INFORMATION ON CHLORAMINES
As recently announced in a WRITTEN NOTICE that was mailed to all of our customers, we will soon be changing our final step of water disinfection from the use of free chlorine to a combined form of chlorine, called chloramine. More specifically, the type of chloramine we will be utilizing is monochloramine. This method of water disinfection has been in use throughout the United States and the world for about 100 years. The written notice provided some information as to the reasons for the change and some answers to several frequently asked questions.
We are committed to providing drinking water that maximizes public health and minimizes potential health risks. For our customers, who also include our families, health and safety is our number one priority. Due to concerns expressed by some of our customers, the Board has voted to postpone the transition to allow more time for discussion and dissemination of information. Some of this additional information is as follows:
What are Chloramines?
Chloramine is a disinfectant used to treat drinking water. The specific type of chloramine formed for drinking water treatment is known as “monochloramine”. It is formed by mixing free chlorine with ammonia at a specific ratio and under specific conditions. Ammonia is added at a relatively low level, depending on the amount of free chlorine present. For example, a common dosage for drinking water with a chlorine level of 2.0 mg/L is 0.44 parts per million (mg/L) of ammonia. Chloramines are safe for humans and most household pets, except for those animals that absorb water directly in the blood stream such as fish.
Maintaining a level of disinfection in the water distribution system is required to keep water safe. Under the Safe Drinking Water Act, the EPA allows drinking water treatment processes to use free chlorine or chloramine (monochloramine) to disinfect drinking water. Research shows that both chloramine and free chlorine have their benefits and drawbacks, however, both disinfection types are tried and true US EPA-listed best available technology for use in drinking water. Chloramine use is closely regulated and has been used widely for over 90 years in the U.S. (1926), Canada, and Great Britain and its use has been on the rise in recent years because it reduces disinfection byproducts associated with use of free chlorine.
More than one in five Americans consume drinking water treated with monochloramine. It has been used safely for decades in major cities such as Boston, Dallas, Houston, San Diego, San Francisco, Tampa Bay, Miami, Denver, Philadelphia, Minneapolis among others.
In Maine, nearly every water system utilizing a surface water supply use monochloramines, serving over 50% of the population of Maine served by water utilities. Regionally they include Auburn Water District, Bangor Water District, Bath Water District, Brewer Water District and Lewiston Water Department. Locally they include Portland Water District, Maine Water (Biddeford & Saco Division), Kennebunk, Kennebunkport, and Wells Water District and York Water District. Some of these local utilities are increasingly important to our long-term system reliability and the sustainability of our high level of service to our customers.
The benefits of monochloramine use for the Kittery Water District are extensive and out-weigh the disadvantages:
• A monochloramine residual maintains an effective level of disinfection over a longer period of time in the distribution system than a free chlorine residual.
• Water treated with monochloramine has less of a chlorine taste and smell than water with free chlorine. According to the EPA, water utilities switching from chlorine to monochloramine report fewer consumer concerns about the taste and odor of the water.
• Monochloramine forms fewer Disinfection Byproducts compared to free chlorine. For surface water supplies (those utilizing ponds, lakes, rivers and streams), the naturally occurring organic material in the water (usually seen as a slight color caused by the decomposition of leaves) will react with free chlorine to form carcinogens; specifically Haloacetic acids (HAAs) and Trihalomethanes (THMs). The US EPA regulates these carcinogens. Although Kittery Water District has consistently met EPA’s standards for HAAs and THMs, it is always best to minimize the formation of any known carcinogens, as further discussed below.
• Chloramine technology is easy to install and operate.
• It’s long been understood that interconnected water systems should seek to avoid differences in water quality to optimize the efficiency and effectiveness of the interconnections. A few of these efficiencies include; water service redundancy, augmented fire flows, improved service response to major main breaks and other events.
There are however some potential disadvantages with the use of chloramines, as follows:
• Like chlorine, monochloramine must be removed from water used when keeping pets like fish, reptiles, some amphibians, and certain other aquatic life, such as Koi fish, lobster, shrimp, frogs, turtles, snails, clams, and living coral. Dogs, cats, ferret, birds, and other animals can safely drink chloraminated water. Consult a local pet dealer or veterinarian if you are unsure about your pet.
• Like chlorine, chloramine must be removed from water used for kidney dialysis. Kidney dialysis patients can safely drink, cook, and bathe in chloramine treated water. The normal digestive process neutralizes chloramine before it enters the bloodstream.
• Like chlorine, chloraminated water may slightly affect beer and bread making (it may affect the action of the yeast). Treatment of process water may need to be additionally adjusted. Carbon filtration remains the best and most economical method, but its removal will require more contact time. Filters may need to be changed more often.
• Poor chloramination practices can lead to potential water quality problems; most notable is nitrification. Providing the treatment process is carefully controlled and operational practices are appropriately adjusted and monitored this problem is avoided. Our staff will use accurate and reliable equipment to ensure we provide high-quality drinking water and ensure our system meets all regulatory standards, as do all of the other Maine water utilities that have successfully utilized chloramination as their primary disinfectant.
Monochloramines and Health:
According to the CDC, Chloramine is recognized as a safe disinfectant and a good alternative to chlorine and has been used as a drinking water disinfectant in places like Philadelphia, San Francisco, Tampa Bay, wand Washington D.C. According to the CDC, in 1998, an EPA survey estimated 68 Million Americans were drinking water disinfected with chloramine. Most places have switched to the disinfectant in order to meet EPA standards to reduce disinfection byproducts. The expected 40-80% reduction in DBPs (THMs & HAAs) would be a secondary benefit for us, as we have always met the EPA’s standards.
We take pride in our ability to provide high-quality, safe, drinking water that complies with the Safe Drinking Water Act. EPA and the State of Maine Drinking Water Program require water utilities to meet strict health standards when using chloramines and other disinfectants. Like with free chlorine, EPA regulates certain disinfection byproduct chemicals formed when chloramines react with natural organic matter. Since the formation of disinfection byproducts (DBPs) is influenced by the disinfectant, we would be required to monitor for additional unregulated DBPs like Nitroso-dimethylamine or NDMA. If it or something new was found, we would make the necessary adjustments to minimize any risk. NDMA was not found in York Water District water so is not expected to be found in KWD water.
The US Environmental Protection Agency (US EPA), Center for Disease Control and Prevention (CDC), and the World Health Organization (WHO) have research and experience that indicates chloramine levels up to 4 mg/L are considered safe and beneficial in drinking water. At this level, no harmful effects are likely to occur. Our normal target dose is expected to be around 2.5 mg/L to maintain at least 1.0 mg/L throughout our system.
EPA continues to encourage research on the safety of chloramines as a drinking water disinfectant. We will continue to monitor the recommendations of the US EPA and CDC as well as relevant research to make sure operations are based on the best available information.
Please see the Links provided below for more information.
If you have additional questions please call our office at (207) 439-1128.
Environmental Protection Agency
Centers for Disease Control and Prevention
Massachusetts Water Resources Authority
Municipal Authority of Westmoreland County
San Francisco Water