Is Baltimore Tap Water Safe to Drink?

Is my service line lead?

How to find out whether your service line is lead

Baltimore maintains a service line inventory (the Baltimore Service Line Partnership, run with the Baltimore County Department of Public Works and Transportation) at www.servicelinepartnership.baltimorecity.gov. Residents can report their own pipe material through the self-reporting survey.

Check your own pipe: the scratch, magnet and tap test

The utility’s guidance for reducing lead exposure

• Flush cold water from the tap before drinking or cooking, especially after long periods of non-use
• Run cold water from the kitchen faucet or shower, or run the washing machine or dishwasher while empty
• Flush first thing in the morning or on returning home from work
• Run water for 3–5 minutes daily
• Clean faucet aerators and showerheads regularly

Residents concerned about lead can contact the City and the Ashburton Laboratory at (410) 396-0150 to have their water tested. The report does not state whether testing is free of charge.

Full contaminant results

Every detected contaminant in Baltimore's 2025 report

Thirteen contaminants appear in the detected-results tables. Eleven were detected at one or more treatment plants; none exceeded a federal maximum contaminant level. Behind these tables sits a much larger program: 100,000 tests a year, including at least 360 distribution samples a month.

Results by treatment plant

Baltimore reports these analytes separately for each of its two plants. We do not average across plants — the differences are real.

Not everything in this report is 2025 data: lead and copper are from 2024, and some rows below were sampled in 2019 and 2024. Each carries its own date where it differs from the report year.

System-wide results

Secondary (aesthetic) parameters

These are measured against secondary standards — federal guidelines for taste, odor and staining, not health-based limits.

PFAS

PFAS refers to a group of more than 4,000 human-made chemicals used since the 1940s in stain- and water-resistant fabrics, carpeting, cleaning products, paints, cookware, food packaging and firefighting foams.

The EPA announced MCLs for six PFAS compounds in April 2024. The report states the MCLs are scheduled to take effect 26 April 2029, with systems required to implement reductions by then where monitoring shows exceedances, and that the EPA has proposed a rule rescinding the regulations for the Hazard Index compounds.

Other unregulated contaminants

Baltimore sampled for unregulated contaminants beyond the regulated tables. One compound was detected:

PFAS

Under the EPA's fifth Unregulated Contaminant Monitoring Rule, Baltimore tested for 29 per- and polyfluoroalkyl substances (PFAS) and 1 lithium from 2024/08 to 2025/05. The City of Baltimore began UCMR5 testing in August 2024 and concluded in May 2025. No constituents under UCMR5 were detected. The same report quantifies PFOA, PFOS, PFBS and PFHxA in compliance monitoring. The CCR does not reconcile the two; UCMR5 minimum reporting levels (4 ppt for PFOA and PFOS) sit above the concentrations Baltimore's compliance monitoring reported, which would allow both statements to be true, but the report itself does not say so — each result stands with its own programme and reporting level.

Violations explained

Baltimore's 2025 report discloses one violation. It was health-based.

Service line notification certification not submitted on time

Water systems must certify to MDE that customers served by a service line classified as Lead, Galvanized Requiring Replacement or Lead Status Unknown were notified. The initial inventory was due to MDE by 16 October 2024; Baltimore submitted it on 25 November 2024. The report was late because roughly 73,000 notifications for properties with unknown pipe material were left out of the original mailing sent on 12 November 2024 — a data management error. Those notifications were mailed on 25 November 2024. The City has revised the Quality Assurance review process for data management to prevent any recurrence.

Unresolved significant deficiencies (sanitary survey)

Separately from any violation, the report prints two unresolved significant deficiencies from the system's sanitary survey. These are inspection findings about infrastructure condition — they are not violations, and the report connects them to no contaminant result.

The system-wide Sanitary Survey was completed in 2017 with follow-up visits in 2018, 2020 and 2024. The follow-ups concerned accumulated sedimentation in 46 of the 60 filters at the Montebello treatment plants. The City plans to rehabilitate all 60 filters — underdrain repair where required, filter media replacement, and rehabilitation of the surface sweep system.

Where your water comes from

Liberty, Loch Raven and Prettyboy reservoirs to your tap

Baltimore draws its drinking water from Liberty, Loch Raven and Prettyboy reservoirs. Baltimore's primary source is surface water from rainfall and snowmelt, collected and stored in three City-owned reservoirs. The watershed lands surrounding them are largely native woodland, established solely to protect the drinking water supply.

Treatment happens at the Ashburton Water Filtration Plant and the Montebello Water Filtration Plants I and II, and the report publishes plant-level results where they differ.

Emergency source: The supply is also linked to the Susquehanna River, which flows from Cooperstown, N.Y. to Havre de Grace, MD. It is used only during severe drought conditions.

How the water is treated

1. Source water storage in one of three reservoirs
2. Disinfection with sodium hypochlorite or chlorine
3. Coagulation with aluminium sulfate (alum)
4. Flocculation and sedimentation
5. Sand filtration
6. Fluoride addition (fluorosilicic acid, sodium fluoride or sodium fluorosilicate)
7. pH adjustment
8. Distribution

Watershed protection: Liberty Reservoir Forest Restoration

A tornado in June 2024 damaged forested areas around Liberty Reservoir, uprooting trees and exposing soil in a way that can increase erosion and affect water quality. The project will re-establish native mixed-hardwood forest in the affected area to reduce sediment runoff, improve habitat and strengthen watershed resilience.

Cryptosporidium in the source water

Baltimore voluntarily samples its source water for Cryptosporidium. These are source-water results, before treatment — the report publishes no finished-water result, and no drinking-water limit applies to source water, so none of these numbers describes tap water.

The distribution system

The report describes 'a pressurized underground pipe network spanning more than 4,500 miles' in one place and 'more than 3,800 miles of water mains' in another. These may describe different things (all pipe versus mains only), but the report does not say so — both figures are printed here as published.

During the winter of 2025, extreme cold contributed to a record number of water main breaks. The system's earliest pipes were hollowed-out logs; a preserved wooden main is pictured in the report.

Under the Water Main Replacement Program, 11.47 miles had been replaced as of 2026/05, against a goal of 15 miles per year through 2030 — the report's own figures, stated as printed.

What you can do

Should you filter Baltimore tap water?

Baltimore's data points at disinfection byproducts: Total Trihalomethanes (TTHM) at 96% of its limit and Haloacetic Acids (HAA5) at 77% of its limit. The compliance averages stayed under the limits, but individual Total Trihalomethanes (TTHM) samples reached 133 ppb against the 80 ppb MCL — no violation, because compliance is the annual average, but these are by far the strongest numbers on this page.

The relevant device for disinfection byproducts is an activated carbon filter — carbon is the standard at-the-tap treatment for trihalomethanes and haloacetic acids. Look for a filter whose certification names TTHM or disinfection byproduct reduction, and verify the claim on the certifier's listing before buying.

Beyond the byproducts: Nitrate (as Nitrogen) sits at 58% (5.81 ppm against a 10 ppm limit). Filter selection for those should follow a test at your own tap, with a certification that names the specific contaminant.

Separately, PFOS sits at 3.3 ppt against its 4 ppt federal MCL and PFOA sits at 2.9 ppt against its 4 ppt federal MCL — limits that take effect 26 April 2029, so nothing is enforceable today. If you are choosing a filter for the byproducts anyway, it can carry a certification for PFOA/PFOS reduction as well; verify both claims on the certifier's listing.

A lead-specific filter is not indicated by this data: the 90th percentile is 2.74 ppb — 18% of the 15 ppb action level — with 0 sites exceeding it. Testing at your own tap is still the only number that describes your house.

Legionella guidance from the utility

Baltimore publishes household guidance on Legionella without publishing any Legionella monitoring results — what follows is the utility's guidance, not a finding about Baltimore's water:

• Maintain a minimum hot water heater outlet temperature of 130°F and flush regularly
• Flush all hot and cold water lines regularly, including exterior faucets and attached hoses
• Remove and clean faucet aerators, screens and showerheads regularly
• An absolute 0.2-micron hollow-fiber membrane filter certified for bacterial removal will remove Legionella
• Clean and disinfect humidifiers and decorative fountains regularly

What this data does not tell you

Every number on this page describes water at the plants, in the mains, or as a system-wide statistic. None of it was measured in your building. If you want to know about your water rather than Baltimore's, testing at your own tap is the only source.

Your pipes tell a different story

The data above shows what leaves the treatment plant—not what comes out of your faucet. Old pipes, lead solder, and building plumbing can add contaminants the city never tests for. Know exactly what's in your Baltimore tap water.

Test Your WaterSee top-rated kits →

Home test kits detect lead, bacteria, pesticides, and 100+ other contaminants. Results in 5-10 business days from certified labs.

If testing does point at a specific contaminant, our filter guides cover certifications and what to verify before buying.

Arsenic filters →AquaTru review →

Frequently asked questions

Sources and methodology

Primary sources

• *2025 Water Quality Report — Baltimore City Department of Public Works* (Consumer Confidence Report), Baltimore City Department of Public Works, PWSID MD0300002 — publicworks.baltimorecity.gov/waterreport
• *Baltimore Service Line Inventory* — www.servicelinepartnership.baltimorecity.gov
• *MDE PFAS Public Water System Study Map (2020–2022)* — marylanddepartmentoftheenvironment.shinyapps.io/MDE_PFAS_PublicWaterSystemStudyMap/
• EPA Safe Drinking Water Information System (SDWIS), PWSID MD0300002
• EPA Enforcement and Compliance History Online (ECHO), facility MD0300002

How we compiled this

We do not test water. Every figure on this page is transcribed from documents published by Baltimore City Department of Public Works or the EPA, and each is attributed to the document it came from.

Lead and copper values are 90th-percentile compliance statistics from the 2024 sampling round — older than the 2025 report because monitoring runs every three years. The report does not state how sampling sites were selected — only that lead and copper are tested at customers' taps. We do not describe this as a citywide or representative sample. We state sample years next to values rather than presenting everything as current.

Last updated: 2026-09-11