Although tap water provided by public supply systems in the US usually doesn’t cause diarrhea, I still believe many people living in regions all over the country wouldn’t mind, if the drinking water quality would actually improve.
Why? Is our water as bad as tap water in India? No, of course not. But that doesn’t mean that we cannot find traces of pesticides, fertilizers, (prescription) drugs and other unnatural and manmade substances in it! And before I forget, since very recently citizens of Iowa can be proud of being the first to find a constant presence of insecticides in their water. Congratulations!
As you can see, filtering your tap water might be a good idea – and I haven’t even started with inorganic contaminants like lead and chlorine. But let’s not spend too much of our energy focusing on the problem, let’s focus on possible solutions…
Solution A: Reverse Osmosis Filtration
The first and in my opinion best solution to contaminated water is the application of an RO filter system. Much can be said about these systems and without trying to sound too scientific, I am going to break it down for you in a short summary:
- Osmosis is a naturally occurring process. Its outcome is that 2 liquid (or gas) solutions with different solute concentrations separated by a semipermeable membrane achieve equal solute concentrations by the diffusion of solvent molecules through the membrane.
- Reverse osmosis describes the movement of solvent molecules in the reversed This can be achieved by applying pressure. No chemicals are needed, meaning we don’t contaminate our water even further and nothing is released into the environment.
- A reverse osmosis filter unit can remove up to 98%-99% of all contaminants present in water. This depends on the individual model itself, of course, and also on the pressure in the respective water system. The general rule is: The higher the pressure, the more substances get removed.
- Almost no contaminant is too small to survive an RO system, which includes ions and metals. At first glance this seems to be a good thing, and it is. It’s nice to get rid of lead, cadmium, etc., but it’s also where the only real disadvantage of RO systems comes into play: Demineralization.
- Water filtered by an RO system lacks minerals that would benefit our health, because they were removed during the filtration. Fortunately, there is an easy workaround. You can add those minerals back into your water by either using mineral-rich salt or an electrolyte powder.
In case you noticed that I didn’t mention water wastage as a disadvantage, it’s because the amount of water that gets wasted can be significantly reduced, if you apply an additional pump to increase water pressure.
I’ve covered reverse osmosis for water desalination in a previous and much shorter post already.
Solution B: Activated Carbon Filtration
The second solution to cleaning contaminated tap water is using activated carbon (or activated charcoal) filters. Activated carbon is a processed form of carbon that has many pores to increase its surface, the reason being that the larger the surface, the more substances can be adsorbed in less amount of time. Filters are also applied for groundwater remediation and air purification.
The reason why I prefer reverse osmosis to activated carbon filtration is that the latter doesn’t really bind certain chemicals (e.g. residues of cleaning detergents), metals (iron, lead and arsenic) and other elements (fluorine among them).
Please don’t get me wrong, water that was cleaned by activated carbon filters is still light years ahead of plain tap water, but simply put, the degree of purity that RO filters achieve is much higher. As a final note: All RO systems that I’ve used throughout the course of my study always had an activated carbon stage for water pre-treatment.
Solution C: Water Distillation
Although water distillers provide exceptionally clean water, I don’t want to get into too much detail about them, because they require way too much energy to function. I want to say just this:
Water distillation means heating water to the point that it vaporizes. The vapor is then led into a cooling container, where it condenses back into water. Have you ever tried to boil half a gallon of water in a pot and waited until all the water has disappeared? You better don’t , because you might not live long enough to witness it.
Now, a water distiller works more efficient than a pot on a stove, but according to one manufacturer, a commercial distiller takes 1 hour to filter 0.4 gallons of water. In a family of 4, where each person drinks 0.4 gallons of water per day, your distiller has to run for 4 hours every single day.
The Worst-Case Scenario
You might say that this sounds all well and good. Reverse osmosis seems to be the best way to purify water, but what do I do, if the worst-case scenario occurs?
First of all, reverse osmosis doesn’t require electrical energy. It only requires water pressure. So as long as this is a given, there is no need to worry.
Secondly, if the water supply system breaks down completely, your remaining option would be to get yourself a pump (about 50 psi/3 bar), a generator and a feed water source, and you could keep your RO filter system running.
Your final option is to filter enough water and store it in a tank, before everything goes down the drain.