Evansville Water to Temporarily Change Disinfection
 Beginning May 11 and continuing until June 22, 2020, the Evansville Water and Sewer Utility (EWSU) will temporarily change the disinfectant used in the water treatment process. EWSU will be using free chlorine rather than the regularly used disinfectant (chloramine) during this time period. This is the first of two such temporary switchovers, with the second one coming in August. A separate notice for that second switchover will also be issued.
What is Chloramine?
Chloramine is a disinfectant used in drinking water to remove bacteria and viruses that can make you sick. It is made up of chlorine and ammonia. EWSU has used chloramine as the disinfectant in its water treatment process since 1999.
What is Free Chlorine?
Free chlorine is a slightly stronger disinfectant than chloramine, and it is used to remove more resistant bacteria and viruses that may be found in the water distribution system.
Why would the EWSU Convert from Chloramines to Free Chlorine?
This brief, scheduled change in disinfectant is a standard water-treatment practice to keep water mains clean and free of potentially harmful bacteria throughout the year. State drinking water guidelines recommend that utilities using chloramine periodically switch to free chlorine for a period of time. The temporary use of chlorine will ensure that a proper level of disinfectant is maintained throughout the network of water mains and pipes that deliver your drinking water.
Free chlorine is a more aggressive disinfectant than chloramine, and this temporary change in the water treatment process denies bacteria the ability to form resistance to the usual disinfection treatment process. Switching to free chlorine is a proactive step to ensure that we maintain optimal levels of disinfectant in the water distribution system.
As always, the drinking water will be regularly monitored to ensure that the water delivered meets, or is better than, federal Safe Drinking Water Act standards.
Why Does EWSU Use Chloramines Most of the Year?
While chlorine is an effective disinfectant, using chlorine alone creates byproducts that are regulated by the U.S. Environmental Protection Agency. These by-product levels can be significantly and cost-effectively reduced through the use of chloramine. Also, chloramine has less odor (compared to chlorine), and remains in the distribution system longer to more effectively prevent bacterial growth. As such, chloramine is a better long-term choice as a regular disinfectant.
Will I Notice a Difference in My Water?
During this time period, some customers may notice a slight change in the taste or odor of their tap water. Free chlorine may have more of a chemical odor, slightly like that of swimming pool water. Each individual customer has his or her own sensitivity level to the taste and/or odor of free chlorine. Many detect no change at all. The mild chlorine taste and odor is normal and poses no health risk.
Are Free Chlorine and Chloraminated Water Safe?
Yes, both form chlorine and chloramine are effective and safe for people and animals for drinking, cooking, and bathing, as well as watering the garden and all other common uses. However, precautions should be taken to remove or neutralize chloramine and free chlorine during the kidney dialysis process, in the preparation of water for fish tanks and ponds, and for businesses requiring highly-processed water. A de-chlorination procedure optimized for chloramine removal will work equally well with free chlorine.
People and businesses that normally take special precautions to remove chloramine from tap water (such as dialysis centers, medical facilities, and aquatic pet owners) should continue to take the same precautions during the temporary switch from chloramine to free chlorine.
Most customers will not need to take any precautions as the water remains safe to drink and is treated according to both state and federal standards.
Kidney Dialysis: Just like chloramines, free chlorine must be removed from water used in kidney dialysis machines. ETSU has contacted representatives from the medical community to inform them of this temporary conversion. We advise customers who are dialysis patients to call their physicians or dialysis centers if there are any questions.
Fish Owners: Like chloramine, free chlorine is toxic to fish. Fish owners need to remove chlorine, ammonia and chloramine from the water before use with tropical fish. Local pet stores carry water conditioners that remove chloramine and free chlorine. If customers have questions, we recommend contacting their pet store for information and detailed instructions.
EWSU is committed to providing high-quality water and related services that meet all regulatory drinking water standards in a manner that prevents pollution, enhances the environment, and promotes sustainability. If you need further information regarding this change, please contact the Utility at (812) 428-0568.
