Pilot Program: StopWaste City of Fremont Residential Food Scrap Recycling November 2016 Report prepared for StopWaste by Action Research 3630 Ocean Ranch Blvd. Oceanside, CA 92056
Contents CONTENTS... 2 TABLE OF FIGURES... 3 TABLE OF TABLES... 4 EXECUTIVE SUMMARY... 5 BACKGROUND AND PURPOSE... 7 METHODS... 7 SAMPLE... 7 OUTREACH DESIGN... 8 Composting Waste Report: Cognitive Dissonance and Social Norms... 8 Hangtags: Prompts... 9 Kitchen Food Scrap Pail: Convenience and Prompt... 10 Control... 10 DATA COLLECTION... 10 Bin Sort Data... 10 Lid Data... 11 Route-level Tonnage Data... 11 Survey Data... 11 Methodology Table... 12 RESULTS... 13 BIN SORT RESULTS... 13 Total Trash Composition... 13 Outreach Materials: Trash Weight... 14 Outreach Materials; Compostable Materials... 15 Outreach Materials: Food Scraps... 16 Outreach Materials: Recyclables... 17 Outreach Materials: Garbage... 17 Outreach Materials: Overall Bin Sort Results... 18 Percentage of Food Scraps in Trash By Household... 19 LID FLIP RESULTS... 23 ROUTE-LEVEL WEIGHTS... 23 Overall Weekly Tonnage Data for all Waste Streams... 24 Monthly Route Level Data: Garbage... 25 Monthly Route Level Data: Yard Debris... 26 Monthly Route Level Data: Recyclable... 26 SURVEY RESULTS... 27 RECOMMENDATIONS... 28 GO BEYOND CONCERN AND GENERAL DIFFICULTY... 28 MANY DIFFERENT AVENUES TO SUCCESS... 28 USE COMMUNICATION BEST PRACTICES... 28 Page 2
CONSIDER COMBINING CONDITIONS... 28 BIN AUDIT DATA PROVIDES A STRONG EVALUATION METRIC... 28 APPENDIX A- SURVEY MATERIALS... 30 PRE-NOTIFICATION POSTCARD... 30 SURVEY COVER LETTER... 30 SURVEY POSTCARDS... 31 Control... 31 Kitchen Pail... 31 Composting Report... 32 Hangtag... 32 REMINDER POSTCARD... 33 Table of Figures Figure 1: Selected Routes Overlaid on Census Blocks with Median Per Capita Income... 8 Figure 2: Trash Bin Characterization Pre-Test... 13 Figure 3: Percent Reduction in Trash Bin Weight... 14 Figure 4: Percentage Reduction in Compostable Material in the Trash... 15 Figure 5: Percentage Reduction in Food Scraps in the Trash... 16 Figure 6: Trash Characterization Pre-test: Kitchen Pails... 18 Figure 7: Trash Characterization Pre-test: Hangtags... 18 Figure 8: Trash Characterization Post-test: Kitchen Pails... 18 Figure 9: Trash Characterization Post-test: Hangtags... 18 Figure 10: Trash Characterization Pre-test: Waste Reports... 19 Figure 11: Trash Characterization Pre-test: Control... 19 Figure 12: Trash Characterization Post-test: Waste Reports... 19 Figure 13: Trash Characterization Post-test: Control... 19 Figure 14: Percentage of Food Scraps in Trash, Pre-test... 20 Figure 15: Percentage of Food Scraps in Trash, Post-test... 20 Figure 16: Difference in Percentage of Food Scraps in the Trash Post-test to Pre-Test, Kitchen Pail... 21 Figure 17: Difference in Percentage of Food Scraps in the Trash Post-test to Pre-Test, Hangtags... 21 Figure 18: Difference in Percentage of Food Scraps in the Trash Post-test to Pre-Test, Report... 21 Figure 19: Difference in Percentage of Food Scraps in the Trash Post-test to Pre-Test, Control... 21 Figure 20: Profile Plot of Percentage Change of Food Scraps in Trash, Kitchen Pail... 22 Figure 21: Profile Plot of Percentage Change of Food Scraps in Trash, Hangtags... 22 Figure 22: Profile Plot of Percentage Change of Food Scraps in Trash, Report... 22 Figure 23: Profile Plot of Percentage Change of Food Scraps in Trash, Control... 22 Figure 24: Weekly Route-Level Tonnage for Green Waste, Garbage, and Recycling... 24 Figure 25: Breakdown of Garbage, Green Waste, and Recycling for All Routes... 25 Figure 26: Monthly Route Level Data for Garbage By Condition... 25 Figure 27: Monthly Route Level Data for Yard Waste By Condition... 26 Figure 28: Monthly Route Level Data for Recyclables By Condition... 26 Page 3
Table of Tables Table 1: StopWaste Pilot Methodology Summary... 12 Table 2. Composition of Trash... 13 Table 3. Change over time in the total weight of all materials found in the trash... 14 Table 4. Change over time in the weight of total compostable material found in the trash... 15 Table 5. Change over time in the weight of food scraps found in the trash... 16 Table 6. Change over time in weight of recyclable materials found in the trash... 17 Table 7. Food Scrap Self-Report and Food Scraps in Waste Audit (N=226)... 17 Table 8: Change in Percentage of Food Scraps in the Trash Pre- and Post-Test... 20 Table 9: Change in Percentage of Food Scraps in the Trash Pre- and Post-Test By Condition... 20 Table 8. Change over time in the fullness of the garbage, recycling, and organics bins... 23 Table 9. Importance and Difficulty of Green Curbside Bin Recycling... 27 Table 10. Outreach Material Survey Questions... 27 Page 4
Executive Summary In the summer of 2016, a pilot program was conducted in the City of Fremont to determine the most effective way to encourage residents to place all of their compostable material in their green recycling bin instead of their trash bin. Three outreach conditions were created based on previous research into the barriers and benefits of green bin recycling in Alameda County (in which the City of Fremont is located). The foundational research found that nearly all respondents thought green bin recycling was important and not very difficult. However, despite their positive attitude and belief that they understood how to participate, waste audits of their trash bins showed that many residents were still placing a significant amount of their compostable waste into their trash bin. The conditions were designed to go beyond providing knowledge of how to participate and include social science strategies to motivate behavior change. The outreach conditions tested were: 1. Mailed Composting Report a. Graphical comparison of their neighborhood s composting rate to nearby neighborhoods, in order to create cognitive dissonance (while residents feel they are already composting all they can, they likely are not), and normative feedback b. Testimonials from local residents c. Instructional and graphical information on green bin recycling d. Delivered once during the outreach period 2. Hangtags a. Instructional and graphical information on green bin recycling b. Prompt to participate c. Delivered twice during the outreach period 3. Kitchen Pail and Instructional Material a. Increased convenience of collecting food scraps b. Sticker prompt to participate c. Instructional and graphical information on green bin recycling d. BPI certified bio bags e. Delivered once during the outreach period Five waste routes were selected for pilot implementation. Three were assigned an outreach condition and two were assigned as control conditions. To evaluate the pilot, approximately 100 pre- and postpilot bin sorts of trash bins and lid flips of green and blue recycling bins were conducted for each treatment. In addition, route-level tonnage data was collected for all routes and a post-pilot survey was sent to 1,200 households, including all households that had received an audit. Evaluation of the outreach was conducted over a four-week period two to three weeks following outreach. Overall, all three of the outreach strategies produced significant reductions in the overall trash weight (between 13% - 35%), the amount of compostable materials in the trash (24% - 42%), and the amount of food scraps found in the trash (41% - 45%). Combined, the conditions reduced the average trash bin weight by 3.50 pounds, and specifically, reduced the compostable material by 1.81 pounds per trash bin. The majority of the reduction in compostable material was due to a decrease in food scraps in the trash bin, an average of 1.36 pounds per bin. Page 5
All three outreach strategies also reduced the percentage of households with more than 20% of the trash consisting of food scraps, whereas the control condition remained relative consistent. In addition, the hangtag and the home waste reports substantially increased the percentage of households with 0% food scraps. Surprisingly, the pail resulted in a small decrease in the percentage of households with 0% food scraps, although it did increase the number of households with.01% to 20% food scraps in the trash. Finally, the survey showed no significant differences between the conditions, but did indicate that all materials were well-received and most households had seen them. Recommendations 1. Go Beyond Concern and General Difficulty a. Most respondents in the foundational research and in this pilot already believe green bin recycling is important and fairly easy, but bin sorts show they still don t act. b. Employ strategies such as social norms, prompts, positive framing, and cognitive dissonance. 2. Many Different Avenues to Success a. All conditions showed a significant decrease b. Different costs (resources and time) to implement 3. Use Communication Best Practices a. Conditions were well-received b. Employ positive framing, eye-catching colors and imagery, and limited text 4. Consider Combining Conditions a. Still room to improve b. Did not test if conditions could have additive effects 5. Bin Audit Data Provides Strong Evaluation Metric a. The level of detail is critical to seeing if conditions are having an effect Page 6
Background and Purpose In the summer of 2015, a mail survey and a telephone survey were conducted with Alameda County residents. Both surveys assessed attitudes, barriers, and self-reported behaviors related to food scrap and food-soiled paper recycling. The mail survey research also identified relationships between survey responses and household waste audits that had been conducted in the previous year. Overall, the research found that nearly all respondents thought green bin recycling was important and not very difficult. However, despite their positive attitude and belief that they understood how to participate, waste audits of their trash bins showed that many residents were still placing a significant amount of their compostable waste into their trash bin. The research identified a few key misunderstandings about green bin recycling, such as confusion about what material can be placed in the bin, as well as several strategies that StopWaste, the cities and/or the haulers could employ to address identified barriers and increase the program s effectiveness. The four strategies tested in this pilot were: (1) Convenience, (2) Education (how to participate) and prompts, (3) Cognitive Dissonance, and (4) Social Norms. Methods In the summer of 2016, StopWaste, Underground, and Action Research partnered with the City of Fremont to test three different programs, compared to a control group, to determine which strategy or strategies best reduced the amount of organic material placed in the trash. The project methodology is described below. At the end of the methods section, a table summarizes the full methodology. Sample The research team identified waste pick up routes within the city that could be carefully monitored over the course of six months. A total of 1,995 households were selected across five similarly sized routes, one for each day of the week; Monday (N=400), Tuesday (N=372), Wednesday (N=448), Thursday (N=426), and Friday (N=349). The routes were selected from different areas of the city, and they generally came from lower-tomedium income regions. Figure 1 shows the selected routes, overlaid on census block-groups showing median per capita income. Page 7
Figure 1: Selected Routes Overlaid on Census Blocks with Median Per Capita Income Outreach Design The study tested the change over time in food scrap recycling among each of the five routes using a prepost design. The three tested outreach strategies were a ZeroCycle composting report, hangtags, and a kitchen countertop pail with 30 compostable bags. All materials used a positive tone and kept the amount of text to a minimum. All materials also had educational information that addressed knowledge gaps and concerns found in the foundational research, as well as clearly and easily conveyed what material should go in the green bin. The educational material conveyed the how-to skills about green recycling bin recycling to lay the foundational framework for residents to know how to fully participate. However, to successfully motivate behavior change, outreach must go beyond education, which is why each material employed additional behavioral strategies. Specifics about the conditions are described below. Composting Waste Report: Cognitive Dissonance and Social Norms Households in the Tuesday route were mailed a composting waste report encouraging them to put compostable food scraps into the green bin, along with a composting meter showing the composting rate of their neighborhood compared to other neighborhoods in the region. In the mail survey research, residents reported they were composting most of their food scraps, but the bin audits for corresponding households showed they were not. The composting meter was meant to create a sense of cognitive dissonance by showing that, in contradiction to their belief, their neighborhood, and likely their household as well, still had a fair amount of food scraps in their trash. The report also drew on social norms in two ways, first by comparing the composting rate to other nearby neighborhoods, as well as by including a local resident testimonial. The backside of the report provided instructional materials and graphics for separating and composting food scraps. Page 8
Hangtags: Prompts Households in the Wednesday route received two different printed messages encouraging them to put their food scraps and food soiled paper into the curbside green bin, along with instructional information about specific compostable materials typically found in the trash. The hangtag also served as a prompt to remind the residents about participation. Each hangtag was placed on the green bin or the trash bin once in each of two successive weeks. FRONT BACK FRONT BACK Page 9
Kitchen Food Scrap Pail: Convenience and Prompt When Fremont added food scraps collection in 2003, a kitchen pail and extensive outreach was provided to each single family household. New accounts get a comprehensive service guide, and can request a pail when they start service. The City includes a contact Republic if you need a replacement pail message on their brochures and newsletters, hands out dozens of pails at Earth Day or other events, and refers residents to Republic to request a pail. There is no cost to the customer and Republic will deliver one to their home. However, it is unknown what percentage of pilot homes already had a Republic kitchen pin is use. Households in the Thursday route received a reusable kitchen countertop pail for compostable material, along with a roll of 30 compostable bags, instructional information and a sticker about specific compostable materials typically found in the trash. The hangtag and sticker both served as prompts to participate. The material was delivered to the home s doorstep. STICKER FRONT BACK Control Households in the Monday and Friday routes served as a comparison group, and no outreach materials were provided to these households during the pilot program. Data Collection Four sources of evaluation data were obtained from households in each route: bin sorts, lid flips, routelevel tonnage, and surveys. Bin Sort Data A sample of ~100 households was randomly selected for a bin sort from each of the three outreach groups and the control group. Every week for a one-month period preceding the outreach, the trash bins from approximately 25 randomly selected households on Monday (control), Tuesday (composting Page 10
reports), Wednesday (hangtags), and Thursday (countertop pail) were wrapped and taken to a sorting location. The contents of the trash bin were weighed, and sorted into different categories: garbage, recycling, plant debris, food soiled paper, and food scraps. The cycle was repeated after the pilot was implemented. Overall, the bin sorts were conducted over a sixteen-day pre-test period and again over a sixteen-day post-test period. A total of 402 bins were sorted during the pre-test period, and 411 during the post-test period. Lid Data For the households that had the trash bins sampled in the bin audit, the field team also conducted visual assessments of the recycling and green bin containers at the curb. For these two bins, the lids of the cans were opened and a visual assessment was made regarding the fullness of the bin (using a scale from 0-100%) and the presence of visible contamination (defined as inappropriate material for that bin). Route-level Tonnage Data In cooperation with the contracted trash hauler for the City, weekly tonnage weight data was obtained for each route for one year preceding the program, the three-month intervention and evaluation period, and two months following. Survey Data Following the completion of the outreach activities, postcard surveys were sent to 1,200 randomly selected households in the five routes, with 300 households selected per condition. All homes that received a bin audit were included in the survey sample. The survey employed Dillman s Tailored Method, with up to four mailings: 1. Pre-notification postcard 2. Postcard survey 3. Reminder postcard (non-responders) 4. Second postcard survey (non-responders) A total of 456 completed surveys were returned, for a response rate of 38%. The survey asked about the importance of recycling, the difficulty of recycling, and four specific questions about the outreach material they received (reduced confusion, easy to understand, prompted recycling, and encouraged them to recycle more). See Appendix A for survey materials. Page 11
Methodology Table Table 1 is a summary of the implementation methodology for this pilot, starting in mid-may 2016 and concluding in early August 2016. For clarity, the date of the Monday of the week is included under the week number. Table 1: StopWaste Pilot Methodology Summary Week # 1 (5/23) 2 (5/30) 3 (6/6) 4 (6/13) 5 (6/20) 6 (6/27) 7 (7/4) 8 (7/11) 9 (7/18) 10 (7/25) 11 (8/1) Monday (Control) Tuesday (Composting Report) -- -- -- -- -- Composting Report Wednesday (Hangtags) Thursday (Kitchen Pail) Friday (Control) Hangtag #1 Kitchen Pail -- -- -- Hangtag #2 -- -- -- -- -- -- -- Survey Survey Survey Survey Survey & Survey & Survey & Survey & Survey & Survey & Survey & Survey & Survey & Survey & Survey & Survey & Survey & Survey & Survey & Survey & Page 12
Results Statistical analyses of the outreach strategies were conducted for each of the four outcome measures: bin sorts, lid flips, route-level tonnage, and survey data. Bin Sort Results A total of 402 trash bins were sampled during the pre-intervention period and 411 were sampled at the post-intervention period. Since not all households set out trash bins each week, paired pre-post bin sort data were obtained from 355 households. In instances where a household was selected for a pre-audit, but at the time of post-audit did not put out a trash bin, the next house in the route was audited. There were 47 households that only had pre-audit data and 56 households with only post-audit data. The analyses below focus primarily on the 355 households with complete data. Total Trash Composition The contents of the trash bins were sorted and weighed. The sorted categories of trash included: garbage, recycling, plant debris, soiled paper, and food scraps. Table 2 shows the mean weights of the trash contents for the 402 pre-test bin sorts and the 411 post-audit bin sorts. Table 2. Composition of Trash Bin sort categories Pre-test Mean Weight (lb) Post-test Mean Weight (lb) Total Material in Trash Bin 15.60 13.00 Garbage 7.29 7.00 Recycling 3.13 1.96 Plant Debris 0.25 0.14 Soiled Paper 2.00 1.89 Food Scraps 2.93 1.05 A sizable amount of recyclable or compostable material was found in the pre-test trash. See Figure 2. Figure 2: Trash Bin Characterization Pre-Test Food Scraps 19% Soiled Paper 13% Garbage 47% Plant Debris 1% Recycling 20% Page 13
During the pre-test, 53% of the material in the trash by weight was either recyclable or compostable. Outreach Materials: Trash Weight Statistical analyses for the effectiveness of the outreach communications focused on the 355 households with complete pre-post data. The first analysis focused on changes in the overall weight of material in the trash bin from pre-test to post-test. The results are shown in Table 3. Outreach condition Table 3. Change over time in the total weight of all materials found in the trash Pre-test Mean Weight (lb) (Std. D*) Post-test Mean Weight (lb) (Std. D) % Change # of Audits Statistical Sig. Countertop Pails 15.19 (6.62) 13.28 (4.78) -13% 93 P**=.02 Hangtags 20.17 (7.96) 13.41 (7.01) -34% 86 p<.001 Composting Reports 13.95 (4.13) 12.12 (3.56) -13% 93 p<.001 Control 13.50 (4.21) 13.38 (5.36) 0% 83 p=.87 (ns***) *Std. D. refers to the standard deviation, or how spread out the measurements for the group are from the average (mean) **p refers to the p-value, which tells us the statistical significance, or the level of likelihood that the observed change did not happen by chance..05 or less is the generally accepted cut off for significance. ***ns refers to a p-value to that is above.05, or not significant Each of the three communication strategies significantly reduced the amount of trash: countertop pails (13%), hangtags (34%), and composting reports (13%). Importantly, the control condition did not significantly change over the same period, providing strong support for the effectiveness of the three interventions. There were no significant differences between the three outreach strategies with regard to their effectiveness at reducing the overall trash weight. Combined, the three outreach strategies reduced the overall trash weight by an average of 3.50 pounds per bin. See Figure 3. Figure 3: Percent Reduction in Trash Bin Weight 0% -5% -1% -10% -15% -20% -25% -30% -13% -13% -35% -40% -34% Countertop Pails Hangtags Home Waste Reports Control Page 14
Outreach Materials: Compostable Materials Next, the analysis focused on the amount of organics found in the trash by weight (plant debris, soiled paper, and food scraps combined). The descriptive results are in Table 4. If the outreach programs were effective, we would expect to see a decrease in the amount of compostable material in the trash. Outreach condition Table 4. Change over time in the weight of total compostable material found in the trash Pre-test Mean Weight (lb) (Std. D) Post-test Mean Weight (lb) (Std. D) % Change # of Audits Statistical Sig. Countertop Pails 5.24 (3.47) 3.96 (2.57) -24% 93 p<.006 Hangtags 7.28 (5.36) 4.21 (3.22) -42% 86 p<.001 Composting Reports 3.92 (2.24) 2.84 (1.78) -28% 93 p<.001 Control 4.56 (2.71) 5.46 (4.41) 23% 83 p=.12 (ns) Each of the outreach strategies significantly reduced the amount of compostable material in the trash. In terms of percentage reduction, the largest difference was observed for the hangtags (a reduction from 7.28 during baseline to 4.21 at post-treatment, 42%), followed by the composting reports (28%), and finally the countertop pails (24%). These percentages are shown in Figure 4. Figure 4: Percentage Reduction in Compostable Material in the Trash 30% 20% 20% 10% 0% -10% -20% -30% -24% -28% -40% -50% -42% Countertop Pails Hangtags Home Waste Reports Control Importantly, the control condition did not change significantly, and in fact, the trend showed an increase in the amount of compostable material in the trash during the intervention period. The control condition reflects seasonal changes in waste and recycling disposal during the pilot period, so the fact that the control condition did not change, whereas each of the outreach conditions decreased, provides clear evidence for the outreach effectiveness. Combined, the weight of compostable material in the trash decreased by an average of 1.81 pounds per bin in each of the three outreach conditions. Page 15
Outreach Materials: Food Scraps One of the potential reasons for the large reduction in compostable material associated with the hangtags is the presence of a handful of households with very large amounts in the trash during the preoutreach bin sorts. To better understand the reduction in compostable material, a more refined comparison was conducted based only on food scraps. These results are shown in Table 5. Outreach condition Table 5. Change over time in the weight of food scraps found in the trash Pre-test Mean Weight (lb) (Std. D) Post-test Mean Weight (lb) (Std. D) % Change # of Audits Statistical Sig Countertop Pails 3.05 (2.40) 1.83 (1.23) -40% 93 p<.001 Hangtags 4.36 (3.48) 2.38 (2.15) -45% 86 p<.001 Composting Reports 2.18 (1.74) 1.29 (.99) -41 % 93 p<.001 Control 2.24 (1.72) 2.76 (2.32) 23% 83 p=.10 (ns) Each of the interventions produced a significant reduction in the amount of food scraps in the trash. The largest reduction continued to be the hangtags (45% reduction), followed by the composting reports (41% reduction), and the countertop pails (40% reduction). These percentages are shown in Figure 5. Figure 5: Percentage Reduction in Food Scraps in the Trash 30% 20% 23% 10% 0% -10% -20% -30% -40% -50% -40% -41% -45% Countertop Pails Hangtags Home Waste Reports Control Importantly, the control condition did not show a statistically significant change from the amount of food scraps found in the trash at baseline, and in line with the previous finding for total compostable materials, was trending toward an increase in the presence of food scraps in the trash. There were no significant differences between the three strategies. Combined, there was an average of 1.36 pounds less of food scraps in each of the bins for households in the three outreach conditions. Page 16
Outreach Materials: Recyclables The next analysis focused on the amount of recycling materials found in the trash. As noted earlier, the pre-test bin sorts showed that 20% of the materials found in the trash were recyclable, and while the outreach materials focused specifically on food scraps, it s possible that the materials heightened interest in recycling among residents which could increase the recycling rate for other materials. The statistical results are shown in Table 6 below. Outreach condition Table 6. Change over time in weight of recyclable materials found in the trash Pre-test Mean Weight (lb) (Std. D) Post-test Mean Weight (lb) (Std. D) # of Audits Statistical Sig. Countertop Pails 3.16 (2.63) 2.37 (1.63) 93 p<.02 Hangtags 4.15 (3.13) 1.52 (1.52) 86 p<.001 Composting Reports 2.71 (1.69) 2.40 (3.06) 93 p=.16 (ns) Control 2.61 (1.89) 1.75 (1.64) 83 p=.03 All three outreach strategies showed trends toward a reduction in the amount of recyclable material found in the trash. However, households in the control condition also showed a significant reduction in the amount of recyclable material in the trash. This change in the control is likely due to seasonal fluctuations in materials generated in the home. Because the control condition decreased at a similar rate, there is no evidence that the communications resulted in improved general recycling rates. Outreach Materials: Garbage Finally, analyses were conducted for changes in the amount of garbage generated in each of the outreach conditions. While the outreach materials did not specifically target source reduction, it s possible that residents in the outreach conditions would change their buying habits in order to generate less garbage. The results are shown below in Table 7. Outreach condition Table 7. Food Scrap Self-Report and Food Scraps in Waste Audit (N=226) Pre-test Mean Weight (lb) (Std. D) Post-test Mean Weight (lb) (Std. D) # of Audits Statistical sig. Countertop Pails 6.76 (3.08) 6.94 (2.77) 93 p=.70 (ns) Hangtags 8.74 (4.78) 7.69 (4.37) 86 p<.15 (ns) Composting Reports 7.33 (3.06) 6.89 (2.36) 93 p=.27 (ns) Control 6.33 (2.96) 6.18 (2.84) 83 p=.72 (ns) There were no significant changes in the amount of garbage found in the trash bins for any group. Page 17
Outreach Materials: Overall Bin Sort Results Taken together, the results from the bin sorts strongly support each of the three outreach methods. All three of the methods significantly reduced the amount of compostable materials in the trash, especially food scraps. Figures 6 to 13 show the trash bin characterization for each of the four conditions during the pre-test and post-test periods. The figures show the changes in the percentage of materials classified in the trash bin. In general, the three outreach conditions resulted in less good stuff in the trash (i.e., food scraps, food soiled paper, recycling). It is important to point out that the figures show the relative composition, and garbage is increasing in the three outreach conditions as a relative proportion of the overall waste in the trash bins, it is decreasing by total weight and volume (as reported above). Figure 6: Trash Characterization Pre-test: Kitchen Pails Figure 8: Trash Characterization Post-test: Kitchen Pails 20% Garbage 14% Garbage 13% 1% 21% 45% Recycling Plant Debris Soiled Paper Food Scraps 16% 0% 18% 52% Recycling Plant Debris Soiled Paper Food Scraps Figure 7: Trash Characterization Pre-test: Hangtags Figure 9: Trash Characterization Post-test: Hangtags 22% Garbage 17% Garbage 13% 43% Recycling Plant Debris Soiled Paper 13% 0% 59% Recycling Plant Debris Soiled Paper 2% Food Scraps 11% Food Scraps 20% Page 18
Figure 10: Trash Characterization Pre-test: Waste Reports Figure 12: Trash Characterization Post-test: Waste Reports 16% 10% 11% 1% 19% 53% Garbage Recycling Plant Debris Soiled Paper Food Scraps 13% 0% 20% 57% Garbage Recycling Plant Debris Soiled Paper Food Scraps Figure 11: Trash Characterization Pre-test: Control Figure 13: Trash Characterization Post-test: Control 16% Garbage 20% Garbage 11% 1% 53% Recycling Plant Debris Soiled Paper 16% 48% Recycling Plant Debris Soiled Paper 19% Food Scraps 3% 13% Food Scraps Percentage of Food Scraps in Trash By Household The three outreach strategies significantly reduced the amount of compostable materials in the trash, especially food scraps, but there several ways this change could have occurred. On the one hand, the change could have resulted from a small number of households that were not previously separating any food scraps to begin placing all of their compostable materials in the green bin. Alternatively, a large number of households could have increased the amount of food scraps that they recycled, but still not achieving 100% diversion. An additional set of analyses was conducted to explore this issue. First, the percentage of food scraps in the trash was calculated, pre- and post-test, for the entire sample. Overall, 19% of the trash consisted of food scraps during the baseline period (Figure 2), and during follow-up period, it was 15%. The overall distribution of food scraps as a percentage of the trash was calculated and plotted in histograms. Figure 14 and Figure 15 show the distribution for the 402 pre-test bin sorts, and the 411 post-test bin sorts. Page 19
Figure 14: Percentage of Food Scraps in Trash, Pre-test Figure 15: Percentage of Food Scraps in Trash, Post-test Food Scrap Percentage Food Scrap Percentage Figure 14 and Figure 15 show that 72 out of 402 households in the pre-test bin sorts (18%) had no food scraps in their trash bins; an additional 42% had less than 20% food scraps. In the follow-up, 83 out of 411 had zero food scraps (20%); an additional 48% had less than 20% food scraps. See Table 8. Table 8: Change in Percentage of Food Scraps in the Trash Pre- and Post-Test Categories of Food Scrap Recyclers Pre-test Post-test 0% (perfect) 18% 20%.01% to 20% 42% 48% More than 20% 40% 32% These categories were then calculated separately for each of the four outreach conditions. See Table 9. Table 9: Change in Percentage of Food Scraps in the Trash Pre- and Post-Test By Condition Categories of Food Scrap Recyclers Pail Hangtag Composting Report Control Pre- Post Pre- Post- Pre- Post Pre- Post- 0% (perfect) 21% 14% 18% 32% 9% 17% 33% 15%.01% to 20% 34% 58% 27% 40% 64% 74% 33% 47% 20.01 and above 45% 28% 55% 28% 27% 9% 34% 38% All three outreach strategies reduced the percentage of households with more than 20% of the trash consisting of food scraps, whereas the control condition remained relative consistent. In addition, the hangtag and the home waste reports substantially increased the percentage of households with 0% food
scraps. Surprisingly, the pail resulted in a small decrease in the percentage of households with 0% food scraps, although it did increase the number of households with.01% to 20% food scraps in the trash. Finally, to better understand the pattern of change, the amount of change was calculated by subtracting the percentage of food scraps in the trash in the post-test minus pre-test percentage for each of the four conditions. The results are shown in Figures 16 to 19 below. In the figures, negative scores indicate that food scraps were a lower percentage of the trash during the follow-up period than during the baseline period (i.e., negative scores reflect a change in the expected, desired direction). Figure 16: Difference in Percentage of Food Scraps in the Trash Post-test to Pre-Test, Kitchen Pail Figure 18: Difference in Percentage of Food Scraps in the Trash Post-test to Pre-Test, Report Difference in Food Scrap Percentage Figure 17: Difference in Percentage of Food Scraps in the Trash Post-test to Pre-Test, Hangtags Difference in Food Scrap Percentage Figure 19: Difference in Percentage of Food Scraps in the Trash Post-test to Pre-Test, Control Difference in Food Scrap Percentage Difference in Food Scrap Percentage The change in the percentage of food scraps in the trash bins from pre-to-post was varied across the conditions. While each of the three outreach conditions resulted in reductions (-6%, -3%, and -5% for Page 21
the pail, hangtag, and composting report respectively), the response was varied. Some households reduced considerably, some not at all, and some increased the percentage of their overall trash that was comprised of food scraps. Importantly, these reductions are percentage and not the overall amount of food scraps by weight, which was reported earlier and decreased by -40%, -45%, and -41%, respectively. Finally, to graphically represent the amount of change in each household, profile plots were created for the four outreach conditions. Figures 20 to 23 show the change in the percentage of food scraps in the trash bin from Time 1 (baseline) to Time 2 (post-treatment). Each line in the graph represents a household, and the axis shows the percentage of the trash that was comprised of food scraps (from 0% to 100%) at each time point. Lines that are increasing reflect more food scraps as a percentage of the trash during the follow-up period, and lines that are decrease represent fewer food scraps as a percentage of the trash. Figure 20: Profile Plot of Percentage Change of Food Scraps in Trash, Kitchen Pail Figure 22: Profile Plot of Percentage Change of Food Scraps in Trash, Composting Report Figure 21: Profile Plot of Percentage Change of Food Scraps in Trash, Hangtags Figure 23: Profile Plot of Percentage Change of Food Scraps in Trash, Control Page 22
Lid Results When the trash bin was pulled for sorting, the lid of the recycling and green recycling bins were also flipped. The two bins were coded for the amount of material (percentage full), and the presence of contamination. These observations were compared between pre-intervention and post-intervention periods. See Table 10. Table 10. Change over time in the fullness of the garbage, recycling, and organics bins Outreach condition Garbage Recycling Organics Pre-test Post-test Pre-test Post-test Pre-test Post-test Countertop Pails 65% 58%** 75% 78% 71% 81% Hangtags 74% 63%** 80% 71% 77% 76% Composting Reports 75% 64%** 78% 75% 68% 72% Control 57% 64% 79% 72% 75% 76% Note: *** indicates a statistically significant change of time, p<.05. Statistical analyses showed that the reduction in the amount of garbage was statistically significant for each of the three treatment routes. The change over time for the amount of recyclables and organics was not significant. These findings for the reduction in trash volume is in line with the previouslyreported analyses of trash weight, showing a reduction in trash for each of the three outreach conditions, but not for the control condition. The lack of change detected for organics is likely due to the relatively small amount and dense volume of food scraps compared to other organic materials such as yard waste. Route-level Weights Based on the bin sorts, all three of the outreach strategies produced significant reductions in the overall trash weight (between 13% - 35%), the amount of compostable materials in the trash (24% - 42%), and the amount of food scraps found in the trash (41% - 45%). However, the bin sorts were only conducted in a period of two to four weeks following outreach, leaving a remaining question of the durability of these changes over time. To address this question, weekly route-level weight data were obtained from each of the five routes, combining the two control routes. Historical route-level data were obtained for a period of 1-year, and follow-up data were obtained for three months following the outreach. It s important to note several limitations with this type of measurement. First, unlike the bin sorts where each household provides a unique data-point, with route-level data only a single weekly data-point is provided for the entire condition. This limits the type of statistical analyses that can be computed. Second, route-level data is prone to large variations, and a single outlying week can strongly influence the results. Finally, with route-level data the important comparison is change over time, rather than comparisons of treatment versus control. With these caveats in mind, route-level data provides an important way to test the longer-term impact of the outreach strategies.
Overall Weekly Tonnage Data for all Waste Streams Weekly tonnage data were obtained from the hauler for recycling, garbage, and green waste. Figure 24 shows the weekly results across the 53-week period. The outreach activities occurred in June. Figure 24: Weekly Route-Level Tonnage for Green Waste, Garbage, and Recycling 30 25 20 15 Yard Waste Garbage Recycling 10 5 0 Sept-15 Oct-15 Nov-15 Dec-15 Jan-16 Feb-16 Mar-16 Apr-16 May-16 Jun-16 Jul-16 Aug-16 Over the 53-week period, the routes included in the outreach program disposed of an average 15.61 tons of yard waste, 13.40 tons of garbage, and 12.36 tons of recycling. The relative percentages are shown below in Figure 25. Page 24
Tons of Material per Route Figure 25: Breakdown of Garbage, Green Waste, and Recycling for All Routes 30% 38% 32% Yard Waste Garbage Recycling Monthly Route Level Data: Garbage To test for the impact of the outreach activities, the weekly data were averaged into a monthly-level resolution. Analyses of the bin sorts showed a reduction in the total amount of material in the garbage bins. This pattern was partially confirmed with the route-level weights. The control condition remained stable from the month preceding the outreach, through the intervention month, post-interview month 1, and post-intervention month 2. Over the three-month period following the outreach, the route that received the composting reports decreased by 21%, the pail route decreased by 12%, but the hangtag route increased by 18%. For comparison, the control route increased by 4%. See Figure 26. Figure 26: Monthly Route Level Data for Garbage By Condition 25 20 15 10 Pail Hangtags Report Control 5 0 Baseline Month Intervention Month Followup-1 Follow-up 2 Page 25
Tons of Material per Route Tons of Material per Route Monthly Route Level Data: Yard Debris Analyses of the bin sorts showed a reduction in the total amount of organic material in the garbage bins, and especially food scraps. Given this finding, we would expect the amount of material in the yard debris bins would increase following outreach. However, this finding was not confirmed. See Figure 27. Figure 27: Monthly Route Level Data for Yard Waste By Condition 25 20 15 10 Pail Hangtags Report Control 5 0 Baseline Month Intervention Month Followup-1 Follow-up 2 Monthly Route Level Data: Recyclable The results from the bin sorts showed no change in the amount of recyclable material in the trash. Given this finding, we would not expect any changes in the route-level data over time, as seen in Figure 28. Figure 28: Monthly Route Level Data for Recyclables By Condition 25 20 15 10 Pail Hangtags Report Control 5 0 Baseline Month Intervention Month Followup-1 Follow-up 2 Page 26
Survey Results Survey respondents rated green bin recycling as very important (range from 8.60 to 8.91 on a scale from 0-10) and relatively easy (range from 2.42 to 2.53 on a 0-10 scale). See Table 11. Table 11. Importance and Difficulty of Green Curbside Bin Recycling Survey question how important is it for your household to participate in green curbside bin recycling? (0-10) how difficult is it for your household to participate in green curbside bin recycling? (0-10) Countertop Pail (N=123) Hangtags (N=122) Composting Report (N=93) Control (N=54) 8.65 8.85 8.60 8.91 2.53 2.42 2.45 2.46 There were no significant differences across the treatment groups for importance or difficulty. For each of the three treatment conditions, specific items were asked about the outreach materials. The survey results for these items is shown in Table 12. Table 12. Outreach Material Survey Questions Survey question Q: Did your household receive the outreach materials. Q: Outreach materials reduced confusion about food scrap composting? (0-10) Q: Outreach materials were easy to understand. Q: Outreach materials helped me remember to compost food scraps. Q: My household is composting more food scraps after receiving outreach materials. Countertop Pail (N=123) Hangtags (N=122) Composting Report (N=93) Control (N=54) 95% 79% 78% N/A 7.12 7.20 7.81 N/A 8.74 8.35 8.43 N/A 7.13 6.97 7.49 N/A 6.68 6.65 6.97 N/A All of the outreach strategies were well-received. A high percentage remembered receiving the materials: countertop pail (95%), hangtags (79%), and composting report (78%). In addition, the materials were rated as easy to understand, reducing confusion, and prompting residents to compost food scraps. Though not a statistically significant difference, the composting reports were rated as better at reducing confusion and serving as a reminder to compost food scraps, whereas the pail was rated as easiest to understand. With regard to self-reported changes in behavior, the composting reports were rated as most effective. Page 27
Recommendations Overall, these results show that all three interventions significantly reduced the amount of food scraps in the trash bin compared to the control. Based on these findings, we have several recommendations. In addition, a few follow-up surveys were conducted post-pilot, and quotes from those surveys are included in callout boxes below. Go Beyond Concern and General Difficulty In both the foundational research and in this pilot, respondents across the board reported that participating in green bin recycling was important to them and not difficult for their household to do. However, despite these attitudes, there were significant differences in their green bin recycling behaviors. While reinforcing the importance and ease of curbside green bin recycling in messaging seems intuitive, the results from the current study highlight the need for messaging that goes beyond these values and addresses other structural and motivational barriers. Many Different Avenues to Success All of the interventions showed a significant decrease in organic material in the trash, with hangtags having the highest percentage drop (while also having the highest starting point). Importantly, each of these interventions has a different cost to produce and deliver, including differences in the need for boots on the ground or reliance on the postal system. We recommend that program managers carefully consider their available resources, knowing that each of these interventions has had demonstrable success. Composting doesn t take much effort, so why wouldn t you do it? It s good for the environment. To make composting cleaner, I recommend using biodegradable liners. They keep my bin from getting dirty when food leaks. Use Communication Best Practices From the survey data, we can conclude that residents liked the interventions and found them helpful. No single intervention was rated significantly better than others. In addition to the motivational strategies, the team focused on keeping the messaging positive, using images, employing simple nontechnical language, and incorporating humor as possible. We recommend future messaging utilize these same communication best practices. Consider Combining Conditions As we did not test any combined conditions, it is unknown if they would have additive effects on motivation. However, as there was still room to improve in all conditions in the post-test findings, it may be worth future research to see if combining two interventions provides an additional decrease in food scraps in the trash bin. Bin Audit Data Provides a Strong Evaluation Metric While bin audits require time and resources, particularly to track the homes that had previously received an audit to then audit them a second time, these data provided a detailed look at whether the Page 28
intervention was successful. Route level data, while important to collect, is often not detailed enough to show success. Moreover, once an intervention has been in place for a sustained periods, bin audits can reveal if continued issues stem from particular materials, a small segment of homes, or other specific target behaviors or audiences. We recommend that these bin audits continue to be used as an evaluation metric moving forward. Page 29
Appendix A- Survey Materials Pre-notification Postcard Dear Resident, YOU WILL BE RECEIVING A SURVEY Within the next few days you will be receiving a survey from the City of Fremont and StopWaste, a public agency responsible for waste reduction and recycling programs in Alameda County. Your household is one of only 1,200 households throughout the county being asked to take part in this important study. Your assistance will help the City and StopWaste promote resource conservation and develop education and outreach services. As a thank you, residents who return the completed survey will receive a $5 Starbucks gift card. If you have any questions, please call (510) 891-6500 or email jettlinger@stopwaste.org. We look forward to hearing from you. Sincerely, Judi Ettlinger Survey Cover letter The same cover letter was used on all surveys, below. Dear Resident, You are receiving this survey from the City of Fremont and StopWaste, a public agency serving all of Alameda County. The goal of this quick survey is to get a better understanding of curbside green bin composting in our community. Your household is one of only 1,200 homes that will be receiving this survey so your opinions are very important to us. As a thank you, residents who return the completed survey will receive a $5 Starbucks gift card. After the survey questions, there is an optional request for your contact information if you are willing to speak with a staff member about your experiences with the curbside green bin composting program. Providing this information is completely optional. You will receive a gift card either way. If you have questions, please call Judi Ettlinger at (510) 891-6500 or email jettlinger@stopwaste.org. Once you have completed the survey, please place this postcard in the mail. Thank you for your participation! Sincerely, The StopWaste Team Page 30
Survey Postcards This section shows only the question section of each treatment s postcard. The postcard was folded such that the respondent could open it, fill it out, tear off the survey, and mail it. Control Kitchen Pail Page 31
Composting Report Hangtag Page 32
Reminder Postcard HAVE YOU COMPLETED YOUR SURVEY? Dear Resident, You recently received a survey from the City of Fremont and StopWaste regarding composting practices of City residents. If you have already completed and returned the survey, thank you. If you have not completed the survey, please take the time to do so today. Your assistance will help the City and StopWaste promote resource conservation and develop education and outreach services. As a thank you, residents who return the completed survey will receive a $5 Starbucks gift card. If you have any questions, please call (510) 891-6500 or email jettlinger@stopwaste.org. We look forward to hearing from you. Sincerely, Judi Ettlinger Page 33