The original post went into some detail on why single-use plastic bottles are bad; here is the nutshell version in case you didn't see the original:
Plastic manufacturing pollutes and uses oil and oil related resources; plastic is suspected of poisoning people by leaching into food; plastic does not break down in either the landfill or the environment, adding toxic chemicals and simple trash to the landscape; and even recycling those bottles use significant energy, create significant pollution, and creates other plastic products that in turn cause all the aforementioned problems.
Although steel has some significant environmental drawbacks in manufacturing, the steel bottles lack the other issues, can be reused hundreds of times (thus spreading the cash and environmental cost out over time), will degrade in nature and landfills (if they wind up there at all), and recycle very easily.
How do we use our bottles? We fill them from the tap and stick them in the refrigerator. That’s it.
Wash them with hot water and soap, refill them. Sometimes we refill them several times during the day, or swap out an empty for a cold, full one.
We calculated that we use each of our five bottles an average once per day (allowing for days when all five got refilled three or four times in summer, and days in winter when only two or three get used a single time). Thus 365 x 5 bottles = 1,825 plastic bottles we did not buy last year. At our local Trader Joe’s a case of bottled water the same size as our steel bottles works out to just over 29 cents per bottle. Thus, 1,825 x $0.29 = $532 in savings last year alone.
Now our bottles were gifts, so our initial cost was zero, but even at the approximately $20 each that they cost at full Internet retail (with shipping), we would have had a net savings in year one of $432, with an additional $532, per year, for the next several years.
Or, another way to look at it is that, in the first year, our amortized cost was about 5½ cents per fill, plus less than ½ cent for the water, so maybe about 6 cents per bottle-full. By December 2009, our cost will be down to about 3 cents for each use over the two years, including water. And if we use the bottles a third year, we pay less than 2½ cents per bottle. If the bottles last five years, at this rate that is less than 1½ cents per bottle of water!
And of course that calculation does not include the $1.00 or more each for bottles of water we did not buy at Disneyland, or the gas station, or the many other special events we’ve attended where water was wanted and for sale at absurd prices.
A good deal all around.