Earlier today 'Juline803' asked, "The local paper today said my water company is temporarily changing the water treatment method from chloramines to free chlorine and that we should not worry if our water smells like chlorine. How much chlorine is too much and what is the difference between chloramines and free chlorine? Why the change in treatment types? Is there a problem they're not telling us?"
Thank you, Juline, for the inquiry. We will begin our response by saying that the change in water treatment methods does not mean your water treatment company has made the decision because they have something to hide. Water plants that use chloramines as the primary disinfection method routinely must perform a free-chlorine conversion (also known as a 'burn') as an added level of disinfection.
Municipalities will typically also flush water lines to clear them of any sediment that may have accumulated since the last flushing and force water in low use or low pressure areas out of the system.
How much chlorine is too much chlorine?
The United States Environmental Protection Agency has set the maximum allowable limit for both free and total chlorine at 4ppm. You can use a product such as the WaterWorks 2 Free & Total Chlorine Test Strip to quickly and easily determine how much free chlorine and total chlorine your water contains.
What is the difference between free chlorine and total chlorine?
Simply put, the total chlorine concentration in a water sample includes all available free chlorine plus all the chlorine that has already oxidized (acted on) contaminants in the water and become combined chlorine (often referred to as chloramines and/or monochloramines).
Free (available) chlorine refers to the concentration of chlorine molecules residing a water sample that have not, yet, oxidized contaminants.
(Total Chlorine) – (Free Chlorine) = Combined Chlorine
For pool water you can use a test strip like the Pool Check 6-Way to determine the free and total chlorine concentrations of a sample.
For drinking water you can use test strips like SenSafe Free Chlorine Water Check to determine the free chlorine concentration of a water sample and SenSafe Total Chlorine Water Check to determine the total chlorine concentration of a water sample.
OR, for an even easier test procedure, you can use the WaterWorks 2 Free & Total Chlorine Test Strip which tests for both free and total chlorine at the same time.
SenSafe Free Chlorine Water Check
Detects 0 - 6 ppm
SenSafe Total Chlorine Test Strips
Detect 0 - 10ppm
Free & Total Chlorine Test Strips