Healthy Environment, Strong Communities, Accountable Government

Water Filters

Long Island has been blessed with an abundant supply of high quality water in our aquifer system. In most areas no filtration is necessary to meet New York State's drinking water standards, which are more stringent than those for bottled water. Tap water costs a fraction of what bottled water does, you can get almost 300 gallons of water from your tap for the cost of a 50¢ pint of bottled water. Over a $1 billion of taxpayer dollars have been spent protecting open space to help secure the future quality and quantity of our groundwater supply.

Water filters are also an option for removing unpleasant taste from tap water. Filters also drastically reduce chlorine, lead, VOCs, THM's, cysts, MTBE and many other drinking water contaminants.

There are many options: pitcher filters, countertop units, in refrigerator water dispensers, under-sink, shower filters, and whole house filters that treat water at the point of entry to the home. For offices, bottle-less water coolers are available the provide filtered water without the cost of water delivery or the inconvenience of storing large water bottles.

Water filter standards are maintained by the American National Standards Institute (ANSI) and the National Science Foundation (NSF) Water Treatment Device Certification Program.

Water filtering and purification technologies include (from the NSF web site):

  • Adsorption (Carbon Filters)
    (NSF/ANSI 42 & 53)
    This is the physical process that occurs when liquids, gases, dissolved or suspended matter adhere to the surface of, or in the pores of, an adsorbent medium. Carbon filters use this technology to filter water.
  • Softeners
    (NSF/ANSI 44)
    Water softening devices covered by Standard 44 use a cation exchange resin, regenerated with sodium chloride or potassium chloride, to reduce the amount of hardness (calcium, magnesium) in the water. The hardness ions in the water are replaced with sodium or potassium ions.
  • Ultraviolet Treatment
    (NSF/ANSI 55)
    This treatment style uses ultraviolet light to disinfect water (Class A systems) or to reduce the amount of heterotrophic bacteria present in the water (Class B systems).
  • Reverse Osmosis
    (NSF/ANSI 58)
    A process that reverses, by the application of pressure, the flow of water in a natural process of osmosis so that water passes from a more concentrated solution to a more dilute solution through a semi-permeable membrane. Most reverse osmosis systems incorporate pre- and post-filters along with the membrane itself.
  • Distillers
    (NSF/ANSI 62)
    These systems heat water to the boiling point and then collect the water vapor as it condenses, leaving many of the contaminants behind, particularly the heavy metals. Some contaminants that convert readily into gases, such as volatile organic chemicals, may be carried over with the water vapor.

If you have identified a specific contaminant whose presence in your water is causing you concern, try to locate products that have been certified to reduce that specific contaminant. The NSF maintains a database of water treatment products by the contaminants they have been certified as effective at reducing.

Rember that all water filters need regular maintenance to operate effectively. Read the operating manual that comes with your water treatment system to ensure you are operating your system in accordance with the manufacturer's directions. Filters should be changed on a regular basis as recommended by the manufacturer.


Neighborhood Network
7180 Republic Airport, East Farmingdale, NY 11735 Tel: (631) 963-5454
Advocates for Long Island's Environment