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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
EPA records for CAMBRIDGE WATER DEPARTMENT • Updated September 2026
Grade B — based on EPA compliance records, lead testing and PFAS monitoring
CAMBRIDGE WATER DEPARTMENT is in good standing with EPA, with only minor deductions for monitoring paperwork, low-level PFAS or historical readings near a limit.
Yes — by EPA's records Cambridge, MA tap water is safe to drink and earns a B. The grade rests on PFOA or PFOS measured at or above the 4 ppt federal limit in 2023–2025 EPA sampling and lead at 8 ppb (90th percentile) — under the 15 ppb action level but above 5 ppb. Lead from your own service line or plumbing is the main risk city-level data cannot see, so homes built before 1986 should still test at the tap.
Yes — by EPA's records Cambridge, MA tap water is safe to drink and earns a B. The grade rests on PFOA or PFOS measured at or above the 4 ppt federal limit in 2023–2025 EPA sampling and lead at 8 ppb (90th percentile) — under the 15 ppb action level but above 5 ppb. Lead from your own service line or plumbing is the main risk city-level data cannot see, so homes built before 1986 should still test at the tap.
CAMBRIDGE WATER DEPARTMENT's most recent Lead and Copper Rule result (2021-01-01 to 2023-12-31) was 8 ppb at the 90th percentile, below EPA's 15 ppb action level. Because lead usually comes from service lines and household plumbing, homes built before 1986 should still test at the tap.
Yes. EPA's UCMR5 sampling (2023-09-13 to 2024-06-12) detected PFHxA, PFOA, PFPeA, with PFOA or PFOS at or above the 4 ppt federal MCL. Reverse osmosis and certified activated-carbon filters reduce PFAS.
CAMBRIDGE WATER DEPARTMENT has 31 violations on file since 2016: 0 health-based in the last five years and 0 monitoring or reporting violations in that window. Monitoring violations are paperwork lapses, not measured contamination.
CAMBRIDGE WATER DEPARTMENT reports surface water as its primary source and serves about 118,214 people (EPA PWSID MA3049000).
We recommend one. Reverse osmosis or a PFAS-certified carbon filter addresses the PFAS result. An NSF/ANSI 53 lead-certified filter addresses lead.
Want to know what's really in your Cambridge tap water?
PFOA or PFOS was measured at or above EPA's 4 ppt limit in Cambridge's UCMR5 sampling.
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CAMBRIDGE WATER DEPARTMENT · SDWIS records since 2016 · 5-year window starts 2021-09-13
EPA records no health-based violations for this system in the last five years.
| Violation | Category | Compliance period | Status |
|---|---|---|---|
| Monitoring, RegularHeptachlor | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularPentachlorophenol | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularToxaphene | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, Regular2,4,5-TP | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularBHC-GAMMA | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularTotal Polychlorinated Biphenyls (PCB) | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, Regular1,2-DIBROMO-3-CHLOROPROPANE | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularDalapon | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularDinoseb | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularGlyphosate | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularHEXACHLOROBENZENE | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularOXAMYL | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularPicloram | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularCarbofuran | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularChlordane | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, Regular2,4-D | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularETHYLENE DIBROMIDE | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularBenzo(a)pyrene | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularLASSO | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularEndrin | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, Regular2,3,7,8-TCDD | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularEndothall | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularHeptachlor epoxide | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularDiquat | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
| Monitoring, RegularAtrazine | Monitoring & reporting | 2019-04-01 → 2019-06-30 | Archived |
Showing 25 of 31 violations on file. Full record on EPA ECHO.
Source: ECHO SDWA bulk download (SDWA_VIOLATIONS_ENFORCEMENT.csv, SDWIS 2026Q2, file dated 2026-07-09, fetched 2026-09-13)
EPA Lead and Copper Rule 90th-percentile results reported by CAMBRIDGE WATER DEPARTMENT
Below the action level, but detectable. In the most recent monitoring period on file (2021-01-01 to 2023-12-31), 90% of the homes CAMBRIDGE WATER DEPARTMENT sampled had lead at or below 8 ppb.
EPA's action level is 15 ppb (dropping to 10 ppb under the 2024 Lead and Copper Rule Improvements). There is no safe level of lead; the 90th-percentile figure describes the system, not your tap — homes with lead service lines or pre-1986 plumbing can be higher.
| Monitoring period | Lead 90th percentile | vs 15 ppb action level |
|---|---|---|
| 2021-01-01 → 2023-12-31 | 8 ppb | Below the action level, but detectable |
| 2018-01-01 → 2020-12-31 | 4 ppb | Well below the 15 ppb action level |
| 2015-01-01 → 2017-12-31 | 7 ppb | Below the action level, but detectable |
| 2012-06-01 → 2014-12-31 | 5 ppb | Below the action level, but detectable |
| 2011-01-01 → 2011-12-31 | 5 ppb | Below the action level, but detectable |
| 2008-01-01 → 2008-12-31 | 9 ppb | Below the action level, but detectable |
| 2003-01-01 → 2005-12-31 | 7 ppb | Below the action level, but detectable |
| 2002-01-01 → 2002-12-31 | 9 ppb | Below the action level, but detectable |
| 2001-01-01 → 2001-12-31 | 9 ppb | Below the action level, but detectable |
| 1998-01-01 → 1998-12-21 | 5 ppb | Below the action level, but detectable |
| 1997-01-01 → 1997-12-31 | 5 ppb | Below the action level, but detectable |
| 1996-01-01 → 1996-12-31 | 5 ppb | Below the action level, but detectable |
Source: ECHO SDWA bulk download (SDWA_LCR_SAMPLES.csv, SDWIS 2026Q2, file dated 2026-07-09, fetched 2026-09-13)
EPA UCMR5 monitoring, 2023-09-13 to 2024-06-12 · 116 PFAS results at entry points to the distribution system
PFOA measured at or above EPA's legal limit in at least one sample. Utilities have until 2029 (2031 under EPA's proposed extension) to comply with the 2024 PFAS rule, so a result above the MCL today is not yet a violation — but it is the number that matters for your health.
| Compound | Detects / samples | Max (ppt) | Reporting limit | EPA MCL |
|---|---|---|---|---|
| PFOA | 1 / 4 | 4.8 | 4 ppt | 4 ppt |
| PFOS | 0 / 4 | < 4 | 4 ppt | 4 ppt |
| PFHxS | 0 / 4 | < 3 | 3 ppt | 10 ppt |
| PFNA | 0 / 4 | < 4 | 4 ppt | 10 ppt |
| HFPO-DA | 0 / 4 | < 5 | 5 ppt | 10 ppt |
| PFBS | 0 / 4 | < 3 | 3 ppt | hazard index only |
| PFHxA | 2 / 4 | 3.1 | 3 ppt | hazard index only |
| PFPeA | 2 / 4 | 3.6 | 3 ppt | hazard index only |
“< 4 ppt” means below the laboratory reporting limit, not zero. ppt = parts per trillion (ng/L). Results are for finished water leaving the treatment plant.
What PFAS are and how to remove them → · Best filters for PFAS →
Source: UCMR5 occurrence data, EPA Data Summary July 2026 (UCMR5_All.txt)
EPA Six-Year Review 4 compliance samples for CAMBRIDGE WATER DEPARTMENT · finished water only · dated data, released 2024
These are the regulated-contaminant samples CAMBRIDGE WATER DEPARTMENT reported to its state between 2012 and 2019 — the most recent nationwide sample-level dataset EPA has published. Haloacetic acids (HAA5) is flagged below; the status column explains why. Treat this as history, not today's tap water.
| Contaminant | Samples | Average | Max | EPA limit | Status |
|---|---|---|---|---|---|
| Arsenic | 60 detects | 0 µg/L | ND | 10 µg/LMCL | Not detected |
| Nitrate (as N) | 279 | 0.417 mg/L | 0.771 mg/L | 10 mg/LMCL | Within MCL |
| Fluoride | 6 | 0.816 mg/L | 1.06 mg/L | 4 mg/LMCL | Within MCL |
| Chromium (total) | 61 detects | 0.217 µg/L | 1.3 µg/L | 100 µg/LMCL | Within MCL |
| Total trihalomethanes (TTHM) | 1,147 | 10.732 µg/L | 32 µg/L | 80 µg/LMCL (LRAA) | Within MCL |
| Haloacetic acids (HAA5) | 228 | 8.298 µg/L | 76.4 µg/L | 60 µg/LMCL (LRAA) | 1 single sample over MCL; average within limit |
| Copper (tap samples) | 1 | 1.3 µg/L | 1.3 µg/L | 1300 µg/Laction level (90th percentile) | Reported, not scored (compliance is on the 90th percentile) |
Averages count non-detects as zero. TTHM and HAA5 limits are locational running annual averages, so a single high sample is not a violation — we grade those on the average only. Lead and copper rows are individual tap samples and are shown for context; compliance (and our score) uses the 90th-percentile result above. LRAA = locational running annual average; ND = not detected.
Source: SYR4 Six-Year Review compliance monitoring data 2012–2019 (released 2024-03)
A point-of-use (under-sink) system typically runs $200-$600 installed; whole-house treatment $1,000-$3,000+ depending on flow and what has to come out. Tell us where you are and a certified water-treatment installer serving Cambridge will follow up - no obligation.
CAMBRIDGE WATER DEPARTMENT · 15,041 service lines inventoried · Q2 2026 snapshot
CAMBRIDGE WATER DEPARTMENT reports 2,195 service lines that are lead or galvanized-requiring-replacement (15% of the lines it has inventoried), plus 104 lines whose material is still unknown. A lead service line is the pipe between the water main and a building, so treated water can pick up lead after it leaves the plant — which city-level testing does not capture. Under EPA's Lead and Copper Rule Improvements, utilities must replace lead lines within 10 years starting in 2027.
Source: EPA SDWIS Service Line Inventory (Q2 2026) · PWS ID MA3049000 · See all Massachusetts lead service lines. We may earn a commission from filters and test kits, at no extra cost to you.
Surface-water systems draw from rivers, lakes or reservoirs and must filter and disinfect, which is why disinfection byproducts (TTHM, HAA5) are the readings to watch.
How to test your tap water and the treatment options that actually fit Cambridge homes
The most reliable way to know what is actually coming out of your tap is a certified mail-in lab test. City-wide EPA data (like the report above) reflects the water leaving the treatment plant, but contaminants such as lead and copper can be picked up from your own service line and household plumbing — so the water at your Cambridge faucet can differ from the system average. A state-certified lab measures dozens of contaminants at once with results you can trust; you can also find one near you through the EPA's certified-lab list at epa.gov/dwlabcert. Hardware-store test strips are cheaper and instant, but they only screen for a few basics (chlorine, hardness, pH, and a rough lead pass/fail) and are far less accurate — treat them as a first look, not a diagnosis.
Match the treatment to what your test finds. Reverse osmosis (RO) removes the widest range of contaminants — lead, arsenic, nitrate, PFAS, and dissolved solids — which makes an under-sink reverse osmosis system the most thorough choice for Cambridge households with heavy-metal or PFAS concerns. If your main issue is taste, odor, or chlorine, an activated carbon filter (pitcher, faucet, or under-sink) is simpler and cheaper and handles chlorine and many organic compounds well, though carbon alone does not remove arsenic, nitrate, or most PFAS. NSF-certified pitchers rated for lead reduction are the easiest way to start today while you decide on a permanent setup.
We may earn a commission from testing kits and filters purchased through these links, at no extra cost to you.
What Cambridge residents measured at their own tap (ZIPs 02138, 02139, 02140, 02141 +1 more). All reader results →
Reader submissions are unverified and shown separately from EPA data. They reflect one tap on one day, not the utility's compliance record.
No reader results for Cambridge yet - yours would be the first. A hardness or TDS number from a $10 strip kit is enough to start the map.
Help build the first reader-sourced water map. Enter whatever your test strip, TDS pen or lab report shows - one number is enough.
Cambridge ranks #38 of 48 graded Massachusetts cities.
Deep-dive guides for the specific contaminants EPA data flagged in Cambridge's water, with removal options for each.
Yes — by EPA's records Cambridge, MA tap water is safe to drink and earns a B. The grade rests on PFOA or PFOS measured at or above the 4 ppt federal limit in 2023–2025 EPA sampling and lead at 8 ppb (90th percentile) — under the 15 ppb action level but above 5 ppb. Lead from your own service line or plumbing is the main risk city-level data cannot see, so homes built before 1986 should still test at the tap.
CAMBRIDGE WATER DEPARTMENT's most recent Lead and Copper Rule result (2021-01-01 to 2023-12-31) was 8 ppb at the 90th percentile, below EPA's 15 ppb action level. Because lead usually comes from service lines and household plumbing, homes built before 1986 should still test at the tap.
Yes. EPA's UCMR5 sampling (2023-09-13 to 2024-06-12) detected PFHxA, PFOA, PFPeA, with PFOA or PFOS at or above the 4 ppt federal MCL. Reverse osmosis and certified activated-carbon filters reduce PFAS.
CAMBRIDGE WATER DEPARTMENT has 31 violations on file since 2016: 0 health-based in the last five years and 0 monitoring or reporting violations in that window. Monitoring violations are paperwork lapses, not measured contamination.
CAMBRIDGE WATER DEPARTMENT reports surface water as its primary source and serves about 118,214 people (EPA PWSID MA3049000).
We recommend one. Reverse osmosis or a PFAS-certified carbon filter addresses the PFAS result. An NSF/ANSI 53 lead-certified filter addresses lead.
PFOA or PFOS was measured at or above EPA's 4 ppt limit in Cambridge's UCMR5 sampling.
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Based on contaminants detected in your water, these resources may be helpful:
Find the right filter for your Cambridge water quality needs:
Tap water is one piece of the picture — our sister sites cover the rest for Cambridge, MA.
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