Pure water is one of the three essentials of life. The Bau-Biology approach is always to look first to nature. For water, we can look to the seagull. In 1969, Steven Sourirajan, professor of environmental studies at the University of California, discovered thatthe seagull has a special membrane in its throat that enables it to drink salt water. The membrane allows water to be absorbed and the extra salt is then spit out through the nasal passage.
This observation allowed Sourirajan to develop the first reverse osmosis water purifier. Today reverse osmosis has been developed into a marvel of modern water purification technology and is being used all over the world. It has become the most effective method ever invented for water purification. It out-performs flocculation, distillation, carbon filtration, and other methods. Entire city-wide reverse osmosis units have been put into production, sometimes costing hundreds of millions of dollars fora municipal system.
Reverse osmosis units are also being installed in homes. These units need annual servicing for several reasons:
• Filters need cleaning as they collect dirt.
• Reverse osmosis membranes can deteriorate.
• Bacteria can develop in the system.
The reverse osmosis membrane is only one part of this system. Fortruly pure water, there are multiple other filters and steps before and after the reverse osmosis membrane. Reverse osmosis membranes have openings that are too small to be called holes. These pores allow water molecules to pass through but preventthe passage of contaminants. If the filters become plugged with trash, the flow of water is slowed down, reducing the pressure of the water stream, which should be around 60 pounds per square inch. Ideal pressure produces the maximum water purity and best flow and extends the longevity of the components.
In addition to salts, other contaminants are frequently found in water and can be effectively reduced by a reverse osmosis system:
• Heavy metals such as lead, cadmium, mercury, and arsenic, found in all water to varying degrees, are removed by the reverse osmosis membrane.
• Volatile contaminants such as chlorine, am-
contaminants that can adversely affect public health and are known or anticipated to occur in water.
Secondary standards (NSDWRs) are nonenforceable guidelines for contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or have aesthetic effects (such as taste, odor, or color) in drinking water. Hie EPA recommends secondary standards but does not require water systems to comply. States may choose to adopt them as enforceable standards.
The EPA Consumer Confidence Rule requires public water suppliers that serve the same people year round (community water systems) to provide a consumer confidence report (CCR) to their customers. These reports, also known as annual water quality reports or drinking water quality reports, summarize sources used (rivers, lakes, reservoirs, or aquifers), any detected contaminants, compliance efforts, and educational information. The reports are due to customers by July 1 of each year. To find the CCR for your municipal
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monia, and trihalomethanes are also found in public water supplies and can be removed with pre-and post-filter activated carbon. The carbon also helps remove other volatile industrial and agricultural residues such as pesticides and herbicides.
• Bacteria are another important concern, but these will typically be killed by the chlorine found in most municipal water systems. Prefilters will then remove the dead bacteria along with other types of sediment. For purification of water supplies that are not chlorinated, ultraviolet purifiers can be added to the system to kill bacteria.
Reverse osmosis units should be tested and serviced on a regular basis. Annual testing of water quality is a good indicator of how well the unit is functioning and when the reverse osmosis membrane needs to be replaced. Poor water quality in some parts of the country means that membranes and filters need to be replaced more frequently there.
Servicing includes not only replacing filters as
necessary but also cleaning and disinfecting the unit. The procedure involves disassembling the reverse osmosis system, cleaning the unit, flushing it with hydrogen peroxide, replacing the filters, and checking the unit’s performance.
Laboratory water quality tests are only as good as the person doing the evaluation. This means water testing should be performed by a qualified water testing laboratory that specializes in water purification and not just testing. It is of little value to know what is in your water if you do not have a way to remove it.
Warren Clough is a chemist, Certified Water Specialist, and Bau-Biologist with 50 years’experience analyzing water quality and making water purification system recommendations. His company offers free initial telephone consultations and charges minimal fees for water testing to evaluate reverse osmosis units. It can be reached six days a week during normal business hours at Ozark Water Service and Air Services, 114 Spring Street, Sulphur Springs, AR. 72768, 800-835-8908, ozark waterandair. org.
