Advantages, Disadvantages and Costs of Various Types of Entry / Use Treatment Devices
Ultraviolet Light:
Advantages: Effective for destroying bacteria and viruses and disinfecting drinking water.
Disadvantages: Will not remove contaminants other than bacteria and viruses. Not effective for Giardia and Cryptosporidium cyst removal.
Costs: Units typically cost between $300 and $700.
Ion Exchange:
Advantages: Effective for removing minerals such as hardness, barium, radium, nitrate, sulfate, calcium and magnesium. Effective for removing iron (provided concentrations do not exceed about 1 mg/L).
Disadvantages: Requires regeneration (usually with sodium chloride or potassium chloride).
Costs: Typical costs vary from $500 to $1200 depending on the resin (anion exchange resins cost more that cation exchange resins) and type of equipment.
Mechanical Filters:
Advantages: Effective for removing suspended particles such as rust, dirt and sediment. Filters tested and approved for Giardia and Cryptosporidium cysts are available.
Disadvantages: Not effective for removing dissolved contaminants such as lead, nitrate, VOCs, etc.
Costs: Use-device mechanical particulate filters typically cost between $30 and $100, with filter replacement cost of $15 to $40.
Activated Carbon Filters:
Advantage: Efective at removing a wide range of organic contaminants such as VOCs and pesticides. Carbon block and precoat designs have been validated as effective for lead reduction. Often effective for reducing taste and odor problems. Does not use electricity or generate wastewater.
Disadvantages: Not effective at removing inorganic materials such as hardness, iron, nitrate or fluoride. Bacteria growth may occur in the carbon filter is not maintained properly. May require post-disinfection facilities.
Costs: Point-of-Use activated carbon filters typically cost between $75 and $350. Replacement filter cost is in the $20 to $40 range. Point-of-Entry treatment devices typically cost between $500 and $1,250. Replacement filters cost $200 to $400.
Activated Alumina Filters:
Advantages: Effective for removal of arsenic, fluoride and lead. Does not use electricity and does not waste water.
Disadvantages: Will usually not remove minerals other than those listed above.
Costs: Similar to Activated Carbon.
Reverse Osmosis:
Advantages: Can remove a wide variety of inorganic and organic contaminants including lead, nitrate and sodium. Normal household water pressure provides good performance.
Disadvantages: Uses from three to five gallons of water for each gallon produced. Some membranes are damaged by chlorine.
Costs: Under the sink use-devices that include a mechanical prefilter and an activated carbon post filter typically cost $400 to $1000. Replacement membranes cost $30 to $100.
Distillation:
Advantages: Removes the greatest variety of contaminants.
Disadvantages: Uses approximately three kilowatts of of electricity per gallon of water. Water-cooled units waste a considerable amount of water. Will require frequent cleaning especially where the water is hard. Removal of minerals may leave bland taste to the water. Process is slow.
Costs: Between $99 and $500 for a countertop model.
Aeration:
Advantages: Effective for removing radon and volatile organic chemicals.
Disadvantages: Expensive to purchase and install. Requires secondary pumping and pressurization.
Costs: Between $4,200 and $3,800.
Chlorination:
Advantages: Only effective way of dealing with large amounts of iron, hydrogen sulfide and colloidal iron. Is also and excellent disinfectant.
Disadvantages: Requires handling and storage of hazardous chemicals. Requires handling and storage of hazardous chemicals. Requires time to insure that chemicals
Costs: Between $800 and $1,500.