How to Treat Your Drinking Water
Coliform Bacteria/E-Coli:These bacteria and many others are found in all drinking water supplies to a greater or lesser extent. If left untreated, these can propagate and form large colony counts that can quickly affect health. In fact, the single largest health threat associated with water supplies is infection by bacteria. Total coliform is used as an indicator for general well infection. If a well is found to contain coliform colonies greater than one colony per hundred milliliters of water, it is assumed to be possibly infected by other forms of bacteria and should be disinfected immediately.
Some research suggests that certain hard-to-detect bacteria found in water supplies worldwide, including the United States, can lead to serious gastrointestinal diseases, including ulcers and certain cancers. The EPA and numerous health agencies recommend that private well-water users disinfect their well at a minimum every two years.
Taste and Odor: For private well-water users, the most common complaints we find are poor taste and a sulfur-like smell. The most common cause of these problems is certain forms of bacteria. These include sulfate-reducing bacteria, iron-related bacteria (IRB), and other forms of Hydrogen sulfide-producing bacteria found in many water supplies.
The simplest and cheapest way to disinfect a well is by chlorinating it. Because of the potential health problems associated with bacterial infection, public water utilities disinfect the water daily, usually by chlorination. They maintain a chlorine residual of 1-2 parts per million free chlorine to assure the water is safe for human consumption.
If Coliform Bacteria and/or E-Coli is present, chlorinate your well immediately and disinfect any water treatment systems in use.
Chlorination is also the treatment for water with a bad taste or odor.
Before installing any water treatment system, it is recommended that the well be chlorinated first to eliminate possible contamination of the treatment equipment.
For public water consumers, odor and taste complaints are, ironically, due to the residual chlorine or other disinfection procedures used by the water supplier.
Iron is a common secondary metal parameter found in many groundwater supplies. Unless found in very large amounts, it poses no health risks but can cause rust staining of fixtures, sidewalks, etc. Iron is usually present as ferrous (non-staining), ferric, (rust staining), or both.
Use a water softener. However, if large amounts of ferric iron are present, a two-tank system is employed, preceded by an acid neutralizer to help precipitate the ferric component.
Manganese is another common secondary metal parameter found in many drinking water supplies. It poses no health risks in small amounts; however, it can produce brown, rust-like staining. In large amounts, manganese can cause discoloration of teeth and potential bone disorders.
Use a water softener.
Lead is a toxic heavy metal usually found as a result of degradation of lead-based solder joints. Lead can also be found as a result of leachate from some landfill or industrial sites but this is less common. In general, the older the plumbing system, the more likely lead will be detected.
The treatment for lead is varied. Reverse osmosis is the most common treatment. In certain cases, depending on the form of lead present, activated carbon can be used.
Arsenic is a toxic heavy metal that can be found in natural ground formations. It can also be present in water supplies as a result of agricultural runoff, industrial-waste pollution, and some pharmaceutical-waste pollution.
Arsenic can be removed by reverse-osmosis filtration or by arsenic-specific treatment systems.
Mercury is a toxic heavy metal that can be found in water supplies from a variety of sources. These include industrial waste, medical waste, pesticides, and general landfill operations. Mercury in its pure form as the metal, once ingested, tends to be stored in the body. In many instances mercury is combined with other molecules that have the effect of reducing its toxicity and making it harder for humans to absorb and store mercury.
Reverse osmosis, activated carbon, or by specific removal systems.
Sodium (Na), Calcium (Ca,) Potassium (K), Magnesium (Mg) :
Since all of these metals can be found in ground formations, they can be found in water supplies everywhere. All of these are considered nontoxic secondary parameters.
All can be removed by reverse osmosis, ion exchange, and in the case of calcium and magnesium, by employing a water softener. Water softeners use either sodium or potassium to regenerate. It’s very important to properly maintain the water softener, otherwise these chemical elements can become elevated in the treated water.
Other toxic heavy metals (e.g., Selenium, Thallium, Beryllium, Chromium, etc.):
When any metal is analyzed, the results are usually given for the concentration of the total metal in its elemental form. If the total metal is present above maximum set levels, the water supply is considered unsafe for consumption unless it is treated. However, it is possible to have certain metals combined in such a way with other molecules, like mercury, that render them less toxic. Fortunately, the chances of these metals being found in most potable water sources in the U.S. are low.
The common treatment for most heavy metals is reverse osmosis, activated carbon, or ion exchange.
Nitrates can be found in potable water from several sources. The most common are nitrogen-containing fertilizers, leachate from septic systems, or runoff from agricultural activity. Nitrates are mainly a health concern for infants under the age of two.
Nitrates can be removed by reverse osmosis or by an ion-exchange resin specific for nitrate removal. An ion-exchange resin functions much like a water softener.
pH and Corrosivity:
The pH of potable water varies across the U.S. The pH is mainly dependent on the type of geological formation in contact with the groundwater. A low pH indicates that the water is more acidic, and in extreme cases, pH less than 5.0 can cause a shortening of the lifespan of metal plumbing and fixtures. It should be noted, however, that pH is not the only factor affecting plumbing. The pH is combined with other measurements such as the total dissolved solids (TDS), total hardness (CaCO3), and alkalinity to determine a number called the Corrosivity, or Langelier Index. This number is shown on a scale from -5 to +5, with 0 being completely non-aggressive water. The more negative the number, the more aggressive the water is to metal plumbing, boiler cores, etc. The more positive the number, the more likely the water will cause scale build up in plumbing. Most water tends to be acidic, so the corrosivity will most likely be on the minus side of the scale.
In order to raise the pH and, therefore, lower the corrosive nature of the water, an acid neutralizer is commonly used. This consists of a tank filled with calcium carbonate or lime, which dissolves in the water and neutralizes the acid.
Fluoride can be found in some natural geological formations and, therefore, in potable water. The most usual reason for the presence of fluoride in drinking water is that it is added to municipal water supplies. More recently, fluoride has been linked to contamination from hydraulic fracturing or hydrofracturing, commonly known as fracking operations.
The most common treatment for fluoride is reverse osmosis treatment.
The type of contamination most closely associated with causing cancers are the organic compounds such as Volatile Organic Compounds (VOCs) and synthetic organic compounds, such as the chlorinated pesticides and polychlorinated biphenyls (PCBs). Most of these compounds find their way into water supplies as a result of industrial waste or through disposal into landfills. Some also contaminate local water supplies as a result of underground tank leakage. Fortunately, most chlorinated pesticides and PCBs have not been used in years in the U.S. and are less likely to be found in water supplies today compared to 25 years ago. Many landfills have been cleaned as a result of the Superfund laws, so industrial-waste contamination is down.
However, some industrial solvents and gasoline additives are still found because of the processes used today. For instance, if Trihalomethanes (THMs) are found in public water supplies, they are most likely caused by the chlorination treatment used to prevent bacteria.
There are many ways to remove organics from drinking water, but the most effective and cheapest for the homeowner remains carbon filtration or reverse osmosis.
Remember, a single water test only provides the user with a snapshot of the water being tested at that time. It is best used as a baseline to determine changes occurring over time in a water system. For example, in a public supply system, when a priority contaminate such as benzene is found, the system is placed on a monitoring program for that contaminant to see if it reduces, remains constant, or increases over time. If the contaminant continues to be at an elevated level, then appropriate treatment to remove the contaminant is performed.
For the private well user, it is best to confirm the presence of any priority contaminant with a second analysis for that contaminant within a short period of time to see if it is still present. If it is, then treat accordingly. Thereafter, periodic testing is recommended to determine the effectiveness of the treatment.
Keep in mind that the most common contamination is bacteriological. This calls for annual water testing and the disinfection of private wells at least every two years to maintain safe bacteria levels.