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Official EPA SDWIS Verified ReportWater Quality & Testing GuideHistorical Record: No Recorded SDWIS Violations

ZIP Code 02139 Water Quality & Testing Report

Cambridge, MA · Middlesex County County · Updated for 2026

Sahajul HaqueCompiled & verified by Sahajul Haque from official EPA SDWIS records
Public Health & Medical Notice: Drinking water quality data on this page reflects historical compliance records submitted under the Safe Drinking Water Act. This information does not constitute medical advice or a real-time safety guarantee. If you are pregnant, nursing, preparing infant formula, or immunocompromised, consult a healthcare provider. Boiling water kills biological pathogens, but does NOT remove chemical contaminants like lead, arsenic, or PFAS.
Quick EPA Verified Answer

Is Tap Water Safe to Drink in ZIP 02139 (Cambridge, MA)?

Caution / Filtration Recommended: Tap water in ZIP code 02139 (Cambridge, MA) has compliance concerns, earning an EPA Safety Grade of C (58/100) due to 0 health violation(s) and 8.0 ppb lead. While treated by Cambridge Water Department, residents are advised to use an NSF/ANSI 53 certified water filter for drinking and cooking.

Safety Score
C

Water Safety Grade

Fair — Some compliance concerns

Health Violations

0

Total Violations

0

Lead Risk

Very High

Contaminants

0

About Tap Water in ZIP Code 02139

Tap water in ZIP code 02139 (Cambridge, MA) is distributed by Cambridge Water Department (EPA ID: MA3049000), serving approximately 118,214 residents. Based on EPA Safe Drinking Water Act compliance records, this system receives a water safety grade of C with a composite quality score of 58/100.

Water System

Cambridge Water Department

EPA ID: MA3049000

Water Source

Surface Water

Population Served

118,214 residents

County

Middlesex County County, Massachusetts

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Lead Levels in ZIP 02139

EPA action level: 15 ppb | Public health goal: 0 ppb

Lead Level: 8.0 ppb — Moderate

The 90th percentile lead level in 02139 is 8.0 ppb. This is below the EPA action level of 15 ppb, but above ideal health goals. Consider a certified lead-reducing filter.

Lead exposure risk in 02139 is rated Very High. EPA models estimate a 73% exposure probability based on housing and infrastructure age.

Lead Level (90th percentile)
8.00 ppb (0.008 mg/L)
Lead (Consumer Confidence Report)

From annual CCR filing

8 ppb
Lead Exposure Risk Rating
Very High
Lead Exposure Probability

EPA model estimate based on housing age and infrastructure

73%
Note: Lead levels above are the 90th percentile from EPA monitoring — meaning 90% of samples were at or below this level. Even "undetected" tap water lead doesn't account for lead leaching from home plumbing. If your home was built before 1986, individual tap testing is recommended.
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Water Hardness & Mineral Content

Grains per gallon (GPG) & Parts per million (PPM / mg/L)

Classification: Soft3.3 GPG · 57 mg/L

Water in ZIP 02139 is classified as Soft (57 mg/L / 3.3 GPG). Soft water produces abundant soap lather, prevents scale buildup in water heaters, and does not leave spots on dishes.

Recommendation: No water softener is needed. Standard carbon filtration is sufficient for taste and chlorine reduction.
Hardness (GPG)

Grains per gallon

3.3 GPG
Hardness (PPM / mg/L)

Parts per million CaCO3

57 mg/L
Appliance Scaling Risk
Very Low

Official EPA SDWIS Database Entry

Utility: Cambridge Water Department · PWSID: MA3049000

Verify on EPA.gov
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Violation History

Past 5 years — EPA SDWIS data

Cambridge Water Department has recorded zero violations in the EPA compliance database over the past 5 years.

Total Violations (5 yr)
0
Health-Based Violations
0
Unresolved Violations
0
Boil Water Advisories
0
Compliance Risk
Low

Regulatory compliance risk for this utility is rated Low based on past reporting and enforcement records.

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Contaminants Detected

Contaminants with health-based violations on record

No health-based contaminant violations are on record for ZIP code 02139 under the Safe Drinking Water Act.

From Consumer Confidence Report:

Lead (8 ppb)

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Water Source & Environmental Factors

Surface Water

This system draws water from lakes, rivers, or reservoirs. Surface water is treated to remove sediment, microorganisms, and chemical contaminants before reaching taps.

Water Source Type
Surface Water
CCR Source Classification
Surface Water
EPA Radon Zone

Highest potential

Zone 1
Annual Flood Risk Cost

Estimated annual flood-related costs per property

$0
Energy Burden

% of household income spent on energy — indicator of older infrastructure

2.6%

EPA Radon Zone 1 — highest potential for radon in indoor air. Homeowners should test their home for radon and consider mitigation if levels exceed 4 pCi/L.

Water Quality Testing in ZIP 02139

Tap Water & Well Testing Recommendations

Residents in ZIP code 02139 served by Cambridge Water Department can test tap water or private well systems to verify water purity. Testing detects hidden contaminants before they impact family health.

Tap Water Testing Steps

  • 1.Conduct a certified lead check if your home was constructed before 1986.
  • 2.Use certified lab testing kits rather than uncalibrated test strips for regulated compliance.
  • 3.Sample water from both your kitchen faucet and water heater to compare line purity.

Private Well Testing Steps

  • •Test for Coliform bacteria and Nitrates annually.
  • •Test for heavy metals, radon, and PFAS every 3 years.
  • •Send samples to a state-certified drinking water laboratory recognized by Massachusetts Department of Environmental Protection.
Certified Lab Testing: Always use an EPA-certified drinking water laboratory in MA for formal legal or real estate compliance testing.

🛡 What Should You Do? — ZIP 02139 Recommendations

  • ⚠ Use a certified NSF/ANSI 53 filter for drinking and cooking water if you have young children
  • ⚠ Never give unfiltered tap water to infants in formula — use certified bottled or filtered water
  • ⚠ Request a copy of the Consumer Confidence Report to see what was detected and when
  • ⚠ Call the EPA Safe Drinking Water Hotline: 1-800-426-4791

Recommended Water Treatment Systems:

🏺

NSF 53 Lead Pitcher Filter

Specifically certified to reduce lead and copper at the tap.

Lead Filter Guide →
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NSF 58 Under-Sink RO System

Advanced filtration for PFAS, fluoride, nitrates, and organic chemicals.

RO System Guide →

Frequently Asked Questions — ZIP 02139 Water Quality

Is tap water safe to drink in ZIP code 02139?+
Tap water in 02139 (Cambridge, MA) meets major standards but has a grade of C due to minor past violations. Vulnerable populations may want to use a certified filter as a precaution.
How do I get my water tested in ZIP 02139 (Cambridge, MA)?+
To test water quality in ZIP 02139, you can order a certified drinking water test kit or send water samples to an EPA/NELAP certified laboratory in MA. Certified testing checks for lead, coliform bacteria, nitrates, hardness, and PFAS that standard test strips miss. Contact Massachusetts Department of Environmental Protection for a list of certified regional labs.
How hard is the tap water in 02139?+
Tap water in 02139 is classified as Soft with an estimated mineral hardness of 57 mg/L (3.3 GPG). No water softener is needed. Standard carbon filtration is sufficient for taste and chlorine reduction.
Should I test private well water in 02139?+
Yes. Unlike municipal systems, private wells in 02139 are not regulated by the EPA or local utilities. Private well owners should test their water annually for coliform bacteria and nitrates, and every 3 to 5 years for heavy metals (lead, arsenic) and volatile organic compounds.
What is the lead level in 02139 tap water?+
The 90th percentile lead level in 02139 is 8.0 ppb. The EPA action level is 15 ppb. This is below the EPA action level.
Is there an active boil water notice in 02139?+
There are currently no active boil water advisories on record for 02139. Water treatment systems are operating within normal parameters.
Who provides tap water to 02139?+
Tap water in ZIP code 02139 is provided by Cambridge Water Department (EPA ID: MA3049000), serving approximately 118,214 residents.
What water filter should I use in 02139?+
Based on water metrics for 02139, we recommend Lead & Microplastic Filter. Look for certifications such as NSF/ANSI 53 (Lead Reduction), NSF/ANSI 42 (Particulate/Taste).

Data Sources & Methodology

Water quality data for ZIP code 02139 is compiled from the EPA Safe Drinking Water Information System (SDWIS), EPA ECHO enforcement database, UCMR5 unregulated contaminant monitoring, and Consumer Confidence Reports filed by Cambridge Water Department. Safety scores are composite metrics derived from violation history, lead levels, enforcement actions, and infrastructure risk indicators. Data reflects a 5-year monitoring window. Last dataset update: 2024. View EPA source data →