Baltimore – Maryland
Baltimore’s Department of Public Works manages one of the oldest municipal water systems in the United States, established in 1804, serving over 1.8 million residents across Baltimore City and nine surrounding jurisdictions. The system includes approximately 3,000 miles of water mains, three major reservoirs, and advanced treatment facilities, delivering roughly 475 million gallons daily to the greater Baltimore metropolitan area.
Baltimore draws its drinking water from two primary sources: Susquehanna River impoundments and Liberty Reservoir, both located in protected watersheds north of the city. The system maintains exceptional source water quality through comprehensive watershed management and protection programs. Baltimore’s water has historically been recognized for its quality and taste, though like many older cities, it faces ongoing challenges with aging infrastructure and lead service lines. The city has implemented significant investments in pipeline replacement, water treatment upgrades, and customer assistance programs to maintain high water quality standards.
Baltimore Water Quality: Current Status (2024-2025)
Latest Testing Results
- Lead Levels: The most recent testing period (January-December 2023) showed 90th percentile lead levels of 9.8 parts per billion (ppb), below the EPA action level of 15 ppb but reflecting the presence of lead service lines in older neighborhoods.
- Testing Scope: Baltimore conducts over 100,000 water quality tests annually across the system, including enhanced lead monitoring at residential sites throughout the distribution network.
- Compliance Status: Baltimore’s water meets all federal and state drinking water standards, maintaining compliance with EPA and Maryland Department of the Environment regulations.
Protected Watershed Sources
- Susquehanna River System: Primary source (70% of supply) includes Prettyboy and Loch Raven reservoirs, both located in protected watersheds with strict land use controls.
- Liberty Reservoir: Secondary source (30% of supply) fed by surface water from the Patapsco River drainage area, also maintained within protected watershed boundaries.
- Watershed Protection: Over 80,000 acres of protected land ensure source water quality through forest management, development restrictions, and recreational use regulations.
Advanced Treatment Technology
- State-of-the-Art Plants: Ashburton and Montebello treatment plants utilize comprehensive treatment processes including coagulation, sedimentation, filtration, and advanced disinfection.
- Ozone Disinfection: Primary disinfection uses ozone treatment which provides effective pathogen control while reducing chemical byproducts.
- Corrosion Control: Optimized orthophosphate addition prevents lead leaching from pipes, with pH adjustment and alkalinity management tailored to system requirements.
Infrastructure Modernization
- Pipeline Replacement: Annual replacement of approximately 25 miles of aging water mains, prioritizing areas with high leak rates and oldest infrastructure.
- Lead Service Line Program: Comprehensive inventory and replacement initiative targeting the estimated 150,000 lead service lines throughout the system.
- Smart Water Management: Advanced metering infrastructure with leak detection capabilities and real-time system monitoring to improve efficiency and water quality management.
Customer Protection Initiatives
Baltimore provides extensive customer support including free water testing, filter distribution programs, and payment assistance for qualified residents. The city’s Lead Safe Home Program offers grants for lead pipe replacement, while educational outreach helps residents understand water quality and conservation. Baltimore’s commitment to environmental justice includes prioritizing infrastructure improvements in historically underserved communities while maintaining transparent communication about water quality and system maintenance. The city’s long history of water provision, combined with ongoing modernization efforts, ensures reliable, high-quality water delivery to one of the East Coast’s major metropolitan areas.
Recommendations for Baltimore Residents
Test for Lead
Request free water testing by calling 311 or visiting publicworks.baltimorecity.gov. Testing is especially important for homes built before 1987 or with known lead service lines.
Join Lead Safe Program
Apply for grants through the Lead Safe Home Program to replace lead service lines at no cost. Call (410) 396-3030 or visit housing.baltimorecity.gov/lead to start the application process.
Use Certified Filters
If you have a lead service line or elevated lead levels, use NSF-certified filters (Standard 53) for drinking and cooking water. Free filters are available through city programs.
Flush Pipes Properly
If water has been sitting in pipes for 6+ hours, run cold water for 1-2 minutes before using for drinking or cooking. Always use cold water for consumption to minimize potential metal exposure.
Report Issues
Contact 311 immediately for water main breaks, pressure problems, or quality concerns. For emergencies after hours, call the water emergency hotline at (410) 396-5775.
Frequently Asked Questions
Is Baltimore’s tap water safe to drink?
Yes, Baltimore’s tap water meets all federal and state drinking water standards. The city’s water comes from protected reservoirs with excellent source water quality and undergoes comprehensive treatment including ozone disinfection and filtration.
However, lead can enter water through service lines and older plumbing in homes built before 1987. Recent testing shows 90th percentile lead levels at 9.8 ppb, below EPA action levels but still a concern for vulnerable populations. The city provides free testing, filters, and service line replacement programs. Residents in older homes should test their water and use certified filters as a precaution.
How do I know if my home has a lead service line?
Baltimore maintains records of service line materials, though many are unknown. To check your home:
1. Look for the service line where water enters your home (usually in basement). Lead pipes are dull gray, soft enough to scratch with a key, and won’t attract a magnet.
2. Call 311 to request a service line inspection
3. Review property records if your home was built before 1950
Baltimore’s Lead Safe Home Program offers grants for lead service line replacement. Homes built before 1947 are most likely to have lead lines, though some were installed through the 1970s.
Why does Baltimore use ozone instead of just chlorine?
Baltimore uses ozone as the primary disinfectant, followed by chlorine for residual protection in the distribution system. This combination offers several advantages:
• Better disinfection: Ozone is more effective against certain pathogens including Giardia and Cryptosporidium
• Fewer byproducts: Ozone produces fewer harmful disinfection byproducts than chlorine alone
• Improved taste: Many people find ozonated water has less chemical taste
• Enhanced treatment: Ozone helps remove algae and other organic compounds
The chlorine added after ozone treatment maintains disinfection throughout the distribution system.
Are there water restrictions in Baltimore?
Baltimore maintains water conservation guidelines but rarely implements mandatory restrictions:
Voluntary Conservation Measures:
• Water lawns during early morning or evening hours
• Use brooms instead of hoses for cleaning driveways
• Install water-efficient fixtures and appliances
• Fix leaks promptly
Drought Response:
During severe drought (which is rare), the city may implement:
• Restrictions on lawn watering
• Limits on non-essential water use
• Public water use prohibitions
Current status and any active restrictions are available through 311 or publicworks.baltimorecity.gov.
Contaminants of Concern
Lead
Source: Lead service lines and older plumbing fixtures in homes built before 1987; Baltimore has approximately 150,000 lead service lines
Health Effects: Developmental delays in children, reduced IQ, learning difficulties, kidney problems, cardiovascular effects in adults
Current Levels: 90th percentile value of 9.8 ppb, below EPA action level of 15 ppb EPA Limit: Action level 15 ppb, but no level of lead is considered safe
Disinfection Byproducts
Source: Form when chlorine (used after ozone treatment) reacts with naturally occurring organic matter in reservoir water
Health Effects: Potential increased risk of bladder cancer and reproductive effects with long-term exposure to elevated levels
Current Status: Maintained well below EPA limits; levels are generally lower than in systems using chlorine-only disinfection
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