Residents use 59 percent of Southern Nevada's water.
Most residents use 70 percent of their drinking water outdoors on landscaping. Residents can use up to 90
percent of their drinking water outdoors during the summer.
20 to 30 percent of the water used in a home is lost to leaks or water waste.
Conservation is every desert dweller's duty. Even small changes can make all the difference.
A garden hose can use more than 10 gallons of water per minute. The Southern Nevada Water Authority (SNWA) recommends that people sweep their driveways instead of using a hose.
It takes 50 gallons of water to wash a car. Commercial car washes are recommended because the facilities capture the used water and send it to the water treatment plant, where it is treated and added back to the water cycle.
Switching to a high-efficiency washing machine can save more than 5,000 gallons of water a year, including 2,200 gallons of hot water.
Washing only full loads in the washing machine or dishwasher can save up to 2,000 gallons of water a year.
Installing a hot water recirculation pump can save 8,000 to 10,000 gallons of water a year.
It takes 20 gallons of water to hand wash the dishes. A dishwasher uses between 12 and 20 gallons. Use the dishwasher to save water.
Leaving the water on while you brush uses 5 gallons of water.
Switching from a high-flow shower head to a high-efficiency shower head can save 8,000 gallons of water a year.
Converting a 20 x 20 foot patch of grass to xeriscape can save about 15,000 gallons of water a year.
Shutting off the sprinklers on rainy days can save 500 gallons of water in one day.
Keeping swimming pools covered when not in use can save 5,000 gallons or more a year.
Properly managing your pool to avoid unnecessary draining and refilling can save 20,000 gallons of water a year.
What contaminants may be found in drinking water?
There is no such thing as naturally pure water. In nature, all water contains some impurities.
As water flows in streams, sits in lakes, and filters through layers of soil and rock in the ground,
it dissolves or absorbs the substances that it touches. Some of these substances are harmless.
In fact, some people prefer mineral water precisely because minerals give it an appealing taste.
However, at certain levels minerals, just like man-made chemicals, are considered contaminants that
can make water unpalatable or even unsafe.
Some contaminants come from erosion of natural rock formations.
Other contaminants are substances discharged from factories, applied to farmlands,
or used by consumers in their homes and yards. Sources of contaminants might be in your
neighborhood or might be many miles away. Your local water quality report tells which contaminants
are in your drinking water, the levels at which they were found, and the actual or likely source of each contaminant.
Some ground water systems have established wellhead protection programs to
prevent substances from contaminating their wells. Similarly, some surface water systems
protect the watershed around their reservoir to prevent contamination. Right now,
states and water suppliers are working systematically to assess every source of drinking
water and to identify potential sources of contaminants. This process will help communities
to protect their drinking water supplies from contamination, and a summary of the results will be
in future water quality reports.
There are 120 inorganic elements that make up the earth's surface. Inorganic minerals are referred to as salts or mineral salts. When these inorganic minerals are dissolved in water they are referred to as "total dissolved solids" or TDS. Throughout our lives we have been taught that we need minerals in our diet; no one disputes this need. However, many dispute the correct source and composition needed to supply our bodies with these necessary minerals.
Should these minerals be organic or inorganic? Many feel that our drinking water is a good source of minerals needed by the human body. Is this so? Should we depend on our drinking water or our food to supply our minerals?
Minerals found in drinking water are known as "inorganic."
Minerals found in our food supply are known as "organic."
Perhaps the following articles and excerpts will be helpful in determining answers for yourself.
Conductivity is defined as the ability of a substance to conduct electric current, which is the
reciprocal of resistivity. All substances posses conductivity to some degree, but the amount
varies widely, ranging from extremely low (insulators such as glass or benzene) to very high
(silver, copper, and metals in general). Most industrial interest is in measuring the conductivity
of liquids, which generally consist of ionic compounds dissolved in water. These solutions have
conductivity midway between insulators and conductors, which can be measured quite easily
by electronic means. This offers a simple test which can tell much about the quality of water,
or the make up of a solution. The basic unit of resistance measurement is the ohm, and the basic
unit of conductivity measurement is the siemens. Conductivity is the conductance as measured between
opposite faces of a 1 cm cube of a given material. This measurement is in units of siemens/cm. For
most solutions this unit of measure is much too large and either m S/cm or mS/cm are used instead.
The corresponding terms for specific resistivity are ohm-cm, Kohm-cm and Mohm-cm. Generally users
of ultra pure water prefer to use resistivity units of Mohm-cm or Kohm-cm, because measurement in this
unit tends to spread the scale out into the range of interest. In these applications, the use of conductivity
has the advantage of an almost direct relationship with impurities, especially at low concentrations. Hence,
a rising conductivity reading shows increasing impurities in the given solution. The draw back to
conductivity is that it is a non-specific measurement; it cannot distinguish between various types of ions
and the reading is proportional to the combined effect of all ions present. Because of this, under certain
circumstances it may be necessary for a through analysis of a given solution to be made. In conclusion,
conductivity offers a fast, reliable, and an in-expensive means of measuring the ionic content of a solution,
with a high degree of accuracy and repeatability.
Absolute Water (pure H20)
Pure Mountain Stream
Power Plant Boiler Water
Good City Water
Maximum for Potable Water
Ocean Water Mid-North Atlantic
pH is a unit of measure which describes the degree of acidity or alkalinity of a solution. It is measured on a scale from 0 to 14. The term pH is derived from ?p?, the mathematical symbol of the negative logarithm, and ?H?, the chemical symbol of Hydrogen. The definition of pH is the negative logarithm of the Hydrogen ion activity.
pH = -log[H+]
Thus pH provides the needed quantitative information by expressing the degree of activity of an
acid or base in terms of hydrogen ion activity. Acid and bases have both free hydrogen and
hydroxyl ions. Since the relationship between hydrogen ions and hydroxyl ions in a
given solution is constant for a given set of conditions, either one can be determined by
knowing the other. If the ratio of the hydrogen ion is greater than that of the hydroxyl ion
the solution is acidic, and has a pH value below 7. If the ratio of the hydroxyl ion is greater
than that of the hydrogen ion the solution is basic, and has a pH value above 7. If the ratio
of the hydroxyl ion is equal to that of the hydrogen ion the solution is neutral, and has a pH value of 7.
Thus, pH is a measurement of both acidity and alkalinity, even though by definition it is a selective
measurement of hydrogen ion activity. A rough indication of pH can be obtained using pH papers or
indicators, which change color as the pH level varies. These indicators are very limited in their accuracy
and can be difficult to interpret correctly. A more accurate way to determine pH is by using a pH meter.
The pH meter electrode can be looked at as a simple battery, with a voltage that varies with the pH of a
measured solution. This voltage is then amplified and displayed providing an accurate and repeatable
reading for analysis. There is a wide variety of applications for pH measurement. For example,
pH measurement and control is the key to the successful purification of drinking water, sewage treatment,
food processing, electroplating, and the effectiveness and safety of medicines. etc. Plants require the soil
to be within a certain pH level to grow properly, and animals can sicken or die if their blood pH level is not
within certain levels. The efficient and balanced control of a solutions pH is easily controlled by either the
addition of a base or acid to neutralize a solution as required
Ultraviolet Light (UV)
What is UV?
Ultraviolet (UV) light is at the invisible, violet end of the light spectrum. Even though we can't see UV light, we are exposed to UV rays from all light sources, including the sun. The water treatment industry uses a high-powered form of UV light called UV-C or "germicidal UV" to disinfect water.
How does it work?
UV-C rays penetrate the cells of harmful bacteria and viruses in your drinking water, destroying their ability to reproduce. Without the ability to reproduce, these organisms die and no longer pose a health threat. It's a simple but effective process, with Trojan's system destroying 99.99% of harmful microorganisms.
Why not use chlorine?
Chlorine changes the taste and odor of water. Chlorinating also produces harmful by-products called Trihalomethanes (THMs) which are linked to the incidence of cancer.
Is pre-treatment of my water required for a UV system to work?
The quality of your water will determine if pre-treatment is required. These three water quality characteristics can affect the performance of a UV unit:
Suspended solids can "shadow" smaller microbes from UV light
Some compounds, particularly iron, can collect on the UV lamp's sleeve, reducing the amount of UV available for disinfecting
UV absorbents, such as humic acids or tannins, can reduce the amount of UV available for disinfecting
Water softeners, iron removal systems and sediment/carbon filters are common pre-treatment technologies available to you. Through O3 water, Trojan offers a free water testing service for hardness, iron and UV transmittance. The UV unit should always be the final link in your total water treatment system.
How do I know what size of UV unit to buy?
You can treat the water for your whole home, or just the drinking water from one tap. We will help you choose the right system for your needs. Be prepared to tell us what flow rate your pump has, how many people live in your home and how big it is.
Does a UV system consume a lot energy?
No, the UV unit will consume about the same amount of energy as a 60 watt light bulb. It is a cost-effective, natural way to increase water quality.
How often would I have to change the UV lamp?
It is essential that you change your UV lamp annually. The ability of the lamp to emit UV light decreases over one year in operation. Our units are sized to achieve the minimum requirements for disinfecting at the end-of-lamp-life (one year). Remember, UV light is invisible! Even through the lamp is still glowing after one year, there will not be enough UV light reaching your water to be effective.
Ozone is Created Naturally
Ozone is a naturally occurring gas created by the force of corona discharge during lightning storms or by UV light from the Sun.
Definition of Ozone:
Ozone (O3) is an allotrope of oxygen (O2). It is 1.5 times as dense as oxygen and 12.5 times more soluble in water and leaves no residuals or byproducts except oxygen and a minimal amount of carbon dioxide and water. It can be manufactured from dry air or from oxygen by passing these gases through an electric field of high potential sufficient to generate a "corona" discharge between the electrodes. Ultraviolet light and shorter wavelength radiation also causes oxygen to undergo conversion to ozone, which may be used for industrial wastewaters (Below 1969). Ozone is a more potent germicide than hypochlorite acid by factors of 10 to 100 fold and disinfect 3125 times faster than chlorine (Nobel 1980).
Ozone is highly unstable and must be generated on site. The measure of an oxidizer and its ability to oxidize organic and inorganic material is its oxidation potential (measured in volts of electrical energy). Ozone oxidation potential (-2.07V) is greater than that of hypochlorite acid (-1.49V) or chlorine (-1.36V), The latter agents being widely used in water treatment practice.
Oxidation potential indicates the degree of chemical transformation to be expected when using various oxidants. It gauges the ease with which a substance loses electrons and is converted to a higher state of oxidation (EPA 1990). Theoretically the substance with the lower oxidation potential will be oxidized by the substance with the higher oxidation potential. A substance can only be oxidized by an oxidizer with a higher potential (EPA 1978). The oxidation potentials of common oxidants and disinfectants associated with water and wastewater treatment are all of a lower oxidation potential than ozone. There is only one element with a higher oxidation potential than ozone and that is fluorine.
Organic compounds treated with a powerful oxidant as ozone will not always be converted totally to carbon dioxide and water, especially under abnormal industrial wastewater conditions.
Therefore, no other commonly employed and less powerful water treatment oxidant (i.e. chlorine, bromine, chlorine dioxide, etc.), all of which have lower oxidation potentials than ozone, will oxidize an organic material completely to carbon dioxide and water if ozone will not.
Is Ozone Safe?
Ozone is very safe - in over 100 years of use, there has never been a fatal accident. While chlorine forms thousands of extremely toxic by-products, ozone forms virtually none. These and other properties make OZONE an IDEAL PURIFICATION and DISINFECTING agent. Ozone is generated electrically and therefore adds no chemicals into the treated water.
TASTE & ODOR CONTROL
Most tastes and odors in water supplies come from naturally occurring or manmade organic material contamination. Bacterial decomposition of humic material imparts taste to surface water, also the action of algae and actinomycetes give rise to objectionable tastes. Chlorination of humic material leads to chlorophenols that are far stronger odor and taste antigonists than the original phenol and the Chlorine. Most of these odors are removed by treatment with Ozone. Even some sulfur compounds such as hydrogen sulfide, mercaptans or organic sulfides can be oxidized to Sulfates with Ozone.
REMOVAL OF HEAVY METALS
Ozone oxidizes the transition metals to their higher oxidation state in which they usually form less soluble oxides, easy to separate by filtration. e.g. iron is usually in the ferrous state when it is dissolved in water. With ozone it yields ferric iron, further oxidized in water to Ferric Hydroxide that is very insoluble and precipitates out for filtration.
Other metals: Arsenic (in presence of Iron), Cadmium, Chromium, Cobalt, Copper, Lead, Manganese, Nickel, Zinc - can be treated in a similar way. At Ozone levels above 4 ppm however, Manganese will form soluble permanganate, showing up as a pink color.
Surface waters are generally colored by natural organic materials such as humic,
folic and tannic acids. These compounds result from the decay of vegetative materials and are generally related to condensation products of phenol like compounds; they have conjugated carbon/carbon double bonds. When the series of double bonds extend upwards of twenty, the color absorption shows up in the visible spectrum. Ozone is attracted to break organic double bonds. As more of these double bonds are eliminated, the color disappears. Surface water can usually be decolorized when treated with 2 to 4 ppm of Ozone.
OZONE vs. CHLORINE
In comparing disinfection efficiency, Ozone is effective 25 x more than Hypochlorous acid (HOCI), 2,500 x more than Hypochlorite (OCI) and 5,000 x more than Chloramine (NH2CL). This is measured by comparison of CT constants - the Concentration & Time needed to kill 99.9% of all microorganisms. Chlorine reacts with organic materials to form Chlorine containing organics such as Chloroform, Carbon Tetrachloride, Chloromethane and others, generally known as Trihalomethanes (THMs).
Ozone reacts with Organics to break them down into simpler compounds. These (e.g. Oxalic Acid) do not readily break down all the way to Carbon Dioxide with just Ozone, but if subjected to bacterial degradation on activated charcoal, they will be removed. This water can be later treated with a low level of Chlorine say 0.2 - 0.3 ppm to maintain sanitation in the distribution system. This way no THMs will be formed. The THMs have been implicated as carcinogens in the development of Kidney, Bladder and Colon Cancer. The regulatory authorities are again decreasing the levels of THMs that can be in Community water systems. At the present time the limit is 0.05 ppm. Based on the scientific research, the level will be most likely soon lowered to 0.01 ppm.
Ozone does not react significantly with THMs as they are more resistant to oxidation - it takes a very long time to achieve full oxidation. Some THMs are removed as a result of physical
sparing by the aeration action of the ozone/air mixture.
Ozonation of a water contaminated with Algae oxidizes and floats the Algae to the top of the reservoir. The ozone will also oxidize the metabolic by-products of the Algae and remove the undesirable odor and taste.
IMPROVED COAGULATION & TURBIDITY REMOVAL
Oxidation of dissolved organic materials by Ozone results in polar and charged molecules that can react with Polyvalent Aluminum or Calcium to form precipitates. Treatment of a surface water with up to 0.5 ppm of Ozone results in a decrease in turbidity, improved
settle ability and a reduction in the number of particles. Referred to as pre-ozonation this treatment destabilizes the colloid with a resultant reduction of the amount of coagulant needed to produce a clear filtrate.
OZONE REACTIONS TO ORGANICS
Ozone reacts rapidly with most simple aromatic compounds and unsaturated aliphatics, such as Vinyl Chloride, 1,1-dichloroethylene, trichloroethylene, p-dichlorobenzene, Benzene, etc. But it reacts slowly with complex aromatics and saturated aliphatics. Ozone will degrade many organic compounds, such as sugars, phenols, alcohols, and as it degrades these materials it returns to Oxygen.
Coupling Ozone with Hydrogen Peroxide will cause the formation of very active Hydroxyl ions which cause a nucleophilic attack on organic compounds. This can cause displacement of Halogens and other functional groups such as Amines and Sulfides. Coupling Ozone with Hydrogen Peroxide will cause the formation of very active Hydroxyl ions which cause a nucleophilic attack on organic compounds. This can cause displacement of Halogens and other functional groups such as Amines and Sulfides.
The solubility of Ozone depends on the temperature of water and concentration of Ozone in the gas phase.
mg/l (ppm) dissolved ozone
If oxidizable chemicals are present in the water, even more Ozone will dissolve to satisfy the demand. One limiting factor is the efficient of the mass transfer device used. In case of a pump and Bubble Diffuser, the water column should be at least 16ft. high. Higher concentrations of Ozone in water cause more vigorous oxidation of even resistant organic compounds.
Ozone is effective against a large variety of water treatment problems. In general, the more problems in the water to be treated with ozone, the less an ozonation system costs when compared to other more conventional treatment methods. When one is comparing the cost of an ozonation system to other treatment systems there are some key factors to consider; here are a few:
There is no need to purchase, ship or store chemical oxidants or disinfectants
There is no labor for handling.
Many health and safety concerns are reduced or eliminated.
Because ozone reacts so much more quickly there is opportunity for substantial savings in space requirements for the treatment system.
Because ozone treatment design is flexible, one of the variety of installations can be adapted to any fit any design circumstance.
It is likely that much of your existing treatment facilities are adaptable to an ozone based treatment system.
The pay back of your investment can be surprisingly short.
Reverse Osmosis is a process in which a semi permeable membrane is used to separate fluids of various qualities into a highly saturated concentrate (brine) and a high quality permeated fluid low in dissolved solids. The separation is accomplished by passing the fluid across the membrane at a specified pressure and velocity. The membranes contain pores which approximate two hundred molecular weight in diameter. This allows the fluid and approximately one to two percent of the solids to pass through and be collected for storage. The concentrated solution (brine) unable to pass through the membrane is then processed out of the system. Unlike standard filtration where contaminates continually build up on the filter surface area and gradually decrease the filtering capabilities of the system, reverse osmosis filtration systems provide a self cleaning system by allowing the unfiltered fluid to continuously pass across the membrane surface removing the contaminants as a concentrated solution and preventing surface fouling.
Typical applications for Reverse Osmosis are the purification of seawater, waste water treatment, brackish well water, and city water. However, as the industry grows many more applications are being both implemented and researched at this time, many of which have nothing to do with water purification. Presently this technology is being expanded to include gas separation in the oil industry, protein concentration, breweries, wine and food processing, maple syrup, dairies, removal of cholesterol from butter, undesirable bacteria removal, undesirable pyrogen removal from I.V.’s, etc. As the market expands I believe the industries future prospects are excellent and should continue to expand well into the next century.
Semi permeable Membranes
Reverse Osmosis Membranes are a spiral wound filtration system using alternating
semi permeable and permeable materials to process and separate the product fluid from the concentrate solution. Their filtration capabilities and application are dependent on several factors; chemical composition of the fluid to be filtered and
semi permeable material required due to this composition, fluid temperature, operating pressure, total dissolved solids to be removed, as well as several other small factors to be taken into account. The filter sizing or permeate flow rates are determined as a function of the sq.ft. of
semi permeable material used in the membrane as well as the factors described above. The typical rejection rate of Reverse Osmosis Filters is 90 to 99.9 percent of Sodium Chloride as well as many other impurities. This constitutes an excellent utilization of available water resources for large scale water purification requirements. Filter sizing for both commercial and residential applications generally range from 2” X 12” to 8” X 40”. These sizes will meet almost all applications in today’s water purification industry.
Semi permeable Materials
Only three major membrane groups are being used in water desalinization at this time. A brief description of each is given below as well as there usage's.
Cellulose Acetate (CA)
pH range is 6.0 to 8.0
Good water production rate
Must be used with a chlorinated water supply
Most widely used membrane on the market
Cellulose Tri-Acetate (CTA)
Resistant to most bacteria
pH range is 4.0 to 8.0
Excellent water production rate
Chlorinated water supply will extend membrane life
Thin Film Composite (TFC)
Chlorine sensitive, chlorine must be removed up stream of the membrane
pH range is 3.0 to 11.0
Highest water production rate of all reverse osmosis membranes
Highest salt rejection characteristics
Longest membrane life
4251 naberville road
3601 n.fairfax drive
Ground Water Association
601 dempscy road
2001 i,streer,nw,stuite 506
Rural Water Association
Small Flows Clearinghouse Or
National Drinking Water Clearinghouse
West Vringinia University
Flouridation Of Drinking Water:
your state health department or
amircan dental association
U.S.Environmental Protection Agency (USEPA)
hours of operation are
pan amcrican committe
83 oakawood avenue norwalk,ct 06850
3475 plymouth road
Water Works Association
42a dills street
700 n.fairfax street