Massachusetts / Reports /

Combined sewer overflow (CSO) reported — CITY OF CAMBRIDGE, Jul 21, 2026

Ended (as reported) · CITY OF CAMBRIDGE (MassDEP sewage notification portal)

Source: CITY OF CAMBRIDGE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal, record 6a1ae207-6861-4856-87b9-25a1bd1ca60d, published Aug 14, 2026, 3:03 PM EDT, retrieved 2026-11-02 10:58 UTC · Read the original notice

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1. Reported wastewater outlet

Operator named in the record: CITY OF CAMBRIDGE (federal wastewater discharge permit, NPDES, MA0101974). Outlet: CAM005 “WEST BANK OF CHARLES JUST SE OF MT AUBURN HOSPITAL”. Location: 42.37356, -71.13276; location source: from the state's or EPA's outfall layer.

Outfall: a pipe or outlet where wastewater enters a water body.

2. Waters named in the notice

The notice names: “CHARLES RIVER”. DirtyWaterWatch links this report to Charles River, MA. Match basis: the water named in the report.

3. Estimated downstream stretch

No downstream estimate is available for this report.

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When it happened and when it was reported

Event and notice times use Eastern Time (EST or EDT). Retrieval times use Coordinated Universal Time (UTC).

Started

Jul 21, 2026, 6:00 PM EDT

Ended

Jul 21, 2026, 6:30 PM EDT

Detail provided by the source

Times known to the minute

Reported to the source

not given

Published

Aug 14, 2026, 3:03 PM EDT

Source last updated

not given

Last retrieved by DirtyWaterWatch

2026-11-02 10:58 UTC

What and how much

Type

Combined sewer overflow (CSO): sewage mixed with rainwater spills from a shared sewer system.

Status in the record

Ended (as reported)

Material

“CSO – UnTreated”

Volume

10,000 gallons (not stated whether estimated or measured)

Volume as reported

“10000”

Advice from CITY OF CAMBRIDGE (MassDEP sewage notification portal)

“Avoid contact with these water bodies for 48 hours after the discharge or overflow ceases due to increased health risks from bacteria and other pollutants. See website for more information on whether specific resource areas, such as bathing beaches, are affected.”

Advice period

48 hours

Basis

314 CMR 16.04(10)(g)

Source and versions

Source

MassDEP CSO API behind the portal

Source record number

6a1ae207-6861-4856-87b9-25a1bd1ca60d

Original notice

Read the original notice

Earlier version

Read the earlier version

Later versions

None

{
  "incidentId": "6a1ae207-6861-4856-87b9-25a1bd1ca60d",
  "incidentNumber": "26017211",
  "incidentDate": "2026-07-21T00:00:00",
  "incidentTime": "18:00",
  "amPm": null,
  "reporterClass": "Verified Data Report",
  "eventType": "CSO – UnTreated",
  "permiteeClass": "CSO",
  "permiteeName": "CITY OF CAMBRIDGE",
  "permiteeId": "MA0101974",
  "outfallId": "CAM005",
  "municipality": "CAMBRIDGE",
  "reportingType": null,
  "location": "WEST BANK OF CHARLES JUST SE OF MT AUBURN HOSPITAL",
  "latitude": null,
  "longitude": null,
  "waterBody": "CHARLES RIVER",
  "waterBodyDescription": null,
  "volumnOfEvent": "10000",
  "rainfallData": "0.90",
  "hours": "0",
  "minutes": "30",
  "month": null,
  "year": null,
  "additionalInformation": "The public email notification was sent as soon as City staff could verify the activation. The discharge volume for this event was less than 10,000 gallon, which is under the reporting threshold.",
  "submittedDate": "2026-08-14T15:03:15.897",
  "parentIncidentId": null,
  "_report_class": "Verified Data Report",
  "_tz_assumed": "America/New_York (portal gives local clock time without zone)",
  "_ended_at_basis": "computed: started_at + verified duration 0 h 30 min (Verified Data Report)",
  "_coords": "MassDEP CSOs layer DEP_OUTFL_ CAM005 (locations are estimates)",
  "_water": {
    "via": "crosswalk on portal waterbody",
    "text": "CHARLES RIVER",
    "confidence": "high"
  },
  "_volume_note": "verified by permittee, reported to MassDEP (metered or modelled not stated)",
  "_advice_source": "required wording of 314 CMR 16.04(10)(g); the permittee's own advisory is only in an attachment the portal will not serve",
  "_link_basis": "same permittee and outfall as notice 26016819; start times 0 min apart"
}