What Memphians Need to Know About Memphis, TN Water Quality

Where Does Memphis, Tennessee’s Drinking Water Come From?

Memphis, TN’s drinking water comes from the Memphis Sand Aquifer, a groundwater resource that was first discovered in 1887 during drilling efforts to identify a clean and stable water supply. According to the University of Memphis Center for Applied Earth Science and Engineering Research, the water “fell as rain over 2,000 years ago.”

Now, the aquifer supplies drinking water to residents of Memphis and Shelby County. Originally, water flowed to the surface naturally via artesian wells, but its water levels have fallen by as many as 100 feet, so now mechanical pumps are required.

Memphis, TN remains one of the few U.S. cities to rely solely on groundwater, with most cities relying heavily on surface water or a combination of the two.

How Clean Is Memphis, TN’s Water Supply?

Memphis, TN’s drinking water is some of the cleanest in the country. The water in the aquifer is protected by layers of clay, preventing most pollution from the surface from getting into the water supply. It’s also filtered through layers of sand, removing many impurities and producing clean, clear drinking water.

That doesn’t mean Memphis water sources aren’t at risk of pollution, though. According to WKMS, “PFAS-contaminated sewage sludge is spreading across Tennessee,” which could put regional water supplies at risk. Scientists have already found breaches in the layers of clay where pollution could get through.

Some parts of Shelby County, TN, are more at risk of water contamination than others. There are several Superfund sites in the county, reports NextCity, and “chemicals from industrial production and waste — including arsenic, lead, chromium and nickel – have contaminated groundwater there.”

Residents who want to learn more can visit Protect Our Aquifer, a nonprofit working to protect water supplies in Tennessee, Arkansas, and Mississippi.

How Is Memphis Tap Water Treated?

Memphis water is distributed by the Memphis Light, Gas and Water Division (MLGW), which pumps up to 120 million gallons of water per day from the aquifer. Although the water is naturally clean, it still requires some filtration and disinfection.

MLGW maintains 10 water treatment plants, as well as several reservoirs. According to the U of M, “water cascades over an aerator to remove iron and oxygen” and “chlorine, fluoride, and phosphate are added to meet drinking water standards.”

Adding chlorine to drinking water produces disinfection byproducts that may pose an increased risk of some cancers over time. Since Memphis tap water requires minimal treatment, these levels are lower than in many other American cities. Residents can further reduce them with an activated carbon filter or a reverse osmosis system.

How Often Is Memphis, TN’s Water Quality Tested?

Municipal water utilities in the U.S. are regulated by the Safe Drinking Water Act, which is enforced by the Environmental Protection Agency (EPA.gov). Water utilities must test for common contaminants and ensure that concentrations remain below legal limits.

To comply with these requirements, Memphis Light, Gas and Water performs as many as 40,000 tests per year and publishes the results in an annual water quality report. You can also enter your ZIP code here to get a local water quality report for your area.

Although Memphis, TN’s water quality meets the guidelines of the EPA, levels of some contaminants exceed the recommendations of independent organizations, such as the Environmental Working Group (EWG). Immunocompromised people may also be at a higher risk of certain waterborne diseases, such as cryptosporidium.

Which Contaminants Are Found in Memphis Tap Water?

Knowing what contaminants are found in your tap water is the first step to choosing a home water filter that can remove them. Here are five contaminants in Memphis tap water that can cause undesirable health effects with long-term exposure.

Chromium-6 (hexavalent)

Chromium-6 is a cancer-causing chemical made famous by Erin Brockovich’s 1993 court case regarding Hinkley, California. Memphis residents can feel confident that chromium-6 levels are below the EWG’s recommended limit, but small quantities measuring 0.0110 parts per billion (ppb) have been detected:

• EPA maximum allowance: No legal limit
• EWG recommended maximum: 0.02 ppb
• Memphis maximum contaminant level: 0.0110 ppb

Haloacetic acids (HAA5)

Haloacetic acids (HAA5) are a group of five chemicals associated with cancer and harm to fetal growth, according to the EWG. These are:

• Monochloroacetic acid
• Dichloroacetic acid
• Trichloroacetic acid
• Monobromoacetic acid
• Dibromoacetic acid

Although levels of HAA5 in Memphis tap water are within the EPA’s limit, they exceed the EWG’s recommendation by 14 times:

• EPA maximum allowance: 60 ppb
• EWG recommended maximum: 0.1 ppb
• Memphis maximum contaminant level: 1.40 ppb

Haloacetic acids (HAA9)

There are four more haloacetic acids that together form the group HAA9:

• Bromochloroacetic acid
• Bromodichloroacetic acid
• Chlorodibromoacetic acid
• Tribromoacetic acid

When measured in this grouping, there’s no legal limit, but the EWG recommends an upper limit of 0.06 ppb, which Memphis tap water exceeds by 26 times:

●     EPA maximum allowance: No legal limit

●     EWG recommended maximum: 0.06 ppb

●     Memphis maximum contaminant level: 28.5 ppb

Radium

Radium (Ra) is a radioactive element measured in picocuries per liter (pCi/L). Although it occurs naturally in many groundwater deposits, high levels of exposure can lead to an increased risk of cancer over time. The tap water in Memphis is within the EPA’s limit of 5 pCi/L, but exceeds the EWG’s recommended maximum by 40 times:

• EPA maximum allowance: 5 pCi/L
• EWG recommended maximum: 0.05 pCi/L
• Memphis maximum detected level: 1.98 pCi/L

Total trihalomethanes (TTHMs)

Trihalomethanes are a disinfection byproduct, which means that they’re formed when chemicals are added to the water to disinfect it. Long-term exposure is associated with an increased risk of cancer and other health effects. Grouped as total trihalomethanes (TTHMs), Memphis TTHM levels exceed the EWG’s recommendation by 41 times:

• EPA maximum allowance: 80 ppb
• EWG recommended maximum: 0.15 ppb
• Memphis maximum contaminant level: 6.11 ppb

What Issues Impact Memphis, TN Water Quality?

Since Memphis gets its drinking water from an underground aquifer, it isn’t as affected by seasonal variations in lakes and rivers the way that some U.S. water systems are. Still, it can occasionally run into issues with its distribution system.

According to the Associated Press (AP), “water infrastructure in the South is not built for heavy snow.” In the winters of 2021 and 2024, MLGW had to issue boil water advisories as “water mains broke, wells failed, reservoirs froze, and motors at pumping stations overheated in a system with some parts dating to the 1930s.”

MLGW has invested over $60 million in system improvements. Residents can visit the MLGW website for updates, or follow them on social media to learn more.

Does Memphis Tap Water Contain Lead?

Lead pipes are a concern in many U.S. cities due to the health risks associated even with small amounts of exposure. Although there’s no detectable lead in Memphis tap water when it leaves the water treatment plant, it can pick up lead along the way.

By some estimates, there are as many as 15,000 lead service lines in the city, many of which are located “along the North and South parkways that split Midtown from North and South Memphis.” MLGW is working hard to replace them, but homeowners are responsible for replacing the portion of the line on their property.

Homes built before 1986 are most at risk, but even newer homes could contain lead plumbing fixtures. Memphis and Shelby County residents can call 901-320-3962 or email waterlab@mlgw.org to get a free lead testing kit.

Does Memphis Tap Water Contain Fluoride?

Yes, to comply with a City of Memphis Ordinance, MLGW adds fluoride to the drinking water to prevent tooth decay. In 2013, it reduced fluoride levels from 1.0 milligrams per liter (mg/L) to 0.7 mg/L, in line with the U.S. Department of Health and Human Services and the Tennessee Department of Environment and Conservation.

Is Memphis Tap Water Safe to Drink?

Memphis, TN’s water quality meets national safe drinking water standards and fares well when compared to other U.S. cities. Most contaminants are well within the EPA’s limits, and only a few exceed the EWG’s public health recommendations. However, lead, PFAS, and other contaminants may still be present in your drinking water.

Residents who want to reduce contaminants and improve the taste of their water can install a home water filter. The HomeWater EZChange 2-Stage Under Counter Under Sink Water Filter fits under your sink and can be installed in as little as 15 minutes.

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