Contaminant 2992
Unresolved Arsenic Rule violation cited in 2023 (contaminant 2992).
PWSID MA2328000 · Surface waterMunicipal
21,567 people served. 1 health-based SDWIS violation recorded in the past 5 years. 22 remain unresolved. Last cited 1 year ago.
Unresolved Arsenic Rule violation cited in 2023 (contaminant 2992).
Unresolved Arsenic Rule violation cited in 2023 (contaminant 2996).
Unresolved Arsenic Rule violation cited in 2023 (contaminant 2987).
Unresolved Arsenic Rule violation cited in 2023 (contaminant 2991).
Health-based violations exceed an MCL or treatment-technique standard. Monitoring violations are reporting failures with no measured exceedance — they tell you the system isn't fully transparent, not that the water is unsafe today.
Treatment technique violation; returned to compliance
Failure to monitor as scheduled
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Monitoring failure; returned to compliance
Monitoring failure; returned to compliance
Failure to monitor as scheduled; returned to compliance
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Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Failure to monitor as scheduled; returned to compliance
Westborough, Massachusetts (Census place; block-group disparity scores aggregated by centroid containment): a service population of 4,381. Local disparity score for pm2.5 (fine particulate) sits well below the reference (18). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 18 | well below the reference |
| Ozone | 28 | well below the reference |
| Nitrogen dioxide (NO₂) | 33 | well below the reference |
| Diesel particulate | 32 | well below the reference |
| Toxic releases (RSEI) | 62 | below the reference |
| Traffic proximity | 70 | below the reference |
| Lead-paint risk (pre-1960 housing) | 73 | below the reference |
| Superfund site proximity | 70 | below the reference |
| RMP-facility proximity | 43 | well below the reference |
| Hazardous-waste site proximity | 63 | below the reference |
| Underground storage tanks | 55 | below the reference |
| NPDES wastewater proximity | 48 | well below the reference |
| Drinking-water non-compliance | 0 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).
Source. EPA Safe Drinking Water Information System · retrieved 2026-05-07. Reporting period 2022-01-01 → 2026-05-07.
What this is not. SDWIS records compliance against federal MCLs — not a direct readout of tap-water concentrations. Active health-based violations are not the same as a current crisis; we link to the EPA record so you can verify return-to-compliance status before forming a conclusion.