June 2011

Collection and Sustainability: Achieving the Triple Bottom Line

With a continued emphasis on environmental stewardship and energy efficiency, many communities have at least started the process of developing energy management plans or climate action plans.

Most of these plans include an examination of the waste sector in addition to buildings and transportation. The waste sector is rising to the top of these plans as an area of opportunity for significant impacts on reducing the “carbon footprint” of the community.

While the collection side of the waste industry may not always take center stage in these energy management efforts, there are opportunities for collection practices to have a positive impact on the triple bottom line—environmental, economic, and social sustainability. Employing technologies and strategies for routing efficiency can allow a community to reduce the number of routes and, therefore, carbon emissions, without affecting customer service. Looking to alternative fuels for vehicles can also help lower emissions and, in some cases, quieter collection, enhancing the social benefit. What we collect at the curb can increase diversion, which may increase the number of trucks on the road, but the net gain can also lower carbon emissions.

Increasing Technology Use
There are many technology tools that can help an organization create routes, optimize scheduling, monitor driver behavior, and record customer set-outs. When used well, these tools can have substantial benefits for the economics as well as the environment. The city of Durham, NC, was able to achieve a 12% budget reduction within two fiscal years, which it attributes to integrating technology applications in daily operations. The city invested in routing software, data capture devices, and a GIS analyst to ensure that these products were being used consistently and correctly. The availability of dedicated and skilled personnel to monitor the implementation of a technology initiative is a critical step in ensuring the investment will yield positive results.

The routing software that Durham used allowed it to give drivers maps with turn-by-turn directions. Drivers were given the opportunity to drive the new routes prior to the actual implementation of the revised routing stops. Prior to routing capabilities, routes across refuse and yardwaste divisions were inefficient and unbalanced. After close data analysis, the number of routes was reduced without reducing customer service or employee morale. Through deliberative personnel management, the department was able to absorb routes without terminating employees. The refuse route creation process became less cumbersome and more efficient by using lessons learned from across collections’ divisions. Refuse routes were designed to mirror the recycling routes to allow the department to calculate recycling diversion per route.

Durham also installed touch screen mobile data capture devices in each truck. With a single touch, drivers can mark and photograph white goods and other bulk service locations. The marked locations will be transmitted electronically to the office and placed on a special collection route for the next day. This system eliminated the need to drive every street in search of debris and allowed Durham to increase collections from monthly to weekly without additional personnel. The same device can also be used to identify unserviceable locations due to construction or vehicle obstructions. During winter months, drivers utilize the devices to help identify potholes locations, and that data is electronically sent to the Street Maintenance Division. The department conducts trend analysis on customer collections misses and combines missed customer accounts with routing information layers to determine performance. Data capture devices are also used to track customer set-outs. This is especially useful in determining participation in the curbside recycling program.

Alternative Fuel Vehicles
There are over 140,000 garbage trucks in the United States. Most of them are operating on diesel fuel and getting less than 5 miles per gallon. However, the future may be very different. Hybrid garbage trucks have been tested in major cities such as Houston, New York, Chicago, and Denver. Our industry is also exploring alternative fuels such as natural gas, biodiesel, and even biomethane.

The city of San Antonio’s Solid Waste Management Department constructed a compressed natural gas (CNG) station—the first CNG facility in the city. It’s equipped with a fast fill dispenser and 30 time-fill CNG fuel dispensers. The department also purchased 30 CNG trucks, the largest CNG municipal fleet in Texas, which services 85,000 homes in the city.

Since the inauguration of the CNG facility in January 2009, the department has closely examined how fleet operations have been enhanced through the use of CNG trucks and has looked at the environmental benefits of having implemented an environmentally clean alternative to solid waste collection. Simultaneous with assessing the gained advantages, the department has carefully monitored challenges encountered with the new technology and collected data in an effort to a better understand CNG fleet best practices.

As expected, one of the biggest advantages to operating CNG trucks is that the fuel cost is significantly less than it is for diesel. Over the course of the last calendar year, diesel fuel cost has increased 26% since January 2010, averaging $2.28 in February 2010 to $2.88 in January 2011. In contrast, CNG fuel cost has decreased 27% since January 2010. The diesel gallon equivalent for CNG averaged $1.16 in February 2010 and reported at 85 cents in January 2011.

Another benefit is that these CNG trucks run more quietly than conventional diesel trucks, a characteristic that enhances collection in neighborhoods.

It should be known that CNG trucks are very different than diesel trucks. These differences have presented some challenges. For example, the CNG engine has an average horsepower of 320 at 2,100 rpm, compared with a diesel engine with an average of 350 horsepower at 1,800 rpm. This reduced horsepower initially presented challenges with the idle set speed. Set too low or high, the computer would shut the engine off. Eventually, the settings were corrected and this issue was resolved. These trucks also require the fuel filter to be drained on a daily basis. This procedure entails burning out the fuel, waiting an hour before proceeding on to the next step, draining the filter, and then reconnecting and opening the time-fill fuel line. One of the larger hurdles with CNG equipment is the initial capital cost. CNG trucks tend to be more expensive than their diesel counterparts. The CNG trucks purchased by the department in 2009 cost $64,000 more than diesels trucks purchased that same year.

The department’s CNG facility is a response to the need to integrate operational collection procedures in line with the overall goals of clean solid waste management practices. The fleet industry, nationwide, is constantly looking for cleaner, more reliable, and less costly forms of conducting its operations. Over the course of the time the CNG facility has been in operation, the department has encountered benefits and challenges alike and recommends that other organizations considering CNG-powered fleets should be aware of the potential challenges that may surface. Presently, the department continues to monitor the progress of its CNG fueling station and trucks in correlation with researching diesel and CNG fuel technologies in an effort to find and implement solid waste management operations that reduce its carbon footprint.

Additional Material Streams—Foodwaste Diversion
In addition to how we collect waste at the curb, the discussion on what we collect at the curb continues to expand. Residential food-scrap diversion is growing in popularity in the US. According to a BioCycle survey from 2007, 42 communities in the US and 50 Canadian communities provide foodwaste diversion programs. San Francisco’s “Fantastic 3” program is the largest in the US, with 150,000 single-family households receiving weekly collection services for recycling, organics (including food scrap), and trash. In Ontario, 1.6 million homes receive foodwaste collection services. Toronto’s “green bin” program includes all foodwaste, compostable paper (paper plates, napkins, tissues, food packaging) and sanitary products (diapers, sanitary products, cat box filler, pet waste). In Toronto, 510,000 households are served, and more than 110,000 tons are diverted annually, with a 90% participation rate.

Four categories of foodwastes can be targeted: fruit and vegetable wastes; bread and cereal wastes; food-soiled paper products; and meat, fish, and dairy wastes. Most programs target the first two categories regardless of collection frequency. Meat, fish, and dairy foodwastes and food-soiled paper are generally targeted only if weekly collection service is provided and the composting facility receiving the waste is equipped to handle it.

Most residential foodwaste collection programs in the US utilize carts and automated collection to co-collect foodwaste and yardwaste, and participation is mostly voluntary. Some communities reduce residential waste collection frequency to encourage participation. Other communities are considering mandatory participation requirements. Both San Francisco and Seattle implemented mandatory participation requirements in 2009.

Collection a Key Component
As communities continue to strive for truly integrated waste management programs and look to the waste sector for ways to reduce their carbon footprint, the collection side of the waste industry will continue to be an area with the potential for positive impacts. Style, frequency, efficiency, alternative fuels and materials collected will continue to bring opportunities for innovation, and reaching the triple bottom line of sustainability.

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