The most common harmful contaminants in water are microorganisms, nitrate, arsenic Herbicides and Pesticides. Microorganisms include bacteria, viruses, and protozoa. Giardia, lamblia, cryptosporidium, coliform, and E. coli are the most common kinds of harmful bacteria.
Bacterial contamination is most likely to have originated from animal waste that has found its way into water sources through runoff. Occasionally, these bacteria will contaminate crops in the field by irrigating with water tainted with raw manure.
Nitrate is a chemical found in most fertilizers, manure, and liquid waste discharged from septic tanks. Natural bacteria in soil can convert nitrogen into nitrate. If ingested, nitrate impairs the ability of our red blood cells to carry oxygen throughout the body.
Ground water can pick up arsenic naturally in varying amounts, but it was used for decades as an insecticide and fungicide in agriculture. A continued controversial practice is to add organic arsenic to poultry feed in the U.S. to increase weight gain for human consumption.
Although organic arsenic is less toxic than pure arsenic, under some conditions it is converted to the more toxic, inorganic form.
Contaminants Removed by Carbon Filtration
Contaminants Removed by Carbon Filtration | |
| Chemicals | Organic Contaminants |
| Acetaldehyde | 2,4,5-TP |
| Acetic Acid | 2,4-D |
| Acetone | Acrylamide |
| Alcohols | Adipates (diethylhexyl) |
| Amines | Alachlor |
| Amyl Acetate | Aldicarb |
| Amyl Alcohol | Aldicarb Sulfone |
| Antifreeze | Aldicarb Sulfoxide |
| Benzene (“fracking” carcinogen) | Atrazine (agricultural herbicide) |
| Bleach | Benz(a)anthracene (PAH) |
| Butyl Alcohol | Benzene (“fracking” carcinogen) |
| Butyl Acetate | Benzo(a)pyrene (PAH) |
| Calcium Hypochlorite | Benzo(b)fluoranthene (PAH) |
| Chloral | Benzo(k) fluoranthene (PAH) |
| Chloamine | Bromodichloromethane |
| Chloroform | Bromoform |
| Chlorine | Butyl benzyl phthalate (PAE) |
| Chlorobenzene | Carbofuran |
| Chlorophenol | Carbon Tetrachloride Chlordane |
| Chlorophyll | Chloroform |
| Citric Acid | Chrysene (PAH) |
| Cresol | Dalapon |
| Defoilants (plant growth inhibitors) | Dibenz(a,h) anthracene (PAH) |
| Detergents | Dibromochloromethane |
| Diesel Fuel | Dibromochloropropane (DBCP) |
| Dyes | Dichlorobenzene (o-,m-) |
| Ethyl Acetate | Dichlorobenzene (para-) |
| Ethyl Acrylate | Dichloroethane (1,2-) |
| Ethyl Alcohol | Dichloroethylene (1,1-) |
| Ethyl Amine | Dichloroethylene (cis-1,2-) |
| Ethyl Chlorine | Dichloroethylene (trans-1,2-) |
| Ethyl Ether | Dichloromethane (methylene chloride) |
| Gasoline | Dichloropropane (1,2-) |
| Glycols (“fracking” toxins) | Diethylhexyl phthalate (PAE) |
| Herbicides | Dinoseb |
| Hydrogen Peroxide | Diquat |
| Hydrogen Selenide | Endothall |
| Hydrogen Sulfide | Endrin |
| Hypochlorous Acid | Epichlorohydrin |
| Insecticides | Ethylbenzene |
| Iodine | Ethylene dibromide (EDB) |
| Isopropyl Acetate | Glyphosate (Round Up herbicide) |
| Isopropyl Alcohol | Heptachlor |
| Ketones | Heptachlor epoxide |
| Lactic Acid | Hexachlorobeneze |
| Mercaptans | Hexachlorocyclopentadiene |
| Methyl Acetate | Indeno (1,2,3-c,d) pyrene (PAH) |
| Methyl Alcohol | Lindane |
| Methyl Bromide | Methoxychlor |
| Methyl Chloride | Monochlorobenzene |
| Methyl Ethyl Ketone | Oxamyl (vydate) |
| Naphtha | Pentachlorophenol |
| Nitric Acid | Picloram |
| Nitrobenzene | Polychlorinated byphenyls (PCBS) |
| Nitrotoluene | Simazine |
| Odors (general) | Styrene |
| Oil Dissolved | Tetrachloroethylene |
| Organic Acids | Toluene |
| Organic Esters | Toxaphene |
| Organic Salts | Trichlorobenzne (1,2,4) |
| Oxalic Acids | Trichloroethane (1,1,1-) |
| PCB?s | Trichloroethylene |
| Perchlorate (used in rocket fuels) | Trichloroethylene (1,1,2-) |
| Pesticides | Trihalomethanes (THMs) |
| Phenol | Vinyl Chloride |
| Plastic Taste | Xylene (total) |
| Propioic Acids | 2,3,7,8-TCDD (Dioxin) |
| Propionaldehyde | |
| Propyl Acetate | |
| Propyl Acid | |
| Propyl Chloride | |
| Rubber Hose Taste | |
| Soap | |
| Sodium Hydrochorite | |
| Solvents | |
| Sulphonated Oils | |
| Tannins | |
| Tar Emulsion | |
| Tartaric Acid | |
| Taste (DI Water) | |
| Taste (From Organics) | |
| THM?s | |
| Toluene | |
| Toluidine | |
| Trchlorethylene | |
| Turpintine | |
| Vinegar | |
| Xanthophyll | |
| Xylene |
Contaminants Removed by Reverse Osmosis
| Contaminants Removed by Reverse Osmosis | |||
| Contaminant | Average Influent (incoming) Concentration (mg/L) | Average Effluent (outgoing) Concentration (mg/L) | Average Percent Reduction |
| Arsenic | 0.28 | 0.0035 | 98.7 |
| Barium | 10.2 | 0.207 | 97.9 |
| Cadmium | 0.036 | 0.0005 | 98.6 |
| Chromium (Hexavalent) | 0.15 | 0.013 | 91.3 |
| Chromium (Trivalent) | 0.17 | 0.01 | 94.1 |
| Copper | 3.1 | 0.03 | 99 |
| Cysts | 149357 #/ml | 5 #/ml | 99.99 |
| Turbidity | 10.2 | 0.26 | 97.5 |
| Fluoride | 8 | 0.5 | 93.9 |
| Lead | 0.15 | 0.002 | 98.6 |
| Radium 226/228 | 25 pCi/L | 5 pCi/L | 80 |
| Selenium | 0.1 | 0.008 | 92 |
| Other Total Dissolved Solid (TDS) contaminants are reduced by up to 98%: Aluminum, Ammonium, Bicarbonate, Calcium, Chlorine, Chromate, Cyanide, Ferro cyanide, Iron, Magnesium, Mercury, Manganese, Nitrate, Phosphate, Silicate, Silver, Sodium, Strontium, Sulfate, Sulfite, Thiosulfate, Zinc. | |||
| Note: Your results may vary depending on the regularity of your maintenance, the general condition of your unit, and the contamination-level of the water supply. |
Contributors to System Performance
Even the best reverse osmosis systems won’t always filter out everything 100%. There are several factors for this, but the best way to maximize your systems performance, is to change the filters out for new ones, at recommended intervals.
This is why it’s recommend to change your water filters frequently, and definitely no later than a filters recommended service period.
- Contaminant level of the incoming water supply.
- Whether or not a sediment filter is used, if incoming water has large particles, such as from a well.
Type of prefiltration (granulated-carbon, carbon-block, activated or not). - Size of pores in the RO membrane (the smaller, the better).
How well the system is maintained (how often the filters are changed).