Bottled water is often marketed as a natural and pure alternative to tap water. A closer look reveals a rather different story. In some situations you would do well to avoid it!
The Food Standards Code is the regulation that covers bottled water in Australia. Safe drinking water acts cover the potable supply in each state. So water in a bottle does not have to meet the same standards as water from the taps. Let’s have a look at the differences.
Tap Water and Spring Water
The Australian Drinking Water Guidelines dictate the quality of drinking water supplied by water utilities to your tap. Individual Sates enforce these guidelines through ‘Safe Drinking Water Acts’. This process ensures a reasonable amount of consistency in water quality so far as microbiology goes. This means bottled water is the responsibility of Food Safety Australia and New Zealand (FSANZ). Their definition of ‘spring or mineral water’ is ‘ground water from subterranean water bearing strata’. This could of course mean bore water, and in many cases that is exactly what it is! Many Australian ‘spring’ and ‘mineral’ waters are softened, filtered and disinfected bore water with or without added bubbles! In contrast European Law specifies that bottling of the all mineral water must occur on site and have no chemical additives. Even trucking it to a bottling plant is illegal. Quite a contrast!
Australia Drinking Water Guidelines stipulate that drinking water must have less than 1 coliform (gut bacterium) per 100mL, and less than 100 other bacteria (called ‘heterotrophic bacteria’) per mL when it reaches your meter. What happens after that is your problem. The water certainly isn’t sterile. It does meet the definition of the World Health Organisation as ‘safe’.
“Safe drinking water is water with microbial, chemical and physical characteristics that meet WHO guidelines or national standards on drinking water quality” – WHO 2005
The FSANZ requirements are slightly different. 5 out of 5 samples must have less then 1 coliform per 250 mL, and less than 100 other bacteria per 100 mL. The test for other bacteria only applies during production and 12 hours after packaging. There are non-compulsory options to test for other bacteria too. The code also acknowledges that some increase in microbial content is likely during the bottling process and after bottling. Microbial quality may change between leaving the factory and reaching your mouth. An interesting twist is that the Polyethylene Terephthalate (PeT) bottles do select for certain bacterial populations. Bacteria like Pseudomonas, Ralstonia and Flavobacteria are common contaminants in PeT bottles. They are also opportunist pathogens. This contamination may be during the bottling process or may come from opening and using the bottle.
Both tap water and bottled water are sources of outbreaks of disease. In both cases disease often comes about by re-growth of the bacteria that survive the initial treatment process. In some instances in bottled water it may be due to ‘wash-back’ from your mouth into the bottle and re-growth. An alarming report shows that drinking bottled water instead of tap water doubled the number of infections in a hospital intensive care unit. Other outbreaks of infection from water bottles have occurred in high risk facilities. It is clear that a well managed building water supply is a safer option than using bottles of water.
Of the two water sources tap water is the clear environmental favourite. Processing, packaging and disposal of mineral waters is costly in terms of energy, petrochemical usage and waste management. Recycling PeT bottles is not a clean and easy process. Estimates are that over 1 million PeT bottles end up in Australian landfills each year, less than half of them are re-processed. Material is packaged to be converted into lower grade products like carpets and fence posts.
Source: Zero Waste SA
Significant amounts go overseas for treatment. In contrast treatment of potable water supplies is less intensive and expensive and results in little or no impact on landfill and waste management. Disinfection at the entry to buildings can further reduce risks.
Some reports suggest that bottled water costs as much as a 100 times more per litre than tap water. The evidence suggests that tap water is the cheapest safest and cleanest water source.
Eckmans et al (2008) An outbreak of hospital-acquired Pseudomonas aeruginosa infection caused by contaminated bottled water in intensive care units. Clin Microbiol Infect 14: 454–458
Rusin et al (1997) Risk Assessment of Opportunistic Bacterial Pathogens in Drinking Water. Rev Environ ContaIn Toxicol 152:57-83