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City water profile

Waltham water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Waltham, Massachusetts.

Median indexed hardness

42PPM

2 indexed ZIPs

Range 40.5–42.8 PPM

State comparison
7 PPM below
State hardness rank
#235 of 302
Matched utilities
2
Active health records
0

City summary

What the indexed records say

Waltham has 2 published ZIP profiles across Middlesex County. The indexed median is 42 PPM, compared with 49 PPM across Massachusetts.

Among the 302 Massachusettscities with an indexed median, Waltham ranks #235from highest to lowest. Across all 328 state ZIP profiles, available estimates run from 24.3to 128 PPM.

The 40.5–42.8 PPM range shows how much the available ZIP estimates vary within the city label.

Hardness distribution

How local ZIP estimates compare

Soft2 ZIPs
Moderately hard0 ZIPs
Hard0 ZIPs
Very hard0 ZIPs

2 of 2 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance
2.5 miles
Profiles with evidence
2/2

Confidence labels

High: 0Moderate: 2Low: 0

Observation window: Jan 4, 2016 to Jun 8, 2026.

ZIP directory

Water reports in Waltham

Open a ZIP for site-level provenance and measurements.

ZIP code

01773

Soft

40.5 PPM

Nearest site
2.1 mi
Confidence
Moderate

View full ZIP evidence →

ZIP code

02452

Soft

42.8 PPM

Nearest site
2.5 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Lincoln Water Dept

PWSID MA3157000

Surface water
System population served
5,593
Last reported
Jun 22, 2026

EPA SDWIS explicitly lists this ZIP in the system's served geography.

Waltham Water Department

PWSID MA3308000

Surface water
System population served
65,218
Last reported
Jun 22, 2026

EPA SDWIS explicitly lists this ZIP in the system's served geography.

Compliance history

What EPA records show

No active health-based violation appears among the associated systems in the represented EPA reporting quarter. This does not mean every contaminant was tested at every tap.

RecordSystemPeriodStatus
Lead and Copper RuleMA3308000Jan 1, 2025Addressed

Practical next steps

Move from index to evidence

  1. 1. Open your ZIP. Check distance, dates, confidence, and the associated utility.
  2. 2. Read the current CCR. Confirm source water, detections, limits, ranges, and notices.
  3. 3. Test the tap when needed. Confirm health concerns or treatment sizing with the right method.

Questions people ask

About water in Waltham

Is the water hard?

The indexed city median is 42 PPM. Open the ZIP report to verify the distance and confidence behind that estimate.

Is the tap water safe?

Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.

Do I need treatment?

Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.