Waltham
Waltham, MA water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
waltham water department
surface water (rivers/reservoirs) · local government · PWSID MA3308000
Below EPA's 15 ppb lead action level at last testing.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1
Waltham, MA is a small but growing city, with a population near 63,378 and the 17th-largest community in Massachusetts. Like much of Massachusetts, Waltham draws its water primarily from Quabbin Reservoir, rivers, and groundwater.
Waltham's water outlook is shaped most by aging infrastructure — the issue that dominates planning across Massachusetts. The Quabbin system gives Boston a robust supply, while smaller systems wrestle with PFAS and lead pipes.
Waltham sits in a state that reuses roughly 4% of treated wastewater (minimal programs) and currently experiences moderate to severe drought.
For the bigger picture, see the Massachusetts state water profile and the related issues below.
Middlesex County water quality
Source: EPA SDWIS · 2026 Q1
At a glance
- Population ~63,378 (17th-largest in Massachusetts)
- Primary sources: Quabbin Reservoir, rivers, and groundwater
- Drought: moderate to severe conditions
- State reuse rate: ~4% of wastewater
Statewide drought history
% of Massachusetts in severe+ drought (Severe (D2) now).
Source: U.S. Drought Monitor
Common questions
Is tap water safe in Waltham?
Waltham's largest water system, WALTHAM WATER DEPARTMENT, serves about 65,218 people. EPA records show 0 health-based violation(s) since 2016 and a most-recent 90th-percentile lead level of 1.9 ppb (EPA action level is 15 ppb). Always check your own provider's annual Consumer Confidence Report.
Where does Waltham get its water?
WALTHAM WATER DEPARTMENT draws primarily from surface water (rivers/reservoirs), part of Massachusetts's supply from Quabbin Reservoir, rivers, groundwater.
Related water issues
Aging 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.
ExplorePFAS Contamination
Per- and polyfluoroalkyl substances persist in water supplies for decades. New federal limits are forcing utilities nationwide to invest in advanced treatment.
Explore