Cambridge's City Wide Trash Volume Survey 4/2022
Introduction and brief summary of findings:
The Cambridge City Wide Trash Volume Survey of 2022 was conducted to assess current usual weekly trash volume produced by households, in order to help facilitate appropriate new trash bin distribution in Cambridge.
This survey addresses trash volume from single families, duplexes and three family houses in Cambridge. In 93% of all 348 residential units surveyed there was less than 35 gallons of trash/week. In approximately 60% of these residential units there was less than 20 gallons of trash/week. Therefore, it would be advantageous to distribute by default a trash cart that correlates with current usage at 35 gallons or less per household unit. The very small number of less than 7% of residents who produce more than 35 gallons of waste/week can take advantage of the city's many waste reduction programs of recycling, composting, yard waste, textile collection and more; or request an additional trash bin. By simply requiring that all receptacles be closed, this would also accomplish all plausible rodent control goals of the new bins, without completely derailing the cities waste reduction goals.
There has been significant household waste reduction since 2019 due to increased awareness of environmental concerns and tremendous community participation in the many city programs that reduce waste. Aligning trash bin distribution size with the trash reductions already achieved would have overwhelming benefits for residents, the city, and the environment!
The 2019 Zero Waste Master Plan ZWMP approved by public process indicates a commitment to further waste reduction. Thirty-five gallon trash carts generously accommodate nearly all current usage, however, they do nothing to affirm the efforts in waste reduction achieved by over 60% of residents whose 32 gallon bins are less than half full. Offering a trash receptacle of around 15- 20 gallons that residents can request would go a long way in legitimizing waste reduction goals!
2022 Summary of City-Wide Trash Volume Survey Results:
(Comparison with the Current Default Distribution of Trash Carts)
Single Family Homes:
One 32 gal. trash cart covers 93% of residents' weekly trash.
65% of single family homes had less than 20 gal. of trash,
This warrants an electable barrel option of around 20 gal.
(The current default distribution: One 45 gal. bin)
Two Families Homes:
Two 35 gallon trash carts cover 93% of residents' usage, or
One 50 gallon bin covers over 81% of residents
52% of duplexes had less than 35 gal. of trash.
(The current default distribution: Two 45 gallon bins)
Three Family Homes:
Three 35 gallon bins cover 93% of residents' usage, or
Two 50 gallon bins would also cover over 93% of residents
67% of three family houses had less than two 35 gallon bins of trash (under 70 gallons)
(The current default distribution: Two 65 gallon bins)
New trash carts to be distributed by default are
More than two times the volume of average usage!
City-wide Trash Volume Data by Dwelling Type from 164 Buildings:
This Represents 348 Residential Units
Summary for 43 Single Family Houses:
Volume of Trash # of Single Family Houses
0 - 20 gallons: 28
65% Under 20 gallons: 28
20 - 32 gallons: 12
93% Under 32 gallons: 40
32 - 50 gallons: 3
100% Under 50 gallons: 43
Summary for 58 Duplexes: (Representing 116 Residential Units)
Volume of Trash # of Duplexes
0 - 20 gallons: 7
20 - 32 gallons: 23
52% Under 32 gallons: 30
32 - 50 gallons: 17
81% Under 50 gallons: 47
50 - 64 gallons: 2
64 - 70 gallons: 5
93% Under 70 gallons: 54
70 - 82 gallons: 3
82 - 100 gallons: 1
100% Under 100 gallons: 58
Summary for 63 Three Family Houses: (Representing 189 Residential Units)
Volume of Trash # of 3 Family Houses
0 - 32 gallons: 7
32 - 50 gallons: 22
50 - 64 gallons: 8
63 - 70 gallons: 5
67% Under 70 gallons: 42
70 - 82 gallons: 6
82 - 100 gallons: 11
93% Under 100 gallons: 59
100 - 150 gallons: 3
150 - 200 gallons: 1
100% Under 200 gallons: 63
Additional study notes, and historical reference
New carts to be distributed by default are over two times the volume of average usage!
This study did not have a city wide representative sample of 4 and 6 family homes, though many were observed and also were far below the default distribution of trash bins.
The 32 gallon trash cart is much more common than 35 gallons. Either size could be used with little effect on the above results. 32 gallons was used as a guide to estimate trash, but since the city chose 35 gallon bins, 35 gallons is used to estimate future bin distribution. Likewise, the 50 gallon and 45 gallon barrels are also close enough in volume to not make a substantial difference, however, the 50 gallon bin is recommended to accommodate greater trash volume, and to help eliminate the use of 65 gallon barrels.
Sixty-five gallon barrels are not recommended as they can be far too heavy when filled with trash. They could easily weigh 200-300lbs, and are difficult to maneuver. They are not permitted by city ordinances. They also break easily, and it will be terribly confusing if they are the same size and color as the recycle bins!
Three other informal trash surveys in March 2022 (two in the Fresh Pond neighborhood and one in the Central Square neighborhood) informed this city-wide survey process. These informal surveys of over 200 receptacles consistently corroborate the need for a substantial downsizing of the planned trash bin rollout to better suit the needs of well over 90% of Cambridge residents.
Historical Context:
The Zero Waste Master Plan's ZWMP 2019 trash volume study states that Cambridge families in 4 of the 5 trash collection zones produce an average of 20 gallons of trash / week / family dwelling unit. It also confirms that "In the order of 75% of all households audited set out less than 32 gallons of trash." Trash reduction since 2019 in the outlying Thursday collection zone has brought it within the normal range accommodated by current recommendations of this 2022 survey.
Three other informal trash surveys from March 2022 (two in the Fresh Pond neighborhood and one in the Central Square neighborhood) informed this 2022 city-wide survey process. These informal surveys of over 200 receptacles consistently corroborate the need for a substantial downsizing of the planned trash bin rollout to better suit the needs of well over 90% of Cambridge residents.
Survey process notes, and raw data to assess city-wide trash volume of 5 trash collection regions, Monday - Friday.
The trash volumes for 164 single families, duplexes and three family houses on random streets in 5 trash collection regions of Cambridge were surveyed, representing 348 residential units. This sample size appears to be statistically significant in comparison to the trash volume report in ZWMP 2019. The limited scope of assessing 1-3 family units allowed for more precise data with a smaller sample. Dwelling types were determined by the number of doorbells, house structure and the number of mailboxes. The residence type had to be reasonably defined and trash had to be associated with a particular type of residence for inclusion in this study so that trash volumes would be representative.
Volumes were assessed visually by comparing trash volume with standard size barrels. Since 35 and 50 gallon barrels were most common, they were chosen as standards. Visual estimates were made looking into all bins. All estimates were made with the understanding that trash bin lids will need to be closed. Derivative volumes are often from multiple receptacles added together; the best estimation of the total volume was recorded in increments. For instance, two 32 gallon bins would be 64 gallons, an upper estimate of 20 gallons in one bin plus a 50 gallon barrel full would be 70 gallons. Most volumes are overestimated since bins were assessed by the upper limit - i.e. a full 42 gallon barrel would be included as up to 50 gallons without differentiation. This should help ensure that in actual usage there should be additional room to close the trash bin lids. This also gives a buffer for normal fluctuations in usage.
The days chosen to collect data were intended to be representative of normal usage. Care was taken to avoid both public school and college spring breaks as well as not including any holiday, so the trash represents 7 days usage. Data collection occurred mid March and concluded April 15, 2022.
The Thursday trash collection area which showed higher/residential unit trash in the 2019 ZWMP are slightly over represented in this study to make sure this area is in a similar range now. The area was found to have slightly increased trash levels in most categories, but the area is currently easily accommodated within the 93%.
Data from 5 Cambridge trash collection zones; Monday- Friday:
Monday:
Single Family Homes:
Less than 20 gallons: 14
Less than 32 gallons: 6
Less than 50 gallons: 1
Duplexes:
Less than 32 gallons: 11
Less than 50 gallons: 6
Less than 70 gallons: 4
Three Family Homes:
Less than 50 gallons: 4
Less than 64 gallons: 2
Less than 82 gallons: 1
Less than 100 gallons: 1
Tuesday:
Single Family Homes:
Less than 20 gallons: 9
Less than 32 gallons: 3
Less than 50 gallons: 2
Duplexes:
Less than 20 gallons: 5
Less than 32 gallons: 5
Less than 50 gallons: 4
Less than 64 gallons: 2
Less than 82 gallons: 2
Less than 100 gallons: 1
Wednesday:
Single Family Homes:
Less than 20 gallons: 1
Duplexes:
Less than 20 gallons:1
Less than 32 gallons: 3
Less than 50 gallons: 6
Three Family Homes:
Less than 32 gallons: 2
Less than 50 gallons: 4
Less than 64 gallons: 1
Less than 82 gallons: 2
Less than 100 gallons: 2
Less than 200 gallons: 1
Thursday:
Single Family Homes:
Less than 20 gallons: 2
Less than 32 gallons: 3
Duplexes:
Less than 32 gallons: 1
Less than 50 gallons: 3
Less than 82 gallons: 1
Three Family Homes:
Less than 32 gallons: 3
Less than 50 gallons: 9
Less than 64 gallons: 3
Less than 70 gallons: 3
Less than 82 gallons: 2
Less than 100 gallons: 4
Less than 150 gallons: 2
Friday:
Single Family Homes:
Less than 20 gallons: 2
Duplexes:
Less than 20 gallons: 1
Less than 32 gallons: 3
Less than 40 gallons: 1
Less than 50 gallons: 3
Less than 70 gallons: 1
Three Family Homes:
Less than 32 gallons: 2
Less than 50 gallons: 5
Less than 64 gallons: 2
Less than 70 gallons: 2
Less than 82 gallons: 1
Less than 100 gallons: 4
Less than 150 gallons: 1
The Cambridge City Wide Trash Volume Survey of 2022 was conducted to assess current usual weekly trash volume produced by households, in order to help facilitate appropriate new trash bin distribution in Cambridge.
This survey addresses trash volume from single families, duplexes and three family houses in Cambridge. In 93% of all 348 residential units surveyed there was less than 35 gallons of trash/week. In approximately 60% of these residential units there was less than 20 gallons of trash/week. Therefore, it would be advantageous to distribute by default a trash cart that correlates with current usage at 35 gallons or less per household unit. The very small number of less than 7% of residents who produce more than 35 gallons of waste/week can take advantage of the city's many waste reduction programs of recycling, composting, yard waste, textile collection and more; or request an additional trash bin. By simply requiring that all receptacles be closed, this would also accomplish all plausible rodent control goals of the new bins, without completely derailing the cities waste reduction goals.
There has been significant household waste reduction since 2019 due to increased awareness of environmental concerns and tremendous community participation in the many city programs that reduce waste. Aligning trash bin distribution size with the trash reductions already achieved would have overwhelming benefits for residents, the city, and the environment!
The 2019 Zero Waste Master Plan ZWMP approved by public process indicates a commitment to further waste reduction. Thirty-five gallon trash carts generously accommodate nearly all current usage, however, they do nothing to affirm the efforts in waste reduction achieved by over 60% of residents whose 32 gallon bins are less than half full. Offering a trash receptacle of around 15- 20 gallons that residents can request would go a long way in legitimizing waste reduction goals!
2022 Summary of City-Wide Trash Volume Survey Results:
(Comparison with the Current Default Distribution of Trash Carts)
Single Family Homes:
One 32 gal. trash cart covers 93% of residents' weekly trash.
65% of single family homes had less than 20 gal. of trash,
This warrants an electable barrel option of around 20 gal.
(The current default distribution: One 45 gal. bin)
Two Families Homes:
Two 35 gallon trash carts cover 93% of residents' usage, or
One 50 gallon bin covers over 81% of residents
52% of duplexes had less than 35 gal. of trash.
(The current default distribution: Two 45 gallon bins)
Three Family Homes:
Three 35 gallon bins cover 93% of residents' usage, or
Two 50 gallon bins would also cover over 93% of residents
67% of three family houses had less than two 35 gallon bins of trash (under 70 gallons)
(The current default distribution: Two 65 gallon bins)
New trash carts to be distributed by default are
More than two times the volume of average usage!
City-wide Trash Volume Data by Dwelling Type from 164 Buildings:
This Represents 348 Residential Units
Summary for 43 Single Family Houses:
Volume of Trash # of Single Family Houses
0 - 20 gallons: 28
65% Under 20 gallons: 28
20 - 32 gallons: 12
93% Under 32 gallons: 40
32 - 50 gallons: 3
100% Under 50 gallons: 43
Summary for 58 Duplexes: (Representing 116 Residential Units)
Volume of Trash # of Duplexes
0 - 20 gallons: 7
20 - 32 gallons: 23
52% Under 32 gallons: 30
32 - 50 gallons: 17
81% Under 50 gallons: 47
50 - 64 gallons: 2
64 - 70 gallons: 5
93% Under 70 gallons: 54
70 - 82 gallons: 3
82 - 100 gallons: 1
100% Under 100 gallons: 58
Summary for 63 Three Family Houses: (Representing 189 Residential Units)
Volume of Trash # of 3 Family Houses
0 - 32 gallons: 7
32 - 50 gallons: 22
50 - 64 gallons: 8
63 - 70 gallons: 5
67% Under 70 gallons: 42
70 - 82 gallons: 6
82 - 100 gallons: 11
93% Under 100 gallons: 59
100 - 150 gallons: 3
150 - 200 gallons: 1
100% Under 200 gallons: 63
Additional study notes, and historical reference
New carts to be distributed by default are over two times the volume of average usage!
This study did not have a city wide representative sample of 4 and 6 family homes, though many were observed and also were far below the default distribution of trash bins.
The 32 gallon trash cart is much more common than 35 gallons. Either size could be used with little effect on the above results. 32 gallons was used as a guide to estimate trash, but since the city chose 35 gallon bins, 35 gallons is used to estimate future bin distribution. Likewise, the 50 gallon and 45 gallon barrels are also close enough in volume to not make a substantial difference, however, the 50 gallon bin is recommended to accommodate greater trash volume, and to help eliminate the use of 65 gallon barrels.
Sixty-five gallon barrels are not recommended as they can be far too heavy when filled with trash. They could easily weigh 200-300lbs, and are difficult to maneuver. They are not permitted by city ordinances. They also break easily, and it will be terribly confusing if they are the same size and color as the recycle bins!
Three other informal trash surveys in March 2022 (two in the Fresh Pond neighborhood and one in the Central Square neighborhood) informed this city-wide survey process. These informal surveys of over 200 receptacles consistently corroborate the need for a substantial downsizing of the planned trash bin rollout to better suit the needs of well over 90% of Cambridge residents.
Historical Context:
The Zero Waste Master Plan's ZWMP 2019 trash volume study states that Cambridge families in 4 of the 5 trash collection zones produce an average of 20 gallons of trash / week / family dwelling unit. It also confirms that "In the order of 75% of all households audited set out less than 32 gallons of trash." Trash reduction since 2019 in the outlying Thursday collection zone has brought it within the normal range accommodated by current recommendations of this 2022 survey.
Three other informal trash surveys from March 2022 (two in the Fresh Pond neighborhood and one in the Central Square neighborhood) informed this 2022 city-wide survey process. These informal surveys of over 200 receptacles consistently corroborate the need for a substantial downsizing of the planned trash bin rollout to better suit the needs of well over 90% of Cambridge residents.
Survey process notes, and raw data to assess city-wide trash volume of 5 trash collection regions, Monday - Friday.
The trash volumes for 164 single families, duplexes and three family houses on random streets in 5 trash collection regions of Cambridge were surveyed, representing 348 residential units. This sample size appears to be statistically significant in comparison to the trash volume report in ZWMP 2019. The limited scope of assessing 1-3 family units allowed for more precise data with a smaller sample. Dwelling types were determined by the number of doorbells, house structure and the number of mailboxes. The residence type had to be reasonably defined and trash had to be associated with a particular type of residence for inclusion in this study so that trash volumes would be representative.
Volumes were assessed visually by comparing trash volume with standard size barrels. Since 35 and 50 gallon barrels were most common, they were chosen as standards. Visual estimates were made looking into all bins. All estimates were made with the understanding that trash bin lids will need to be closed. Derivative volumes are often from multiple receptacles added together; the best estimation of the total volume was recorded in increments. For instance, two 32 gallon bins would be 64 gallons, an upper estimate of 20 gallons in one bin plus a 50 gallon barrel full would be 70 gallons. Most volumes are overestimated since bins were assessed by the upper limit - i.e. a full 42 gallon barrel would be included as up to 50 gallons without differentiation. This should help ensure that in actual usage there should be additional room to close the trash bin lids. This also gives a buffer for normal fluctuations in usage.
The days chosen to collect data were intended to be representative of normal usage. Care was taken to avoid both public school and college spring breaks as well as not including any holiday, so the trash represents 7 days usage. Data collection occurred mid March and concluded April 15, 2022.
The Thursday trash collection area which showed higher/residential unit trash in the 2019 ZWMP are slightly over represented in this study to make sure this area is in a similar range now. The area was found to have slightly increased trash levels in most categories, but the area is currently easily accommodated within the 93%.
Data from 5 Cambridge trash collection zones; Monday- Friday:
Monday:
Single Family Homes:
Less than 20 gallons: 14
Less than 32 gallons: 6
Less than 50 gallons: 1
Duplexes:
Less than 32 gallons: 11
Less than 50 gallons: 6
Less than 70 gallons: 4
Three Family Homes:
Less than 50 gallons: 4
Less than 64 gallons: 2
Less than 82 gallons: 1
Less than 100 gallons: 1
Tuesday:
Single Family Homes:
Less than 20 gallons: 9
Less than 32 gallons: 3
Less than 50 gallons: 2
Duplexes:
Less than 20 gallons: 5
Less than 32 gallons: 5
Less than 50 gallons: 4
Less than 64 gallons: 2
Less than 82 gallons: 2
Less than 100 gallons: 1
Wednesday:
Single Family Homes:
Less than 20 gallons: 1
Duplexes:
Less than 20 gallons:1
Less than 32 gallons: 3
Less than 50 gallons: 6
Three Family Homes:
Less than 32 gallons: 2
Less than 50 gallons: 4
Less than 64 gallons: 1
Less than 82 gallons: 2
Less than 100 gallons: 2
Less than 200 gallons: 1
Thursday:
Single Family Homes:
Less than 20 gallons: 2
Less than 32 gallons: 3
Duplexes:
Less than 32 gallons: 1
Less than 50 gallons: 3
Less than 82 gallons: 1
Three Family Homes:
Less than 32 gallons: 3
Less than 50 gallons: 9
Less than 64 gallons: 3
Less than 70 gallons: 3
Less than 82 gallons: 2
Less than 100 gallons: 4
Less than 150 gallons: 2
Friday:
Single Family Homes:
Less than 20 gallons: 2
Duplexes:
Less than 20 gallons: 1
Less than 32 gallons: 3
Less than 40 gallons: 1
Less than 50 gallons: 3
Less than 70 gallons: 1
Three Family Homes:
Less than 32 gallons: 2
Less than 50 gallons: 5
Less than 64 gallons: 2
Less than 70 gallons: 2
Less than 82 gallons: 1
Less than 100 gallons: 4
Less than 150 gallons: 1