Columbia
Columbia, MD water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
howard county d.p.w. distribution
surface water (rivers/reservoirs) · local government · PWSID MD0130002
Below EPA's 15 ppb lead action level at last testing.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1
Columbia, MD is a small but growing city, with a population near 99,615 and the 2nd-largest community in Maryland. Like much of Maryland, Columbia draws its water primarily from Potomac River, Chesapeake tributaries, and coastal aquifers.
Columbia's water outlook is shaped most by saltwater intrusion — the issue that dominates planning across Maryland. Chesapeake Bay restoration drives heavy investment in stormwater and nutrient management.
Columbia sits in a state that reuses roughly 7% of treated wastewater (developing programs) and currently experiences severe to extreme drought.
For the bigger picture, see the Maryland state water profile and the related issues below.
Howard County water quality
Source: EPA SDWIS · 2026 Q1
At a glance
- Population ~99,615 (2nd-largest in Maryland)
- Primary sources: Potomac River, Chesapeake tributaries, and coastal aquifers
- Drought: severe to extreme conditions
- State reuse rate: ~7% of wastewater
Statewide drought history
% of Maryland in severe+ drought (Extreme (D3) now).
Source: U.S. Drought Monitor
Common questions
Is tap water safe in Columbia?
Columbia's largest water system, HOWARD COUNTY D.P.W. DISTRIBUTION, serves about 286,158 people. EPA records show 0 health-based violation(s) since 2016 and a most-recent 90th-percentile lead level of 3 ppb (EPA action level is 15 ppb). Always check your own provider's annual Consumer Confidence Report.
Where does Columbia get its water?
HOWARD COUNTY D.P.W. DISTRIBUTION draws primarily from surface water (rivers/reservoirs), part of Maryland's supply from Potomac River, Chesapeake tributaries, coastal aquifers.
Related water issues
Saltwater Intrusion
As coastal aquifers are over-pumped and seas rise, saltwater pushes inland and contaminates freshwater supplies for cities from Florida to California.
ExploreAging Infrastructure
Much of America's water infrastructure is decades past its design life, leaking trillions of gallons a year and demanding hundreds of billions in reinvestment.
ExploreStormwater Capture
Cities are reengineering streets and parks to capture rain that once ran to the sea, recharging aquifers and reducing flooding at the same time.
Explore