Chlorine Water Test

Chlorine in Drinking Water: Why the Disinfectant That Makes Your Water Safe Can Also Make It Less Healthy

Chlorine is the most widely used disinfectant in municipal water treatment and for good reason. It is effective at killing bacteria, viruses, and other pathogens that would otherwise make public water supplies dangerous to drink. But the same chemical properties that make chlorine an effective disinfectant also make elevated levels in drinking water a genuine health concern, and the story does not end with chlorine itself.

When chlorine reacts with naturally occurring organic matter in water, such as decaying leaves, algae, and soil particles that enter the water supply, it forms a group of chemical byproducts called trihalomethanes, or THMs. These disinfection byproducts including chloroform, bromodichloromethane, dibromochloromethane, and bromoform have been linked to increased risk of bladder cancer, colon cancer, and rectal cancer with long term exposure. They have also been associated with reproductive issues, liver and kidney damage, and disruption of the gut microbiome. Chlorine and its byproducts are also volatile, meaning they can be absorbed through the skin and inhaled as steam during showering, sometimes delivering as much exposure as drinking the water itself.

The EPA sets a maximum residual disinfectant level for chlorine in drinking water at 4 milligrams per liter, but even at levels below this threshold some people experience taste and odor issues, skin and eye irritation, and digestive discomfort. For households with sensitive individuals including young children, pregnant women, and anyone with compromised immune function, knowing your actual chlorine level is an important part of understanding your overall water quality picture.

This test is also valuable for households with water filtration systems. Carbon filters, reverse osmosis systems, and other treatment technologies are designed to remove chlorine but they do not last forever. Testing your chlorine level is one of the most straightforward ways to verify that your filtration system is still performing as intended.

For the most complete picture of disinfectant related compounds in your drinking water we recommend pairing this test with our Volatile Organic Compounds test which screens for more than 60 compounds including the full range of trihalomethanes and other disinfection byproducts that chlorine can produce as it breaks down in your water supply. Together these two tests give you a comprehensive view of both the chlorine itself and the chemical reactions it has already set in motion in your water.

How It Works

Order your test and we will mail you a sample collection kit with easy to follow instructions. Collect a water sample from your tap and send it back to our in-house laboratory. Results are delivered within 1 to 3 business days from the date your sample arrives at our lab.

Understanding Your Results

Chlorine results are measured against EPA maximum residual disinfectant levels so you know exactly where your water stands. Every test includes a free consultation with one of our in-house water quality experts. If your chlorine levels come back elevated or if you want to understand the full picture of disinfectant byproducts in your water we will walk you through your options including appropriate filtration solutions and whether additional VOC testing is recommended for your situation.

This test is recommended for households on city or town water who want to verify their actual chlorine concentration, anyone who notices a strong chlorine taste or odor in their tap water, households with carbon filters or other chlorine reducing systems who want to confirm their system is working effectively, anyone concerned about the health effects of long term chlorine exposure, and city water customers who want to understand whether their chlorine levels are producing disinfection byproducts at concerning concentrations.