Water Purification System

A Portable Pump And Filter System For Producing Clean, Potable Water From
Creeks, Rivers or Waterholes.

A Pump and Purification System, designed for topping up Caravan
Water Tanks while Free/Bush Camping.


The Pump/Filter Unit is carried (on a collapsible fold-up trolley) to a nearby water source and is powered by its own 12v 40AH AGM Battery. The pump is 40 PSI, 17 L/Min and the Battery has its own dedicated 5w Solar Panel for re-charging.

The raw, untreated water is pumped through a Multiple Filter System located with the pump at water's edge, then on to the 'holding tank' (a 20 litre Food Grade bucket). 

The Filter Unit is a flexible setup, depending on the 'quality' of the water being pumped...i.e. the turbidity. Visually clear running water is processed through one less sediment filter than other water. For still, turbid water (which I avoid like the plague and rarely use) one extra sediment filter is added to the mix. In this case, the extra filter is a less expensive 10" x 2.5" Sediment Pre-Filter, which combined with the others, removes all the sediment particles.

Otherwise, the first stage is a quality 0.5 micron Sediment Filter (that will even trap Giardia I am told) and the second stage is a 1 micron Coconut Carbon Filter, also 10" x 2.5" size and the third stage is a B.E.S.T. inline filter.

 

At this stage, the water is crystal clear, but still not suitable for drinking. It is important to understand that water filters do not 'purify' water, they only clean it. And clean water isnít enough. It must be purified, because even clean filtered water may still contain traces of bacteria and viruses.

The water is now pumped into one or two 20 litre buckets, where it is treated to *kill the remaining germs. This can be accomplished in 3 ways:

1. Chlorine in the form of Liquid Pool Chlorine, which usually has 12% active ingredient. For that strength, 4ml per 100L is recommended, will render it biologically safe. Care must be taken when handling this product, so be sure to follow all precautions. Do not add it to your water tanks undiluted.

2. Hydrogen Peroxide (Food Grade) suitably diluted. If this is your choice, I'd suggest using a product called HydroSil-ULTRA, a Silver Stabilised Peroxide Water Sanitiser 7.8%. It acts to oxidise bacteria, without leaving any dangerous residues behind. It sanitizes and protects your tanks and water storage devices, making the water safe and suitable for human consumption. HydroSil-ULTRA is not a chlorine based chemical like most sterilizers on the market today. It is non toxic, and safe to use around your home and family.
 

3. Katadyn Micropur Classic Powder. This is the method I have chosen.

The Katadyn Micropur powder utilizes Silver Ions and preserves water for up to 6 months. However it is not cheap. A 500g tub costs around $150, but it has a 10 year shelf life and a little goes a long way. The recommended dose is 1gram per 100 litres, so my 500g tub will treat 50,000 litres. As I'm normally only 'topping up' in 20 litre batches, each top-up costs only 6cents. A complete fill of our 2x60 litre tanks would cost 36cents!

Katadyn Micropur powder renders the prefiltered water perfectly SAFE after 2 hours. It is then pumped into the vans water tanks through a 0.5micron activated carbon filter, to remove any surviving pathogens (highly unlikely).

This water is now suitable for washing, showering and drinking, but for peace of mind more than anything, we again filter it through a Doulton UltraCarb 10" Ceramic Water Filter Cartridge, under the sink just before the kitchen tap, to improve taste and catch any possible residual bugs.

With this setup, we can take water (except sea water) from virtually any source (creeks, rivers, lagoons,
billabongs and in a pinch, even cattle troughs and puddles!) and produce clean drinking water.

An alternative to using Chlorine, Hydrogen Peroxide or Micropur, would be to pump the filtered creek water through a Reverse Osmosis set-up and the resulting 'pure' water fed directly into the van water tanks. However, RO is a slow process requiring good pressure and flow rate (not always available with most 12v water pumps) and as much as 300 litres (perhaps more) would need to be processed to obtain 100 litres of pure water, which would take all day. You also have the 'problem' of disposing of the waste water, which represents the majority of the water processed.

* Micropur Classic Powder deactivates bacteria after 2 hours - Fact Sheet                                 

All 'Holding Tank' Components and other bits and pieces pack away in the bucket. The Pump and Battery Box stores the snap-on and flexible hose fittings, which fits neatly in the back of the vehicle. The Filters and hoses store in a plastic tub and the fold-up trolley slides into a small space in the back of the vehicle. The entire Kit takes up very little space.

 

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