Freshwater treatment through chemical disinfection is often found on yachts, let’s have a deeper look into this.
Commonly used chemisterilants such as Chlorine or heavy metals (e.g. Silver- or Copper-Ions) are useful to prevent growth of any organic matter within your tanks just like it is used by most water suppliers providing large quantities of water to municipalities. Using such oxidation agents a couple of times per year followed by a thorough rinse is unproblematic and is often part of standard maintenance. Dosing systems for permanent use will keep your tanks, piping and service water clean, yet when the tank water is used without post-filtration (activated carbon) a displeasing feeling on your skin or hair can be quickly experienced after a shower. (Think about dry skin or elderly women with purple hair….)
In regards to drinking water these treatment methods are rather adverse though. While pathogens (virus, bacterium, protozoa, prion, or fungus) can be simply overcome by UV or Ultra-filtration, any chemisterilants like chlorine will introduce disinfection byproducts (DBP’s) which are considered carcinogenc and are suspected to damage the liver, kidneys and central nervous system.
The concentration of DBP’s is related to the amount of Total Organic Carbon found in your raw water source which varies from port to port. So far, various types of DBPs have been identified but most research has been carried out on chlorinated disinfection due to it’s extensive use. The amount of information out there on this particular subject is shear unbelievable, yet it hasn’t found its way to common knowledge?!?
Sadly it is the same case with pesticides, pharmaceutical residues and hormones. Actually we can often read that especially pharmaceutical residues in surface water in the Western world are of increasing concern for water service providers in their task to provide good public drinking water.
On yachts we have the advantage that we are already quite familiar with organizing our own ‘(drinking) water plant’. Most important though is that we do it the right way to get healthy drinking water and not just ‘potable’ water.
Having the right drinking water solution on board at the point of use does not only substantially reduce our plastic waste, it also provides a healthy version of the “prime source of life”.