Waste Prevention and Reuse

Drinking Water
A Comparison of Bottled and Tap Water Using Life Cycle Analysis

Frequently Asked Questions
Background and Methodology

Questions

1. Why did DEQ conduct this study?
2. How was this study funded?
3. Why did DEQ choose water?
4. What is a Life Cycle Assessment (LCA)?
5. What life cycle stages are included in this study?
6. Is this study an inventory assessment or an impact assessment?
7. What impact categories are included in DEQ’s study?
8. Did you study the quality of the water?
9. Where can I learn more about the safety and health impacts of bottled water and/or tap water?
10. What about bisphenol-A?
11. Does DEQ’s study evaluate specific brands?
12. What variables are evaluated for bottled water?
13. What variables are evaluated for tap water?
14. What different kinds of home/office delivery options does DEQ’s study evaluate?
15. Are the results customized to Oregon?
16. Can the results be used outside of Oregon?
17. Does DEQ’s study follow ISO standards for life cycle assessment?

Answers

1. Why did DEQ conduct this study

DEQ commissioned this study for three reasons:

• To evaluate and communicate the “waste management hierarchy” in state law that establishes preferred methods for managing wastes. In the hierarchy, recycling is preferable to disposal, but waste prevention (the “reduce, reuse” part of “reduce, reuse, recycle”) is even more preferred. However, we often hear “I’m recycling, isn’t that enough?” and “Recycling is just as good as prevention at keeping wastes out of the landfill, so recycling and prevention are equal, right?” This study uses a substance consumed by all Oregonians (drinking water) as a lens through which to evaluate the environmental benefits of recycling vs. disposal, and prevention vs. recycling.
• To bring clarity to the debate about tap water vs. bottled water. While several organizations have made claims about the impacts of bottled water, such claims have sometimes not been well documented and typically have been limited to only energy and/or greenhouse gas impacts, without consideration of other environmental impacts. In addition, some water bottlers have responded by “lightweighting” bottles, increasing recycled content, or supporting recycling. Until now, the impacts of these initiatives have not been well documented.
• To identify which characteristics of bottles, washing practices, etc. are environmentally significant and which are not. DEQ expects this information will be valuable to producers and consumers alike as we work together to reduce environmental impacts.

2. How was this study funded?

The study was funded by the Oregon Department of Environmental Quality (DEQ). The study was conducted by ERG, acting as an independent contractor to DEQ. The conclusions of the study are strictly those of ERG. The study was not funded or subsidized by manufacturers, trade associations, or other nongovernmental organizations.

3. Why did DEQ choose water?

Water is necessary for human health, is consumed on a regular basis, and bottled water is a convenient way to obtain drinking water. Water bottles are one of the fastest-growing components of waste generation: 32 million bottles disposed in Oregon in 1998, rising to 126 million disposed in 2005.

4. What is a Life Cycle Assessment (LCA)?

Life Cycle Assessment (LCA) is an evaluation of the environmental burdens and impacts over the entire life cycle of a product or service. LCA has been recognized as a scientific method for making comprehensive, quantified evaluations of the environmental impacts and tradeoffs for the entire life cycle of a product system. This LCA evaluates the environmental impacts for disposable and reusable systems for delivering drinking water. For a product such as disposable water bottles or reusable cups, LCA evaluations can quantify the environmental impacts of raw material extraction, production, transportation, use and final end-of-life management of that product. The benefit of LCA is that it is comprehensive and a very strong tool for quantifying environmental tradeoffs of alternatives.

5. What life cycle stages are included in this study?

The study includes all the life cycle stages from raw material extraction to end-of- life management. It goes all of the way back to producing the raw materials (coal, etc.) that are used for energy in all stages of the life cycle. It includes the energy and materials used to obtain water from ground and surface sources, to treat the water using a variety of technologies, and to transport the water, packaging and wastes.

The study includes the extraction of raw materials such as oil, natural gas, bauxite, steel, wood and corn; the production of primary packaging materials, such as polyethylene and aluminum; the fabrication of those materials into water bottles and other packaging; the filling and packaging of those bottles; and each transportation step along the way, including transport to the retailer and then to the home.

In some cases, consumers choose to cool their water, either in their refrigerator, or via a water cooler, or through the use of ice. These energy requirements are included.

When containers are reused, such as reusable bottles or drinking glasses, as well as the reusable 5-gallon containers, they’re washed, and that requires energy and water. There’s also wastewater that has to be managed. These processes are also included.

And finally, everything, from the single-use bottles and the protective packaging they’re shipped in, to the drinking glass or reusable bottle, is eventually discarded, and either recycled or disposed of, or in the case of bioplastics, potentially composted. The study includes the energy and associated emissions associated with these processes, as well as several different methods of allocating the impacts and benefits of recycling between systems.

All processes are explained in greater detail in the study’s appendices, which can be downloaded here:

• Life Cycle Assessment of Drinking Water Systems: Bottled Water, Tap Water, and Home/Office Delivery Water Final Report

6. Is this study an inventory assessment or an impact assessment?

DEQ’s study includes both inventory and impact assessment.

“Inventory assessment” is an accounting of the energy and raw materials used in each stage of the life cycle, and solid wastes, atmospheric emissions and waterborne emissions resulting from each stage of the life cycle. For example, inventory assessment reports the quantities of carbon dioxide and methane emitted, without expressing them in terms of their relative impact.

“Impact assessment” takes the results of an inventory assessment and expresses it in terms of impact categories. For example, carbon dioxide and methane are both greenhouse gases, but a pound of methane has greater greenhouse gas impacts than a pound of carbon dioxide. Impact assessment takes the quantities of emissions from the inventory assessment and converts them to “carbon dioxide equivalents,” a measure of the impact of all releases of greenhouse gases.

Via the use of impact assessment, the roughly 240 different atmospheric and waterborne emissions included in DEQ’s study can be condensed to a smaller number of categories, and readers are not required to understand, for example, the relative global warming impacts of carbon dioxide vs. methane, or the cancer potential of arsenic vs. toluene.

7. What impact categories are included in DEQ’s study?

In this study, DEQ chose to use an impact assessment methodology developed by EPA (TRACI, “Tool for the Reduction and Assessment of Chemical and other environmental Impacts”). The impact categories in DEQ’s study include acidification potential, carcinogenic potential, ecotoxicity potential, eutrophication potential, global warming potential, non-carcinogenic potential, ozone depletion potential, respiratory effects potential, and smog potential. Each provides a different measure of the potential impacts on human health and/or the natural environment.

8. Did you study the quality of the water?

No. Both tap and bottled water consumed by Oregonians come from a wide variety of surface and groundwater sources. It was not within the scope of this study to assess the quality of all tap water sources and compare them to all bottled water options throughout Oregon. The focus of this study was evaluating the impacts of processing, transporting, packaging, and the washing (for reuse) or recycling and disposal of drinking water packaging. The study results clearly show that tap water is an environmentally preferable option compared to bottled water. There are resources in Oregon to help address water quality questions and concerns.

9. Where can I learn more about the safety and health impacts of bottled water and/or tap water?

For questions about regulations, water quality and testing of water supplies:

• For private wells: Oregon Department of Water Resources at (503)986-0851 oversees installation of wells. The department’s County Watermasters can help with general groundwater quality questions in each county. There are no laws that require consistent monitoring of private wells in Oregon; it is up to homeowners to determine the safety of their drinking water. More information on private wells can be obtained at:
  • DEQ's Information for Private Well Owners Web page.
• For public water supplies: Information on water quality testing and results can be obtained from the Oregon Department of Human Services – Drinking Water Program at (971)673-0405 or visit: oregon.gov/DHS/ph/dwp/index.shtml.
• For bottled water: The U.S. Food and Drug Administration (FDA) regulates the quality of bottled water based on Safe Drinking Water Act (SDWA) standards, which apply to public water systems as well. The requirements for testing and reporting may vary due to the source of the water and the quantity bottled. For information on specific bottled water, check the label and contact the bottler. The FDA regulations can be reviewed at: www.fda.gov/RegulatoryInformation/Legislation/FederalFoodDrugandCosmeticActFDCAct/FDCActChapterIVFood/ucm107854.htm.

10. What about bisphenol-A?

Bisphenol-A is a suspected endocrine disrupter that is found in the lining of some reusable bottles and used in the manufacture of some plastics. DEQ’s study does not evaluate the presence of bisphenol-A or the health impacts of ingesting it.

11. Does DEQ’s study evaluate specific brands?

No. Although the study uses container weight and packaging data obtained by weighing purchased samples of various brands of bottled water and reusable drinking containers, and import distances are estimated based on the locations of several countries where popular brands of imported water are bottled, the companies producing these brands did not participate directly in this study, and their specific operations may be significantly different from the data sets and modeling assumptions used in DEQ’s report. The results presented in DEQ’s report are not intended to represent specific brands of bottled water or reusable containers available in the marketplace.

12. What variables are evaluated for bottled water?

Specific to single-serve bottles, the study evaluates a large number of variables, including the following:

• the bottle material (PET, PLA, and glass);
• bottle weights and sizes (volumes);
• virgin vs. recycled content (PET only);
• energy requirements for plastic molding;
• cap weight;
• weight and content of protective packaging (corrugated cartons and/or film plastic);
• sources of water (surface vs. ground) and treatment technologies (including reverse osmosis, ozone treatment, and ultraviolet treatment);
• bottles produced at the same location as filling or elsewhere;
• distance filled bottles travel to retail, and the mode of transport (truck vs. ocean freighter);
• distance customers travel to purchase their bottled water and how the impacts of that transportation are co-allocated to other purchases or errands;
• chilling in the home vs. unchilled bottles;
• rate at which PET bottles are recycled and the method for allocating the impacts and benefits of recycling between the system producing the recycled waste and the system using it to make new product; and
• management of PLA bottles via composting vs. landfilling, and the decomposition of PLA in landfills.

13. What variables are evaluated for tap water?

For tap water, DEQ’s study evaluates:

• types of reusable drinking vessels (glass drinking cups and aluminum, steel and PET durable bottles);
• volumes of drinking vessels;
• replacement rates for drinking vessels (how long they’re used);
• recycling vs. disposal;
• recycling allocation methods;
• hilling with ice;
• frequency that the drinking vessel is washed; and
• type of dishwasher it is washed in and whether it is run full or half-full.

14. What different kinds of home/office delivery options does DEQ’s study evaluate?

Home/office delivery (HOD) systems require some kind of drinking vessel so, akin to tap water, DEQ’s study evaluates many of the same variables (e.g. vessel type, size and dishwashing characteristics). Specific to HOD, DEQ’s study also evaluates:

• HOD bottle type (PET and polycarbonate);
• HOD bottle weight;
• number of reuses;
• water source type and treatment technologies (as with single-serve bottles);
• distance between the point of filling and the distribution center;
• route distance; and
• optional use of energy for operating chillers contained in many HOD dispensing units.

15. Are the results customized to Oregon?

While much of the data used in the study is based on U.S. or international averages, Oregon-specific data and assumptions were used for: the mix of fuels to produce electricity used for processes expected to occur in Oregon (such as dishwashing), transportation distances for bottled water; mix of residential (tap) water from wells vs. municipal sources; recycling rates for PET bottles, glass bottles and corrugated packaging; disposition of non-recovered wastes (landfilling, waste-to-energy combustion, and combustion without waste-to-energy); modes and distances for transport of postconsumer solid waste sent to landfills and combustion facilities; and management of landfill gas.

16. Can the results be used outside of Oregon?

Because the study was partially customized to reflect Oregon conditions (see above), the results do not exactly comport with average national conditions. In many cases, these differences are expected to be small. Generally speaking, the impacts of both tap and bottled water systems outside of Oregon are probably slightly higher than results portrayed in DEQ’s study. For tap water systems, this is a result of the lower carbon content of electricity sold into Oregon (primarily an issue for producing hot water for washing). Higher reliance on fossil fuels for electricity in some areas of the country will make home washing in those areas less attractive than in Oregon. For single-serving bottles, Oregon’s bottle bill translates into a relatively high recycling rate (62% for PET bottles), and this reduces the greenhouse gas impacts of purchasing the single-serving bottles. In states without bottle bills, the life cycle greenhouse gas impacts of single-serve bottles are likely higher than portrayed in DEQ’s study, because they are recycled at a much lower rate.

17. Does DEQ’s study follow ISO standards for life cycle assessment?

ISO refers to the International Standards Organization. The methodology of DEQ’s study is consistent with ISO 14040:1997 and ISO 14044:2006, the international standards for life cycle assessment. Because the study makes comparative assertions and discloses them to the public, DEQ also commissioned a panel of three external experts to independently review the study. The panel’s report (and responses from DEQ’s contractor) is included as an addendum to DEQ’s study.

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