Status of Baltimore Water Quality in 2024: Get the Facts

Where Does Baltimore’s Tap Water Come From?

The Baltimore City Department of Public Works (DPW) is in charge of providing clean drinking water to over 600,000 people in Baltimore County. It also supplies water to surrounding areas like Carroll, Harford, Howard, and Anne Arundel County.

Baltimore collects surface water from multiple watersheds, including the Susquehanna River, and uses three reservoirs to store the water. It has a system of dams and tunnels in place to transport the water, and three water filtration plants, including the Ashburton and Montebello plants, that can process up to 400 million gallons per day.

Who Is Responsible for Water Quality in Baltimore, MD?

Because Baltimore’s water system relies so heavily on surface water, including rainfall and snowmelt, it’s susceptible to common water contaminants, including bacteria and viruses, agricultural runoff, and industrial pollutants.

The Maryland Department of the Environment conducts water sampling as part of its source water assessment program, while the Baltimore City DPW is responsible for ensuring public health by testing its treated tap water on an ongoing basis.

Each year, it releases a water quality report that shows how well it meets the federal regulations set by the U.S. Environmental Protection Agency.

How Is Baltimore’s Drinking Water Treated?

Baltimore’s water goes through a multi-step treatment process before it’s distributed to consumers. Here’s what that looks like at Baltimore’s water purification plants:

• Chlorination: First, the DPW adds chlorine to the water to kill viruses, bacteria, and other pathogens, and to inhibit the growth of algae.
• Coagulation and flocculation: Next, they add aluminum sulfate, a coagulant that causes particles to clump together so they can be removed. Then, large paddles stir the water in flocculation basins so the heavy particles settle.
• Sedimentation: Large scrapers are used to remove the large particles, which may include chemicals, sediment, heavy metals, and other contaminants.
• Filtration: Once the large clumps are removed, the water is filtered through sand and gravel to filter out any smaller particles.
• Fluoridation: Like most American cities, Baltimore adds fluoride to its water as a public health measure intended to reduce tooth decay.
• pH adjustment: Finally, DPW adjusts the pH of the water by adding lime, which reduces the amount of lead and copper that leaches out of pipes.

What Contaminants Are Found in Baltimore’s Drinking Water?

Baltimore’s water treatment process is designed to remove common contaminants and provide clean drinking water to consumers. However, the water treatment process itself can produce harmful disinfection byproducts, and other contaminants may get into the water supply in the distribution system after it leaves the treatment plant.

According to the Environmental Working Group (EWG), Baltimore’s water quality data shows 25 total contaminants, nine of which exceed the EWG’s recommendations.

Here are five types of contaminants to look out for in your drinking water:

Haloacetic acids (HAA5)

This group of five haloacetic acids, referred to as HAA5, is linked to an increased risk of cancer and harm to fetal growth. The EPA’s maximum limit is 60 parts per billion (ppb), but the EWG recommends a more cautious limit. The amount of HAA5 in Baltimore's tap water exceeds this public health recommendation by 341 times:

• EPA maximum allowance: 60 ppb
• EWG recommended maximum: 0.1 ppb
• Baltimore maximum contaminant level: 34.1 ppb

Haloacetic acids (HAA9)

Another group of haloacetic acids, called HAA9, includes four more acids in addition to HAA5. When measured in this way, there’s no legal limit, but the EWG recommends a maximum of 0.06 ppb to maintain a one-in-a-million lifetime risk of cancer. Baltimore’s water exceeds this guideline by 824 times:

• EPA maximum allowance: No legal limit
• EWG recommended maximum: 0.06 ppb
• Baltimore maximum contaminant level: 49.4 ppb

Total trihalomethanes (TTHMs)

Trihalomethanes are a byproduct of the disinfection process, and are produced when chemicals like chlorine interact with soil, plant matter, and other impurities in the water system. Because Baltimore’s water supply comes from surface water, it has relatively high levels of these impurities, resulting in high trihalomethane levels.

Although they’re within the EPA’s legal limit, they exceed the EWG’s recommendation by 337 times, indicating an increased risk of cancer with long-term exposure:

• EPA maximum allowance: 80 ppb
• EWG recommended maximum: 0.15 ppb
• Baltimore maximum contaminant level: 50.6 ppb

Nitrates and nitrites

Nitrates and nitrites get into the water supply from urban and agricultural runoff, and are associated with an elevated cancer risk and harm to fetal growth. Although Baltimore’s levels are within the legal limit, they exceed the EWG’s maximum by 12 times:

• EPA maximum allowance: 10 ppm
• EWG recommended maximum: 0.14 ppm
• Baltimore maximum contaminant level: 1.74 ppm

Radium

Radium is a radioactive substance that’s associated with serious health risks like bone cancer. Under federal regulations, levels of radium-226 and radium-228 can’t exceed 5 picocuries per liter (pCi/L), but some public health guidelines, including the California Public Health Goal, recommend a more cautious limit of 0.05 pCi/L.

According to the Maryland Department of the Environment, some private wells in Anne Arundel County exceeded the EPA’s limit. Baltimore’s tap water is within the legal limit, but 7.4 times the public health goal:

• EPA maximum allowance: 5 pCi/L
• EWG recommended maximum: 0.05 pCi/L
• Baltimore maximum detected level: 0.37 pCi/L

Can You Get Sick From Drinking the Tap Water in Baltimore?

Ordinarily, healthy people won’t get sick from drinking the tap water, but there are water quality issues from time to time. In 2022, the DPW found E. coli in West Baltimore, and in 2023, it detected low levels of Cryptosporidium in the Druid Lake Reservoir.

Because two of the city’s reservoirs are uncovered, they’re at greater risk of bacterial contamination from bird waste and other environmental contaminants.

You can check with the Department of Public Works or Baltimore City Comptroller to see if there’s a boil water advisory in place. If there is, you may be able to request a bottled water delivery, or pick up bottled water from a distribution center.

In 2022, Mayor Brandon Scott gave Baltimore residents a 25% discount on their water bills to make up for Baltimore’s water quality issues.

Does Baltimore’s Drinking Water Contain Lead?

Baltimore uses corrosion control measures to prevent lead from leaching out of pipes, and the tap water doesn't contain any lead when it leaves the treatment plant. However, because of the city’s aging infrastructure, some service lines and plumbing fixtures may contain lead, especially in older buildings.

Residents can take a survey at publicworks.baltimorecity.gov to identify whether their service line contains lead and needs to be replaced.

Since there’s no safe amount of exposure to lead, it’s a good idea to test your tap water and use an NSF 53 filter that’s designed to remove lead.

Does Baltimore’s Drinking Water Contain PFAS?

Forever chemicals are a class of man-made chemicals that are used in manufacturing and other industrial purposes, and are linked to a myriad of health problems. The EPA has only recently begun requiring American water utilities to test for these chemicals, also known as per- and polyfluoroalkyl substances, or PFAS.

According to the 2022 Consumer Confidence Report, “PFAS levels are below the U.S. Environmental Protection Agency’s (EPA) proposed action threshold” in Baltimore.

That same year, the City of Baltimore filed a lawsuit against PFAS manufacturers to hold them responsible for releasing PFAS into the environment.

Despite these steps, there’s still a lot that’s unknown about the prevalence of PFAS in the drinking water. Baltimore residents may want to take matters into their own hands and install an activated carbon or reverse osmosis filter to remove PFAS.

Does Baltimore’s Tap Water Contain Sodium?

Although trace amounts of sodium appear naturally in drinking water, it can be harmful in large quantities, especially for people with high blood pressure. Because Baltimore relies on surface water for drinking, the use of rock salt during the winter months can increase sodium levels in the water supply.

According to the 2022 water quality report, sodium levels were just over 20 parts per million, which is considered safe for most consumers.

Is Baltimore Harbor Safe to Swim in?

Tap water isn’t the only water quality concern in Baltimore. Residents may want to know whether it’s safe to go swimming in Baltimore Harbor. According to the Healthy Harbor Report Card, the answer is yes — with some caveats.

First, you should avoid swimming for two days after rain, since wet weather can result in stormwater discharge and sewage overflows. You’ll also need to be conscious of boat traffic since there are several ports and marinas in the Harbor.

Because of this, they recommend that you only go swimming on dry weather days “at designated locations and during scheduled events like Harbor Splash.”

Is Baltimore’s Tap Water Safe to Drink?

Baltimore’s tap water uses modern water treatment methods to keep contaminant levels within the EPA’s public health guidelines. In 2017, BestLife rated it as the 10th best city in America for drinking water quality. But whether it’s safe to drink depends on whether you’re comfortable with its relatively high levels of disinfection byproducts.

You can use an activated carbon filter at home to reduce your exposure to some of the most common contaminants in Baltimore drinking water, or a reverse osmosis filter to get rid of additional contaminants like radium, heavy metals, and PFAS.

Enter your ZIP code to check your local water quality report and find out which home water filtration system is right for you.