Understanding Water Filtration

understanding water

Understanding Water Filters For Municipal Water & NSF Standards


 Water is the most abundant resource found on Earth,
but only a small percentage of it can be used for drinking water.


Concerns about water quality have been around for many years as the environmental movement raised consumer awareness of polluted water supplies. Today, water safety is more important than ever as those contaminated water sources make their way into our drinking water. The purpose of a water filter is to remove contaminants from the water. These impurities can be broken down into three categories:

 1. Organic and Inorganic suspended solids, cysts and microbiological contaminants

 2. Chemical contamination

 3. Dissolved minerals and gases

Filters can remove some microbiological contaminants, most suspended solids and some chemicals using either mechanical filtration, chemical filtration or both. Dissolved minerals (TDS) and gases require treatments such as softening or reverse osmosis.

Good As Gold Coffee makes use of a variety of filters or combination of filters to address most of our water concerns. The three methods of filtration that we utilize are;

     1.    Mechanical Filtration – It is the process of removing or separating suspended solids and cysts from the water. Simply, a mechanical filter is a barrier with a large number of tiny holes. The mixture of water and solids is pushed through this barrier by water pressure and any solid particles larger than the holes are trapped. The size of these “holes” determines the level of filtration in terms of micron rating. A micron is the measurement used to describe the physical size of solid particles in any water supply. As a point of reference, one micron equals approximately 1/25,000 of an inch, and solid particles that measure less than one micron in size are occasionally referred to a “colloidal,” or sub-micron, particles.  Good As Gold utilizes Everpure precoat(a pleated membrane coated with powdered carbon called micro pure) and carbon block (extruded activated carbon)filters that are rated .5 microns and below. By mechanical filtration they are able to remove cysts (giardia and cryptosporidia) as well as suspended solids both inorganic materials such as silt, clay and ferric iron, and organic materials such as decaying plants from our water. Pre-filters are the first line of defense by mechanically filtering the larger particles before they clog up the fine filtration filters.

    2.   Chemical Filtration – It is the process used for the removal of dissolved wastes and chemicals from     our water. Activated carbon is the most common component employed in chemical filtration. Carbon can rem ove chemicals by either absorption or by adsorption, also called catalytic reduction. Absorption is where the molecules of the chemicals are attracted to the carbon and adhere to it. Adsorption or catalytic reduction is a process by which the carbon breaks the chemical down. In the case of chlorine, carbon reduces it to a chloride ion. Organic chemicals are removed by absorption and disinfectants such as chlorine and chloramine are removed by adsorption. The amount of chemical reduction by carbon will depend on the specific chemical, the amount and type of carbon, and the flow rate or contact time through the carbon bed. Chloramine removal requires a much longer contact time with the carbon than chlorine. 

    3.    Reverse Osmosis filtration – Is a filtration method that involves the application of pressure to force water through a “selective” semi-permeable membrane from a more concentrated solution to a weaker solution. This prevents large molecules or ions from passing through the membrane such as salts and allows the solvent (water) to pass through reverse osmosis involves the application of pressure to force water to move through a porous, semi-permeable membrane from a more concentrated solution to a weaker. The membrane allows water to pass through, but blocks the passage of bulkier salt molecules. The end result is water without salt on one side of the membrane. It is effective in removing minerals and organic materials, such as bacteria and pathogens from the water.  Reverse osmosis is ideal for removing contaminants in areas not using municipally treated water. However, it is a very wasteful system.  In order to create one gallon of filtered water, four or more gallons goes down the drain.

  

Understanding NSF Water Standards

Municipal water systems are required to meet the standards for contaminant levels established by the EPA under the authority of the Safe Drinking Water Act. The EPA entrusts the States to adhere to these standards but may set their own standards but no less stringent than the EPA’s.

The Environmental Protection Agency's (EPA) Consumer Confidence Reports (CCRs) have helped raise public awareness of water safety. While municipalities follow strict guidelines to disinfect water and protect against contamination, the threat still exists. Water distribution pipes leading from most of the nation's treatment plants often allow rust, lead and other corrosive metals to contaminate previously treated water. Plus, despite increased vigilance from municipalities, certain harmful cysts, like Cryptosporidium, remain resistant to common disinfectants like chlorine and ammonia. And, in rural areas, where water is sourced from untreated wells, the safety of what's coming out of the tap is even more questionable.

So understanding what's in your water is the first step towards water safety. Check with your local municipality for a copy of your CCR. Or, have your water tested by a Water Treatment Specialist or laboratory. Once you know what's in your water, investigate and understand the treatment technologies available to treat the problems that are lurking in your water. Then, select the most cost-effective solution for your needs.

To help you sort through the different product offerings and technologies available, independent testing agencies set product standards for water filtration. NSF International's Drinking Water Treatment Unit Certification Program is the most widely accepted certification program. NSF Certification means the contaminant reduction claims listed on the label are true and accurate, the materials of construction do not add anything to the water, the system is structurally sound and that advertising claims are true and accurate.

NSF has developed a series of standards to reflect various levels of filtration. NSF/ANSI Standard 42 for Aesthetic Effects list several "classes" of performance for the basic functions of adsorption and mechanical filtration. These are measured by percentage reduction over the stated life of a unit.

Taste & Odor Reduction and Chlorine Reduction: Class I: At least 75% reduction (highly effective) Class II: 50 to 75% reduction (somewhat effective) Class III: 25 to 50% reduction (least effective)

Particulate Reduction: Class I: 0.5 to 1 micron (smoke, small clay particles) Class II: 1 to 5 microns

Class III: 5 to 15 microns (most protozoa, pollen, silt) Class IV: 15 to 30 microns (mold, spores, rust particles) Class V: 30 to 50 microns (barely visible root hairs, rotifers) Class VI: over 50 microns (sand, leaf fragments, insect parts)

NSF's second standard to which filtration systems are tested is NSF/ANSI Standard 53 for Health Effects. This is NSF's highest standard available for protection against health hazards such as lead and cysts. With Standard 53, there are no class distinctions, but merely a pass/fail test. Contaminant reduction levels are as follows:

Cyst Reduction: 99.95% reduction of particles in the 3-4 micron range. Turbidity Reduction: Over 90% reduction of 10-12 units of turbidity in water.

Lead Reduction: Minimum 90% reduction of 15 ppb lead to 15 ppb or less at both high and low pH levels. Asbestos Reduction: 99% reduction of fibers exceeding 10 micrometers in length. Chemical Reduction: Usually 95% reduction of severe pollution levels to the MCL or lower, for the unit's entire rated capacity.

NSF/ANSI Standard 58: Reverse Osmosis Drinking Water Treatment Systems. These systems typically consist of a pre-filter, RO membrane, and post-filter. Standard 58 includes contaminant reduction claims commonly treated using RO, including fluoride, hexavalent and trivalent chromium, total dissolved solids, nitrates, etc. that may be present in public or private drinking water.

Another organization that does water testing is the The Water Quality Association (WQA) and has a certification program called the Gold Seal. WQA's Gold Seal represents the oldest independent third-party testing and validation program in the water treatment industry and is a mark of product quality and integrity. WQA awards the Gold Seal only to water treatment equipment that has been tested to meet or exceed industry standards for performance, capacity and integrity in removing a variety of water supply contaminants. The Gold Seal program also validates products under Standards 42 and 53.

Good As Gold understands the important role water plays in our daily lives. We also understand that even if our water is safe to drink, with a cost effective filter system we can improve upon it. We can make it better tasting and provide an additional level of protection against many common health-related contaminants which may get into our water.