Solid Waste & Recycling

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Cumberland County

In 1995 Nova Scotia developed its Solid Waste Resource Management Strategy. A lynch pin of this strategy was the bold move to ban organic wastes from landfill disposal and incineration effective Novem...


In 1995 Nova Scotia developed its Solid Waste Resource Management Strategy. A lynch pin of this strategy was the bold move to ban organic wastes from landfill disposal and incineration effective November 1998. This spurred diversion activity within the province and in the intervening years a number of composting facilities were built (which are currently in operation).

Most facilities receive their organic waste feedstock from an aerated cart-based collection program (typically biweekly). Composting facilities that accept residential and industrial, commercial, institutional (IC&I) waste all have a composting system with an indoor component. Technologies include bed systems, channel systems, windrow systems and an in-vessel system (i.e., container). A significant amount of compost curing also takes place indoors.

Cumberland County is one of the last regions in the province to initiate and implement a composting program to capture organic wastes banned from landfills.

Cumberland County

Cumberland County is in the north-central part of the province, with the northern portion of the County bordering New Brunswick. It’s one of the larger regions with an area of approximately 4,100 square kms. The population of approximately 33,000 (ca. 14,000 households) is split almost evenly between urban and rural populations. There are five municipal units. The main urban areas include the towns of Amherst (population 9,500), Springhill (4,300), Parrsboro (1,500) and Oxford (1,300). The County and its rural population function as the fifth municipal unit. The Cumberland Joint Services Management Authority (CJSMA) provides waste management services to the five municipal units within Cumberland County.

The technology

The CJMSA elected to go with a fairly low-tech method of composting. It developed a 5,000 tonne per year capacity aerated windrow facility and opened it in July 2001. The facility, located at the Little Forks Landfill near Springhill, is enclosed in a 200-foot by 70-foot “cover-all building” (see photo) with a concrete pad. There’s a small picking station for the removal of contaminants and a small shredder for size reduction. Shredded organic wastes are formed into a windrow using a wheeled loader.

Aeration is provided via turning the piles with a wheeled loader but more prominently with a mechanical aeration system. A combination of fans and 30 longitudinal perforated-steel plate-grates on 34-inch centers provide negative aeration. Composting material remains in the facility for 20 to 30 days prior to discharge for curing. The facility is currently under-capacity and the material residence time in the building is up to six months. Temperature data is manually collected to confirm pathogen reduction requirements.

Curing takes place outdoors on a clay-lined pad. Any leachate generated in this area is directed towards the compost leachate tank, which is removed and re-circulated at the second-generation landfill site or sent for disposal offsite. Air is removed from the building and sent to a biofilter for odour scrubbing. To date all compost has been sold to a local company that produces soil blends. Compost is sold for $31 per tonne.

Collection

Private waste contractors collect all residential and IC&I waste and separated organic waste in Cumberland County. Thus far the main feedstocks accepted at the facility are IC&I waste, predominantly from a food-processing factory (2,000 tonnes per year).

More recently the facility has accepted some organic wastes from the residential sectors. In the latter half of 2002 the communities of Amherst, Springhill and Oxford initiated residential organic waste collection programs. It’s up to each individual unit to develop and implement a program similar to other municipalities. CJSMA is available to educate residents and help if needed but each unit is responsible for biweekly collection of food and yard waste. Households are supplied with a wheeled and aerated 240l Rehrig Pacific Organicart.

The Town of Parrsboro is expected to come on line in 2003. The County is currently diverting a portion of its organic waste with a backyard-composting program.

Costs

The facility capital cost (after a grant from the Resource Recovery Fund Board) was just over $815,000. The costs of the wheeled aerated carts are borne by the municipality and thus are not included in capital cost figures. (See Table 1.)

Annual operating costs are $47.76 per tonne, with debt retirement adding another $48.00 per tonne. These calculations are based on the approximately 2,500 tonnes of organic waste processed in 2002. As the facility approaches its capacity of 5,000 tonnes it’s expected that these per tonne operating costs will decrease by approximately 40 to 50 per cent. The landfill site subsidizes the compost facility on the disposal tip fee.

Capital and Operating Costs

Capital Costs Cost Per Tonne of Comments
Processing
Capacity
Total $1,140,922 $228.18 There were no land purchase costs
Includes land preparation, building, aeration system and biofilter, picking line, shredder, wheeled loader
Costs do not include HST
Debt retirement is $120,000/year for ten years
Actual $ 815,166 $163.03 A grant of $325,756 was received from the Resource Recovery Fund Board
Per Tonne
Operating Costs Processed
Labour and
Equipment Costs $119,387 $47.76 Includes labour (1.5 employees) and other costs
Debt Retirement $120,000 $48.00 This concludes in ten years
Total Annual Cost $239,387 $95.76 As annual incoming tonnage is increased to 5,000 Operating Costs will decrease by approximately 50 per cent

Paul van der Werf owns and operates composting and waste management consultancy 2cg, based in London, Ontario. To contact Paul, visit www.2cg.ca


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