The largest problem in the US drinking water system is purely its structure. The sheer amount of distance that water must travel from source to consumption is enormous. Even when water is sourced from pristine locations, it still must travel through miles of pipes to the point of use.
As global populations increased in the 1800's, the problems started to emerge in densely populated cities. Outbreaks of waterborne illnesses became shockingly common, killing untold thousands of people in the world's leading cities. These illnesses (Cholera, Typhoid, Cryptosporidium, E. coli, etc) are a result of waste-water contaminating drinking water. Cities were growing so large that pristine sources of water were too small or distant to serve the demand. Something had to be done to sanitize drinking water prior to delivery to customers. The answer to this problem was chlorination, water system operators started injecting chlorine. The first chlorination system was installed in New Jersey in 1906, and within 10 years, every major water utility followed suit.
You could ask "why did it take so long for operators to add disinfectant when typhoid rates were dropping like a rock in cities with chlorination?" this question is the core of the current water crisis in the US. Why did it take so long for proven science and real-world solutions to be implemented? Well it's because change is hard, and change on a large scale is even harder. Add government pace, politics and funding constraints to the mix and you've created a leviathan.
The world's early water utility operators got really lucky with chlorine, it was cheap, available and was able to kill most waterborne microorganisms without significant harm to humans during consumption. Chlorination is still used in nearly every water utility today.
But the body does not have a chlorine requirement. Humans gain nothing ingesting chlorine, they only benefit from the effects of the chlorine on the microorganisms in said water.
Modern Water Systems
While chlorination was a clear win in the humans vs microorganisms war, the technology has been stretched to its limit in modern utility systems. While we don't see typhoid or cholera outbreaks in the developed world at a scale we used to, we are losing a war against a totally new enemy: Contaminates.
It is helpful to sort all things in potential drinking water into two categories:
- Living contaminates: Viruses, bacteria, protozoa, and multicellular parasites
- Non-Living contaminates: Chlorine, Lead, PFAS (millions more)
Living contaminates are fairly straight-forward to mitigate - you just kill them. When a living contaminant is destroyed, the remnant molecules are not dangerous to ingest. Methods of killing these organisms include chlorine, ozone, and UV. While chlorine must be mixed in with the water while it is delivered to the point of use, ozone and UV leave no trace of their presence, only the dead remnants of living contaminates.
The second, and much scarier issue in drinking water are the non-living contaminates. These could be anything from well understood and easily testable lead levels, to modern unregulated research PFAS. The sizes of these contaminates are tiny in comparison to the living ones, and sadly we can't just kill them. We have two options in treating for these chemicals:
- Trap - Keep these molecules suspended outside of the product water flow and discard them in solid or waste water. An example of this is using a carbon block filter to trap chlorine molecules, removing them from the stream.
- React - Use a chemical reaction to change the molecules into something that is not harmful. An example of this is using KDF filter media to create a galvanic reaction and turn chlorine into harmless chloride.
Parts Per Trillion
When working to trap or react modern contaminates, we have to adjust our scale of thinking. Many of these substances are so harmful, that the maximum contamination levels (MCLs) set by the EPA are measured in parts per trillion.
To put that into perspective, one part per trillion is one drop in twenty Olympic swimming pools.
We are talking about tiny amounts of a given substance that has the ability to cause significant bodily harm when consumed. The old methods of delivering clean drinking water to every home are failing rapidly in the face of modern contaminates. These molecules were designed in laboratories specifically to be extremely hard to break down.
Decentralized Treatment
Enough with the problems, it is extremely clear that most of the water delivered to consumers today has unacceptable levels of many chemicals. So how do we treat this water in the most effective and efficient way possible? My view is that those who care will start treating their own drinking water in their homes. We know that less than 1% of water going into any house will be used for consumption, so the volume of water in need of treatment is very low relative to other uses.
Of the decentralized treatment methods there are two types:
- Point of Use: The water is filtered right where it will be dispensed for drinking or cooking.
- Point of Entry: The water is filtered when it enters the house, and then distributed via the internal water lines to the hot and cold systems.
Point of use water filtration has been my focus, mostly because it is solvable for more people in aggregate. Point of entry systems require large amounts of floor space, as well as expert plumbing, monitoring and maintenance. Point of use systems can be much smaller and can be maintained by the consumer.