Global Warming Impact of Alachua County’s
Curbside Recycling Program
Jennifer N. Apell*, Kenneth R. Friedman, Richard N. Williams
Black Hall, University of Florida, Gainesville, FL 32611
J.apell@gmail.com
Abstract
Florida currently has a recycling initiative in place to reduce waste production. However,
there are concerns over the pollution caused by the curbside recycling program since it requires
more energy for collection, sorting, and transport to the final destination. To address this concern,
a life cycle analysis (LCA) was performed comparing the global warming potential (GWP) of both
recycling and landfilling the recyclables collected in Alachua County, Florida. Data acquired from
Alachua and the companies involved in waste management in the county were used to calculate
the emissions produced collecting recyclables separately and the additional emissions produced if
recyclables were collected as refuse.
In 2005, Alachua collected 18,732 tons of curbside recyclables, which produced
13,680,738 lb eq. of CO2 based on the current recycling scheme. The alternative plan of landfillng
was determined to generate 62,827,102 lb eq. of CO2. The primary difference between the two
systems was the landfill gas produced by the landfilled recyclables. Several sensitivity analyses
were conducted to illustrate the changes in global warming potential when parameters of the LCA
1
were changed.
Although some sensitivity analyses showed dramatic decreases the GWP of
landfilling, in no case did landfilling recyclables appear more favorable than recycling.
Keywords: Life cycle assessment (LCA); global warming potential (GWP); Alachua County,
Florida; curbside recycling; recycling; municipal solid waste (MSW)
1 Introduction
The United States currently recycles 32.5 percent of its waste, which is double the
recycling rate from 15 years ago. This can be attributed to a dramatic increase in the recycling of
certain materials: 52 percent of all paper, 31 percent of all plastic soft drink bottles, 45 percent of
all aluminum beer and soft drink cans, 63 percent of all steel packaging, and 67 percent of all
major appliances are now recycled. Along with an increased recycling rate, curbside collection
programs and materials recovery facilities have become more abundant in the United States over
the last 15 to 20 years. Over this time span, curbside collection has expanded from a single
program to over 8,660 programs, while over 500 materials recovery facilities have been
established to process the collected materials (USEPA Municipal Solid Waste Division).
Alachua County, Florida, is an example of a municipality which has recently adopted a
curbside collection program and established a materials recovery facility.
Alachua County
currently recycles 28.5 percent of the materials that are collected curbside, which is close to the
national average. The county’s curbside recyclables consist of six materials; glass, plastic bottles,
aluminum cans, steel cans, newspaper, and cardboard. Recyclables are collected from orange and
blue bins using separate trucks from general waste pickup. The orange bins are for newspaper,
magazines, telephone books, and corrugated cardboard. The blue bins are for plastic and glass
bottles and jars and metal cans. The recycled goods are then sent to a nearby materials recovery
facility for further processing (Alachua County Recycling).
2
Although the country’s recycling initiative has saved landfill space and natural resources
for making new materials; curbside collection, materials recovery, transportation and reprocessing
of recycled materials has resulted in significant greenhouse gas emissions. These greenhouse gas
emissions are of concern due to their global warming potential.
Based on several IPCC
(Intercontinental Panel on Climate Change) reports, there is clear evidence that human activities,
including activities associated with recycling, have affected the concentrations of these gases in the
atmosphere. For recycling activities, carbon dioxide, NOx, and methane are the major greenhouse
gases of concern since they are generated from the combustion of fossil fuels, which is used for
transportation and processing of recycled materials. Fossil fuel burning accounts for 77% of all
greenhouse gas emissions. Furthermore, transportation is the second leading source of CO2
emissions in the U.S (USEPA, 2007). These findings have prompted some cause for concern over
the emissions generated by recycling practices due to the quantity of transportation and processing
which takes place.
Although recycling generates significant emissions, the alternative of landfilling all
materials contributes emissions as well. Methane and carbon dioxide are the primary greenhouse
emissions generated at landfills. Landfills generate 34% of all human caused methane emissions,
more than any other activity (USEPA, 2007). In addition, materials in a landfill generate emissions
for the lifetime of their existence in the landfill, unlike most emission sources (Ecobalance, 1999).
Based on these recent recycling emission findings, Alachua County decided to perform a
life cycle assessment on its current recycling program, to evaluate the environmental impacts
associated with the program. This life cycle assessment considered emissions associated with
collection, processing, and transportation of the county’s recycled materials, and compared these
emissions to the alternative of placing all waste in the landfill. This study could be used by
3
Alachua County to re-evaluate the efficiency of their recycling program, and make necessary
adjustments to reduce emissions associated with the program.
2 Methods
In order to determine the emissions associated with collection and disposal, direct data
were obtained from a wide variety of sources. All information pertaining to recycling rates and the
operations of the transfer station were provided by Alachua County Waste Management. Data that
were used in calculating emissions associated with collection of materials was obtained from the
company Waste Management. Gainesville Regional Utility’s (GRU) billing information was used
to estimate electricity consumption. Finally, SP Recycling Corporation supplied the information
about the destination of the recyclables.
Secondary information provided useful landfill gas production data, coal and diesel
combustion emissions, and distances to re-processing facilities. Using these data, the greenhouse
gas emissions from the management of one year of recyclables was able to be calculated.
2.1 Goal and scoping
The primary goal of this LCA was to determine the global warming impact from the
emissions associated with the collection and disposal of Alachua County’s recyclables whether the
materials are recycled or landfilled. The ultimate objective was to quantify the greenhouse gases
released from recycling and landfilling the materials that were recycled in the county in 2005.
The scope of the analysis was from the point of collection (i.e., a residence) to the point of
disposal. For recycling, this includes curbside collection, MRF sorting, and shipment to the
recycling facility. For landfilling, this includes curbside collection, transfer station processing,
4
shipment to the landfill, and gases produced from material degradation in the landfill. Level II
diagrams for these processes can be seen in Figure 1 and 2.
Figure 1. Level II diagram of landfilling materials and relevant emissions from each process.
Figure 2. Level II diagram of recycling materials and relevant emissions from each process
2.1.1 Functional unit
The functional unit chosen was the amount of each material recycled in 2005. The values
used were provided by the Alachua County Waste Management division and are the values that are
5
required to be reported to the Florida Department of Environmental Protection (FDEP). Since a
different amount was recycled for each material, the weight used in the impact analysis varies.
The values are presented in Table 1.
Table 1. Tons of different materials collected as recyclables in Alachua County.
Material
#1 Plastic
#2 Plastic
Aluminum
Cardboard
Glass
Newsprint
Steel Cans
Amount Collected
503
445
259
8,787.0
3,264.0
5130
344
tons
tons
tons
tons
tons
tons
tons
2.2 Assumptions
The first assumption made was that the distance between the transfer station and the
materials recovery was negligible relative to the other transportation distances since the MRF and
the transfer station are located on the same property. Therefore, the emissions from this were also
negligible.
Also, collection trucks were assumed to be at full capacity when the route is
completed. This was necessary to calculate emissions due to collecting recyclables as trash.
In addition, all of the landfill gas generated from recyclables was assumed to be emitted
directly into the atmosphere to create a worst-case scenario. However, a portion of the gas is
flared at the landfill, which would reduce the landfill gas emitted to the atmosphere.
Gas
emissions over a 100-year period of time served as the basis for the emission calculation.
However, waste in a landfill would produce gas for a longer period of time, which would increase
emissions. The 100-year values were used to serve as a reference value.
3 Data inventory
6
3.1 Recycling data
Recycling rate data was provided by the Alachua County Waste Management division and
contained the total amount of collected tons and recycled tons for each recyclable material for the
year 2005 (Supporting Information Table S1).
This information was used in calculating
transportation and collection emissions of the recyclables, and the recyclables contribution to
overall landfill emissions.
3.2 Collection
MSW routes are complex, but are created to collect MSW in the most efficient way
possible. Since analysis of collection routes is beyond the scope of this project, a more simplistic
approach was taken. On average, the vehicles that collect refuse use 50 gallons of diesel per day.
Using known information about the amount of refuse collected in 2005 and the number of vehicles
in use, an average of 255 tons collected per week per vehicle was calculated. The weight of
recyclables collected per year was changed to a weekly basis and divided by the weekly capacity
of a refuse truck (255 tons), which can be seen in Equations 1 & 2. An additional 1.41 refuse
vehicles would be needed to collect the additional weight. Although it is not possible to have a
fractional number of vehicles, it is assumed that the additional amount of diesel used would be
1.41 vehicles worth (Supporting Information Table S2).
(1)
TDC = Total diesel consumed (gal/yr)
DPT = Diesel used per recycle vehicle (gal/vehicle/week)
N = Number of recycle vehicles used
7
tons


360

 
gal
days 
weeks
gallons
week
   50
  52
TDC  
5
 18,369

tons
week 
year
year

  vehicle  day
 255

week  vehicle 

(2)
Akin to the refuse vehicles, the recyclable collection vehicles also use an average of 50
gallons per day. With the known information that 11 vehicles are used every business day (5 days
a week), the yearly gas consumption rate per vehicle was calculated and then multiplied the
number of vehicles employed as shown in Equation 3 (Supporting Information Table S3)

gal
days 
weeks
gallons
  52
TDC  11vehicles   50
5
 143,000
week 
year
year
 vehicle  day
(3)
3.3 Transfer station processing and shipment to landfill
In order to determine the impacts from transporting Alachua County’s waste from the
transfer station to the landfill, several pieces of information were provided by the county
(Supporting Information Table S4). The total diesel consumed from transportation was calculated
using this information and Equation 4.
GRU billing data supplied the energy usage of the transfer station (from April 2006 to
March 2007). The energy usage was normalized to be 1.32 kWh/ton waste. Since 18,732 tons of
curbside recyclables were generated in 2005, the total additional electricity usage for the transfer
station was calculated to be 24,765.62 kWh/yr.
(4)
Where
TDC = Total diesel consumed for transfer of waste to landfill (gal/yr)
8
SPY = Shipments per year (shipments/yr)
D = Distance to landfill (miles/way)
GM = Gas mileage of vehicle (mpg)
3.4 Materials recovery facility sorting and transport
Data were gathered from the MRF to determine the impacts from sorting the recyclables
and transportation to re-processing facilities. Yearly electricity consumption (from April 2006 to
March 2007) was provided by Gainesville Regional Utilities billing. Although this data is not
from 2005, it is believed to be a very good estimate.
In addition, SP Recycling Corp. (Atlanta, GA) provided the final destination of each
recycled material. SP Recycling Corp. is in charge of the Alachua County MRF and the transport
of the recyclables to the processing facilities is contracted out to Trucks Inc. The number of
shipments made to each re-processing facility per year was calculated based on shipment weights.
The shipment weight for plastic and aluminum was based on the trucks volume capacity, while the
rest of the materials’ shipment weights were restricted by road weight limits.
Distances to each facility were estimated using Google Earth with the starting point being
the Alachua County MRF, located at 5121 NE 63rd Ave., Gainesville, FL 32609 (Supporting
Information Table S5).
This information was used to calculate the total gallons of diesel
consumed to ship the recyclables by means of Equation 4 (Supporting Information Table S6).
3.5 Combustion emissions
Emission data for the combustion of diesel fuel and bituminous coal were located in the
U.S. Life-Cycle Inventory (LCI) Database, found online at www.nrel.gov/lci/database. The diesel
9
emissions were taken from the Transportation Data Module and are for diesel fueled combination
truck transportation (Supporting Information Table S7). Combination trucks are those that are
greater than 14,000 pounds in gross weight as defined by the U.S. LCI Database Project.
Bituminous coal emissions for utility boilers were located in the Primary Fuel Combustion Data
Module (Supporting Information Table S8).
3.6 Emissions
3.6.1 Landfill emissions
Landfill emission data were needed to determine each of the recyclables’ contribution to
landfill emissions. This information will provide landfill emissions for the hypothetical scenario
where Alachua County does not recycle. In order to allocate the appropriate portion of landfill
greenhouse gas emissions, three pieces of information were needed: gas emissions from a landfill,
the fraction of total waste each material would represent in the landfill, and what percent of the
total emissions each material would generate. Studies previously conducted on other landfills
(Ecobalance, 2007) were used as the source of this information.
Their findings were then
summarized to represent an average landfill (Supporting Information Tables S9 and S10). These
applicable data were presented in Table 2.
For this analysis, the gasses of interest were methane (CH4), carbon dioxide (CO2), and
nitrogen oxides (NOx). NOx is not generated by landfill waste, and therefore was excluded from
this section of the analysis. Of the recyclables of interest, only the cardboard and newsprint
contribute to the landfill gas yield, and therefore were the only materials considered in the
emission calculations. The recycling data combined with the landfill gas production and waste
component data were used to calculate the CH4 and CO2 emissions from putting the cardboard and
10
newsprint generated in a landfill. The calculations of these emissions were done using Equation 5,
and the results are displayed in Table 2. It should be noted that the densities of CH4 and CO2 at
standard temperature and pressure (STP) were used in the calculation in order to convert to the
proper units.
(5)
Where
DPi,j = Diesel production for material I for gas j (lb gas/yr)
DPt,j = 100 years diesel production for gas j (ft3/ton waste)
DPi = Gas production attributed to material i (%)
ρj = Density of gas j (lb/ft3)
WFi = Waste fraction for material i (ton i/ton waste)
Ri = Amount recycled for material i (ton material)
Table 2. Landfill Emissions from Recyclables
Potential Gas Generated From Landfilled Recyclables
3
Total Gas Production (ft /ton waste)
3
Gas Density (lb/ft )
Gas Production Allocation (%)
Fraction of Waste (ton material/ton waste)
Gas Generation Potential (lb/year)
Methane
2,692
Carbon Dioxide
2,202
0.0441
0.115
Newsprint
4.5
0.052
527,036
Cardboard
25.0
0.139
1,876,202
Newsprint
4.5
0.052
1,124,195
Cardboard
25.0
0.139
4,002,036
3.6.2 Electricity and diesel emissions
11
Based upon the transfer, collection, and coal and diesel data previously presented, the
emissions from the collection and transfer of the recyclables were calculated. The emissions from
each process were calculated separately, and then summed together.
All vehicles used in the transport of materials ran on low-sulfur diesel. Therefore, emission
data for this diesel was applied to all fuel consumed. It was assumed the electricity used by the
transfer station and MRF was generated through coal combustion since GRU produces the vast
majority of its power in this manner.
The procedure for calculating the emissions are the same for all four processes.
To
calculate the diesel emissions, the amount of diesel fuel used for each process as determined
previously was multiplied by the appropriate emission factor (see Equation 6).
The diesel
emissions were calculated separately for each pollutant and can be seen in Table 3.
(6)
Where
DEi,j = Diesel emissions for pollutant I and process j (lb pollutant/yr)
DUi = Diesel usage for process j (gal/yr)
EFi = Emission factor for pollutant I (lb pollutant/gal diesel
12
Table 3. Emissions from diesel used in collecting and transporting materials.
Diesel Emissions
Diesel Used
(gal/yr)
CO2 Emitted
(lb/yr)
CH4 Emitted
(lb/yr)
NOx Emitted
(lb/yr)
18,369
143,000
14,528
40,004
215,901
449,779
3,501,405
355,722
979,512
5,286,419
7
56
6
16
85
2,997
23,333
2,370
6,527
35,228
Trash Collection
Recyclables Collection
Trash Transfer
Recyclables Transfer
Total
To calculate the coal emissions for the two transfer processes, the previously determined
electricity usages for the two processes were converted to pounds of coal used per year using the
heating value of Bituminous Coal (GRU, 2005). This value was then multiplied by the appropriate
emission factor (see Equation 7). The coal emissions were calculated separately for each pollutant
and can be seen in Table 4.
(7)
Where
CEi,j = Coal emissions for pollutant i and process j (lb pollutant/yr)
CUj = Coal usage for process j (lb/yr)
EFi = Emission factor for pollutant I (lb pollutant/lb diesel)
HVB = Heating value for bituminous coal (kWh/lb)
Table 4. Emissions from coal combustion due to electricity consumed by facilities.
Coal Emissions
Trash Transfer
Recyclables Transfer
Total
Electricity Used
(kWh/yr)
Coal Used
(lb/yr)
CO2 Emitted
(lb/yr)
CH4 Emitted
(lb/yr)
NOx Emitted
(lb/yr)
24,766
280,380
305,146
7,931
89,788
97,719
17,377
196,727
214,103
0.15
1.71
1.86
49
550
599
13
Finally, the total emissions for each pollutant were determined by summing up the
emissions for a given pollutant for each process and fuel type (See equation 8). These total
emission values were then used to analyze the global warming impact of recycling and landfilling.
(8)
Where
CEj = Coal emissions from process j (lb pollutant/yr)
DEj = Diesel emissions from process j (lb pollutant/yr)
TE,i = Total emissions for pollutant I (lb pollutant/yr)
4. Impact analysis
For this life cycle analysis, the goal was to quantify the global warming potential (GWP)
for the two options. Using the values from the TRACI database in Table 5 and the total emissions
from each process in Table 6, the GWP was calculated for both landfilling the recyclables and
recycling them. The calculations can be seen in Equation 9 and Equation 10 and are represented
graphically in Figure 3.
14
Table 5. Global warming potentials of applicable gasses.
GWP (lb CO2 eq./lb X)
Carbon Dioxide
Methane
Nitrous Oxide
1
23
296
Table 6. Total emissions from both landfilling and recycling the materials recycled in Alachua County in 2005.
Total Emissions
Landfilling Recyclables
CO2 Emitted:
5,949,110 lb/year
CH4 Emitted:
2,403,251 lb/year
NOx Emitted:
5,416 lb/year
Global Warming: 62,827,102 lb. eq. of CO2
Recycling Recyclables
CO2 Emitted:
4,677,644 lb/year
CH4 Emitted:
73.98 lb/year
NOx Emitted:
30,410 lb/year
Global Warming: 13,680,738 lb. eq. of CO2
lb
lb.eq.CO2
lb
lb.eq.CO2
1
 2,403,251
 23
year
lb
year
lb
lb
lb.eq.CO2
 5,416
 296
 62,827,102lb.eq.CO2
year
lb
(9)
lb
lb.eq.CO2
lb
lb.eq.CO2
1
 73.98
 23
year
lb
year
lb
lb
lb.eq.CO2
 30,140
 296
 13,680,738lb.eq.CO2
year
lb
(10)
GWPlandfill  5,949,110
GWPrecycle  4,677,644
15
Global Warming Potentials (lb CO2 eq.)
13,680,738;
18%
Landfilling
Recycling
62,827,102;
82%
Figure 3. Comparison of GWPs of recycling and landfilling the recyclables collected in Alachua County in 2005.
4.1 Sensitivity analysis
A sensitivity analysis must be performed to assure that assumptions will not change our
conclusions.
4.1.1 Flaring landfill gases
Flaring of landfill gases is a common practice in the United States. When the methane in
landfill gases is ignited, it utilizes oxygen in the atmosphere to produce carbon dioxide and water
as shown below in Equation 11. The possibility of NOx formation is considered to be zero in this
analysis. Since carbon dioxide is a global warming gas, the amount produced from the combustion
of methane needs to be quantified.
CH 4  2O2  CO2  2H 2O
(11)
16
1lbCH 4 
lbmolCH 4 lbmolCO2
44lb


 2.75lbCO2
16lb
lbmolCH 4 lbmolCO2
(12)
One pound of methane creates 2.75 pounds of carbon dioxide when combusted. Even
though nearly three times as much carbon dioxide was formed from flaring the methane, the global
warming potential decreased due to carbon dioxide being 23 times less potent of a greenhouse gas.
The global warming impact of landfilling the recyclables was reduced dramatically, but it still
remains higher than the recycling option (Supporting Information Table S11 and Figure S1).
4.1.2. Closer recycling facilities
Another alternative considered was the possibility of recycling facilities being located
closer to the Alachua County MRF. A distance of 40 miles away was chosen because it is
comparable to the 36 mile distance to the New River landfill. The change will only affect the
amount of diesel used in transporting recyclables from the MRF (Supporting Information Table 12
and Figure S2).
By changing the transport distance to the recovery facilities, the global warming potential
was reduced by 15.3% as seen in Equation 12.
GWP 
13,680,738  11,581,132
 100  15.3%
13,680,738
(13)
4.1.3. Shorter landfill emission time period
Quantifying landfill emissions will differ depending on the length of time considered. For
the original analysis, a 100 year period was used. Since landfill emissions are a major contributor
17
to the global warming potential, the data was recalculated using a 20 year period instead
(Supporting Information Table S13 and Figure S3).
4.1.4 Operating at maximum recycling potential
Currently, about 28.5% of the curbside recyclables disposed of in Alachua County is sent
to a re-processing facility. If all possible materials were recycled, the emissions and global
warming potential would change dramatically (Supporting Information Table S14 and Figure S4).
4.1.5 Graphical summary of sensitivity analyses
Graphs are presented that summarize the results from the four sensitivity analyses in Figure
4.
5 Conclusion and recommendations
5.1 Conclusion
Based on the emissions and global warming impact determined in this life-cycle analysis,
recyclables that are landfilled contribute the most emissions by far with approximately 5.1 billion
and 2.4 billion pounds of methane and carbon dioxode, repectively. This can be attributed to the
long time the recyclables spend in the landfill. It is interesting to note that although the landfilled
recyclables have the most emissions, these emissions are attributed to the degradation of paper
products only. Glass, plastic, and metal recyclables have little or no impact on emissions once
they are disposed of in the landfill. Some landfills reduce the methane produced by flaring the gas,
which greatly reduces the global warming potential from approximately 63 billion to
approximately 14 billion by converting the methane to less harmful carbon dioxide. However, the
GWP for landfilling is still worse than that of recycling, so it is concluded that recycling
constributes less to global warming than lanfilling based on the scope of this LCA.
18
Figure 4. Summary of sensitivity analyses results.
19
5.2 Recommendations
In the course of constructing this life-cycle analysis, ideas for future life-cycle analysis
topics and proposals for the reduction of the global warming potentials for landfilling and
recycling were identified. A potential follow-up LCA is the analysis of the emissions from
creating products from virgin material versus recycled materials to determine if recycled products
are more environmentally and economically feasible.
Some ideas for the reduction of GWPs are: locating markets closer to Alachua County to
reduce the emission from transport; the use of alternative fuels, such as hydrogen or biodiesel, that
might help reduce or eliminate the emissions associated with the transportation and collection of
the recyclables; considering the possibility of harnessing the methane produced by landfilled
recyclables as a fuel source for electricity or heat production; and finally the promotion of waste
reduction as an alternative to recycling to decrease the amount of recyclables to be collected,
sorted, and transported.
Literature cited
Alachua County Recycling. http://www.alachuacounty.us/government/depts/pw/waste/recycling
(accessed Dec 6, 2007).
Ecobalance. Life Cycle Inventory of a Modern Municipal Solid Waste Landfill. Ecobalance Inc.,
Bethesda, MD, June 1999.
GRU. 2005 Ten-Year Site Plan. Gainesville Regional Utilities, Gainesville, FL., April 2005.
USEPA. Greenhouse Gas Emissions and Sinks: 1990-2005, EPA Headquarters, Washington, D.C.,
2007; Chapters 1 & 2.
USEPA Municipal Solid Waste Division. http://www.epa.gov/msw/recycle.htm#Figures (accessed
Dec 6, 2007).
U.S. Life-Cycle Inventory Database. http://www.nrel.gov/lci/database (accessed November 26th,
2007).
20
Global Warming Impact of Alachua County’s
Curbside Recycling Program
Jennifer N. Apell, Kenneth R. Friedman, Richard N. Williams
Black Hall, University of Florida
Gainesville, Fl 32611
Supporting Information: Pages: 10, Tables: 13, Figures: 4
S1
TABLE S1. Alachua County Recycling Data.
Municipal Solid Waste Collection And Recycling
Alachua County (Population: 240,764)
Materials Type
Glass
Aluminum Cans
Plastic Bottles
Steel Cans
Corrugated Paper
Newspaper
Total
Collected Percent
Pounds per
Recycled Percent
Tons
Total Tons Capita per Day
Tons
Recycled
6,590
10
0.15
3,264
50
1,883
3
0.04
259
14
4,236
6
0.10
948
22
3,060
5
0.07
344
11
37,656
57
0.86
8,787
23
12,474
19
0.28
5,130
41
65,899
100
18,732
28.4
TABLE S2. Data for Collection as Refuse.
Collection As Refuse
Given Data
Diesel Consumption:
Recyclables Collected:
Refuse Collected:
Number of Refuse Vehicles:
Weight Percent of Total Refuse:
Calculated Data
Recyclables Collected:
Refuse Collected Per Week Per Vehicle:
Diesel Consumption:
Additional Diesel Consumed:
50
18,732
159,080
12
11.78%
360
255
250
18,369
gal/vehicle/day
tons/year
tons/year
vehicles
tons/week
tons/week /vehicle
gal/vehicle/week
gal/year
S2
TABLE S3. Data for Collection as Recyclables.
Collection As Recyclable
Given Data
Diesel Consumption:
Recyclables Collected:
Number of Recyclable Vehicles:
Calculated Data
Diesel Consumption:
Diesel Consumed:
50 gal/vehicle/day
18,732 tons/year
11 vehicles
250 gal/vehicle/week
143,000 gal/year
TABLE S4. Diesel Consumption of Landfill Shipments.
Landfilling Data
Given Data
Distance to Landfill:
Gas Mileage of Vechiles:
Tons per Shipment:
Calculated Data
Shipments per Year:
Total Diesel Used:
36 miles/way
4.5 mpg
20.63 tons/truck
908
14,528 gal/year
TABLE S5. Alachua County Recycling Data.
Recyclable
Location
#1 Plastic
Summerville, GA
#2 Plastic
Troy, AL
Aluminum Cans
Greensboro, GA
Cardboard
Jacksonville, FL
Glass
Jacksonville, FL
Newspaper/Magazines
Dublin, GA
Steel Cans
Fairfield, AL
Distance
423 miles
312miles
320 miles
65 miles
65 miles
320 miles
488 miles
S3
TABLE S6. Diesel Consumption of Transporting Recyclables.
Diesel Used for Shipping Recyclables to Re-Processing Facilities
Aluminum
#1 Plastics
#2 Plastics
Steel Cans
Glass
Cardboard
Newspaper
Totals
Shipments
Per Year
21
34
20
15
142
382
223
-
Distance to Facility
(miles/way)
320
423
312
488
65
65
230
-
Gas Mileage of Total Diesel
truck (mpg)
Used (gal/yr)
6
2,240
6
4,794
6
2,080
6
2,440
6
3,077
6
8,277
6
17,097
40,004
TABLE S7. Emissions From Diesel Fuel Consumption (US Life-Cycle Database)
Pollutant of Interest Emission (lb/gal)
CO2
CH4
NOX
24.5
0.0004
0.16
TABLE S8. Emissions From Coal Consumption (US Life-Cycle Database)
Pollutant of Interest Emission (lb/lb coal)
CO2
CH4
NOX
2.19
0.00019
0.00612
S4
TABLE S9. Waste Component Percent Contribution to Gas Yield. (Ecobalance, 1999)
Waste Component Percent Contribution to Gas Yield
Waste Component
Description
Avg Waste Composition
(wt. frac)
Yard Trimmings, Leaves
Yard Trimmings, Grass
Yard Trimmings, Branches
Old Newsprint
Old Corr. Cardboard
Office Paper
Coated Paper
Paper User
Paper Other
HDPE
PET
Plastic User
Plastic Other
Ferrous Cans
Ferrous Other
Aluminum Cans
Non Ferrous Other
Glass- Clear
Glass- Brown
Glass- Green
Glass- Other
Food Waste
Misc.
Total
0.041
0.068
0.027
0.052
0.139
0.033
0.012
0
0.161
0.006
0.003
0
0.08
0.013
0.042
0.008
0.006
0.032
0.014
0.008
0.006
0.064
0.185
1
Adjusted Gas Yield per
Tonne of waste (m3)
2.3
17
3.2
7.2
39
13
1.9
0
40
0
0
0
0
0
0
0
0
0
0
0
0
36
0
160
Percent of Total
Gas Yield (%)
1.5
11
2
4.5
25
8.3
1.2
0
25
0
0
0
0
0
0
0
0
0
0
0
0
22
0
100
S5
TABLE S10. Landfill Gas Production Over 100 Years. (Ecobalance, 1999)
Landfill Gas Production Over 100 Years
Component
Methane
Carbon Dioxide
Benzene
Chloroform
Carbon Tetrachloride
Ethylene Dichloride
Methylene Chloride
Trichloroethene
Perchloroethene
Vinyl Chloride
Toluene
Xylenes
Ethylbenzene
Total
3
Gas Production (ft /ton)
2,692
2,202
0.009
9.30E-05
2.00E-05
0.002
0.07
0.014
0.018
0.036
0.19
0.059
0.023
4,894
TABLE S11. Emissions and GWP with Flaring.
Total Emissions
Landfilling Recyclables
CO2 Emitted:
12,558,012 lb/year
CH4 Emitted:
13.14 lb/year
NOx Emitted:
5,416 lb/year
Global Warming: 14,161,545 lb. eq. of CO2
Recycling Recyclables
CO2 Emitted:
4,677,644 lb/year
CH4 Emitted:
73.98 lb/year
NOx Emitted:
30,410 lb/year
Global Warming: 13,680,738 lb. eq. of CO2
Landfilling Recyclables
CO 2 Emitted:
12,558,012 lb/year
CH 4 Emitted:
13.14 lb/year
NO x Emitted:
5,416 lb/year
Global Warming: 14,161,545 lb. eq. of CO 2
Recycling Recyclables
CO 2 Emitted:
4,677,644 lb/year
CH 4 Emitted:
73.98 lb/year
NO x Emitted:
30,410 lb/year
Global Warming: 13,680,738 lb. eq. of CO 2
S6
TABLE S12. Emissions and GWP with Closer Re-Processing Facilities.
Total Emissions
Landfilling Recyclables
CO2 Emitted:
5,949,110 lb/year
CH4 Emitted:
2,403,251 lb/year
NOx Emitted:
5,416 lb/year
Global Warming: 62,827,102 lb. eq. of CO2
Recycling Recyclables
CO2 Emitted:
3,971,388 lb/year
CH4 Emitted:
62.59 lb/year
NOx Emitted:
25,704 lb/year
Global Warming: 11,581,132 lb. eq. of CO2
TABLE S13. Emissions and GWP Using Shorter Landfill Time Period.
Total Emissions
Landfilling Recyclables
CO2 Emitted:
3,085,683 lb/year
CH4 Emitted:
1,060,580 lb/year
NOx Emitted:
5,416 lb/year
Global Warming: 29,082,254 lb. eq. of CO2
Recycling Recyclables
CO2 Emitted:
4,677,644 lb/year
CH4 Emitted:
73.98 lb/year
NOx Emitted:
30,410 lb/year
Global Warming: 13,680,738 lb. eq. of CO2
S7
TABLE S14. Emissions and GWP if Operating at Maximum Recycling Potential.
Total Emissions
Landfilling Recyclables
CO2 Emitted:
22,787,092 lb/year
CH4 Emitted:
9,321,890 lb/year
NOx Emitted:
19,110 lb/year
Global Warming: 242,847,009 lb. eq. of CO2
Recycling Recyclables
CO2 Emitted:
16,198,563 lb/year
CH4 Emitted:
256.11 lb/year
NOx Emitted:
105,270 lb/year
Global Warming: 47,364,258 lb. eq. of CO2
Global Warming Potentials (lb CO2 eq./lb X)
Flaring Landfill Gases
13,680,738;
49%
Landfilling
Recycling
14,161,545;
51%
Figure S1. Global Warming Potentials Flaring Landfill Gases.
S8
Global Warming Potentials (lb CO 2 eq./lb X)
Closer Re-processing Facilities
11,581,132;
16%
Landfilling
Recycling
62,827,102;
84%
Figure S2. Global Warming Potentials From Closer Re-processing Facilities.
Global Warming Potentials (lb CO2 eq./lb X)
20 Year Landfill Emissions
13,680,738;
32%
Landfilling
Recycling
29,082,254;
68%
Figure S3. Global Warming Potentials From 20-year Landfill Emissions.
S9
Global Warming Potentials (lb CO 2 eq./lb X)
Recycling at Maximum Capability
47,364,258;
16%
Landfilling
Recycling
243,160,278;
84%
Figure S4. Global Warming Potentials From Recycling at Maximum Capability.
S10