By Bob Gardner, PE, BCEE
For many municipalities, the solid waste collection budget represents a significant portion of its overall solid waste budget. Qualitative and material savings can be realized by focusing on optimizing a municipality’s solid waste collection routing.
A routing analysis involves assessing the performance metrics of your existing collection system, evaluating its unique characteristics, special considerations, and the geography of the municipality; then modeling the system using GIS database information and various modeling software; and lastly running optimization scenarios. The optimization scenarios allow testing of your routing model demonstrating the impact of various assumptions on productivity creating opportunities to improve your overall routing solution.
The City of Virginia Beach is the largest city in the Commonwealth, with a population of nearly 450,000. The City encompasses approximately 307 square miles, of which 248 square miles is land area and the rest water or wetlands. The City self-performs residential solid waste collection for approximately 122,000 customers. The northern sector of the City is devoted to more urban uses while the southern area remains more rural. Solid waste services include weekly automated residential household pickup, weekly manual yard waste collection and scheduled pick up of bulky wastes. The City contracts with a private company to collect and process single stream recyclables on an every-other-week basis.
SCS Engineers in conjunction with Route Optimization Consultants recently assisted the City to optimize their automated residential solid waste collection routes. The following improvements were realized as a result of the route optimization:
• 26% reduction in daily routes
– From 153 to 114 per week
– 38.25 to 28.5 per day
• $2,250,000 reduction in equipment inventory
• $1,100,000 annual savings in personnel, equipment maintenance, and fuel
• Route completion time extended from 7.6 to 9.2 hours, which translates into better utilization of personnel.
In short, the City of Virginia Beach by optimizing their solid waste routes created a sustainable solution and a positive return on investment.