How can I save money on drinking water?

When I moved in to my new house, I knew that the water there wasn’t good enough to drink without filtration. So, I went ahead and bought the most basic (and probably the cheapest) kind of filter – the faucet-mounted "activated" charcoal filter. However, I soon realised that this filter didn't meet my needs – the water tasted bad, and I noticed some health issues that I had never had before. After some thinking, I decided to go with the easiest option – bottled water. I opted for a water delivery service and started drinking bottled water. The water tasted good, I had the satisfaction that I was drinking clean water, and the supply was virtually uninterrupted. I was happy.

But then, one of my colleagues installed a Reverse Osmosis (RO) system in her house, and she insisted that installing an RO system – though it has some upfront capital costs – is much cheaper in the long run, compared to bottled water. Before this, I had never thought of the “economics” of bottled water. After all, who cares when you spend less than $25 a month on bottled water? But after listening to my colleague’s argument (she seemed to have done her bit of research on this), I decided to do my own research to understand the economics. Here is my “research” in a snapshot.

Bottled Water

Let’s begin with the economics of bottled water. As I mentioned earlier, I am spending little less than $25 a month on the water delivery service. To be exact, I am ordering 5-gallon jugs, 3 times a month. Each 5-gallon jug costs me $8.25. So, I am spending ($8.25 x 3 jugs) $24.75 per month. 

Each gallon of bottled water is costing me $1.65. 

Reverse Osmosis Water

Now let’s look at the cost of installing an RO system. Since I want only my drinking water to be treated (there are also “Whole House RO Systems” that supply RO treated water to all faucets in the house), I decided to go with an “under the sink” RO system. These systems are placed under the sink, are quite compact and hence occupy a small footprint. More details are available here. These Under the Sink RO systems seem to be quite easy to install. Check out this blog. I zeroed-in on the Nelsen 4-stage RO system. This system costs $195 and can deliver 50 gallons of purified water per day. The manufacturer recommends changing the filters once a year, and a replacement filter set costs $89. Factoring in the cost of the annual filter replacement, and calculating for an average daily usage of 5 gallons per day (please note that this usage is much higher than my present usage of bottled water), over a five year period, 

the cost of RO treated water turns out to be only $0.06 per gallon! 

I also created a chart that compares the yearly cost of having bottled water delivered at home vis-à-vis installing an RO system. By the end of the first year, I have already paid the water delivery company $297, whereas I could have bought a brand new RO system for $195, and gotten many more gallons of purified water than I got from the water delivery company!

I was amazed at this stark difference. Considering all the advantages of RO-treated water – RO treatment removes virtually all contaminants such as arsenic, cadmium, lead, selenium, bacteria, viruses, etc. and even complex contaminants such as chemicals, drugs, carcinogenic compounds and radioactive minerals from water – installing an RO system under my kitchen sink seems to be the smartest thing to do.

There have been some concerns with the “absolute purity” of RO treated water – RO treatment strips off almost all dissolved matter from water, including the “good” minerals such as calcium and magnesium which are essential to humans. The World Health Organization (WHO) has clarified that the majority of essential minerals needed by the human body are obtained from food, and not from drinking water. Moreover, bottled water is also RO treated water. If we are OK with bottled water, then there should not be any concern over RO treated water.

Now I am totally convinced of the idea of buying an RO system, and have in fact already placed an order for the Nelsen 4-stage RO System. I recommend you to do the same. Rest assured, this will definitely be a smart decision.