Portable Water Purifier Requirements
A Water Purifier Should:
- Be effective against the target contaminants it's supposed to remove, under
essentially any and all conditions to be encountered.
This seems self-evident but it isn't always the case. "Pesticide" product effectiveness, in particular, varies and is affected by temperature, concentration, time available, other chemicals in the water (iron, nitrates, phosphates, etc.) and by silt, mud, algae, organics, in some cases by pH, and the condition of the unit. "Device" products typically are not affected, or are little affected by most of these considerations.
- Signal when it is working effectively, and, more importantly, perhaps, when it is not working.
Again, this seems self-evident. With "Device" products the signal is specific --- if water is coming through it should be safe from particles including cysts, mud, silt, etc., and possibly bacteria, depending upon the absolute micron retention. "Pesticide" units give no signal other than taste, which should be monitored with each use. "Pesticide" units fitted with carbon post filters lack even this signal. Resin systems rely on rapid and intimate interaction between target organisms and iodine in the resins. Iron, mud, and silt can coat the resins reducing or eliminating this interaction. "Devices", annoyingly, can clog, but it's better to know the end of capacity than to continue to rely on a process that will continue to flow long after effectiveness is depleted.
- Protect users from concentrations of pathogens accumulated on component surfaces.
Our immune systems, especially in the case of bacteria and viruses, can often defend against low level concentrations of bacteria while larger numbers of concentrated pathogens will cause clinical illness. Therefore, concentrations of pathogens should be contained, isolated, and made inaccessible to users. For units requiring brushing, aerosolised residue and backwash effluent present the potential hazards of post purification inoculation and infection, sometimes by secondary transfer - from filter surface to fingers to cookware or clothing and then to mouth, for example.
- Remove chemical hazards as well as microorganisms.
Even small amounts of some chemicals such as dioxin, for example, can cause health problems and even minute traces can have long term effects.
- Remove asbestos and other microfine debris.
A known carcinogen when inhaled, asbestos is considered to be a possible carcinogen when ingested. Mud and other debris can host a wide range of microscopic organisms and parasites including cysts, bacteria, and viruses, and can contain traces of pesticides. The largest U.S. waterborne disease outbreak (in Milwaukee, WI) was attributed to debris encrusted Cryptosporidia.
- Be convenient to use and versatile.
It's desirable to be able to use a unit in pump mode or in gravity assist mode and it should be straight forward to attach it to a trail bottle or other storage bottle.
- Be designed to avoid cross-contamination between inlet and outlet fittings and hoses, and should have a sanitary cover to prevent contamination of the outlet, even in campsite and meal preparation areas.
- Be field maintainable with easily accessible pump parts.
If it can malfunction, it eventually will.
- Provide deliciously refreshing drinking water, free of chemical taste, odours, colours and sediment.
- Be rugged and intrinsically reliable as to it's basic function, i.e., if it "works" it should produce safe drinking water.
It should not be easily damaged by freezing, dropping, tinkering, poking or other general misuse. Preferably, some method of checking integrity should be included or described, to check and assure proper functioning after shipping, dropping or servicing the unit.
- Be selected for your particular mode of use.
Sometimes weight and compactness, after meeting all of the above requirements, are prime considerations. At other times flow rate, ease of use, ease of maintenance, flexibility of use or other considerations will be more or less important. With the wide selection of products available today you can choose what's best for your intended use.
- Be reasonably priced.
Cost per litre usually is not a prime consideration, and even convenience of use, while important, should be secondary to effectiveness and dependability.
You should try to learn about various products you are considering and also about the manufacturers.
- How long have the products been on the market?
- Who has used them?
- Have they been proven effective in preventing waterborne health hazards?
- What about warranties, test results, customer service and other very important factors?
- What other markets does the manufacturer serve and who are its customers, (sophisticated users such as medical research teams, airlines, and corporations can't afford mistakes and often evaluate products thoroughly!)?
All of these are important factors and probably say more than editorial "choices" and tabulated feature and fluff comparisons about your eventual satisfaction with the systems you select to protect your drinking water health. After all, you are the one responsible for your own drinking water safety and health. You can see the effectiveness of the First Need Deluxe water purifier here.