Composting In Vancouver

Composting in Vancouver: 10 Years of Progress J. Paul Henderson, M.A.Sc., P.Eng [email protected] Manager of Landfill Operations City of Vancouver Engineering Services Landfill Operations Branch 7/10/99

In February 1989, Vancouver City Council passed a resolution calling on Vancouver staff to develop programs aimed at reducing the amount of garbage by 50%. That resolution and many subsequent ones have allowed Vancouver to develop a comprehensive waste reduction and recycling strategy. From the outset, composting programs have played an integral part of Vancouver's strategy.

Leaf Composting Vancouver's original composting program commenced in 1989 and involved composting approximately 4,000 tonnes of leaves collected through a mechanical street leaf collection program. The leaves had historically been landfilled along with other waste. The composting facility was located at the City's landfill in Delta to take advantage of land and equipment available at the facility. Composting was conducted on an unimproved surface using front-end loaders and agricultural rototillers. This system provided a cost-effective way to manage leaves, but did not address the larger issue of yard and garden waste management.

Backyard Composting Vancouver's first backyard compost bin distribution program began in 1990. Although at that time there were already a few backyard compost bin distribution programs operating in North America, there was a general sentiment that a composter was a pile of debris at the back of the yard. In cooperation with City Farmer, a Vancouver non-profit group that has been instrumental in promoting backyard composting in Canada, and various composter manufacturers, Vancouver developed standards for rodent resistant composting. Vancouver's approach was developed in cooperation with local environmental health

officials and focussed on reducing the attractiveness of backyard composters to rodents. Residents are encouraged not to compost meat and other preferred food sources and also the bins sold to residents are designed to be "rodent resistant". Vancouver's approach has ensured that the promotion of backyard composting has not created nuisance and public health impacts associated with increased rodents and other pests. To date, Vancouver has distributed more than 25,000 backyard composters among approximately 90,000 singlefamily households. In addition to backyard composting, Vancouver and City Farmer have been promoting worm composting in Vancouver since the early 1990s. Worm composting provides a composting alternative for residents without access to the space required for backyard composting. Through City Farmer, Vancouver has been distributing worm composters to Vancouver residents since 1993. To ensure that residents adequately understand the complexity of operating a worm composter each resident that purchases a worm bin is required to attend a one-hour workshop on worm bin care and maintenance. Since the inception of the program, a total of 2000 worm bins have been distributed to Vancouver residents. City Farmer also offers composting and worm workshops to schools and other community groups.

Backyard Composting Education Vancouver and City Farmer have been working together to educate residents on the benefits of composting since the outset of Vancouver's composting program. City Farmer operates a compost demonstration garden and compost hotline (the hotline is funded by the Greater Vancouver Regional District) that provide residents with detailed information on the benefits of composting as well as how-to information. City Farmer has also been able to act as a focal point for media attention on composting education. Each year approximately 9000 people either visit the garden or phone the compost hotline. In addition to its work with Vancouver, City Farmer has operated a web site www.cityfarmer.org on composting and urban food growing since 1994. The site is recognized internationally as one of the premier Internet resources on composting. City Farmer's web site has been visited by people from nearly 150 countries and has had in excess of 170,000 file transfers in a single month.

Yard and Garden Waste Composting Along with other member municipalities, as part of the 1995 Greater Vancouver Regional Solid Waste Management Plan, Vancouver committed to provide residents convenient access to yard and garden waste composting systems. In 1995, Vancouver expanded its leaf composting facility to allow the composting of yard and garden trimmings. The expansion included the paving of 1.8 hectares at the composting facility, the construction of a stationary 400 HP electric grinding plant, and the purchase of additional mobile equipment including a Wildcat compost turner, a Case 821 rubber tired loader, and a Retech trommel screen. The total cost of the facility was

approximately $2.5 million. In addition to the City's equipment, the facility intermittently uses various rental equipment including grinders, excavators, front-end loaders and specialized mixing buckets manufactured by Allu in Finland. The composting facility has 5 full-time staff.

Since 1996, the annual throughput of the facility has grown from 17,000 tonnes to 27,500 tonnes in 1998. The unit cost for processing the yard waste has dropped from $48.40 per tonne in 1997 (including operating and capital recovery costs, revenue from compost sales, but excluding revenue from tipping fees) to $37.50 per tonne in 1998.

Compost Quality The production of a high quality product from both a chemical and physical perspective has been one of the goals of Vancouver's composting program since its outset. To ensure high quality product, City staff monitors yard waste drop-off areas. People dropping off the yard waste must remove it from plastic bags and no garbage is allowed. Staff on the grinding plant pullout plastic and other debris prior to the grinding of the yard waste. The final compost is screened in a trommel screen with 0.75 inch screens in the winter and 0.5 inch screens in the summer to remove any remaining debris. The average finished compost analytical results for 1998 and 1999 are shown in Table 1. Table 1 shows that the compost consistently meets British Columbia's criteria for unrestricted use of the compost. Table 1: City of Vancouver Compost Quality

Parameter

Compost Quality 1998July 1999

B.C. Regulation for the Production and Use of Compost: Criteria for Unrestricted Distribution

.

Mg/L

Mg/L

Arsenic

2.3

13

Cadmium

0.39

2.6

Cobalt

4

26

Chromium

17

210

Copper

31

100

Foreign Matter <1 (%)

1

Mercury

0.054

0.8

Molybdenum

<4

5

Nickel

13

50

Lead

68

150

Selenium

<0.5

2

Zinc

106

315

Compost Utilization One of the challenges of operating a composting facility is ensuring that suitable markets for compost can be developed. Vancouver has expanded its screened compost sales from 4,000 cubic metres in 1996 to 25,000 cubic metres in 1999. Net revenue (after delivery costs) is expected to exceed $150,000 in 1999. Vancouver's compost has been primarily sold in bulk to landscapers and municipal Park Boards. The material is primarily used as landscaping mulch or blended with other products to produce topsoil. In 1999, several innovative projects were implemented by the City's Park Board blending sand with compost at varying rates for the restoration of Hastings Park in East Vancouver and the reconstruction of two large playing field complexes. In the Hastings Park project, the compost was preblended 3:1, compost:sand, and spread approximately 30 cm thick over approximately 3 hectares. In the playing field projects, sand was first imported to the sites and approximately 7 cm of compost was spread uniformly onto the sand layer with manure spreaders. The compost was then mixed into the sand with rototillers. In each case, the addition of compost dramatically improved the growth of grass and other plants in the parks.

Future Direction In 1999, Vancouver began a residential yard waste collection program. A residential fall leaf collection program has been in-place in Vancouver since 1990, but up to now residents had only the options of composting their yard waste at home or dropping it off at the City's transfer station. The initial program was simply an expansion of the fall leaf collection program, providing pick-up once each five-week period throughout the summer. The trial program has shown that residents would prefer more frequent collection of yard trimmings Several options for increasing collection frequency in the City's yard waste collection program are being considered. One potential option involves scaling back residential recycling collection to once each two weeks and alternating recycling and yard waste collection. A survey of Vancouver residents showed that reducing recycling collection to biweekly to reduce the cost of implementing yard waste collection was supported by 60% of the population. A report on options for implementing yard waste collection is being prepared by the City's Solid Waste Management Branch. The report is expected to be submitted to Vancouver City Council in early 2000.