Solid Waste Collection Route Optimization and Implementation Plan

In early 2013, the City of Homestead, FL successfully transitioned fromcollection of recyclables and bulky waste from twice a month to once a week.

Ravi Kadambala, Abdul Mulla Saleh and Julio Brea

The city of Homestead Public Works and Engineering Department, Solid Waste Division (SWD), is responsible for residential municipal solid waste (MSW), which includes garbage, single stream recycling, and bulky waste collection and management for the city. Each waste stream has its own defined collection zones, for which SWD provides personnel and equipment to perform services. The city collects garbage twice per week, recyclables twice a month and bulky waste twice a month. The City hauls garbage and bulky waste to the South Dade Landfill and recyclables to Homestead Landfill and Recycling Facility owned by Waste Management. The City has recently passed an ordinance that took effect on January 2, 2013, to increase collection of recyclables and bulky waste from twice a month to once a week.

Homestead is currently divided into 12 zones for garbage collection, as shown in Figure 1. The garbage is being collected twice a week from each zone. The collection days for garbage from each zone are either Monday and Thursday or Tuesday and Friday. The city wishes to maintain the existing zones and collection schedule for garbage. The main project objectives are to:

• Increase the collection of recyclables and bulky waste from twice a month to once a week.
• Align collection days for recyclables and bulky waste with their existing garbage collection days.
• Alternate bulky waste collection each week so that all the residents receive either Monday or Tuesday pickup every other week (early week collection once every two weeks).
• Optimize bulky waste and recyclable zones so that the collection time from each zone is as close as possible.
• Develop public communication plan for the revised schedule and zones to provide for smooth implementation of the new collection schedule.
• Train city staff for the new zones so that the implementation of the revised schedule takes effect on January 2, 2013.

Since the City wanted to coincide the days of recyclables and bulky waste collections with their existing garbage schedule, four zones were developed for recyclables/bulky waste collection by using the existing garbage collection zones as shown in Figure 2.

Data Collection and Assumptions

The city of Homestead has 12 zones for garbage collection and the days of collection are Monday, Tuesday, Thursday and Friday. For recyclables, there are five zones and the days of collection are Monday through Friday. Lastly, there are eight zones for bulky waste collection and the days of collection are Monday, Tuesday, Thursday and Friday. The city has provided the residents with 96-gallon containers, called super cans, for garbage and recyclables collection. The bulky waste is placed at curbside of each house without any containers.

The following data was required to model the existing garbage zones and new recyclables/bulky waste zones:

• Number and type of collection equipment (e.g., trucks, cranes) for each type of waste collection
• Personnel available for each type of waste collection
• Size and capacity of collection equipment
• Average amount of waste generated per day per household for the various types of waste
• Average pickup time from waste collection equipment for the various types of waste
• Location of all city residents in GIS format with street-level details
• Location of SWD facility, South Dade Landfill and Waste Management’s Homestead Landfill and Recycling facility

The average pickup time by collection equipment for the various types of waste was assessed by conducting field investigations and observations. CDM Smith followed the trucks for a day on each representative waste collection zone to evaluate the average pickup time at each stop. Video and pictures were taken for each representative zone. Several drivers were interviewed to determine the routes followed in all the zones for all three waste categories. The main objective of interviewing the drivers was to obtain their input on revising the collection zones for recyclable and bulky waste. The following assumptions (based on the conducted field observations and input from the SWD staff) were used for the average pickup time at each stop for the various waste categories:

• The average pickup time of garbage from an auto-side loader was approximately 12 seconds.
• The average pickup time of recyclables from an auto-side loader was approximately 12 seconds.
• The average pickup time of bulky waste using a crane and a dump truck was 1 minute.

Analysis of videos and interview with the drivers indicated that not all the houses were generating recyclable and bulky waste. So, assuming that every house is generating recyclables and bulky waste in modeling waste collection zones may not be valid. Based on video analysis, interview with the drivers and discussion with the SWD staff, the following assumptions were made:

• Every third house generates recyclables
• Every tenth house generates bulky waste.

The city provided the data for waste generated during the year 2011 – 2012. Since it was assumed that only every third house is generating recyclables and every tenth house is generating bulky waste, Table 1 shows the revised waste generated by household per week to account for the total amount of waste generated.

Modeling and Optimization

Because one of the goals was to coincide the days of recyclables and bulky waste collection with the existing garbage collection days, the garbage zones were used as a basis for modeling the recyclables/bulky waste zones and collection routes. Four proposed zones were developed for recyclables/bulky waste collection (zones A-D) as shown in Figure 2. A GIS-based route optimization modeling software was used to model the existing garbage zones and the new recyclables/bulky waste zones for efficient and realistic collection routes for crews. The benefits of using this model include:

• Balances route times, service days and districts
• Maximizes productivity of vehicles
• Reduces labor/overtime costs
• Optimizes travel paths to reduce deadheading (travel vehicle time without pickup)
• Decreases fuel consumption, mileage driven and maintenance costs
• Reduces time and cost of updating routes and rerouting
• Easily integrates new customers into routes to facilitate expansion
• Improves customer service
• Proficiently trains new drivers

The12 zones for garbage were modeled using the software and the assumption described above. Figure 3 shows a summary report for all the garbage routes for each zone. The waste collection time varied from 4.5 to 8 hours. The average waste collection time was approximately 6.5 hours. The summary report estimated quantities of waste generated, number of homes serviced, stops made, estimated mileage, and trips to the landfill facility for each zone. The summary report also provided analysis on the number of straight roads, left and right turns, U-turns and dead ends, and U-turns made in a zone during waste collection.

The existing garbage zones have six zones that are serviced on Monday and Thursday. Based on the garbage collection time obtained from modeling, the six zones were then grouped into two zones: A and B. The remaining six garbage zones are serviced on Tuesday and Friday. Based on the garbage collection time obtained from modeling, the remaining zones were grouped into two zones: C and D. The proposed zones were the same for both recyclables and bulky waste and were modeled and optimized based on the assumptions for recyclables and bulky waste zones respectively.

Results and Analysis

Modeling results for recyclables and bulky waste were analyzed and the GIS maps with the various waste collection zones were finalized. The recyclables collection time for the zones varied from 6.5 to 9 hours. The average waste collection time was around 8 hours. The estimated quantity of recyclables generated per zone was around 2.27 tons. The average number of residential homes serviced in a zone was around 3,340. The average mileage per trip was around 83 miles and the average trip to the Waste Management’s Homestead Landfill and Recycling facility was estimated to be once. Since bulky waste collection, using one crane and two trucks for each crew, is different than garbage and recyclables collection using side-loading trucks, modeling parameters were adapted to reflect continuous truck loading and travel operation to the landfill until the entire waste is collected from each zone. The bulky waste collection time for the zones varied from 9 hours to 11 hours. The average waste collection time was around 10 hours. The average number of residential homes serviced in a zone is around 3,340. The average mileage per trip was around 92 miles.

These results are based on estimated quantities from the collected data. Actual quantities may fluctuate based on seasonal and participating residence variations. A contingency plan has been developed to accommodate these variations with input from the SWD. The waste collection time for the various zones varied for both recyclables and bulky waste and is based on calculated waste quantities from the collected data. In reality, actual waste quantities and collection time varies for each zone based on several factors. These factors include lifestyle of certain communities, the degree of waste recycling and the size of lots in the communities. However, the results seem to be reasonable and conservative to a certain degree.

The proposed zones were finalized with input from the SWD staff. The finalized zones (A through D) are shown in Figure 2.The recycling schedule remains the same every week. Zone A, B, C and D will have Monday, Tuesday, Wednesday, and Thursday recyclables pickup, respectively.  One of the project goals was that the bulky waste collection be alternated each week so that all the residents receive either Monday or Tuesday pickup every other week (early pickup). In order to accommodate this, Zones A and B will have an alternate Monday and Thursday pickup of bulky waste, and Zones C and D will have an alternate Tuesday and Friday pickup of bulky waste. The schedule for the zone A is shown in Figures 4 as an example. Similar schedules were developed for the remaining zones.

Implementation Plan

An implementation strategy was developed to educate the public on changes to the waste collection zones and schedule by creating a public communications plan. The SWD staff was provided proper training to ensure that the revised schedule and zones for recyclables and bulky waste collection would be implemented smoothly on January 2, 2013.

As a member of the project team, Media Relations Group, LLC, St. Cloud, Florida, worked with the City to develop the content of the public communications plan for this project.  In the third week of November 2012, the residents were informed of the good news that the city was increasing the collection of recyclables and bulky waste from twice a month to once a week, beginning January 2, 2013, at no additional cost. The residents were informed via bill inserts sent to their homes along with their monthly billing statement. This message was also posted on the website. Several advertisements were also placed in local radio stations and the residents were also informed via post cards sent directly by the City. Once the final map and the zones were developed, it was posted on the website. A magnet calendar was developed for each of the four   zones and included the entire year’s schedule for garbage, recycling and bulky waste collection. The residents were instructed to stick their calendars to the refrigerator or any other visible area to easily remind them of their scheduled pick-up dates. As a follow up to the massive advertisement campaign, an information hotline was established to answer any questions that the residents may have in regard to the new service and changes. This hotline would remain active until the last week of January 2013.

CDM Smith conducted two training sessions with the City staff during the first three weeks in December. Detailed maps for the various zones and collection days for each waste stream were developed for training. Enlarged maps with turn-by-turn directions were also developed. CDM Smith provided training on the revised zones and schedule for recyclables and bulky waste collection. Training was also provided on turn-by-turn directions all the zones to optimize the waste collection routes. CDM Smith emphasized to the SWD staff the changes to the recyclables and bulky waste collection routes, the annual calendars for the zones, and the importance of understanding and implementing these changes in the field successfully. Truck drivers will be given extra calendars for their zones to disseminate to the public, as needed, and assist them if they have any questions. CDM Smith also provided the City with an excel spreadsheet that includes residential addresses of all the zones in the City of Homestead that receive residential waste collection, along with a schedule for garbage, recycling and bulky waste pickup.

Waste Collection with the Revised Zones and Schedule

The revised schedule and zones for recyclables and bulky waste collection was successfully implemented by the City on January 2, 2013. The staff adopted the revised schedule and zones very well and did not have any issues. The residents also adapted the revised schedule without any problems. The residents welcomed the increased collection of recyclables and bulky waste and the smooth transition to the new waste collection schedule.

Dr. Ravi Kadambalais an Environmental Engineer for CDM Smith (Cambridge, MA) and works out of the West Palm Beach, FL office. Dr. Kadambala has more than four years of design and field experience in solid and hazardous waste engineering, water and wastewater engineering. He has experience in designing and operating bioreactor landfills, designing and permitting municipal solid waste landfills, gas collection system and surveying. Dr. Kadambala can be reached at (561) 689-3336 or via e-mail at [email protected].

Dr. Abdul Mulla Salehis an Environmental Engineer for CDM Smith and works out of the Tampa, FL office. Dr. Mulla Saleh has more than 32 years of landfill engineering and other solid waste management experience, including sustainable waste management cradle to cradle, zero waste, and carbon neutral concepts. He has sited, designed, permitted, managed, and provided technical guidance for solid waste projects throughout the country and abroad, including lined landfills and transfer stations, landfill closures, groundwater contamination assessment and remediation plans, drainage systems, and leachate collection and treatment systems. Dr. Mulla Saleh can be reached at (813) 281-2900 or via e-mail at [email protected].

Julio Breais Director of the City of Homestead’s Director of Public Works and Services since 2003. Julio has more than 23 years of experience in the field of Civil Engineering, specializing in the design, construction and operation of public utilities and infrastructure. Before coming to the City of Homestead, Julio practiced Civil Engineering for over 18 years as a consultant specializing in water, wastewater, solid waste and environmental engineering for municipal utilities in the United States and abroad. He can be reached at (305) 224-4770 or via e-mail at [email protected].

Figure 1

Twelve zones for existing garbage collection.

Figure 2

Proposed zones A, B, C and D for both recyclables and bulky waste collection.

Figure 3

Summary report for all the garbage routes for each zone.

Table 1

Revised waste generated by household per week.

Images courtesy of CDM Smith