A Review of Existing Water Footprint Calculators

I have several different parts of this project running simultaneously; while I’m compiling all of the information from the dance competition, I want to introduce a second major component of this environmental footprint analysis: water consumption. I aim to analyze the water I consume directly in my home and activities, as well as water consumed indirectly to produce goods and services to quantify my total water footprint for 2017.

Similar to my approach to my carbon footprint, I’m starting by researching the tools already available, namely online water footprint calculators. Generally, these water footprint calculators incorporate water used directly in the home, as well as secondary water uses for food production, transportation and energy, purchased goods, etc. Compared to carbon footprint calculators, these are much easier to use as a college student because they focus on consumption activities (e.g. how many times per day do you flush a toilet? How much beef do you eat per week?) rather than consumption via utility bills. I used three water calculators to calculate my footprint while living in the Rice University dorms, and the results (average gallons of water per day used) are given below:

I also estimated my own water footprint based on a literature review and measurements around my dorm room, deriving a total of 73.8 gal/day. You can find all of my calculations summarized in this document.

Much like the carbon footprint calculators, these results are extremely varied. The first two calculators (GRACE Foundation and National Geographic) considered the widest range of factors and asked for the most specific inputs, and from my perspective, their relatively close results boosts their credibility. In contrast, the Water Footprint Network used my gross yearly income to estimate a large portion of my footprint (which seems largely inaccurate due to an inevitably large number of assumptions), and my own calculations neglected several material production calculations, like the water consumed to produce my clothing. Thus, my intuition suggests that the correct number is in the 1,200 gal/day range, and we’ll see how this number progresses with my calculations over the course of the year.

Austin Swing Dance Championship

This Martin Luther King weekend, I’m traveling to Austin, Texas for the Austin Swing Dance Championship. This is a west coast swing competition – a full weekend of workshops, competition, performances, and social dancing, punctuated by small amounts of sleep, brief meals, and a few other social activities. Tracking my environmental impacts while adventuring outside of my daily routines at Rice University will require some preparation, so this post is dedicated to that preparation. I’m planning to track the impacts associated with driving, food, water and electricity, and goods and services, and methods for doing so are described below.

Driving: I will record how many miles I travel in what type of vehicle with how many people, and the fuel efficiency (mpg) of that vehicle. I can use this data to approximate the associated carbon and water footprints, similar to how I have been tracking my footprint for travel in personal vehicles thus far this year.

Food: I will continue my current practice of writing down what I eat at every meal, so that I can later assign carbon and water footprints to my food.

Water and Electricity: Depending on the data that I can obtain from the hotel in Austin, I’m considering three methods to calculate the impacts associated with staying at the hotel for the duration of the competition:

  1. Most accurate: Assuming I consume water and electricity at an average rate, I can ask the hotel for data on their water and electricity consumption, and use the number of people at the hotel to calculate an average usage per person per day (or similar metric). This depends heavily on the hotel staff having those numbers readily available and being willing to share them with me, but hopefully it will be possible.
  2. Slightly less accurate: Assuming I consumer water and electricity at an average rate, and assuming the hotel is a typical hotel, use values from literature/research to approximate the impacts. I would likely need the square footage, number of rooms, and maximum occupancy numbers from the hotel in order to complete this calculation.
  3. Least accurate: Note of the number and type of lights in the room and ballroom, and note the brand/model of the water fixtures in the bathroom; use specifications from these products and estimate usage time to estimate energy and water usage. Then, use energy modeling or other numerical information to estimate the energy required for conditioning and ventilation. This is the least accurate method since conditioning the building is likely the largest component of the energy and water usage, and estimating the load with basically no information on building construction or mechanical equipment would be very inaccurate.

Goods and Services: There are two activities specific to a large dance competition that may have a larger energy consumption, and the first is specialized dance equipment. This weekend, I may buy a new pair of Sway’D dance boots (shown below). There are environmental impacts associated with manufacturing and transporting these boots (or any other dance footwear), and I will attempt to quantify that impact in the coming weeks. Second, DJ equipment, large speakers, and other sound equipment are constantly running during the weekend (I kid you not, social dancing goes until 6 or 7 am Thursday, Friday, Saturday, and Sunday nights). While at the competition, I will talk to the DJ to better understand what sound equipment is used at the event so that I can research and incorporate this additional energy into my footprint next week (likely using the number of attendees at the event to find my share of the total emissions).


A Review of Existing Carbon Calculators

In week one of the project, I investigated several existing online tools to estimate carbon footprints. These “carbon calculators” essentially measure your impact on the environment in terms of carbon dioxide emissions (typically in mass of CO2 equivalents produced per year). Generally, these tools target average people living in houses or apartments, as they use consumption rates from utility bills to calculate footprints associated with electricity, natural gas, and water usage. Thus, none of these calculators are appropriate for use by college students, since we don’t receive utility bills.

To investigate existing carbon calculators, I used a common set of assumptions in each calculator to estimate my carbon footprint for life after graduation, when I will be living and working in Houston. The results are listed below:

The results, detailed in the table below, vary widely – ranging from 10,500 lb CO2/year to 56,700 lbs CO2/year. From the seven calculators, my average carbon footprint was 24,960 lb CO2/year, with a standard deviation of 16,400 lb CO2/year. Clearly, these results are not in close agreement, to say the least, and a variety of factors could have led to this wide range:

  1. Each calculator considered a slightly different set of carbon sources. At minimum, each incorporated transportation and energy used in the home for heating and electricity. In fact, these are the only factors incorporated in the Warwick University calculator, which may explain why it is the lowest estimate. All of the other calculators considered at least one additional factor, and these varied between calculators, including shopping, education, public transportation, food, etc. The highest footprint (56,700 lbs CO2/year via Oroeco) encompassed the largest number of carbon sources.
  2. Online calculators seem to be designed primarily for maximum generality and ease of use, which makes sense, since the average American is not an expert in life cycle analysis and carbon footprinting. However, it was sometime difficult to gauge how to input specific quantities to obtain accurate results. For example, several of the calculators asked for the number of people in the household, presumably to properly apportion carbon impacts from heating, cooling, and electricity use in the home. However, it was unclear if the miles traveled by each reported vehicle were similarly divided among the members of the household. In my case, I plan to share an apartment with a roommate – thus splitting home energy costs – but have my own car, so it was tricky (and unclear) how to ensure it was correct. I eventually decided to say there were two people in my household, and then input two identical vehicles (with the same miles traveled per year and mpg).
  3. Following a trend in the other carbon analyses I have seen over the years (a trend that has become somewhat of a pet peeve), results given in “tons” generally do not specify if these are English tons (2000 lb/ton) or metric tons (2200 lb/ton). Using the wrong conversion from tons to pounds could introduce a relatively significant amount of error into the footprint. For example, for the “26 ton” Nature Conservancy footprint, the difference between English and metric tons represents about 10% of the footprint calculated with English tons. In general, I used English tons for calculators developed in the United States, and metric tons for calculators developed in Europe.

Of the seven, my favorite calculator was by far Oroeco. Not only does it consider the most comprehensive set of carbon sources, it also integrates with mint.com (a finance-tracking service) which theoretically gives a more detailed, accurate carbon footprint while simplifying the process for the user. It also integrates with Facebook, allowing you to compare carbon footprints with your friends and community. This adds social and competitive aspects to the numerical value, which I believe makes the results more meaningful and gives a larger incentive to reduce your footprint.

As I mentioned earlier, none of these calculators relevant to my current living situation, as I live on the Rice campus and do not have access to utility bills. However, in my research, I did find documentation for one carbon calculator geared towards college students: CarbonTerp. This tool was developed in 2008 specifically for students living in dorms at the University of Maryland. The student answers questions about electricity usage (for example, what electronics do you use and for about how long); the calculator uses the responses and generalized data for the student’s specific dorm to estimate a carbon footprint. Much like Oroeco, the tool also has the ability to compare carbon footprints between students. However, while there is full documentation for the tool online, the tool itself is not publicly available (as far as I could find). Even if it were, it is specific to the Maryland campus, and its results would not be accurate for Houston (since it is different buildings and climates). Thus, I was not able to use this tool to estimate my own footprint, though it would serve as a good example or template for future tools oriented towards college students.

Since I was unable to find a carbon calculator applicable in a Houston dorm setting, and given the large variance in seemingly over-simplified online calculator tools, my next step in this project will be to start calculations for my own carbon footprint.

New Year, New Project

With the start of the new year comes the start of a new project: quantifying my personal impact on the environment. This will be a particularly interesting year to undertake this project, since I will be graduating college and starting work as a full time engineer. Thus, I can investigate and compare the impacts associated with dorm vs. apartment life, walking to classes vs. commuting to work, dorm food prepared in mass quantities vs. individual servings prepared at home, etc. Also, I will be traveling quite a bit this year, giving me the opportunity to explore transportation via car, truck, bus, train, boat, and plane.

My goal for the first year, 2017, is not necessarily to calculate my footprint with 100% accuracy, but rather to set up a solid framework that will allow me to do that in the future, starting with carbon and water footprints. This will include defining the boundaries of my analysis (for example, scope 1, 2, and 3 emissions), coming up with ways to measure my personal consumption of resources (particularly difficult in a dorm setting, since I do not pay utility bills), and developing a useable recording method. If I can collect enough data, I will estimate my total footprint and pick out its major components. Most importantly, this project is an opportunity to bring my environmental impacts to the forefront of my lifestyle choices and ultimately allow me to lead a more sustainable life.

Long-term goals for this project are to more accurately quantify my personal environmental impacts, generalize this framework so it can be used by more people, and perhaps work to create an app or similar platform that would allow average consumers to easily track their own footprints.

I aim to attack this project in week-long chunks, and update this blog after each week. With this in mind, my plan for week one is to conduct background research, as must be done at the start of any good design project. I will investigate if this been done before, what tools are already available, etc. I will then modify my goals for the project based on this analysis (if necessary), more precisely define the scope and assumptions of this project, and begin my investigation in-depth.