Does Your Water Contain an Unsafe Level of Carbon Tetrachloride?

Today, I’ll continue my review of some of the more common drinking water contaminants with a look at Carbon Tetrachloride. I’ll touch on how Carbon Tetrachloride can affect water quality, and I’ll also share information on things you can do to minimize your family’s exposure to the contaminant.

Carbon Tetrachloride is a manufactured chemical and does not occur naturally in the environment. It usually gets into our drinking water supply through waste discharged by chemical plants and other industrial activities. Consuming water containing Carbon Tetrachloride at levels in excess of 0.00 mg/L can cause adverse health effects.

Fortunately, Carbon Tetrachloride is one of the drinking water contaminants regulated by the EPA. This means public water companies are required to monitor their water supply for Carbon Tetrachloride and work to ensure the water they provide their customers does not exceed the legal limit for the contaminant. However, even with this standard in place, it’s still possible for your tap water to contain excessive amounts of Carbon Tetrachloride.

How Carbon Tetrachloride Can Affect Water Quality and Your Health

Manufacturing facilities, like chemical plants, can produce significant amounts of wastewater. When these facilities discharge or dispose of wastewater, it can cause our water supply to become contaminated with a host of chemicals, including Carbon Tetrachloride.

What is Carbon Tetrachloride, exactly? Carbon Tetrachloride is a chemical historically used in the manufacture of refrigerant fluids and propellants.

How can drinking water that contains Carbon Tetrachloride affect your health? If you consume water that contains elevated levels of Carbon Tetrachloride over a prolonged period, you might develop liver problems, and you may have an increased risk of cancer.

At what level can Carbon Tetrachloride cause health problems? Carbon Tetrachloride is known to cause adverse health effects when its concentration in drinking water is above 0 mg/L.

In an effort to protect our health, the EPA established legally enforceable standards to limit the amount of Carbon Tetrachloride in our drinking water. Public water companies are required to ensure the concentration of Carbon Tetrachloride in the water they provide their customers is kept at or below 0.005 mg/L.

Given available treatment technology, water utility companies should be able to provide drinking water that meets this quality standard. However, at least one public water system violated the regulatory limit for Carbon Tetrachloride in 2019.

Does Your Drinking Water Contain a Harmful Amount of Carbon Tetrachloride?

Public water companies are required to provide customers with an annual water quality report, also known as a Consumer Confidence Report (CCR). Inside this report, you’ll find important information about your drinking water, including where it comes from, and whether it tested positive for any regulated contaminants like Carbon Tetrachloride.

Most Populated Areas with Violations for Carbon Tetrachloride from 2017 to 2019:

Water System
Crescent City, FL
Crescent City WTP
Garber, OK
Garber Municipal Authority
Edwardsport, IN
Edwardsport Water Utility

If you’re curious to know how much Carbon Tetrachloride was found in your city’s drinking water, grab a copy of the latest CCR and look for the section of the report that covers “Organic Chemicals.” Here, you’ll find test results for Carbon Tetrachloride as well as other contaminants like Benzine and Tetrachloroethylene.

How to Interpret Your Water Quality Report

When looking at your water quality report, you’ll see test results for Carbon Tetrachloride reported in Parts per Billion (ppb). 1 mg/L equals 1,000 ppb, so 0.005 mg/L is equivalent to 5 ppb.

Below is an example of what you might see on your annual water quality report if Carbon Tetrachloride is detected in your town’s drinking water:

Example Water Quality Report

MCLG (1)MCL (2)Average
Your Water
Carbon Tetrachloride

Definitions from the EPA:
1. Maximum Contaminant Level Goal (MCLG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
2. Maximum Contaminant Level (MCL) – The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. MCLs are enforceable standards.

In this example, water samples contained an average of 8 ppb of Carbon Tetrachloride, exceeding both the public health goal level (MCLG) and the legal limit (MCL) for the contaminant.

Will You Be Notified If Your Water Contains an Unsafe Level of Carbon Tetrachloride?

In addition to providing you with an annual quality report, your water company is required by the EPA to notify you if they identify a problem with your drinking water.

If your water company delivers water that could negatively impact your health, they have to notify you of the situation within the timeframe set by the EPA. Depending on the severity of the issue, the company is given 24 hours to 30 days to provide this notice.

If your city’s water exceeds the Maximum Contaminant Level (MCL) for Carbon Tetrachloride, your water company must notify you within 30 days of the violation. Typically, you will receive this notice via the media or through the mail.  

What Can You Do to Remove Carbon Tetrachloride from Your Tap Water?

Fortunately, if you want to limit your family’s exposure to Carbon Tetrachloride, there are several affordable yet effective options for removing the contaminant from your tap water.

But how can you tell which products work and which ones don’t? Well, if you want peace of mind, I recommend choosing a water treatment product that is certified by NSF International (NSF) to be effective at removing Carbon Tetrachloride from water.

What does the NSF certification represent? When a product is NSF certified to remove Carbon Tetrachloride, you can rest assured that:

  • the manufacturer’s contaminant reduction claims have been verified;
  • the system was tested to confirm it adds nothing harmful to the water;
  • the system has been found to be structurally sound;
  • the product’s advertising, literature, and labeling have all been verified as accurate;
  • and there is testing in place to determine whether the quality of the product is consistent over time.

Do all NSF certified water filters work against Carbon Tetrachloride? Water treatment devices can earn certification for meeting one or more NSF standards or protocols. But only those products that meet NSF standard NSF/ANSI 53 for Carbon Tetrachloride are certified to reduce the amount of the contaminant that’s in your water.

One such product, the Clean Water Machine by Aquasana, is NSF certified to remove up to 98% of the Carbon Tetrachloride found in your tap water. The device sits on your countertop and does not require a lengthy installation process so you can set it up in a matter of minutes.

3 steps for selecting the right water treatment system for your family:

  1. Review your area’s annual water quality report to find out what’s in your drinking water.
  2. Determine which contaminants you’d like to reduce from your water.
  3. Select a water treatment product that is NSF certified to work effectively against those contaminants you’d like to reduce from your tap water.

Just remember, no matter which water treatment product you choose, you need to make sure to perform the routine maintenance suggested by the manufacturer. This will help keep the device in proper working order and limit your family’s exposure to Carbon Tetrachloride.



I’ve moved several times over the years, so I know just how stressful it can be to relocate. I want to help put your mind at ease. That’s why I research and write about all the things I think you should consider when moving to a new town.

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