Chlorinators

Q. My well water has tested positive for coliform bacteria, is chlorination the best method for disinfecting my well water?
A. Chlorination can be the best method, depending on the water chemistry and the application. The main advantages of chlorination is that the chlorine injection is relatively inexpensive to set up, and a chlorine residual can be cheaply detected in the distribution lines of the piping system assuring proper disinfection.

Q. How do I know which chlorinator (metering pumps and solution tank) to get for my application?
A. All the metering pumps we carry are slightly different. Pumps are rated by the amount of solution they will pump in one hour, by the maximum pressure they can develop, and by voltage. To find out more about sizing and choosing a metering pump, see our article on Sizing Metering Pumps for Chlorination.

Q. What are my other options?
A. Two other types of disinfection systems we carry, are ultraviolet sterilization and ozone systems. The advantage of these systems is that there is no chlorine tastes or odors in the household or process water. This same feature could be a disadvantage, however, since it is harder to know for sure that complete disinfection has occurred without continually testing for bacteria. With chlorination, a simple chlorine residual test can allow you to know that the water still has potential to disinfect.


Q. Why would I want to use an ozone or an ultraviolet sterilizer in place of a chlorinator?
A. An ozone or ultraviolet sterilizer, properly set up and installed, can be easier to maintain than an chlorinator. A liquid chlorine injection system for instance, requires that one add fresh solution to the solution tank every one to two months (ideally), whereas an ozone or ultraviolet sterilizer can go for six to twelve months without routine maintenance.

Q. I am on a small community system in the United States, and I have been informed that our water has a coliform problem, is chlorination the best approach for our entire community system?
A. Generally, yes. Public health agencies want to make sure that there is a small residual of "free" or available chlorine out in the distribution system or piping of community, to make sure that any bacteria that occur or originate out in the distribution system are killed. An ultraviolet sterilizer or ozone system will provide no disinfectant residual. Often we use ozone as a primary oxidizer or disinfectant at the main holding tank, as part of a treatment process, but we almost always recommend that a slight chlorine residual be used as a final step, to protect the distribution system piping.

Q. My community system or small shared well system periodically has coliform problems, but the other residents on the system do not want to, or have no plans to chlorinate. Is there anything I can do, just at my own home?
A. If your water is clear, and low in iron and manganese, you could install an ultraviolet sterilizer right at your home, to disinfect only the water that comes directly to your house.

Q. Isn't chlorine toxic and cancer-causing?
A. High levels of chlorine are toxic, but low levels (as found in most municipally treated water) are not acutely toxic. There is controversy over the actual carcinogenic effects of long-term low exposure to chlorine. However it is relatively easy to dechlorinate water for showering and drinking.

Q. When should I use a pellet feeder, as opposed to a liquid injection system?
A. A pellet feeder, which drops small chlorine pellets down the well, every time the well pump runs, can be a good solution if you have no holding tank or retention tank, which is required for liquid chlorine injection. Pellet feeders can be ineffective if your well has wire protectors, or other obstructions that block the pellets from falling. If your well has a small access plug on the top of it, you can obtain some pellets and drop a few down the well to see if they fall into the water, which you can usually hear pretty clearly. Pellet feeders are often much more expensive to operate, as the pellets cost more than liquid sodium hypochlorite (bleach). Most of our clients using chlorination, use liquid sodium hypochlorite injection, but pellets are useful in some cases.

Q. Can I really just use regular household bleach to sanitize my water?
A. Bleach, which is approximately 5% sodium hypochorite, will sanitize your water, as will pool chlorine (12% sodium hypochlorite). However, we recommend contacting a local supplier of potable water grade 12% sodium hypochlorite. This chlorine is certified for potable water use, is generally fresher and won't contain some of the impurities that regular bleach and pool chlorine will contain. Often your local pool supplier can talk to their sodium hypochlorite supplier, who carries both kinds.


Q. I know I have bacteria in my water, should I have my water tested for other things besides bacteria?
A. Its a good idea to have your water tested first, since there can be other parameters, such as pH, iron, manganese and turbidity that can affect the dosage and contact time of the chlorination. If you have further questions you can then fill in our Online Chlorination Worksheet for help on selecting the best system for your application. Or if you just have general questions, you can contact our staff before having your water analyzed, but it is often very difficult to specify a proper system without a complete water analysis, including general mineral and bacteriological, at a minimum.

Q. Should all well water be disinfected (sanitized of bacteria)?
A. Generally yes, however the vast majority of private wells in the US and Canada have no disinfection of any kind, and actual waterborne disease outbreaks appear to be rare. If the well is less than ten years old and properly constructed with a sanitary seal, and the lab test comes back with no coliforms detected, then often disinfection is not required. If the well is older, has a cracked or missing seal, is shallow (less than 100 feet deep) or is under the influence of water from surface run-off, then it may be a good idea to disinfect the water, or test routinely for coliforms, particularly during rainy periods.

Q. Shouldn't I hire a local expert to help me?
A. Generally the answer is yes. Sometimes well water problems such as bacteria, odor or high iron or manganese can be difficult to treat. If you have a local water treatment expert who can assist you on-site, we would recommend you start with them first. Make sure the water treatment contractor is licensed in your State and knows well water conditions (not just city water systems). It helps if the contractor is a certified water specialist and member of the Water Quality Association (if in the US). We have assisted hundreds of homeowners who have not been able to find local professionals who can solve their problems, but if you do have one locally, then it is often best to start there.