WATER NEWS - BOATING & RV'S

Pure Water Tips - Potable Water Storage Tanks


Potable water storage tanks aboard yachts, aircraft, recreational vehicles and mobile homes frequently provide an almost ideal environment for the rapid multiplication of bacteria, algae, fungi, mold, mildew, Giardia, Cryptosporidia, amoebic cysts, microscopic worms, larvae and other undesirable creatures and plants.

The problem is exacerbated by using different water sources. Most water supplies, including "city water", contain bacteria, usually non-pathogenic, but even these "harmless" bacteria occasionally can become troublesome if present in sufficient numbers. Ground water sources can contain iron bacteria and slime in addition to having a higher probability of contamination from sewage intrusions and leaks into supply aquifers . . . sometimes many miles away. Campgrounds and yacht harbors - - particularly those on tidal water, with floating docks, pump-out stations and outside toilets are particularly vulnerable to leak and intrusion problems.

Along with carrying a 3 to 6 ppm residual of sodium hypochlorite (chlorine) in the potable water storage tank to keep the tanks clean and free of slime, algae and excess bacteria build up, an effective drinking water system in the galley provides the best protection. Sodium hypochlorite is readily available under several well known trade names such as Clorox®, Purex®, etc. (see Summary for dosing levels).

Although useful for killing many pests, chlorine is not especially effective against cysts and larger parasites- a leading source of dysentery, worldwide- and provides essentially no protection against Cryptosporidium. (More than 400,000 people were sickened by Cryptosporidium in Milwaukee in 1993; thousands were hospitalized, and more than 100 deaths were attributed to this parasite. More died in Las Vegas the next year, and there have been many other incidents... mostly on "safe" water supplies meeting all health safety standards.) Cryptosporidium, Giardia, and amoebic dysentery cysts are found essentially everywhere. Additionally, foul tastes and odors, sometimes coming from fiberglass storage tanks holding chlorinated water, can render water almost undrinkable, especially in the concentrations necessary for assured protection against bacteria growth.

Importantly, in addition to microbiological and aesthetic considerations, it is now well established that chlorine contributes to many known and suspected cancer-inducing agents such as chloroform, carbon tetrachloride and many other halogenated hydrocarbons. (Chlorine also has been implicated in heart disease.) Halogenated hydrocarbons are hydrocarbon pollutants that link chemically with chlorine, iodine, bromine or fluorine. This reaction needs only trace amounts of contaminant compounds, and since our nation's waterways and water sources are practically all contaminated to at least a minor extent, the E.P.A. has estimated that probably all water supplies contain at least some cancer causing agents.



Of the various water systems on the market, the General Ecology® drinking water purifiers are the all-around single best systems available. There are literally dozens of products on the market ranging from ordinary charcoal filters (which have been shown to actually support bacteria growth) to the non-purifying, silver ion/granular charcoal bacteriostatic units which seem to be little better than charcoal filters.

The fact that some units must be E.P.A. registered creates a great deal of confusion. In addition to an EPA "Establishment Registration" number, which all manufacturers must have, products which incorporate "economic poisons" i.e. pesticides, must carry a second EPA registration for the product. This EPA product registration does not mean the product is a purifier. All products, including "Comet" cleanser for example, are required to have this second registration number.

Seagull®IV purifiers and Nature Pure® Ultrafine purifiers work quite differently from such chemical pesticidal units in that each is a "purification device" that physically removes cysts, microscopic parasites and even viruses through a 3-stage process of ultrafine microstraining, broad spectrum molecular capture, and electrostatic removal. It is properly described as a non-chemical system because it doesn't rely on injecting pesticide into the water and eventually into the environment.

Furthermore, Seagull IV purification system and Nature Pure purification system, each is rated among the best, of all units tested, in removing chlorine and other such chemical contaminants. Unlike other products, it is easy to tell when you need a new purification cartridge because it eventually clogs, reducing water flow until it finally stops. Consumers should be aware of filtration products that "last several thousands of gallons". This usually means only that they will still be able to pass water, long after whatever effectiveness they might have had is expended.

Seagull IV purifiers and Nature Pure Ultrafine purifiers operate at a minimum water pressure of about 20 to 30 psi. Flow rate and cartridge life are given for 35 psi of pressure. General Ecology, Inc. offers a hand pump for Seagull IV systems having inadequate pressure. Seagull IV water purifiers are available with average 1gpm and 2 gpm flow rates and average 1000 gallon, 2000 gallon, respectively. Nature Pure water purifiers are available with average 1/2 gpm flow rate and an average 500 gallon capacity.

Note: Seagull IV and Nature Pure "Structured Matrix" purification cartridges should be removed and air-dried if your water system is inactive, i.e., when winterized. (NEVER put antifreeze into your cartridge) The drycartridge should then be placed in a tightly closed plastic bag. Be sure to drain the Seagull IV or Nature Pure pressure vessel if freezing could occur.

Summary: For an effective and a safe water supply, do the following: