1. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 Seasonal Variation on Combustible Set-outs under “Door-to-door” Collection Method with “Pay-as-you-throw” system 1 Shinya Suzuki, Ayako Tachifuji, Yasushi Matsufuji Department of Civil Engineering, Fukuoka University 8-19-1 Nanakuma, Johnan-ku, Fukuoka, 814-0180 Japan ssuzuki@fukuoka-u.ac.jp E-mail: ssuzuki@fukuoka-u.ac.jp

2. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 1-1 Background in Japan 1)Increasing number of municipalities begun “charge” for waste collection - in many cases, “Pay-as-you-throw” system - by using specific waste bag 2) Some municipalities convert way of waste collection - from “station” collection (traditional method in Japan) - to “door-to-door” collection 2) Some municipalities convert way of waste collection - from “station” collection (traditional method in Japan) - to “door-to-door” collection - specify common waste collection point for multiple households - unspecified people dispose of waste carelessly, which makes there dirty - too heavy for elderly people or physically-challenged people to bring waste - specify common waste collection point for multiple households - unspecified people dispose of waste carelessly, which makes there dirty - too heavy for elderly people or physically-challenged people to bring waste - Each household set out waste bag in front of entrance of housing - clarify waste generator’s responsibility, stimulate waste separation - anxiety on increase of cost of waste collection - Each household set out waste bag in front of entrance of housing - clarify waste generator’s responsibility, stimulate waste separation - anxiety on increase of cost of waste collection Specific waste bag - in order to realize waste minimization effectively

3. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 1-2 Objective In previous our study, - most households decided to use only 1 kind of waste bag - from long time experience - tended to keep from setting out waste bag - for adjustment of amount of waste in bag - additional survey in summer season In previous our study, - most households decided to use only 1 kind of waste bag - from long time experience - tended to keep from setting out waste bag - for adjustment of amount of waste in bag - additional survey in summer season For better management on waste collection, To clarify characteristics on waste set-outs - set-out frequency, - number of waste bag, - capacity of waste bag,- weight of waste bag But, seasonal variation still remained to be clarified - under “door-to-door” collection method - with “pay-as-you-throw” system - under “door-to-door” collection method - with “pay-as-you-throw” system

4. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 2-1 Solid Waste Management Fukuoka city, Japan One district in “Fukuoka city” was selected for survey of combustible waste - 1,664 peoples- 673 households - 9,800 people/km 2 Typical residential area in Japan. “Fukuoka city”, 8th largest city, 1.4 million people, - for MSW, “pay-as-you-throw” system, since Oct. 2005. 1) Combustibles, 2) Incombustibles, 3) recyclables “Glasses and PET bottles”, 4) Bulky waste Combustibles - average unit amount of waste: 0.6 (kg/person/day) (90% of MSW) - 10% reduction occurred by introducing “pay-as-you-throw” system - Households can buy any capacity they like - collected twice a week in night time under “door-to-door” collection method Combustibles - average unit amount of waste: 0.6 (kg/person/day) (90% of MSW) - 10% reduction occurred by introducing “pay-as-you-throw” system - Households can buy any capacity they like - collected twice a week in night time under “door-to-door” collection method - 15 litters (15 yen/bag), 30 litters (30 yen/bag), 45 litters (45 yen/bag; )

5. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 2-2 Analytical Methods 50 sample households 50 sample households - with a variety of household size - used specified waste collection point - on Mar. 7 th 2006, Mar. 10 th, Mar. 14 th, Mar. 17 th, continuously in spring - on Aug. 26 th 2008, Aug. 29 th, Sep. 2 nd, Sep. 5 th, continuously in summer - enabled us to confirm retention time in each waste bag In summer season, many households set out “garden waste” with usual combustible waste generated from daily activities, - such households have been excluded from this analysis. In summer season, many households set out “garden waste” with usual combustible waste generated from daily activities, - such households have been excluded from this analysis. Actual measurement survey on amount of waste - to clarify actual status on waste set-outs Actual measurement survey on amount of waste - to clarify actual status on waste set-outs

6. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 3-1-1) Actual Status on Waste Set-out Pattern 6 CATEGORIES confirmed for waste set-outs in summer season - more than 2bags? 1 bag? - 45 L? 30 or 15 L? 6 CATEGORIES confirmed for waste set-outs in summer season - more than 2bags? 1 bag? - 45 L? 30 or 15 L? CATEGORY 3) was not confirmed in spring season. - changed capacity of waste bag - to avoid long storage of waste - to keep from bad smell CATEGORY 3) was not confirmed in spring season. - changed capacity of waste bag - to avoid long storage of waste - to keep from bad smell

7. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 3-1-2) Difference of Waste Set-out Pattern In summer season, households tended to set out, - more frequently, more than 2 bags, with smaller capacities of waste bag - Percentage of 30 or 15 L of waste bag was much higher In summer season, households tended to set out, - more frequently, more than 2 bags, with smaller capacities of waste bag - Percentage of 30 or 15 L of waste bag was much higher

8. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 3-2-1) Unit Amount of Waste in each CATEGORY Distribution of unit amount of waste changed - in some CATEGORIES Distribution of unit amount of waste changed - in some CATEGORIES C-1) 45 L >2 bags C-4) 45 L 1 bag C-2) 2 kinds >2 bags C-5) 2 kinds 1 bag C-6) 30 or 15 L 1 bag C-3) 30 or 15 L >2 bags C-4): 1.0 – 2.0 (kg/household/day) - in spring season 1.0 – 1.5 (kg/household/day) - in summer season C-3): near 1.5 (kg/household/day) - in summer season C-4): 1.0 – 2.0 (kg/household/day) - in spring season 1.0 – 1.5 (kg/household/day) - in summer season C-3): near 1.5 (kg/household/day) - in summer season To clarify relationships between waste set-out pattern and amount of waste, Coverage of each unit amount of waste: - very narrow Coverage of each unit amount of waste: - very narrow

9. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 3-2-2) Seasonal Change of Waste Set-outs Capacity: 30 or 15 L Capacity: 45 L More than 2 bags 1 bag Spring Summer VARIABLE ZONE Relationships between number and capacity of waste bag In spring season, -Households who have a large amount of waste: - tend to use larger capacity of waste bag - tend to use 45 L and set out 1 bag every time In spring season, -Households who have a large amount of waste: - tend to use larger capacity of waste bag - tend to use 45 L and set out 1 bag every time In summer season, -Some households changed capacity of waste bag In summer season, -Some households changed capacity of waste bag Variable zone was formed only around border line of more than 2 bags or 1 bag every time Larger amount of waste Smaller amount of waste

10. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 3-2-3) Impact on Profile of Waste Set-outs Spring Summer 30 or 15 L >2 kinds 45 L We should take care of annual change of waste amount Seasonal change of waste set- outs occurred only for limited households - 1.0 – 1.5 (kg/household/day) - as stated before - 1.5 – 2.0 (kg/household/day) - set out more than 2 kinds of waste bag Seasonal change of waste set- outs occurred only for limited households - 1.0 – 1.5 (kg/household/day) - as stated before - 1.5 – 2.0 (kg/household/day) - set out more than 2 kinds of waste bag Seasonal change - very small - negligible Seasonal change - very small - negligible

11. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 3-3-1) Annual change? 30 or 15 L >2 kinds 45 L C-4)C-2)C-3) Amount of waste still continued to decrease gradually - distribution of unit amount of waste will change year after year - drastic change of waste set-outs will occur in near future? Amount of waste still continued to decrease gradually - distribution of unit amount of waste will change year after year - drastic change of waste set-outs will occur in near future?

12. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 4-1 Conclusions Seasonal variation on waste set-outs Actual condition survey in one district in Fukuoka city, Japan Seasonal variation on waste set-outs Actual condition survey in one district in Fukuoka city, Japan But households who used smaller capacities of waste bag were restricted - between 1.0 - 2.0 (kg/household/day) But households who used smaller capacities of waste bag were restricted - between 1.0 - 2.0 (kg/household/day) Seasonal variation really existed - in summer season, households tend to set out - more frequently, more than 2 bags, with smaller capacities - to avoid long storage of waste - to keep from bad smell Seasonal variation really existed - in summer season, households tend to set out - more frequently, more than 2 bags, with smaller capacities - to avoid long storage of waste - to keep from bad smell So, this seasonal change of waste set-outs - very small - negligible So, this seasonal change of waste set-outs - very small - negligible

13. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 1. Introduction 2. Materials and Methods 3. Results and Discussion 4. Conclusions 4-2 Conclusions But, we should take care of annual change of waste amount -Amount of waste still continued to decrease gradually - by introducing “pay-as-you-throw” system, -Coverage of each unit amount of waste - very small But, we should take care of annual change of waste amount -Amount of waste still continued to decrease gradually - by introducing “pay-as-you-throw” system, -Coverage of each unit amount of waste - very small Perhaps drastic change of waste set-outs will occur in near future? We should check such change in summer season! - easier for us to find change of waste set-outs We should check such change in summer season! - easier for us to find change of waste set-outs

14. Shinya Suzuki, Fukuoka University, Japan. APLAS Seoul 2010 Thank you very much for your attention !