Life Cycle Analysis: Store­Bought Milk vs. Home­Delivered Milk

Anne Cheng Caleb Chi Lauren Kean Shannon Miner

Environment 159 ­ Life Cycle Analysis Professor Deepak Rajagopal Spring 2016

Table of Contents

Executive Summary…………………………………………………………………………2 ​ Goals and Scope……………………………………………………………………………..3 ​ Literature Overview…………………………………………………………………………3 ​ Methodology………………………………………………………………………………...4 Functional Unit………………………………………………………………………….4 ​ System Boundary and Flow Diagrams………………………………………………….4 ​ Container Manufacturing………………………………………………………………..5 ​ Transportation…………………………………………………………………………...5 ​ Disposal……………………………………………………………………...……….…6 ​ Results……………………………………………………………………………….……....7 ​ Life Cycle Inventory Analysis…………………………………………………………..7 ​ Life Cycle Impact Analysis……………………………………………………………...8 ​ Cost Effectiveness……………………………………………………………………….11 ​ Sensitivity Analysis………………………………………………………………………….11 ​ Conclusion……………………………………………………………………………….…..14 ​ Limitations……………………………………………………………………………….14 ​ References……………………………………………………………………………….…..15 ​ Contributions………………………………………………………………………………...17 ​ Appendix……………………………………………...……………………………….…….18 ​

1 Executive Summary Milk boxes and milkmen seem out of place in today’s society, especially when it is so convenient to stop by the local grocery store or gas station to pick up a gallon of milk. Nonetheless, in some places, including some urban areas, home­delivered milk is making a comeback. This report uses a combination of data from various existing life cycle studies on different aspects of the dairy and container industries, and Carnegie Mellon University’s EIOLCA tool to compare the cost and lifecycle environmental impacts, in terms of greenhouse gas emissions, nitrogen oxide (NOx) emissions, and end­of­life solid waste, of store­bought milk, ​ ​ typically sold in high­density polyethylene (HDPE) jugs, and home­delivered milk, typically bottled in reusable glass containers. The life cycles considered begin with container manufacturing and end with container disposal, excluding impacts from container transport after manufacturing and milk packaging in order to focus on impact differences resulting from container type and transportation. The unit of analysis used is the amount of milk consumed by the average American family in a week, which, based on literature cited, is one gallon. In the base case scenario, one week of milk consumption with all empty containers sent to the landfill, manufacturing of glass containers for home milk deliveries had a greater impact in terms of both GHG and NOx emissions. However, this was countered by transportation impacts, ​ ​ for which the home­delivery milk had significantly lower emissions than the store­bought milk due to differences in distance traveled. In the disposal category, transporting glass to the landfill resulted in greater GHG emissions due to weight, but glass, when crushed, takes up much less volume in the landfill. Overall, home­delivered milk is the more environmentally­friendly, but pricier option. To reflect this variability in some of the assumptions made for the base case scenario, sensitivity analyses on the effects of glass container reuse, transportation distance, and amount of milk carried per truck were also performed. As the number of glass bottle reuses increases, the environmental benefits of home­delivered milk also increases, as does the cost­effectiveness. As transportation distance of store­bought milk increases, home­delivered milk becomes even more preferable. On the other hand, larger brands tend to ship milk over longer distances, but in larger trucks with much greater quantities of milk at once, decreasing the per gallon of milk emissions and tipping the scales back in favor of store­bought milk.

2 Goals and Scope The purpose of this analysis is to compare home­delivered milk (usually held in reusable glass containers) and store­bought milk (usually held in HDPE plastic jugs) in terms of monetary cost and environmental impacts as measured by greenhouse gas emissions, nitrogen oxide (NOx) ​ ​ emissions, and end­of­life solid waste, beginning with container manufacturing and ending with container disposal, with a focus on container manufacturing, milk transportation, and disposal. Container transportation after manufacturing, milk packaging, and milk storage will not be included in the analysis. In addition to the base case comparison, we will also analyze the sensitivity of data to variations in the number of glass bottle reuses, the distance from the farm to retail, and the amount of milk carried per truck.

Literature Overview In the past several decades, supermarkets and wholesale corporations have dominated the food market. Groceries have never been easier to purchase and with current forms of agriculture, produce has never been fresher and lasted longer. Among the groceries that families buy, milk is and has been a mainstay. But milk was not always an item bought at the store. In the mid­1900s, local dairy farms and creameries delivered milk to front doors as a home­delivery service on a regular basis. However, over the past half century, milk became easier and cheaper to buy, while embracing changes that extended its shelf life. In a 2010 study conducted by AdAge, milk was the fourth most­consumed beverage at 20.4 gallons per American per year behind carbonated soft­drinks at 44.7 gallons, bottled water at 28.3 gallons, and beer at 20.8 gallons per American per year (Polis, 2011). A survey from the Department of Agriculture on milk illustrates that in 1963, about 30 percent of consumers had milk delivered (Tahmincioglu, 2007). In twelve years, the percentage of home­deliveries dropped to less than 7 percent, and by 2005 the number dropped to a low 0.4 percent. However, the milkman seems to be returning in many parts of the United States. Patrick Borella, also known as the Bay Area Milkman, delivers milk in glass bottles to San Francisco, the East Bay and Peninsula (http://www.bayareamilkman.com). Surprisingly, he ​ ​ is not the only milkman in the United States. Many other states, including New York, Ohio, and North Carolina, also house companies that offer this service. Their purpose: to promote the purchase of fresh and locally acquired products while hoping to decrease the carbon footprint on the environment. In regards to the environmental impacts of the milk industry, production and transportation of milk containers will be reviewed to understand and determine which method ­­ store­bought or home­delivered ­­ is the most cost effective and environmentally friendly. Several life cycle assessments have been conducted on milk packaging systems and their production. A correlation between the conclusions of the literature explored was the idea that the one of the largest contributors to pollution lies in the weight of the container. Lightweighting, a term most closely tailored to the auto industry, is the manufacturing of an enhanced element without sacrificing improvements in material reduction, such as increased durability and versatility. This form of manufacturing has been adopted by corporations in beverage container production and has shown to be environmentally beneficial, since “lower container weight means

3 fewer emissions from both container production and shipping” (The Glass Packaging Institute, 2010). However, despite an overall improved manufacturing method, different materials express different values and emit different amounts of greenhouse gases during production. Plastic from store­bought milk and glass from home­delivered milk, the main focus materials of this life cycle assessment, are the most common types of containers that milk is distributed in. The synthesizing of the substance and the mode of transportation vary, both of which will be evaluated to ascertain which container has the most minimal environmental impact.

Methodology

Functional Unit Our base case functional unit of comparison was one week of milk consumed by an average American family, which we estimated to be one gallon based on existing data on average annual milk consumption in the United States and average family size (Polis, 2011). In order to reflect the reuse of glass bottles, we also compared greenhouse gas emissions, NOx releases, and ​ ​ end­of­life solid waste from two through eight weeks of milk consumption in our sensitivity analysis.

System Boundary and Flow Diagrams

Figure 1. Process Diagrams for Home­Delivered and Store­Bought Milk Highlighted cells are processes this study will look at in greater detail. Double­sided arrows indicate round trip transportation.

4

Each lifecycle begins with container manufacturing, which is followed by container transportation to processing and packaging plants, milk packaging, and transportation to retail stores and consumers. Each lifecycle ends with container disposal (Figure 1). We defined the beginning of container manufacturing as Stage 2 in the container manufacturing unit process as derived from Carnegie Mellon’s EIOLCA tool (Appendix). These processes consisted mainly of raw material procurement, processing, and transport. We defined end of container disposal as arrival at the landfill and post­processing at the recycling or incineration plant. Because our analysis was focused on the two main differences between home­delivered and store­bought milk, container type and milk transportation, it does not include impacts from container transportation and milk packaging. Additionally, we did not include impacts from round trip transportation from home to store, because those who receive home­delivered milk must still make the trip to the store for other groceries.

Container Manufacturing Using the prices of empty containers, we derived unit processes of container manufacturing from Carnegie Mellon University’s EIOLCA tool. The prices were $1.28 for two half­gallon glass bottles and $0.30 for one gallon HDPE jug, which we then scaled up by $1 million in order to obtain higher resolution data (Spitzley, Keoliean, & McDaniel 1997). For glass milk containers, we used the glass container manufacturing sector, and for HDPE milk jugs, we used the plastics bottle manufacturing sector. We analyzed data up to Stage 2 of the unit process, as anything further back yielded numbers too small to be displayed in the EIOLCA tool’s tables. For Stage 1, we included only those sectors that generated at least 6 metric tonnes of CO2 equivalent and eliminated sectors whose direct economic impacts were still too small to ​ ​ be displayed after scaling price up to $1 billion. For Stage 2, we included only those sectors that generated at least 1 metric tonne of CO2 equivalent, with the exception of truck transportation in ​ ​ plastics bottle manufacturing, because truck transportation is included in glass container manufacturing. For each stage, we recorded the total greenhouse gas emissions, total NO ​x releases, and economic activity, adjusted for our functional unit.

Transportation A key difference between store­bought milk and home­delivered milk is the distance the milk is transported. In this study we assume that store­bought milk is transported from the farm to a processing plant to the store, and finally to the home. We also assume that home­delivered milk is transported directly from the farm to the home. A similar case study was conducted in the Washington DC area which confirms these assumptions (King 2010). In calculating the carbon dioxide emission for each delivery system we used the fuel economy of 10 miles per gallon for the delivery trucks (King 2015). Store­bought milk travels an average of 320 miles (640 miles round trip) from the farm to the processing plant and to the store (Campbell 2016). The average distance from the home to the consumer’s primary local store is 7.58 miles round trip but because people would still drive to the store to get other groceries we will leave this part out of the total mileage calculation (Ver Ploeg 2015). Using the fuel economy stated above for the delivery truck we can calculate gallons used in transportation as 64 gallons of diesel fuel. Home­delivered milk travels an average of 175 5 miles (350 miles round trip) from the farm to the home (King 2010). With the fuel economy stated above we calculated total gallons of diesel used to be 35 gallons.Using this data we can calculate the total amount CO2 and NOx emissions for each kind of milk system which is stated ​ ​ ​ ​ with the results. The study conducted in Washington DC found that milk trucks delivering milk from the farm to the store deliver more gallons of milk per truck than the trucks delivering milk directly to the home (King 2010). Delivery trucks for store­bought milk used .067 gallons of fuel per gallon of milk while home­delivered milk used .164 gallons of fuel per gallon of milk (King 2010). We can use this data to calculate the total CO2 and NOx emissions per gallon of milk to get a better ​ ​ ​ ​ comparison of fuel efficiency of each kind of milk system which is stated as part of the results.

Disposal Evaluating the disposal of both container types, we separated the disposal category into the three different possible processes for both HDPE plastic gallon jugs and clear glass containers (2 half­gallon containers). These three processes were recycling, combustion/incineration, and landfill. For both recycling and landfill the emissions from the process itself were taken into account as well as the emissions from transportation for each process. For the process of the landfill, the emissions from transportation were the same amount in both HDPE and glass. In addition, no methane or emissions are released from the breakdown of HDPE or glass, so there were no recorded emissions from the landfill directly. The majority of the data was taken from the U.S. Environmental Protection Agency’s (EPA) LCA for both plastic and glass disposal. The emissions from each process were given in metric tons of carbon dioxide equivalents (MTCO2E) per short ton of material disposed. We converted both the emissions and the weight of the material into kilograms, and multiplied that by the weight of a single container in order to represent the amount of emissions for our functional unit of 1 gallon of milk per week. For HDPE plastic milk jugs the weight was .06 kg, and for clear glass containers the weight was .934 kg (Miller, 2004). For landfill disposal, we also factored into the evaluation the amount of space and weight that each product occupied. We used an open­loop model for recycling, meaning that we assumed not all recycled container material would be used to re­produce the same type of container. Some material might be diverted toward the manufacturing of other containers, or other uses entirely. Therefore, we calculated impacts based on whether containers were recycled, landfilled, or incinerated (not a combination thereof), and subtracted offsets from container manufacturing emissions if the containers were recycled. Offset amounts were taken from EPA studies on greenhouse gas reductions resulting from use of recycled material (23% for glass, 10% for HDPE) instead of 100% raw material (EPA Waste Reduction Model 2015)..

6 Results

Life Cycle Inventory Analysis

Home­Delivery Milk, Glass Container 2 Half­Gallon Bottles for 1 Week’s Delivery

Unit Process Materials Input or Input GHG NOx Releases Solid Waste Data ​ ​ Output* Quantity Emissions (kg) (cu. ft.) Source (kg CO ​2 equivalent)

Glass Power Generation & $0.057 .6470 .001200 N/A a Container Supply Manufacturin g

Oil & Gas Extraction $0.0005 .0710 .000131 N/A a

Coal Mining $0.009 .0530 .000123 N/A a

Alkalies & Chlorine $0.019 .0490 .000069 N/A a Manufacturing

Lime & Gypsum Product $0.008 .0346 .000053 N/A a Manufacturing

Truck Transportation $0.018 .0700 .000252 N/A a

Transportation Diesel 350mi. 1.360 .011542 N/A c, d (Delivery Round Trip) 35 gal.

Disposal If Landfill .0412 N/A .00844 b

Total 2.396 .0135 .00844

If Incineration .0515 N/A N/A b

Total .2.406 .0135 0

If Recycling .2574 N/A N/A b

Total 2.324 .0135 0 Table 1. LCI for Home­Delivered Milk *only displays Stage 1 sectors; see Appendix for detailed LCI tables and flow diagram Data Sources: a. EIOLCA Tool (U.S. 2002 Benchmark Model) b. U.S. EPA Life­Cycle Assessment and Emission Factor Results c. U.S. EPA Average In­Use Emissions from Heavy­Duty Trucks d. Comparing the Structure, Size, and Performance of Local and Mainstream Food by Robert P. King (2010) ​

7 Store­Bought Milk, HDPE Jug 1 Gallon Jug for 1 Week’s Consumption

Unit Process Materials Input or Input GHG NOx Releases Solid Waste Data ​ ​ Output* Quantit Emissions (kg) (cu. ft.) Source y (kg CO ​2 equivalent)

Plastics Bottle Power Generation & $0.011 .1580 .000294 N/A a Manufacturin Supply g

Other Basic Organic $0.018 .0473 .000112 N/A a Chemical Manufacturing

Plastics Material & Resin $0.057 .0454 .000042 N/A a Manufacturing

Petrochemical $0.015 .0325 .000015 N/A a Manufacturing

Oil & Gas Extraction $0.00003 .0285 .000052 N/A a

Petroleum Refineries $0.0005 .0197 .000018 N/A a

Truck Transportation $0.0026 .0063 .000055 N/A a

Transportatio Diesel 640 mi. 3.329 .0283 N/A c, d n (Transportation & 64 gal. Distribution)

Disposal If Landfill .0027 N/A .0692 b

Total 3.810 .0291 .0692

If Incineration .1845 N/A N/A b

Total 3.991 .0291 0

If Recycling .0093 N/A N/A b

Total 3.725 .0291 0

Table 2. LCI for Store­Bought Milk *only displays Stage 1 sectors; see Appendix for detailed LCI tables and flow diagram Data Sources: a. EIOLCA Tool (U.S. 2002 Benchmark Model) b. U.S. EPA Life­Cycle Assessment and Emission Factor Results c. U.S. EPA Emission Facts d. Comparing the Structure, Size, and Performance of Local and Mainstream Food by Robert P. King (2010) ​

Without taking reuse into account, the manufacturing process for glass bottles used in home­deliveries have a greater impact than the HDPE jugs that store­bought milk comes in­­over twice the amount of GHG emissions and NOx releases. However, the scales are firmly tipped the ​ ​ 8 opposite way when transportation is added into the equation. The larger distance that store­bought milk travels because of the extra stop it must make at a processing and packaging plant brings transportation impacts of store­bought milk to nearly three times the amount of

GHG emissions and over two times the amount of NOx releases for home­delivered milk. ​ ​ Transportation is by far the area of highest impacts, and thus also the area with the most potential for improvement.

For store­bought milk, a total of 22.38 pounds (10.15 kilograms) of CO2 is emitted per ​ ​ gallon of diesel (EIA 2016). This gives a total of 649.6 kg CO2 emitted per week and 2598.4 kg ​ ​ CO2 emitted per month. For home­delivered milk, we calculated total CO2 emissions to be 355.3 ​ ​ ​ ​ kg CO2 per week and 1421 kg CO2 per month. For store­bought milk, we calculated NOx ​ ​ ​ ​ ​ emissions to be 5.51kg per week. For home­delivered milk we calculated NOx emissions to be ​ ​ 3.01 kg per week. In terms of efficiency, store­bought milk releases .680 kg CO2 per gallon of ​ ​ milk and home­delivered milk releases 1.66 kg CO2 per gallon of milk. Transportation of ​ ​ store­bought milk emits .012 kg of NOx per gallon of milk and transportation of home­delivered ​ ​ milk emits .o28 kg NOx per gallon of milk. So while transportation of store­bought milk emits ​ ​ more CO2 and NOx total, it more efficiently delivers the milk to it’s final destination. ​ ​ ​ ​ For disposal, recycling is the best course of action (after reuse), incineration the worst. If the containers are sent to the landfill, glass containers generate more transportation emissions because of their significantly greater weight, but HDPE jugs take up more space when flattened than glass bottles do when crushed.

Life Cycle Impact Analysis

Lifetime GHG Lifetime NO Solid Solid ​x Emissions Releases Waste Waste

(kg CO2 equivalent) (kg NO2 equivalent) (kg) (cu. ft.) ​ ​ ​ ​ Home­Delivery 2.396 .0135 .3386 .00844 (1 Week)

Store­Bought 3.810 .0291 .0692 .0692 (1 Week) Table 3. Life Cycle Impacts

9

Figure 2. Lifecycle Impacts

For calculating lifetime emissions, we only took into account landfill emissions and data in order to create a more comparable analysis. The lifetime greenhouse gas emissions for store­bought milk are significantly higher than the lifetime emissions of home­delivered milk. Lifetime nitrogen oxide releases are only slightly higher for store­bought milk. Additionally, the amount of solid waste volume was higher for store­bought milk, however the solid waste weight in landfill was fairly lower for store­bought milk than home­delivered milk containers.

10 Cost Effectiveness

Cost ($) GHG savings GHG savings NOx savings NOx savings ​ ​ ​ ​ (kg CO2 E) per extra (kg NO2 E) per extra ​ ​ ​ ​ dollar spent dollar spent

Home­Delivery $9.34 1.141 .2288 .0155 .0025

Store­Bought $3.16 Table 4. Cost­Effectiveness Home­delivered milk costs significantly more than store­bought milk­­nearly three times more, based on price averages we took from various home­delivery companies’ websites. Home­delivery customers pay a premium for the convenience of having milk delivered to their door, for milk that is advertised to be fresher and better tasting than store­bought milk, and for the glass bottles, which are much pricier than HDPE jugs. This premium also comes with environmental benefits. For every extra dollar spent on home­delivery milk, .2288 kg of greenhouse gases and .0025 kg of NOx are prevented from being released into the atmosphere. ​ ​ The decision to pay the premium ultimately depends on how much the consumer values the benefits.

Sensitivity Analysis For the sensitivity analysis we focussed on two sections of the life cycle of store­bought milk and home­delivered milk: transportation and reuse. Our goal in focusing on the transportation of milk is to account for both small and large milk companies. Smaller milk companies for example carry fewer gallons of milk per truck but also travel fewer miles between the milk’s original and final destination. Larger companies carry more gallons of milk per truck but also travel more between the milk’s original and final destination. To do this we looked at 4 different cases that represented small companies, large companies, and a mix between the two. Case 1 represents a small local company with relatively smaller delivery mileages and fewer gallons of milk per truck. For Case 2 we held every variable constant but changed the delivery mileage to test how much this variable influenced CO2 and NOx emissions. For Case 3 we kept ​ ​ ​ ​ all the same variables as Case 1 but changed the number of gallons of milk each truck carried.

Again we looked at how this sole variable influenced CO2 and NOx emissions. For Case 4 we ​ ​ ​ ​ changed both the delivery mileage and number of gallons of milk per truck to better reflect a large company that supplied milk to farther destinations but also carried more milk at once.

11 Miles Gallons of Kilograms Kilograms NO NO Data Source ​x ​x Milk per of CO of CO Emissions Emissions ​2 ​2 Truck Emitted Emitted per (Kilograms (kg) per Gallon of NO Gallon of ​2 Milk Milk

Case 1

Store­Bought 640 477.6 649.6 1.36 5.51 0.0115 e,h,i

Home­Delivered 350 106.7 355.3 3.33 3.01 0.0283 j,h,i

Case 2

Store Bought 2280 477.6 2314.2 4.85 19.6 0.0411 f,h,i,j

Home­Delivered 312 106.7 316.7 2.97 2.69 0.0252 g,h,i,j

Case 3

Store­Bought 640 5800 649.6 0.112 5.51 0.000950 e,f,h,i

Home­Delivered 350 500 355.3 0.711 3.01 0.00603 g,h,i,j

Case 4

Store­Bought 2280 5800 2314.2 0.399 19.6 0.00339 f,h,i

Home­Delivered 312 500 316.7 0.633 2.69 0.00537 f,g,i Table 5. Sensitivity analysis for transportation with variations in delivery mileage and gallons of milk per truck Data Sources: e. (Campbell 2016) f. (Henderson, Thoma et al. 2012) g. (Capital at Play 2014) h. (U.S. EPA 2005) i. (U.S. EPA 2008) j. (King 2010)

From our analysis we can see that mileage has a direct effect on the total CO2 and NOx ​ ​ ​ emissions. The more miles milk has to be transported the greater the emissions of these two gasses are. The efficiency of the milk delivery, however, is based on how many gallons of milk are being transported. Case 3 has the lowest emissions per gallon of milk because short delivery mileage combined with a high volume of milk per truck is the most efficient transportation combination. The lowest efficiency is represented by Case 2 which has high delivery mileage and low volume of milk per truck. Our next sensitivity analysis demonstrates the benefits of reusing the glass bottles and compares it to the environmental impact of buying new plastic jugs every week. Our base case

12 looks at only one week’s worth of milk so in order to incorporate the reusability of glass bottles our sensitivity analysis looks at the CO2 and NOx emissions for 8 weeks worth of reused glass ​ ​ ​ ​ bottles and new plastic jugs.

Figure 3. GHG Emissions sensitivity analysis over time period of 8 weeks

Figure 4. NOx Release sensitivity analysis over time period of 8 weeks ​ ​

As the graphs show, the CO2 and NOx emissions for glass bottles and plastic jugs are ​ ​ ​ ​ relatively comparable after the first week. In the first week the difference between CO2 emissions ​ ​ is only 45%, with higher emission coming from the store­bought plastic jugs. By the end of the eighth week there is an 80% difference in CO2 emission with higher emission still coming from ​ ​ the store­bought plastic jugs. In the first week there is a 73% difference between NOx emissions ​ ​ with higher emissions coming from the plastic jugs. By the end of the eighth week there is an

83% difference between NOx emissions with higher emissions still coming from the plastic jugs. ​ ​ There is a higher change in the CO2 emissions over the course of the eight weeks which is ​ ​ understandable considering CO2 accounts for a larger portion of the total emissions. ​ ​

13 Conclusion In terms of volume of landfill space used, glass bottles, which take up relatively little space when crushed, have a lower impact. However, in terms of weight of material in landfill, HDPE plastic jugs are significantly lighter than glass, and thus have a lower impact. Looking at our two impact categories, lifetime greenhouse gas emissions and lifetime nitrogen oxide releases, it is clear that glass bottles have a significantly lower impact than HDPE jugs. A large factor of this difference was found in transportation emissions, which were almost 3 times higher for store­bought HDPE jugs. Sensitivity analyses indicated that the environmental footprint can be decreased by reusing glass containers as many times as possible, increasing the amount of milk carried per truck, and decreasing the distance from farm to home or farm to retail. While home­delivered milk may not be affordable for everyone, store­bought milk can still be comparably environmentally friendly if consumers and retailers alike choose local milk whenever possible. As demand increases, supply will follow, and naturally, transportation efficiency will increase as larger amounts of milk are delivered per trip.

Limitations We chose to use the EIOLCA tool to assess container manufacturing impacts because it was an efficient, centralized way to collect the desired data. However, the tool has two major limitations. Firstly, the EIOLCA data is an aggregation of data from across the industry. Glass container manufacturing includes containers other than milk bottles. Plastics bottle manufacturing is not specific to HDPE jugs. Secondly, the EIOLCA tool cannot be manipulated to reflect different percentages of recycled material use. Our transportation emissions data was gathered from different years depending on the category of information and what was available to us. For the data collected on milk container transportation, the metrics used for measurement varied between the different sources acquired. Additionally, there seems to be an overall lack of data in regards to the varying specifics in regards to transportation data, such as quantity transported, distance, etc. The distance of the transportation from farm to final destination for the milk product differed widely between areas. Some other general limitation in our report included the fact that the weight used to calculate the emissions per container varies between product for both HDPE jug and glass container. Additionally, the data for glass container weight was based on 1 gallon glass containers as there was no data for 2 half­gallon containers in regards to material weight. When analyzing the price of each product, the average price of home­delivered milk had high variability depending on the location of the delivery and the farm or company running the delivery service. Finally, the data on nitrogen oxide releases was unavailable for the different categories of disposal.

14 References [www.bayareamilkman.com] Bay Area Milkman ­ Your Straus Milk Delivery. (n.d.). Retrieved ​ ​ June 02, 2016, from http://www.bayareamilkman.com/home­dairy­milk­organic­delivery.html ​

[Campbell 2016] Campbell, John R., and Robert T. Marshall. "Dairy Production and Processing: The Science of Milk and Milk Products." Page 287.Google Books. Waveland Press, 29 Jan. ​ ​ 2016. Web. 19 May 2016.

[Capital at Play 2014] Capital at Play (2014) “Zen & the Art of Milk Delivery.” Capital at Play Featured Capitalist Archive. Web. http://www.capitalatplay.com/zen­of­milk­delivery/ ​

[Carnegie Mellon University 2008] Carnegie Mellon University Green Design Institute (2008) “Economic Input­Output Life Cycle Assessment (EIO­LCA), US 2002 Industry Benchmark Model.” Web. http://www.eiolca.net ​

[GPI 2010] The Glass Packaging Institute (2010) “Environmental Overview Complete Life Cycle Assessment of North American Container Glass.” The Glass Packaging Institute. Web. http://www.container­recycling.org/assets/pdfs/glass/LCA­GPI2010.pdf

[Helmer 2014] Helmer, J. (2014) “The Milkman Cometh: An Old­Fashioned Tradition Revived.” Modern Farmer. Web. http://modernfarmer.com/2014/05/milkman­cometh/ ​

[Henderson, Thoma et al. 2012] Henderson, A. & Thoma, G. et al. (2012) “U.S. Dairy’s Environmental Footprint: A summary of findings, 2008­2012.” Innovation Center for U.S. Dairy. Web. http://www.usdairy.com/~/media/usd/public/dairysenvironmentalfootprint.pdf.pdf ​

[King 2010] King, Robert P. "Comparing the Structure, Size, and Performance of Local and Mainstream Food Supply Chains." Pages Google Books. DIANE Publishing, 2010. Web. 19 ​ ​ May 2016.

[King 2015] King, Robert P., Michael S. Hand, and Miguel I. Gomez. "Growing Local: Case Studies on Local Food Supply Chains." Page 240. Google Books. U of Nebraska Press, 1 Feb. ​ ​ 2015. Web. 19 May 2016.

[Miller 2004] Miller, C. (2004) “HDPE Bottles.” Waste 360. http://waste360.com/mag/waste_hdpe_bottles_2

15 [Polis, 2011] Polis, C. (2011). “By The Numbers: What Americans Drink In A Year”. Retrieved June 02, 2016, http://www.huffingtonpost.com/2011/06/27/americans­soda­beer_n_885340.html ​

[Spitzley, Keoleian, & McDaniel 1997] Spitzley, D. V., Keoleian, G. A., McDaniel, J. S. (1997) “Life Cycle Design of Milk and Juice Packaging.” United States Environmental Protection Agency Research and Development.

[Tahmincioglu, 2007] Tahmincioglu, E. (2007). “Remember the Milkman? In Some Places, He’s Back.” Retrieved June 02, 2016, from http://www.nytimes.com/2007/12/16/business/yourmoney/16milk.html

[U.S. EPA 2015] United States Environmental Protection Agency (2015) “Glass.” U.S. EPA Waste Reduction Model. Web.

[U.S. EPA 2005] United States Environmental Protection Agency (2015) “Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel.” U.S. EPA Office of Transportation and Air Quality. EPA420­F­05­001. Web.

[U.S. EPA 2008] United States Environmental Protection Agency (2008) “Average In­Use Emissions from Heavy­Duty Trucks.” U.S. EPA Office of Transportation and Air Quality. EPA420­F­08­027. Web.

[Ver Ploeg 2010] Ver Ploeg, Michele, Lisa Mancino, Jessica E. Todd, Dawn Marie Clay, and Benjamin Scharadin. "Where Do Americans Usually Shop for Food and How Do They Travel To Get There? Initial Findings From the National Household Food Acquisition and Purchase Survey." United States Department of Agriculture, Mar. 2015. Web. 19 May 2016.

16 Contributions Anne Cheng ❖ Flow Diagrams & LCI Tables ❖ Container Manufacturing Data and Analysis ❖ Cost Effectiveness ❖ Totals Data Spreadsheet

Caleb Chi ❖ Executive Summary ❖ Goals and Scope ❖ Literature Overview

Lauren Kean ❖ Transportation Data, Analysis and Results ❖ Sensitivity Analyses with Tables and Graphs ❖ Transportation Spreadsheet

Shannon Miner ❖ Life Cycle Impact Analysis and Graph ❖ Container Disposal Data, Analysis, and Results ❖ Conclusion and Limitations

17 Appendix

EIOLCA­Derived Unit Processes for Container Manufacturing

GHG Emissions NOx Releases Economic Lifecycle Section (kg CO2 equivalent) (kg) Activity

Glass Container Production (Total For 2 Half Gallon Containers) 0.99437 0.002006

Power Generation and Supply 0.64700 0.001200 $0.0570

Coal Mining 0.01310 0.000030 $0.0040

Oil and Gas Extraction 0.00735 0.000014 $0.0040

Pipeline Transportation 0.00382 0.000001 $0.0010

Oil and Gas Extraction 0.07100 0.000131 $0.0005

Power Generation and Supply 0.00010 0.000026 $0.00001

Coal Mining 0.05300 0.000123 $0.0090

Power Generation and Supply 0.00243 0.000005 $0.0002

Alkalies & Chlorine Manufacturing 0.04900 0.000069 $0.0190

Power Generation and Supply 0.01990 0.000037 $0.0020

Other Basic Organic Chemical Manufacturing 0.00402 0.000009 $0.0030

Oil and Gas Extraction 0.00334 0.000006 $0.0003

Other Nonmetalic Mineral Mining 0.00297 0.000021 $0.0030

Petroleum Refineries 0.00192 0.000002 $0.0010

Plastics Material & Resin Manufacturing 0.00133 0.000001 $0.0020

Lime & Gypsum Product Manufacturing 0.03460 0.000053 $0.0080

Power Generation and Supply 0.00406 0.000008 $0.0003

Truck Transportation 0.07000 0.000252 $0.0180

Power Generation and Supply 0.00160 0.000003 $0.00005

Oil and Gas Extraction 0.00159 0.000003 $0.0001

Petroleum Refineries 0.00131 0.000001 $0.0010

Couriers & Messengers 0.00093 0.000011 $0.0010

18

Plastics Bottles Manufacturing (Total For 1 Gallon Jug) 0.47772 0.000810 $0.3000

Power Generation and Supply 0.15800 0.000294 $0.0110

Coal Mining 0.00252 0.000006 $0.0007

Oil and Gas Extraction 0.00142 0.000003 $0.0007

Pipeline Transportation 0.00074 0.0000002 $0.0002

Other Basic Organic Chemical Manufacturing 0.04730 0.000112 $0.0180

Power Generation and Supply 0.00787 0.000015 $0.0004

Oil and Gas Extraction 0.00448 0.000008 $0.0003

Petroleum Refineries 0.00318 0.000003 $0.0020

Plastics Material and Resin Manufacturing 0.04540 0.000042 $0.0570

Power Generation and Supply 0.02430 0.000045 $0.0010

Petrochemical Manufacturing 0.02200 0.000010 $0.0150

Other Basic Organic Chemical Manufacturing 0.01970 0.000047 $0.0140

Oil and Gas Extraction 0.01350 0.000025 $0.0004

Petroleum Refineries 0.00997 0.000009 $0.0050

Petrochemical Manufacturing 0.03250 0.000015 $0.0150

Oil and Gas Extraction 0.00980 0.000018 $0.0040

Petroleum Refineries 0.00862 0.000008 $0.0080

Power Generation and Supply 0.00523 0.000010 $0.0002

Other Basic Organic Chemical Manufacturing 0.00474 0.000011 $0.0040

Oil and Gas Extraction 0.02850 0.000052 $0.00003

Power Generation and Supply 0.00001 0.000000 $0.0000005

Petroleum Refineries 0.01970 0.000018 $0.0005

Oil and Gas Extraction 0.00061 0.000001 $0.0003

Power Generation and Supply 0.00052 0.000000 $0.00001

Pipeline Transportation 0.00005 0.000000 $0.000009

Truck Transportation 0.00629 0.000055 $0.0026

Power Generation and Supply 0.00023 0.0000004 $0.00001

Oil and Gas Extraction 0.00023 0.0000004 $0.00001

Petroleum Refineries 0.00019 0.0000002 $0.0001

Couriers & Messengers 0.00013 0.000002 $0.0001

19 20

21 Transportation Results

Total Miles Gallons of Kilograms Gallons of Kilograms NO NO ​x ​x Transported Diesel Fuel of CO Fuel used of CO Emissions Emissions ​2 ​2 (roundtrip) Used Emitted per Gallon Emitted per (kg) (kg) per (per of Milk Gallon of Gallon of week/per Milk Milk month)

Store­Bought 640 64 649.6/259 .134 1.36 5.51 .012 Milk 8.4

Home­Deliv 350 35 355.3/142 .328 3.33 3.01 .028 ered Milk 1

Sensitivity Analysis (Reuse)

Home Delivery, Glass Store Bought, HDPE Bottles Jugs (2 half­gallon bottles (1 gallon jug per per week) week)

GHG Emissions NOx Releases GHG Emissions NOx Releases

(kg CO2 E) (kg) (kg CO2 E) (kg) ​ ​ ​ ​ Week 1 (Base Case) 2.40 .0135 3.81 .0291

Week 2 4.79 .0271 7.62 .0581

Week 3 6.15 .0386 11.4 .0872

Week 4 7.51 .0502 15.2 .116

Week 5 8.87 .0617 19.0 .145

Week 6 10.2 .0733 22.9 .174

Week 7 11.6 .085 26.7 .203

Week 8 13.0 .0963 30.5 .232

22