Baltimore’s municipal water system, overseen by the Baltimore City Department of Public Works (DPW), serves approximately 1.8 million people in the metropolitan area. Although the system faces complex infrastructure challenges due to aging pipes, the water delivered consistently meets the legally mandated safety standards. This compliance is ensured through rigorous regulatory oversight at both the state and federal levels.
The Current Safety Verdict
Baltimore’s tap water is officially deemed safe for consumption, meeting or exceeding all Maximum Contaminant Levels (MCLs) established by the U.S. Environmental Protection Agency (EPA) and the Maryland Department of the Environment (MDE). The DPW maintains a strong record of compliance, reporting no recent violations related to regulated contaminants. This means the water meets the legal definition of safety under the Safe Drinking Water Act.
The definition of “safe” refers strictly to meeting these legally enforceable federal and state standards. Concerns persist because some contaminants, such as disinfection byproducts, may exceed stricter, non-enforceable public health guidelines developed by independent scientific organizations. These guidelines often reflect newer research and lower risk tolerances than the federal government’s older regulatory limits. The DPW is actively addressing infrastructure requirements, such as those related to covering or treating finished water reservoirs like Druid Lake and Ashburton, following past EPA administrative orders.
Water Sources and Treatment Infrastructure
Baltimore’s drinking water originates from surface water collected from the Gunpowder Falls and Patapsco River watersheds, stored in three major reservoirs: Prettyboy, Loch Raven, and Liberty. The raw water is directed to one of three primary treatment facilities—the Ashburton Filtration Plant or the Montebello Filtration Plants I and II—which together produce hundreds of millions of gallons of treated water daily.
The purification process is a multi-step procedure beginning with chlorination to eliminate harmful bacteria and viruses. Aluminum sulfate is added in a process called coagulation, which causes microscopic particles to clump together into larger masses known as floc. This floc settles out during sedimentation, and the remaining water is passed through filters composed of sand and gravel. Finally, the treated water is disinfected again before it enters the distribution system.
The primary contamination risk occurs within the aging municipal distribution pipes and household plumbing, not typically at the source or treatment plants. The presence of lead service lines (LSLs) connecting the water main to a home remains a localized issue. Lead can leach into the water as it contacts these old pipes, a problem known as point-of-use contamination. The DPW is currently undertaking a large-scale effort to identify and inventory all LSLs to manage this risk.
Testing Standards and Consumer Reporting
Water safety is maintained through an intensive regulatory framework involving the Baltimore DPW, the MDE, and the EPA. The DPW operates two MDE-certified laboratories at the Montebello and Ashburton plants, which together conduct approximately 150,000 water quality analyses each year. These tests monitor a wide spectrum of potential contaminants, including microbiological agents, inorganic chemicals, lead, copper, and disinfection byproducts like Total Trihalomethanes and Haloacetic Acids.
Public accountability is demonstrated through the annual Consumer Confidence Report (CCR), also called the Water Quality Report, mandated by the EPA. This document details the water source, regulatory testing results, and detected contaminants, comparing those levels to legally mandated standards. Baltimore residents can access the most recent CCR online at the DPW website, providing a transparent view of the water’s quality.
Customers should review detected contaminant levels, particularly those with a health-based guideline below the legal limit, to make informed decisions about household water use. For residents concerned about lead or other point-of-use issues, especially in older homes, a certified home water test is the most practical action to assess localized risk. City residents can call 311 to request a printed copy of the CCR or to report water quality concerns.