How to Choose the Best Method of Water Treatment

The market is literally flooded with water treatment options. Reverse osmosis systems, water filters, and distillers all promise sparkling, clean water, but how do you know which one is really best? With a little research, you can find the ideal water treatment system for you.

Steps

1. Find out the source of your home's water. If you are receiving water from a well on your property rather than municipally treated water, your needs will be much different. You may want to purchase a distiller or reverse osmosis system to remove tough bacteria.
2. Learn about specific water contaminants in your area. A lot of this information can be found out through the EPA. Also, each year your city should produce a water safety report, discussing the incidence of specific contaminants in your city's water.
3. Find out about the use of pesticide chemicals in your area. Water in Midwestern states is much more likely to contain chemicals from pesticide runoff.
4. Determine if your city receives its water from surface water or groundwater sources. Groundwater is much cleaner, overall, and may need only mild treatment with a home water filter. However shallow wells or dug well can be contaminated by pesticides, petroleum spills and animal droppings.
5. Find out if your community fluoridates its water. Fluoride can be particularly damaging to the elderly and has been linked to cases of Alzheimer's disease.
6. Evaluate the needs of your family. If anyone in your family is prone to asthma or respiratory illness, you will want to cut down on chlorine fumes in your home with the use of a whole house water filter or other point-of-entry filtration system.
7. Learn about your home's plumbing system. Many homes built before 1998 contain lead in their pipes that can corrode into drinking water. If you have lead pipes, you will definitely need a point-of-use water treatment system.
8. Recognize that some believe that distillation is the only method in which water can be purified. The thinking goes that the only real definition for pure water is "H20" with a complete absence of any contaminants. Distillation mimics the hydrologic cycle of evaporation (boiling to steam), precipitation (precipitation in a aparatous, normally a condensing coil), and condensation leading to rain (water cooled usually by a fan and and drips into a sterile container).
9. Take all of the above factors into consideration when researching and purchasing a water treatment system. Water filters are best for municipally treated, chlorinated water while reverse osmosis systems and distillers are best for treating well water. The EPA recommends that if you have a well it should be tested annually for bacteria and other impurities. A Ultra Violet light sterilization unit might be a better way than a Reverse Osmosis system to eliminate bacteria. Keep in mind that Distillation systems are expensive and Reverse Osmosis systems might not produce the water rate you desire for your water needs. Remember that not only do you drink water but you brush your teeth and wash your fruits and vegetables and dishes in water that could be contaminated. Testing is the only way to determine if your water is suitable for drinking and other uses. It is best to have the test performed by a chemist or a certified laboratory. The best water solutions are designed by technical people with access to scientists. There are many variable to be considered. Before you purchase a system be sure that you are satisfied that the system seller understands your water source and uses for the water.

Water Treatment Comparison

This page shows a summary of various water treatment methods and their relative advantages and disadvantages. If you are unsure which system you need, perhaps you should take a look at the problem pages.

Method		Advantages		Disadvantages		Costing
Water Conditioners		Output water is suitable for low sodium diets Prevents Limescale, water utilizing appliances last longer Increases heating efficiency Improves soap efficiency Calcium retained, good for diet Low running cost		Won't treat anything but specific hard water problems		Small Property - $146 (£95) Typical System - $244 (£150) Large Residential / Industrial - $511 (£95315))
Water Softeners		Prevents Limescale Increases heating efficiency Lengthens lifespan of clothes		Output water may not be suitable for drinking Expensive to install and maintain		£400 ($765) 35,000 grain capacity £460 ($869) / 48,000 grain capacity
Activated Carbon (AC) Water Filters		Effective in removing organic contaminants from water, will also remove chlorine		AC filtration does not remove microbes, sodium, nitrates, fluoride, and hardness. Assume that it wont remove lead or other heavy metals unless specified by the manufacturer		Point of use system - $50+ Whole house system- $550+
Ultraviolet (UV) Water Filters		Generally kills 99.9% of bacteria and viruses High Filtration Capacity (10 Gallons per minute)		Only kills bacteria, doesn't remove the dead cells and won't remove other contaminents		approx $500
Water Distillers		Mimics the natural water cycle process. Distilled Water is almost completely pure, free from all forms of contaminent		Low Filtration Capacity (6 Gallons per day!) High running cost (25 cents per gallon)		$250 - $1700
Sand Filters		Removes most bacteria, and turbity. High Filtration Capacity Generally best used for swimming pools and ponds.		Take up a lot of space Sulphates and Calcium generally not removed		$300+
Reverse Osmosis		Removes substances that would otherwise cause the water supply to be unhealthy or unappealing, for instance foul tastes, smells or colours. Removes Salts and Minerals (lead/mercury)		Typically, reverse osmosis systems will only recover about 5% of the water that passes through them, the remainder of which goes down the drain as wastewater. The storage unit for treated water will support bacteria growth unless regularly disinfected.		From $259 (comes self assembled and ready to install) Replacement Membranes $5-$130

Water Filters

There are a number of methods of water filtration, each with varying degrees of effectiveness, and varying costs. The general purpose of filtering water is to improve the water's hygiene and aesthetic qualities. Some of the available water filters are described below:

Activated Carbon (AC) Water Filters

Activated Carbon Filtration is an established technology that works through absorption of the problematic compounds, primarily to remove taste and odour but systems will also remove some harmful contaminents. AC is a highly porous material with a very large surface area. Chemical pollutants are attracted to and held by the AC's surface. These water filters are best suited for the removal of organic compounds.

Ultraviolet (UV) Water Filters

UV Filters are able to kill the majority of bacteria and viruses in the water which passes through them. However, they won't remove chemical pollutants from the water. Also you should note that the treatment is ineffective outside of the treatment area, so water should be used immediately after it is treated.

Water Distillation (Water Distillers)

Water Distillation involves heating the water to boiling point and condensing the steam. Pollutants with a boiling boint near that of water are hard to remove, but generally the distilled water is of a very high quality.

The major drawback to this method is that it requires a large amount of energy. Some people will also complain that the distilled water tastes flat (this is due to less dissolved oxygen).

Sand Filters

Sand based water filters have been used for over 100 years to treat waste water. They are generally used on a larger scale to treat a water supply for a whole community, and will be custom made. Most units require a constant flow of water to work correctly, and so wouldn't be suitable for well water treatment. However, recently a Canadian scientist, David Manz developed an intermitent unit. You can buy pre-built commercial units for home use which are typically used with swimming pool pumps.

Reverse Osmosis

In water filter terms, reverse osmosis (or hyper-filtration) is the process of filtering water under pressure through a semi-permeable membrane, allowing water to pass through but rejecting other particles such as bacteria, toxins, salts, and anything bigger than around 150 Daltons.

Drinking Water Problems

Drinking water in the UK is usually of very high standards; occasionally however, drinking water is not up to standard and can cause health problems. Examine your drinking water, it should appear clear and bright. If it is discoloured, cloudy or has an unwanted taste or smell you should contact your local water company and have your water tested.

The following table highlights some common problems with metals and minerals in drinking water and suggests a suitable form of water treatment. For problems with contaminents of an organic nature (viruses, bacteria) please check here.

Problem	Effect on Water	Suggested Treatment
pH	Low alkalinity water tends to dissolve minerals and metals. Water with high alkalinity tend to precipitate minerals and metals	Use Soda Ash to raise, Use white vinegar or citric acid to lower
Aluminum	Discolored water	Reverse Osmosis Distillation
Chloride	Salty taste	Reverse Osmosis Distillation
Color	Visible tint	Reverse Osmosis Distillation Activated Carbon Filtration
Copper	Blue-green coloration, metallic taste	Reverse Osmosis Distillation
Corrosion	Metallic Taste Corrosion Fixture Staining	Calcite Filter Soda Ash Chemical Feed Polyphosphate Feed Sodium Silicate Feed
Fluoride	Spotting and mottling of teeth	Reverse Osmosis Distillation
Foaming Agents (MBAS)	Suds, Bitter Taste, Odor	Chlorination Activated Carbon Reverse Osmosis Distillation
Hard Water	Limescale deposits in plumbing and water appliances, Reduced heating efficiency, Lowers lifespan of boiler units, Requires more soap	Water Conditioner Water Softener
Iron	Rusty color Sediment Reddish or orange stains Metallic tase	Oxidizing Filter Chlorination -> AC Filter
Manganese	Dark brown / Black stains Bitter, metallic taste	Oxidizing Filter Chlorination -> AC Filter
MTBE (Methyl Tertiary Butyl Ether)	Sweet solvent odor Possbile carcinogen	Activated Carbon Filter
Odor	Rotten egg Musty Garlic Chemical Smell	Activated Carbon Filter
Silver	Skin discoloration Grey tint in white part of eye	Activated Carbon Filtration Reverse Osmosis Distillation
Sulfate	Medicinal taste Acts as a laxative	Reverse Osmosis Distillation
Total Dissolved Solids	Hard Water Deposits on glass and fixtures	Reverse Osmosis Distillation Water Conditioner Water Softener
Zinc	Metallic taste	Reverse Osmosis Distillation

Ground Water Contaminants

There are many sources of ground water pollution that can cause nasty tastes and odours, and that may be a risk to human health. Contamination of your well water may occur naturally or be a result of human activity.

* Microorganisms – There are many different types of microorganisms that can cause human illness or result in discolouration of the water or produce nasty tastes and odours. Microorganisms include bacteria, viruses, algae, parasites and many more. Shallow wells are most at risk from contamination by microorganisms, as are those located near farms, wildlife hotspots and high risk flood zones. Water run-offs from these areas are usually the cause of contamination.
* Nitrates and nitrites – High levels of nitrates are usually a direct result of human activity. They are contained in fertilisers which are used on farms, with the potential to run-off and contaminate ground water. If a large amount is consumed this can be damaging to human health.
* Heavy Metals – Much of the underground rocks and soil contain heavy metals such as lead, chromium and many others. They can be damaging to human health but are not usually found to contaminate wells that are properly constructed and maintained.
* Radionuclides – These may lie in the ground water or underlying rock of the well. They are radioactive substances, such as radium, that may be carcinogenic and damaging to human health.
* Radon – The natural breakdown of uranium in the soil produces radon gas. This is a carcinogenic gas that is most threatening when inhaled.

What Can You Do?

If you have a private well there are many steps you can take to ensure that contamination does not become a problem.

* The construction of your well should be done professionally. Poorly constructed wells result in a higher risk of contamination. Monitor your well regularly and fix any problems as quickly as possible. Make sure that the water system is disinfected after construction before it used for drinking water.
* There are many contaminants that are not considered to be a health risk, such as iron and sulphate, but they can give drinking water an unpleasant taste, odour or colour. You could solve many of these problems by conditioning the water supply using water softeners, iron removal techniques, aeration, reverse osmosis or water filters.
* Make sure that the well water is tested periodically for potential contaminants. It is recommended that your well water be tested on a yearly basis for coliform bacteria, nitrates, dissolved solids and pH levels. If you suspect other contaminants due to taste, colour or odour differences, test for those when you notice a problem.
* Make sure you know your area well, identify nearby human activities such as agricultural practices and industry. Find out what flood protection is nearby if you live in a high risk area. This will help you to recognise potential problems and give you a better idea of what contaminants to test for.

types of private drinking wells used

There are generally 3 types of private drinking wells used today:

Dug

Dug - These wells are made by digging a hole in the ground and then casing the hole with a strong material to prevent collapse, such as stone, brick or tile. Dug wells are not very deep, usually ranging from 10 to 30 feet, this short depth means these types of wells are most at risk from contamination. There are a number of features your dug well should have to minimise the chances of contamination:

• The well should be cased with a strong, watertight material.
• The opening of the well should be covered by a concrete lid that is positioned about a foot off the ground.
• Build a mound around the opening of the well so that surface water runs away from the well.
• Try and have your water pump leading to a separate building rather than right next to the well.

Driven

Driven - These types of wells are usually deeper than dug wells, ranging from 30 to 50 feet in depth. This is still reasonably shallow and therefore a driven well has quite a high risk of contamination. There are a number of features your driven well should have to ensure proper construction and minimise the chances of contamination:

• 2 to 3 inch diameter metal pipes should be driven into the ground, with a screen at the end of the pipe. This helps to drive the pipe through sand and gravel so that the water that enters the well is filtered from particulate contaminants.
• Put the pump on top of the well or in a separate building.M
• The well and pit should be capped with the same kind of tile used for dug wells.
• Follow the same instructions as given for dug wells.

Drilled

Drilled – Drilled wells are the deepest form of well and range from 100 to 400 feet in depth. They intersect bedrock cracks containing ground water and this enables a water supply to be given. There are a number of features your driven well should have to minimise the chances of contamination:

• A metal or plastic casing should extend into the bedrock to prevent any shallow ground water from entering the well.
• Your well pump should be installed and serviced regularly by a professional.
• Try and adopt a pitless adapter design for your well, this seals the point where the water leaves the well and enters your home.
• You can increase the yield of your well and maybe improve its quality by a process called hydrofracting. This is where water or air is pumped into the well at high pressure, opening up existing fractures and creating new ones.

source : http://www.water-treatment.org.uk

Drinking Water Standards

Arsenic
The Safe Drinking Water Act requires EPA to revise the existing 50 parts per billion (ppb) standard for arsenic in drinking water. EPA is implementing a 10 ppb standard for arsenic.

Ground Water Rule
EPA proposed a rule which specified the appropriate use of disinfection in ground water and addressed other components of ground water systems to assure public health protection.

Lead and Copper
EPA estimates that approximately 20 percent of human exposure to lead is attributable to lead in drinking water.

Microbials & Disinfection Byproducts
A major challenge for water suppliers is how to balance the risks from microbial pathogens and disinfection byproducts. This web site includes development of the Ground Water Rule, as well as the two new final rules: Long Term 2 Enhanced Surface Water Treatment Rule and Stage 2 Disinfectants and Disinfection Byproducts Rule.

MTBE
MTBE (methyl-t-butyl ether) is a member of a group of chemicals commonly known as fuel oxygenates. MTBE replaces the use of lead as an octane enhancer since 1979.

Radionuclides
EPA has updated its standards for radionuclides in drinking water.

Radon
Radon is a naturally-occurring radioactive gas that may cause cancer, and may be found in drinking water and indoor air.

source : United States Enviromental Protection Agency