Rubberized Asphalt Program
Background
Grey County implemented its first asphalt rubber paving project in November 1991.
Despite Grey County having no experience with rubber being used in asphalt, this project proved a tremendous success. Grey County used in excess of 40,000 tires which were removed from all the local landfill sites in Grey County. Given the severity of the County's scrap tire problem in 1991, it was Grey County Council's judgment that the opportunity to help eliminate a serious local environmental threat justified the much smaller risk associated with the evaluation of an alternative paving technology. Grey County was also experiencing a lot of problems with cracking in its asphalt roads.
In the preparatory work leading up to our first project and prior to the actual paving program, my staff and I were active in securing rubber for the project by planning and executing the remediation of eleven different scrap tire stockpiles at various township landfill sites within the County. This first project gave our County staff hands-on experience in the grading, de-rimming, washing, loading and transportation of used tires from their locations in landfill sites to a recycling facility.
As a result of this work, in which about 40,000 used tires were recycled, considerable insight was gained into the requirements of a well-planned collection system, including a centralized storage and pre-processing facility, for the recycling of scrap tires at high efficiency.
The knowledge acquired on the physical aspects of scrap tire management was complemented by the commercial understanding of the used tire industry gained during the project. Waste management services in the County are the responsibility of the individual Townships, but on the 1991 project, supervision of the scrap tire remediation work was handled by the Transportation Services Department because the work was a line item on the project budget. The result has been that excellent communication has developed between Grey County Transportation Services and solid waste interests in the County.
It was immediately apparent from the remediation work in 1991 that a poorly run scrap tire storage system i.e. at a landfill site, adds substantially to future remediation costs. For example, if municipalities accept used tires with rims in place, a great deal of extra expense will be incurred in their removal. In a similar way, used tires are normally accumulated in mini-stockpiles (to meet the requirements of the Ontario Fire Code) and the material handling is commonly done with heavy construction equipment.
Inevitably, many of the tires would become contaminated with mud requiring high pressure water washing before they could be recycled. Clearly, the industry and the Ministry were in need of a model municipal storage and processing facility for scrap tires.
Such a facility would demonstrate the value of accepting used tires only to a pre-defined standard and processing them promptly in a clean and well-equipped facility that was designed for efficient handling to the point at which the processed tire shreds could be loaded onto vehicles and sent for recycling into crumb rubber.
The best opportunity to control the quality and minimize the handling costs of scrap tires accepted into the facility occurs when the tire units are received directly from the generators (mainly retail tire dealers). The County thus recognized the need to introduce a collection system as part of its overall recycling approach.
The concept of scrap tire recycling also required a realistic market for the recovered rubber. The County's favourable experience with asphalt rubber technology made it the logical choice for a market outlet. It is also a large consumer of rubber from scrap tires and was therefore a good choice on which to base a permanent scrap tire management program. A secondary market is being looked at for the use of the crumb rubber in fabricated articles, such as pylons, for highway use, etc.
The overall which we used was to set up a demonstration of a complete closed loop recycling program in which used tires are collected locally and recycled completely into local roads and assorted fabricated rubber goods.
This is the first example of such a program in the Province serves as an example for other municipalities to study in contemplating their own scrap tire management plans.