I spent a month in Peru last summer investigating water quality and pathogens in the water supply. During this time, I only drank bottled water. Few things ruin an international travel experience like intense stomach cramping and constant trips to the toilet. Luckily, this worked out well for me; I remained healthy for my whole trip. Even in the United States, many private wells and other drinking water sources can be aesthetically displeasing (unpleasant smell and/or taste) or are actually contaminated with lead or other nastiness, like pesticides, solvents, or flammable gases (check out the link below from the movie Gasland).
[youtube=http://www.youtube.com/watch?v=4LBjSXWQRV8]
For others traveling overseas and for people who are not connected to municipal water, bottled water is very useful. It makes sense to drink bottled water in situations like the ones listed above, especially when you can light your water on fire! However, I was surprised to find out that 8-9 billion gallons of bottled water are consumed annually in the United States, making the US the top bottled water consumer in the world. Surely our water isn’t that bad, is it? This made me wonder: is bottled water actually safer, or do people perceive water quality as being so poor in the USA that they prefer to buy bottled water?
After doing some searching, I found an interesting paper published by researchers who examined perceptions of bottled water and tap water among students and faculty at Purdue University. As background context, Purdue had a well publicized incident in 2009-2010 where several buildings were found to have lead levels in their water that exceeded EPA standards. This paper evaluated:
- The current consumption patterns of bottled water in students in faculty
- The perceived benefits of drinking bottled water compared to drinking tap water from a re-usable bottle
- The perceived environmental impacts of bottled water consumption
- How perceived health risks from bottled water, tap water, and reusable water bottles affect the behaviors of students and staff
Overall, surveyed individuals drank about 5 bottles of water per week, with 62% drinking at least one bottle per week and 44% drinking more than 3 bottles per week. While most respondents had used a reusable bottle to drink tap water at some point, only 40% of the surveyed individuals used them more than three days per week. Women drank more bottled water than men, and younger people drank more bottled water than older people.
People who drank more bottled water were more concerned about health issues due to tap water at Purdue and in general, preferred the taste of bottled water, and felt that bottled water was more convenient. People who drank little or no bottled water thought that they significantly reduced their environmental impacts by not drinking bottled water and thought that bottled water was much more expensive. However, many respondents had the perception that bottled water must be more tightly regulated since it was more expensive. Most study participants agreed that bottled water contributed to negative environmental impacts, but thought that recycling significantly mitigated these environmental impacts.
The researchers concluded that extensive media coverage of outbreaks and other contamination issues in municipal water has contributed to the perceived risk of municipal water. Few respondents had any knowledge of health risks associated with drinking bottled water, and also had little understanding of the disparity between the amount of energy that it takes to produce bottled water compared to tap water. Most respondents thought that bottled water was more tightly regulated than tap water, and therefore trusted bottled water more than tap water. Based on other literature that I found, these perceptions are quite common.
These insights piqued my curiosity, so, I thought I’d do a little fact finding mission about bottled water and tap water to see if the beliefs that people held were congruent with the actual regulations about tap and bottled water. Here’s what I found:
- The FDA uses less stringent measures to enforce bottled water quality than the EPA uses for tap water quality. For example, the FDA does not test for Cryptosporidium parvum (a protozoan that causes bloody diarrhea and stomach cramping) in bottled water, and bottled water turbidity (often a sign of microbial contamination) is allowed to be up to 5 times higher in bottled water than the typical level allowed in municipal water. I also discovered that lobbying groups for the bottled water industry have published studies about how environmentally friendly they are, while using obfuscating study designs to mask the true impact of bottled water.
- Unlike tap water, bottled water is not required to be tested if it is sold in the same state that it was bottled. This accounts for 60-70% of bottled water.
- Companies are allowed to bottle tap water and sell it.
- Bottled water companies are rarely inspected by the FDA.
- Bottled water has no mandated expiration date. While manufacturers may choose to put an expiration date on their bottled water, if it is properly bottled the FDA considers bottled water to be safe forever.
- Certain brands of bottled water have violated both industry standards and state standards for safe drinking water.
So, contrary to the perceptions of the study participants, it appears that bottled water is less regulated and less tested than tap water. However, this does not mean that either one is safer; indeed, this has not been conclusively shown in any studies that I have seen. Perhaps this perception could be due to the fact that when municipal water systems break down, thousands of people can be affected, as we saw during the Cryptosporidium parvum outbreak in Milwaukee in 1993 or the recent chemical contamination of water in West Virginia. Or perhaps it is that people perceive bottled water to be a luxury good, with different tastes and flavor profiles, like a fine wine? Check out the the clip below.
[https://www.youtube.com/watch?v=JdvJOF-2mm0]There has also been a media campaign against tap water on behalf of the bottled water industry, pushing the idea that tap water is unsafe. The effects of all of these different factors is difficult to quantify, but one thing is certain: the amount of bottled water that Americans buy has steadily increased over the past decades.
So, in this intellectual excursion, we’ve determined that:
- Bottled water has some valuable uses (especially for those who are on a contaminated water supply or traveling).
- People regularly pay an up-charge for bottled water, typically because they think it is safer and more convenient than tap water.
- Bottled water is actually less regulated than tap water, and may be nothing more than bottled municipal water.
- Both bottled and tap water have violated the standards set forth by regulators.
So what does this mean for my behavior? This has made me consider multiple drinking water choices. Tap water is more highly regulated and a better environmental choice than bottled water, so I will continue to drink out of the tap, unless it tastes terrible or I know that the local water is unsafe. Happily, most cities make this information easily available. If I know my water is unsafe (or if I want better tasting water), I will consider buying a water filter before going straight to bottled water; there are many companies that make water filters that are certified to remove heavy metals, microbial contaminants, pesticides, and chlorine.
If I really doubt the safety of my water (e.g. when traveling overseas), I will definitely drink bottled water. While there is a time and a place for it, as consumers, we need to decide when it is actually worth the expense to invest in bottled water.
Adapted from my original post on Mind the Science Gap
References:
- Saylor, Amber, Linda Stalker Prokopy, and Shannon Amberg. “What’s wrong with the tap? Examining perceptions of tap water and bottled water at Purdue University.” Environmental management 48.3 (2011): 588-601. DOI
- Doria, M. D. “Bottled water versus tap water: understanding consumers-preferences.” J Water Health 271 (2006): 276. DOI
- Gleick, Peter H., and Heather S. Cooley. “Energy implications of bottled water.” Environmental Research Letters 4.1 (2009): 014009. DOI
- Ferrier, Catherine. “Bottled water: understanding a social phenomenon.”AMBIO: A Journal of the Human Environment 30.2 (2001): 118-119. link
- United States Environmental Protection Agency. “Drinking Water Contaminants”. 3 Jun 2013. Visited 27 Oct 2013. link
- United States Food and Drug Administration. CFR – Code of Federal Regulations Title 21. 1 April 2013. link
- United States Food and Drug Administration. “Bottled Water Everywhere: Keeping it Safe”. link
- United States Food and Drug Adminstration. “February/March 2002 Ask the Regulators — Bottled Water Regulation and the FDA.” link