distribution of subsidized compost bins and simple construction plans. Similarly, the collection and disposal of tree limbs, plant cuttings, brush and wood waste need not be the responsibility of the Municipality for processing. The provision of a portable, mobile chipping service to the residents of Bowen Island could drastically reduce the municipal disposal load. In addition, a product would be created that could be used on-site as either a mulch or as a compost amendment. Furthermore, providing an on-demand chipping service would reduce the temptation to burn unwanted woody waste, fulfilling in part the island s commitment to reduce airborne pollutants. As the separation of organic waste is further developed, the emphasis on waste stream collection must also be modified. Currently, the weekly collection of garbage and the weekly collection of green waste from mid-april to mid-october is effectively, on average, 1.5 pick-ups per week. As the collection of organic waste incorporates food waste in the future, the frequency should increase at the expense of garbage collection such that a weekly collection of organic waste is established and the collection of garbage is reduced to bi-weekly (maintaining the 1.5 pick-ups per week) or even monthly. This policy is self-policing in that most complaints will originate from residents who are not utilizing the organics collection program. To transition to this schedule, once the weekly collection of green waste begins in mid-april 2012, the collection of green waste should be maintained year-round. Further diversion improvements would also occur if garbage were contained in clear bags; a number of Nova Scotia municipalities have experienced dramatic increases in recycling and composting waste streams through the implementation of clear garbage bags. Finally, the personal disposal of any waste stream, including a yard trimmings collection site, could always take place at the BIRD/waste transfer facility, for residents are frequently within proximity due to the nature of an island community with a ferry service which centralizes the passage of vehicular traffic. In terms of a centralized compost processing system on Bowen Island, there are a number of considerations that help select the appropriate technology. Obviously, the technology must be proven; generally, the more sophisticated the technology, the higher the cost, consequently, a greater amount of material is required for processing to justify higher expenses. In short, centralized compost facilities are a net cost in that, despite compost sales revenues, the value of the product never recoups the cost of the material management; like wastewater treatment facilities or water purification systems, they provide a municipal service whose costs are Bio-Logic Environmental Systems 7 Bowen Island Organics Assessment covered through tip fees. The challenge is to choose a technology with an associated cost that is less than the next best alternative which is shipping it elsewhere. Although there are a number of process options available, the relatively low amount of organic matter on Bowen Island, coupled with the high ratio of green waste-to-food waste will probably not support a high-tech option other than some method of (aerobic) composting. This conclusion could be borne out through a request for proposal (RFP) process in which companies are solicited to offer process options that are competitive with existing and projected costs. Regardless of the feedstock or the selected composting technology, moisture control is the most important parameter to manage and control. For compost operations, a cover over the organic mass (whether fabric or fixed) eliminates the issue of leachate production and treatment and is a prerequisite for all technology options, regardless of the degree of sophistication. Furthermore, a loader, water supply (rainwater), pump, and hose would be required at a minimum to mix and moisten the compost mass. Appendix I displays different styles of covered aerobic systems that could be appropriate for Bowen Island. 5.0 Regulatory Compliance The conditions of operation from a regulatory perspective involve the region of Metro Vancouver and the provincial government for compost operations, and the Municipality of Bowen Island for zoning. If the Municipality owns and o
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