Water - Where And How To Drink It
Andy, the Wales Outdoors owner has walked the hills for years, taking sips and long draughts alike from mountain streams, and he seems fine ;) However, there is a risk to health and this article explains those risks and offers solutions to wild water drinking.
THE DANGERS
Drinking water directly from streams and rivers can be hazardous because such sources could contain Pathogens; a Pathogen is a disease causing organism commonly referred to as a germ.
There are four types of water-borne pathogens that are of concern:
Protozoa – single cell organisms often transferred through human and animal faeces. They are highly resistant to chemical treatments but are easily filtered because they are relatively large. They can also be treated with UV Light and heat. Giardia, Cryptosporidium.
Bacteria – single cell organisms that can reproduce in water. Medium sized, they can usually be removed by filters though not all will have this capability. Can also be treated with UV and heat. E. Coli, Salmonella, Cholera.
Viruses – these are spread through water but only reproduce in a host. They can be difficult to filter because they are small, they are sensitive to chemical, UV and heat treatments. Hepatitis A, Norwalk, Rotavirus.
Multi-cellular parasites – Large and can be easily filtered, can also be treated by boiling. Resistant to UV and chemicals. Hookworm and Roundworm.
LOCATION, LOCATION, LOCATION
The primary threats in water collected from rural, relatively pristine sources are Bacteria and Protozoa, the likelihood of Viruses being present is very low.
To see the products available and choose the most suitable for you GO HERE!
Water Treatment Options:
Pump Filtration
Effectiveness - Effectively removes Protozoa, Parasites and Bacteria
Method - Water is pumped through a filter unit
Drawbacks - Most do not remove Viruses
Gravity Filtration
Effectiveness - Effectively removes Protozoa, Parasites and Bacteria
Method - Gravity provides the force to move the water through the filter unit
Drawbacks - Most do not remove Viruses
Bottle/Squeeze Filtration
Effectiveness - Some models effectively remove Protozoa, Parasites and Bacteria
Method - Convenient but most have limited capacity and flow rate
Drawbacks - Most do not remove Viruses. Many do not remove organisms
UV Light Treatment
Effectiveness - Effectively removes Protozoa, Bacteria and Viruses
Method - Uses Ultra Violet light rays to destroy Bacteria, Protozoa and Viruses. Lightweight & convenient
Drawbacks - Water MUST be clear, may not be reliable unless water is pre-filtered
Not effective against metazoa (multi celled parasites eg nematode worms, flukes
Chemical Treatment
Effectiveness - Effectively kills or deactivates most Protozoa (some don't kill cryptosporidium), Parasites, Bacteria & Viruses.
Method - Liquid or tablets added to water. Can impart a taste to the water, effectiveness reduced for cloudy water. Lightest, most compact option. Waiting period is required, 30 minutes up to 4 hours
Drawbacks - Reduced effectiveness in cloudy water
Boiling
Effectiveness - Effectively removes Protozoa, Parasites, Bacteria and Viruses
Method - One of the most effective ways to purify water, requires a rolling boil for 1 minute
Drawbacks - Does not remove chemicals or inorganic matter
Mechanical Purification - Ultra Filtration
Effectiveness - Removes Protozoa, Parasites, Bacteria and Viruses
Method - Purifies water using the same 'process' as a filter
Drawbacks - Greater initial expense
