Massachusetts / Waters /
Mystic River
River in Massachusetts · near Boston, Medford, Somerville, Sullivan Square
Status now
Unresolved: no end reported
A discharge here was reported but its end never was. Sources often skip the "ceased" notice, so after the first week the water is shown hatched yellow until 30 days have passed, and the event stays flagged on its pages after that.
Why this colour: Unresolved: no end reported: no end reported. Rationale: From day 7 to day 30 the reach or water is shown hatched yellow 'unresolved: no end reported', listed under active discharges with that label. (source: data/rules.json) How long a water stays coloured, and why
CSO of Oct 11 23:02: unresolved, no end reported · CITY OF SOMERVILLE · tidal or estuary: movement not modeled · since Oct 26, 2026, 12:06 PM EDT
Source: CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9f9cd5fd-1531-474f-bf92-62ae79451d8b, published Oct 12, 2026, 12:06 PM EDT, retrieved 2026-11-02 11:54 UTC · notice
As of Nov 2, 2026, 6:56 AM EST.
Events behind the colour
- Unresolved: no end reported Combined sewer overflow · CITY OF SOMERVILLE · SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 · Oct 11, 2026, 11:02 PM EDT to ended, time not reported · not reported · Unresolved: no end reported, until Nov 11, 2026, 11:06 AM EST
Source: CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9f9cd5fd-1531-474f-bf92-62ae79451d8b, published Oct 12, 2026, 12:06 PM EDT, retrieved 2026-11-02 11:54 UTC · notice
- Unresolved: no end reported Combined sewer overflow · MASSACHUSETTS WATER RESOURCES AUTHORITY · MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS · Oct 11, 2026, 8:00 PM EDT to ended, time not reported · not reported · Unresolved: no end reported, until Nov 11, 2026, 10:58 AM EST
Source: MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record e716b9d4-05cd-416d-b1bd-264f613ff14f, published Oct 12, 2026, 11:58 AM EDT, retrieved 2026-11-02 11:54 UTC · notice
What the authorities advise
“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.”
Source: CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9f9cd5fd-1531-474f-bf92-62ae79451d8b, published Oct 12, 2026, 12:06 PM EDT, retrieved 2026-11-02 11:54 UTC · notice
Map
Source: water outlines from OpenBoatLaunch and OpenStreetMap contributors (ODbL); outfalls from EPA ECHO and the state outfall layers; modeled reaches computed by DirtyWaterWatch from USGS NLDI, NHDPlus and the nearest USGS gauge (Jobson 1996); basemap OpenFreeMap and OpenMapTiles.
Outfalls are small brown dots.
Modeled downstream reaches on Mystic River
No discharge colours a modeled reach on this water now.
The last 90 days
- Unresolved: no end reported: Oct 26, 2026, 1:00 PM EDT to now · set by event 1, event 2
- Caution: Oct 11, 2026, 8:00 PM EDT to Oct 26, 2026, 1:00 PM EDT · set by event 1, event 2
- Caution: Sep 30, 2026, 10:00 AM EDT to Oct 1, 2026, 10:00 AM EDT · set by event 1, event 2, event 3, event 4
- Advisory in effect: Sep 27, 2026, 7:00 AM EDT to Sep 30, 2026, 10:00 AM EDT · set by event 1, event 2, event 3, event 4
- Caution: Sep 15, 2026, 1:00 PM EDT to Sep 16, 2026, 1:00 PM EDT · set by event 1
- Advisory in effect: Sep 13, 2026, 12:00 PM EDT to Sep 15, 2026, 1:00 PM EDT · set by event 1
- Caution: Aug 25, 2026, 3:00 PM EDT to Aug 26, 2026, 3:00 PM EDT · set by event 1
- Advisory in effect: Aug 23, 2026, 1:00 PM EDT to Aug 25, 2026, 3:00 PM EDT · set by event 1
- Unresolved: no end reported: Aug 4, 2026, 7:00 PM EDT to Aug 20, 2026, 7:00 PM EDT · set by event 1
- Caution: Aug 4, 2026, 8:00 AM EDT to Aug 4, 2026, 7:00 PM EDT · set by event 1
Source: hourly statuses computed by DirtyWaterWatch (pipeline build/status.py) from the events linked above and the rules on the methods page; history as of 2026-11-02 11:56 UTC.
Discharges over the years
- Discharge events, last 12 months28Dec 2025 to Nov 2026
- Days with a discharge, last 12 months18Dec 2025 to Nov 2026
- Hours under advisory, last 12 months668Dec 2025 to Nov 2026
- 2026 season under advisory13%May to October; 567 h
Discharge events per month
217 events, Jan 2022 to Nov 2026. Counted from 215 verified or annual reports, 2 public notices.
- Combined sewer overflow
- Sanitary sewer overflow
- Bypass, blended or other
- No source
- Partly covered or sparse source
No source covers 2022-01 to 2022-04. MassDEP portal records begin 2022-06-30. Verified Data Reports arrive after the month ends, so the latest months count public notices.
Source: MassDEP sewage notification portal. Covered 2022-06-30 to 2026-11-02.
Show table
| Month | Combined sewer overflow | Sanitary sewer overflow | Bypass, blended or other | Total | Counted from | Coverage |
|---|---|---|---|---|---|---|
| Jan 2022 | 0 | 0 | 0 | 0 | No source | |
| Feb 2022 | 0 | 0 | 0 | 0 | No source | |
| Mar 2022 | 0 | 0 | 0 | 0 | No source | |
| Apr 2022 | 0 | 0 | 0 | 0 | No source | |
| May 2022 | 0 | 0 | 0 | 0 | Partly covered or sparse source | |
| Jun 2022 | 0 | 0 | 0 | 0 | Partly covered or sparse source | |
| Jul 2022 | 0 | 0 | 0 | 0 | ||
| Aug 2022 | 2 | 0 | 0 | 2 | Verified or annual reports | |
| Sep 2022 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Oct 2022 | 4 | 0 | 0 | 4 | Verified or annual reports | |
| Nov 2022 | 5 | 0 | 0 | 5 | Verified or annual reports | |
| Dec 2022 | 4 | 0 | 0 | 4 | Verified or annual reports | |
| Jan 2023 | 5 | 0 | 0 | 5 | Verified or annual reports | |
| Feb 2023 | 0 | 0 | 0 | 0 | ||
| Mar 2023 | 7 | 0 | 0 | 7 | Verified or annual reports | |
| Apr 2023 | 4 | 0 | 0 | 4 | Verified or annual reports | |
| May 2023 | 2 | 0 | 0 | 2 | Verified or annual reports | |
| Jun 2023 | 12 | 0 | 0 | 12 | Verified or annual reports | |
| Jul 2023 | 27 | 0 | 0 | 27 | Verified or annual reports | |
| Aug 2023 | 13 | 0 | 0 | 13 | Verified or annual reports | |
| Sep 2023 | 3 | 0 | 0 | 3 | Verified or annual reports | |
| Oct 2023 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Nov 2023 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Dec 2023 | 8 | 0 | 0 | 8 | Verified or annual reports | |
| Jan 2024 | 7 | 1 | 0 | 8 | Verified or annual reports | |
| Feb 2024 | 0 | 0 | 0 | 0 | ||
| Mar 2024 | 7 | 0 | 0 | 7 | Verified or annual reports | |
| Apr 2024 | 4 | 0 | 0 | 4 | Verified or annual reports | |
| May 2024 | 4 | 0 | 0 | 4 | Verified or annual reports | |
| Jun 2024 | 5 | 0 | 0 | 5 | Verified or annual reports | |
| Jul 2024 | 3 | 0 | 0 | 3 | Verified or annual reports | |
| Aug 2024 | 6 | 0 | 0 | 6 | Verified or annual reports | |
| Sep 2024 | 0 | 0 | 0 | 0 | ||
| Oct 2024 | 0 | 0 | 0 | 0 | ||
| Nov 2024 | 3 | 0 | 0 | 3 | Verified or annual reports | |
| Dec 2024 | 7 | 0 | 0 | 7 | Verified or annual reports | |
| Jan 2025 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Feb 2025 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Mar 2025 | 6 | 0 | 0 | 6 | Verified or annual reports | |
| Apr 2025 | 3 | 0 | 0 | 3 | Verified or annual reports | |
| May 2025 | 7 | 0 | 0 | 7 | Verified or annual reports | |
| Jun 2025 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Jul 2025 | 4 | 0 | 0 | 4 | Verified or annual reports | |
| Aug 2025 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Sep 2025 | 7 | 0 | 0 | 7 | Verified or annual reports | |
| Oct 2025 | 12 | 0 | 0 | 12 | Verified or annual reports | |
| Nov 2025 | 0 | 0 | 0 | 0 | ||
| Dec 2025 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Jan 2026 | 0 | 0 | 0 | 0 | ||
| Feb 2026 | 0 | 0 | 0 | 0 | ||
| Mar 2026 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Apr 2026 | 0 | 0 | 0 | 0 | ||
| May 2026 | 2 | 0 | 0 | 2 | Verified or annual reports | |
| Jun 2026 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Jul 2026 | 15 | 0 | 0 | 15 | Verified or annual reports | |
| Aug 2026 | 1 | 0 | 0 | 1 | Verified or annual reports | |
| Sep 2026 | 5 | 0 | 0 | 5 | Verified or annual reports | |
| Oct 2026 | 2 | 0 | 0 | 2 | Public notices (no report yet) | |
| Nov 2026 | 0 | 0 | 0 | 0 |
Hours under advisory per month
Hours this water was under an advisory, by the map's red rules.
- Advisory in effect
- No source
- Partly covered or sparse source
No source covers 2022-01 to 2022-04. 2 discharge events have no reported end and no ongoing status; under the status rules they set caution, not an advisory, and add no hours here. MassDEP portal records begin 2022-06-30. Verified Data Reports arrive after the month ends, so the latest months count public notices.
Source: MassDEP sewage notification portal. Covered 2022-06-30 to 2026-11-02.
Show table
| Month | Hours under advisory | From discharge windows | Hours in month | Coverage |
|---|---|---|---|---|
| Jan 2022 | 0 | 0 | 744 | No source |
| Feb 2022 | 0 | 0 | 672 | No source |
| Mar 2022 | 0 | 0 | 744 | No source |
| Apr 2022 | 0 | 0 | 720 | No source |
| May 2022 | 0 | 0 | 744 | Partly covered or sparse source |
| Jun 2022 | 0 | 0 | 720 | Partly covered or sparse source |
| Jul 2022 | 0 | 0 | 744 | |
| Aug 2022 | 97 | 97 | 744 | |
| Sep 2022 | 50 | 50 | 720 | |
| Oct 2022 | 61 | 61 | 744 | |
| Nov 2022 | 103 | 103 | 720 | |
| Dec 2022 | 200 | 200 | 744 | |
| Jan 2023 | 149 | 149 | 744 | |
| Feb 2023 | 0 | 0 | 672 | |
| Mar 2023 | 163 | 163 | 744 | |
| Apr 2023 | 23 | 23 | 720 | |
| May 2023 | 103 | 103 | 744 | |
| Jun 2023 | 251 | 251 | 720 | |
| Jul 2023 | 405 | 405 | 744 | |
| Aug 2023 | 293 | 293 | 744 | |
| Sep 2023 | 115 | 115 | 720 | |
| Oct 2023 | 50 | 50 | 744 | |
| Nov 2023 | 51 | 51 | 720 | |
| Dec 2023 | 163 | 163 | 744 | |
| Jan 2024 | 165 | 165 | 744 | |
| Feb 2024 | 0 | 0 | 696 | |
| Mar 2024 | 258 | 258 | 744 | |
| Apr 2024 | 108 | 108 | 720 | |
| May 2024 | 188 | 188 | 744 | |
| Jun 2024 | 162 | 162 | 720 | |
| Jul 2024 | 61 | 61 | 744 | |
| Aug 2024 | 133 | 133 | 744 | |
| Sep 2024 | 0 | 0 | 720 | |
| Oct 2024 | 0 | 0 | 744 | |
| Nov 2024 | 99 | 99 | 720 | |
| Dec 2024 | 96 | 96 | 744 | |
| Jan 2025 | 52 | 52 | 744 | |
| Feb 2025 | 50 | 50 | 672 | |
| Mar 2025 | 148 | 148 | 744 | |
| Apr 2025 | 147 | 147 | 720 | |
| May 2025 | 155 | 155 | 744 | |
| Jun 2025 | 51 | 51 | 720 | |
| Jul 2025 | 140 | 140 | 744 | |
| Aug 2025 | 92 | 92 | 744 | |
| Sep 2025 | 167 | 167 | 720 | |
| Oct 2025 | 284 | 284 | 744 | |
| Nov 2025 | 23 | 23 | 720 | |
| Dec 2025 | 51 | 51 | 744 | |
| Jan 2026 | 0 | 0 | 744 | |
| Feb 2026 | 0 | 0 | 672 | |
| Mar 2026 | 50 | 50 | 744 | |
| Apr 2026 | 0 | 0 | 720 | |
| May 2026 | 113 | 113 | 744 | |
| Jun 2026 | 49 | 49 | 720 | |
| Jul 2026 | 230 | 230 | 744 | |
| Aug 2026 | 53 | 53 | 744 | |
| Sep 2026 | 122 | 122 | 720 | |
| Oct 2026 | 0 | 0 | 744 | |
| Nov 2026 | 0 | 0 | 32 |
Days with a discharge per month
A day counts when any counted discharge was under way on it (start to reported end, local time); an event with no end counts its start day.
- No source
- Partly covered or sparse source
No source covers 2022-01 to 2022-04.
Source: MassDEP sewage notification portal. Covered 2022-06-30 to 2026-11-02.
Show table
| Month | Days with a discharge | Coverage |
|---|---|---|
| Jan 2022 | 0 | No source |
| Feb 2022 | 0 | No source |
| Mar 2022 | 0 | No source |
| Apr 2022 | 0 | No source |
| May 2022 | 0 | Partly covered or sparse source |
| Jun 2022 | 0 | Partly covered or sparse source |
| Jul 2022 | 0 | |
| Aug 2022 | 2 | |
| Sep 2022 | 1 | |
| Oct 2022 | 2 | |
| Nov 2022 | 3 | |
| Dec 2022 | 3 | |
| Jan 2023 | 3 | |
| Feb 2023 | 0 | |
| Mar 2023 | 3 | |
| Apr 2023 | 1 | |
| May 2023 | 3 | |
| Jun 2023 | 6 | |
| Jul 2023 | 10 | |
| Aug 2023 | 6 | |
| Sep 2023 | 2 | |
| Oct 2023 | 1 | |
| Nov 2023 | 1 | |
| Dec 2023 | 3 | |
| Jan 2024 | 4 | |
| Feb 2024 | 0 | |
| Mar 2024 | 6 | |
| Apr 2024 | 2 | |
| May 2024 | 5 | |
| Jun 2024 | 3 | |
| Jul 2024 | 2 | |
| Aug 2024 | 2 | |
| Sep 2024 | 0 | |
| Oct 2024 | 0 | |
| Nov 2024 | 2 | |
| Dec 2024 | 2 | |
| Jan 2025 | 1 | |
| Feb 2025 | 1 | |
| Mar 2025 | 3 | |
| Apr 2025 | 3 | |
| May 2025 | 4 | |
| Jun 2025 | 1 | |
| Jul 2025 | 5 | |
| Aug 2025 | 1 | |
| Sep 2025 | 4 | |
| Oct 2025 | 7 | |
| Nov 2025 | 0 | |
| Dec 2025 | 1 | |
| Jan 2026 | 0 | |
| Feb 2026 | 0 | |
| Mar 2026 | 1 | |
| Apr 2026 | 0 | |
| May 2026 | 4 | |
| Jun 2026 | 1 | |
| Jul 2026 | 6 | |
| Aug 2026 | 1 | |
| Sep 2026 | 3 | |
| Oct 2026 | 1 | |
| Nov 2026 | 0 |
Reported volume per year
Gallons, summed from the 215 events that gave a number (2 did not).
- Partly covered or sparse source
2 of 217 events gave no volume as a number; only numbers are summed.
Source: MassDEP sewage notification portal. Covered 2022-06-30 to 2026-11-02.
Show table
| Year | Gallons | Events with a number | Events without | Coverage |
|---|---|---|---|---|
| 2022 | 17,827,600 | 16 | 0 | Partly covered or sparse source |
| 2023 | 175,664,334 | 83 | 0 | |
| 2024 | 103,493,511 | 47 | 0 | |
| 2025 | 49,805,997 | 44 | 0 | |
| 2026 | 20,435,612 | 25 | 2 |
Hours under advisory per year
Hours under advisory each year; 2026 to date.
- Advisory in effect
- Partly covered or sparse source
2 discharge events have no reported end and no ongoing status; under the status rules they set caution, not an advisory, and add no hours here.
Source: MassDEP sewage notification portal. Covered 2022-06-30 to 2026-11-02.
Show table
| Year | Hours under advisory | Share of the year | Coverage |
|---|---|---|---|
| 2022 | 511 | 5.8% | Partly covered or sparse source |
| 2023 | 1,764 | 20.1% | |
| 2024 | 1,270 | 14.5% | |
| 2025 | 1,359 | 15.5% | |
| 2026 | 617 | 8.4% |
Discharge events by calendar month, all years
Every counted discharge event, by the calendar month it began.
Months are summed over every year a source covers; the table gives the number of years behind each month.
Source: MassDEP sewage notification portal. Covered 2022-06-30 to 2026-11-02.
Show table
| Month | Events | Years of records |
|---|---|---|
| Jan | 14 | 4 |
| Feb | 1 | 4 |
| Mar | 21 | 4 |
| Apr | 11 | 4 |
| May | 15 | 4 |
| Jun | 19 | 5 |
| Jul | 49 | 5 |
| Aug | 23 | 5 |
| Sep | 16 | 5 |
| Oct | 19 | 5 |
| Nov | 9 | 5 |
| Dec | 20 | 4 |
Discharge events by outfall
The 8 outfalls with the most events of 8, all years.
MassDEP portal records begin 2022-06-30. Verified Data Reports arrive after the month ends, so the latest months count public notices.
Source: MassDEP sewage notification portal. Covered 2022-06-30 to 2026-11-02.
Show table
| Outfall | Discharger | Events |
|---|---|---|
| MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | MASSACHUSETTS WATER RESOURCES AUTHORITY | 107 |
| BOS009 CORNER OF SUMMER & NEW ST | BOSTON WATER & SEWER COMMISSION | 39 |
| SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | CITY OF SOMERVILLE | 33 |
| CHE004 PEARL ST | CITY OF CHELSEA | 14 |
| BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | BOSTON WATER & SEWER COMMISSION | 11 |
| BOS017 BETWN SPRINGFIELD COLLEGE 465 MEDFORD RD | BOSTON WATER & SEWER COMMISSION | 7 |
| BOS012 @310 BORDER ST | BOSTON WATER & SEWER COMMISSION | 4 |
| CHE003 END OF WINNISIMMIT ST | CITY OF CHELSEA | 1 |
| Outfall not stated | 1 |
How these charts are counted
Discharge events are counted once: where a source publishes both public notices and verified reports (MassDEP, Vermont DEC), a discharger's month with any verified report counts its verified reports only, and other months count notices. Revisions are folded into the record they revise, and EPA copies of a state report are not counted twice. Monthly and yearly totals (Maine DEP, EPA discharge monitoring reports, Portsmouth) are shown on their own and never added to the event counts. Hours under advisory follow the map's red rules. A muted band marks periods no source covers: a gap there is missing data, not a quiet month.
- EPA ECHO sewer overflow events: 2022-05-03 to now (sparse)
- MassDEP sewage notification portal: 2022-06-30 to now
Every event on Mystic River
| Start | End | Discharger | Outfall | Type | Volume | Source | Links |
|---|---|---|---|---|---|---|---|
| Oct 11, 2026, 11:02 PM EDT | ended, time not reported | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflow | not reported | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9f9cd5fd-1531-474f-bf92-62ae79451d8b, published Oct 12, 2026, 12:06 PM EDT, retrieved 2026-11-02 11:54 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Oct 11, 2026, 11:02 PM EDT · Map |
| Oct 11, 2026, 8:00 PM EDT | ended, time not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record e716b9d4-05cd-416d-b1bd-264f613ff14f, published Oct 12, 2026, 11:58 AM EDT, retrieved 2026-11-02 11:54 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Oct 11, 2026, 8:00 PM EDT · Map |
| Sep 28, 2026, 8:43 AM EDT | Sep 28, 2026, 9:09 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 230,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record c5e88853-bab9-4931-bbea-61a5bbbb6010, published Oct 8, 2026, 4:08 PM EDT, retrieved 2026-11-02 11:54 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Sep 28, 2026, 8:43 AM EDT · Map |
| Sep 28, 2026, 8:43 AM EDT | Sep 28, 2026, 9:09 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record e5d9fd46-70b6-454a-be92-b3563e33c15d, published Sep 28, 2026, 2:58 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Sep 28, 2026, 8:43 AM EDT · Map |
| Sep 27, 2026, 10:45 AM EDT | Sep 27, 2026, 2:30 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflow | 1.09 million gal | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 0fd214b4-b1ad-4423-895c-3582894da7d4, published Oct 8, 2026, 4:04 PM EDT, retrieved 2026-11-02 11:54 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Sep 27, 2026, 10:45 AM EDT · Map |
| Sep 27, 2026, 10:30 AM EDT | Sep 27, 2026, 2:30 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflowrevised | not reported | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 00ba4dd7-d5a3-4ade-a69d-eb5d4e9413df, published Sep 27, 2026, 9:21 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Sep 27, 2026, 10:30 AM EDT · Map |
| Sep 27, 2026, 10:25 AM EDT | Sep 27, 2026, 1:00 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflow | 34,722 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 6d2b964a-77f5-4132-b44d-2f716871bbf0, published Oct 14, 2026, 12:33 PM EDT, retrieved 2026-11-02 11:54 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Sep 27, 2026, 10:25 AM EDT · Map |
| Sep 27, 2026, 10:25 AM EDT | Sep 27, 2026, 1:00 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 1505c666-61e1-4dfc-839f-cefefbb292a4, published Sep 27, 2026, 11:04 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Sep 27, 2026, 10:25 AM EDT · Map |
| Sep 27, 2026, 7:21 AM EDT | Sep 27, 2026, 4:14 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 3.03 million gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 4ec52936-aba5-43f1-8406-306f9fefe88e, published Oct 8, 2026, 3:58 PM EDT, retrieved 2026-11-02 11:54 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Sep 27, 2026, 7:21 AM EDT · Map |
| Sep 27, 2026, 7:21 AM EDT | Sep 27, 2026, 4:14 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record eb3d0ea8-881f-4c8f-8bfd-1bd07b57d4a5, published Sep 27, 2026, 9:19 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Sep 27, 2026, 7:21 AM EDT · Map |
| Sep 13, 2026, 12:30 PM EDT | Sep 13, 2026, 12:55 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 570,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record e316114c-ec5d-457a-97c5-e66066d05f0e, published Oct 8, 2026, 3:49 PM EDT, retrieved 2026-11-02 11:54 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Sep 13, 2026, 12:30 PM EDT · Map |
| Sep 13, 2026, 12:30 PM EDT | Sep 13, 2026, 12:55 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record c4417935-367a-46bb-b7f3-9fa70bc2e4cd, published Sep 13, 2026, 6:02 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Sep 13, 2026, 12:30 PM EDT · Map |
| Aug 23, 2026, 1:32 PM EDT | Aug 23, 2026, 2:03 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 840,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 4aa80e87-f459-43a8-887e-0e70476dc250, published Sep 9, 2026, 10:44 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Aug 23, 2026, 1:32 PM EDT · Map |
| Aug 23, 2026, 1:32 PM EDT | Aug 23, 2026, 2:03 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 3a572fab-aaf7-4cba-ae1a-91a240ef8053, published Aug 23, 2026, 6:01 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Aug 23, 2026, 1:32 PM EDT · Map |
| Jul 30, 2026, 12:59 AM EDT | Jul 30, 2026, 1:18 AM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflow | 60,000 gal | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record d7d46d3c-4520-4291-9730-81b78f15dbc3, published Aug 5, 2026, 2:16 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Jul 30, 2026, 12:59 AM EDT · Map |
| Jul 30, 2026, 12:59 AM EDT | Jul 30, 2026, 1:18 AM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflowrevised | not reported | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 78d7560c-7e80-44ae-ae79-36f25cc8d45a, published Jul 30, 2026, 6:23 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Jul 30, 2026, 12:59 AM EDT · Map |
| Jul 29, 2026, 11:54 PM EDT | Jul 30, 2026, 4:22 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 98b5027c-ed2f-46dd-abe9-e4ee1295801f, published Jul 30, 2026, 6:20 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 29, 2026, 11:54 PM EDT · Map |
| Jul 29, 2026, 11:53 PM EDT | Jul 30, 2026, 4:22 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 960,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 70ae5118-fa37-4133-8ebc-a8c543026578, published Aug 5, 2026, 2:12 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 29, 2026, 11:53 PM EDT · Map |
| Jul 29, 2026, 11:45 PM EDT | Jul 30, 2026, 12:40 AM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflow | 41,666 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 4de6e9b9-9be4-4981-b937-85eb70547ece, published Aug 12, 2026, 1:00 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Jul 29, 2026, 11:45 PM EDT · Map |
| Jul 29, 2026, 11:45 PM EDT | Jul 30, 2026, 12:40 AM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record dc969ca5-3951-45ae-965d-14a4c0666375, published Jul 30, 2026, 3:58 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Jul 29, 2026, 11:45 PM EDT · Map |
| Jul 22, 2026, 5:05 PM EDT | Jul 22, 2026, 5:40 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflowrevised | not reported | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 71485eac-5c92-4495-ae11-841df1512520, published Jul 22, 2026, 7:24 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Jul 22, 2026, 5:05 PM EDT · Map |
| Jul 22, 2026, 4:45 PM EDT | Jul 22, 2026, 5:40 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflow | 1.61 million gal | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 8fa65d5c-7c7e-49cc-8cdc-6fd6b8abc654, published Aug 5, 2026, 2:25 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Jul 22, 2026, 4:45 PM EDT · Map |
| Jul 22, 2026, 4:25 PM EDT | Jul 22, 2026, 4:50 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflow | 20,833 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 6ececfa1-717c-4b52-8e8c-8ddf37d34d44, published Aug 12, 2026, 12:10 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Jul 22, 2026, 4:25 PM EDT · Map |
| Jul 22, 2026, 4:25 PM EDT | Jul 22, 2026, 4:45 PM EDT | CITY OF CHELSEA | CHE004 PEARL ST | Combined sewer overflow | 20,444 gal | CITY OF CHELSEA (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record f82e7cdd-81c2-49d2-8ef9-30114516ad78, published Jul 24, 2026, 10:20 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF CHELSEA, Jul 22, 2026, 4:25 PM EDT · Map |
| Jul 22, 2026, 4:25 PM EDT | Jul 22, 2026, 4:45 PM EDT | CITY OF CHELSEA | CHE004 PEARL ST | Combined sewer overflowrevised | not reported | CITY OF CHELSEA (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record dee05342-5514-45ab-bbe3-a5547ca69acc, published Jul 23, 2026, 11:50 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF CHELSEA, Jul 22, 2026, 4:25 PM EDT · Map |
| Jul 22, 2026, 4:25 PM EDT | Jul 22, 2026, 4:50 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 4d292010-644d-4052-95bd-54bb3faf79ef, published Jul 22, 2026, 6:56 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Jul 22, 2026, 4:25 PM EDT · Map |
| Jul 22, 2026, 4:20 PM EDT | Jul 22, 2026, 6:31 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record ed4361a5-292a-4790-9460-e823a3a1109d, published Jul 22, 2026, 7:27 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 22, 2026, 4:20 PM EDT · Map |
| Jul 22, 2026, 4:19 PM EDT | Jul 22, 2026, 6:31 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 1.92 million gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 42ffa418-0a0c-412e-af73-f467236efd7c, published Aug 5, 2026, 2:08 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 22, 2026, 4:19 PM EDT · Map |
| Jul 21, 2026, 8:45 PM EDT | Jul 21, 2026, 9:00 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflow | 290,000 gal | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9bcfc5f3-d151-49f6-8238-91ec5c1374de, published Aug 5, 2026, 2:22 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Jul 21, 2026, 8:45 PM EDT · Map |
| Jul 21, 2026, 8:41 PM EDT | Jul 21, 2026, 9:00 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflowrevised | not reported | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record c3b7c085-68ed-4787-a210-d497bc0bb01d, published Jul 22, 2026, 6:26 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Jul 21, 2026, 8:41 PM EDT · Map |
| Jul 21, 2026, 6:15 PM EDT | Jul 21, 2026, 8:50 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflow | 45,139 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record a406c3a6-3be5-4083-bceb-2677267ff2fc, published Aug 12, 2026, 11:42 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Jul 21, 2026, 6:15 PM EDT · Map |
| Jul 21, 2026, 6:15 PM EDT | Jul 21, 2026, 8:50 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 771a6a50-3038-44fd-a076-699423e045c5, published Jul 22, 2026, 8:49 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Jul 21, 2026, 6:15 PM EDT · Map |
| Jul 21, 2026, 5:51 PM EDT | Jul 21, 2026, 9:54 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 3.02 million gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record d4d4a15c-7213-425d-9ba7-451b992e2d8b, published Aug 5, 2026, 1:57 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 21, 2026, 5:51 PM EDT · Map |
| Jul 21, 2026, 5:51 PM EDT | Jul 21, 2026, 9:54 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record df06e7b0-311b-4a20-8ac6-72bd39e2cbb6, published Jul 22, 2026, 6:23 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 21, 2026, 5:51 PM EDT · Map |
| Jul 21, 2026, 5:45 PM EDT | ended, time not reported | CITY OF CHELSEA | CHE004 PEARL ST | Combined sewer overflow | not reported | CITY OF CHELSEA (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record b4b38171-499b-4300-8007-01b6a8c0874e, published Jul 21, 2026, 6:05 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF CHELSEA, Jul 21, 2026, 5:45 PM EDT · Map |
| Jul 7, 2026, 6:30 PM EDT | Jul 7, 2026, 8:00 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflow | 1.84 million gal | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record f8e575c0-ca41-40dd-a1b5-a915624c13e2, published Aug 5, 2026, 2:18 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Jul 7, 2026, 6:30 PM EDT · Map |
| Jul 7, 2026, 6:30 PM EDT | Jul 7, 2026, 8:00 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflowrevised | not reported | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 0f8d5954-34f1-48ae-bdc4-70bb48b8fd20, published Jul 8, 2026, 9:59 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, CITY OF SOMERVILLE, Jul 7, 2026, 6:30 PM EDT · Map |
| Jul 7, 2026, 6:15 PM EDT | Jul 7, 2026, 7:45 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflow | 65,972 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record fc067b97-cd89-42e6-a5be-e370d272ee55, published Aug 12, 2026, 11:28 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Jul 7, 2026, 6:15 PM EDT · Map |
| Jul 7, 2026, 6:15 PM EDT | Jul 7, 2026, 7:45 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 09a02de5-ff71-4c00-9dbb-0b4aec4e29d4, published Jul 8, 2026, 12:16 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, Jul 7, 2026, 6:15 PM EDT · Map |
| Jul 7, 2026, 5:54 PM EDT | Jul 7, 2026, 9:18 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 3.49 million gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9dc8dca8-ba62-4246-90d9-027b71564c44, published Aug 5, 2026, 1:33 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 7, 2026, 5:54 PM EDT · Map |
| Jul 7, 2026, 5:54 PM EDT | Jul 7, 2026, 9:18 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 004317ce-d243-4bc3-a70b-122c05906e6b, published Jul 8, 2026, 9:48 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 7, 2026, 5:54 PM EDT · Map |
| Jul 7, 2026, 8:44 AM EDT | Jul 7, 2026, 9:29 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 420,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record d67fc684-3aa5-4086-97e4-b7e940401e7b, published Aug 5, 2026, 1:48 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 7, 2026, 8:44 AM EDT · Map |
| Jul 7, 2026, 8:42 AM EDT | Jul 7, 2026, 9:29 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9b1d8d20-d464-4260-ba28-8520dd6a839b, published Jul 8, 2026, 12:21 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 7, 2026, 8:42 AM EDT · Map |
| Jul 4, 2026, 7:09 PM EDT | Jul 4, 2026, 7:36 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 70,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record d342c906-793e-409c-bb32-8979bc97615c, published Aug 5, 2026, 12:52 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 4, 2026, 7:09 PM EDT · Map |
| Jul 4, 2026, 7:09 PM EDT | Jul 4, 2026, 7:36 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record aef5b36c-b157-4abe-b510-33baa8efb01d, published Jul 4, 2026, 10:58 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jul 4, 2026, 7:09 PM EDT · Map |
| Jun 18, 2026, 6:34 PM EDT | Jun 18, 2026, 7:33 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 40,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 94917c77-aa62-4dcf-a84f-d716fb9a6297, published Jul 8, 2026, 2:18 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jun 18, 2026, 6:34 PM EDT · Map |
| Jun 18, 2026, 6:33 PM EDT | Jun 18, 2026, 7:33 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record af5c49ad-6f9c-41ed-99c7-f1163a6a485e, published Jun 18, 2026, 9:30 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, MASSACHUSETTS WATER RESOURCES AUTHORITY, Jun 18, 2026, 6:33 PM EDT · Map |
| May 19, 2026, 6:40 PM EDT | May 20, 2026, 9:00 AM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflow | 223,567 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 21b203bc-daa1-44b7-8df8-ba34511c6861, published Jun 11, 2026, 4:13 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, May 19, 2026, 6:40 PM EDT · Map |
| May 19, 2026, 6:40 PM EDT | May 20, 2026, 9:00 AM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9fd4f718-7abe-4b16-bd02-f05a41a83298, published May 20, 2026, 11:10 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, May 19, 2026, 6:40 PM EDT · Map |
| May 13, 2026, 9:35 PM EDT | May 14, 2026, 12:25 AM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflow | 3,269 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 1b44e4ec-fd76-412b-b023-26622bfc79ba, published Jun 12, 2026, 9:21 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, May 13, 2026, 9:35 PM EDT · Map |
| May 13, 2026, 9:35 PM EDT | May 14, 2026, 12:25 AM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record d49b4b8d-d075-4f2d-bad7-bbdaf31a0b3e, published May 14, 2026, 9:26 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | Event: Combined sewer overflow, BOSTON WATER & SEWER COMMISSION, May 13, 2026, 9:35 PM EDT · Map |
| Mar 16, 2026, 7:56 AM EDT | Mar 16, 2026, 9:48 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 500,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 19e1d000-50cd-41cf-a47b-91dc61e65641, published Apr 8, 2026, 10:30 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Mar 16, 2026, 7:56 AM EDT | Mar 16, 2026, 9:48 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 1411c46a-7139-4c31-a020-30144d69ad8c, published Mar 16, 2026, 8:54 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 29, 2025, 2:12 PM EST | Dec 29, 2025, 5:11 PM EST | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 130,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 7bd6f1e7-f653-4595-9621-21851ce4ba16, published Jan 7, 2026, 8:14 AM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 29, 2025, 2:12 PM EST | Dec 29, 2025, 5:11 PM EST | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record cce664e7-6da2-4819-8e9a-718605740158, published Dec 29, 2025, 9:21 PM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 30, 2025, 10:18 PM EDT | Oct 30, 2025, 11:13 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 56eb7611-308e-46a1-a111-fa90c72fea95, published Oct 31, 2025, 2:11 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 30, 2025, 10:17 PM EDT | Oct 30, 2025, 11:13 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 940,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 31b2c5ac-67c2-42e6-9c66-9a5bbd0442ac, published Nov 12, 2025, 9:36 AM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 22, 2025, 8:55 AM EDT | Oct 22, 2025, 10:30 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 390,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 32aaed7f-4f2d-466d-b654-a8869c0bb0f0, published Nov 12, 2025, 9:34 AM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 22, 2025, 8:55 AM EDT | Oct 22, 2025, 10:30 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 85d733b6-2e6a-4881-af32-af094207aa3b, published Oct 22, 2025, 2:40 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 20, 2025, 11:53 AM EDT | Oct 20, 2025, 2:36 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 20037fa2-a8a8-4113-a274-f72695b2864c, published Oct 20, 2025, 4:30 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 20, 2025, 11:52 AM EDT | Oct 20, 2025, 2:36 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 330,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 7a05c399-a5d2-4941-a222-fb89ad6d3b3f, published Nov 12, 2025, 9:32 AM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 14, 2025, 6:05 PM EDT | Oct 14, 2025, 8:30 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflow | 47,000 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 1710d57c-8d1a-4e31-bfee-830701ec35ff, published Nov 14, 2025, 5:13 PM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 14, 2025, 6:05 PM EDT | Oct 14, 2025, 8:30 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9fc1950f-5749-45d2-8978-32eb0f6b2a3b, published Oct 15, 2025, 9:36 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 14, 2025, 3:50 PM EDT | ended, time not reported | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflow | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 38b8bb2f-8afe-4d69-aaf8-ecb7d6f2ed4e, published Oct 13, 2025, 10:02 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 13, 2025, 4:09 PM EDT | Oct 13, 2025, 6:15 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflowrevised | not reported | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 53de697b-4c6c-47e4-a6e1-1ce87d05c00f, published Oct 14, 2025, 8:13 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 13, 2025, 4:00 PM EDT | Oct 13, 2025, 6:15 PM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflow | 590,000 gal | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 4d637f83-2105-4c23-bd37-b4a8a8d3f59f, published Nov 12, 2025, 9:31 AM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 13, 2025, 3:50 PM EDT | Oct 13, 2025, 5:40 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS009 CORNER OF SUMMER & NEW ST | Combined sewer overflow | 80,000 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record b0907a4f-3106-473a-8e1b-e15f359b52b7, published Nov 14, 2025, 5:03 PM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 13, 2025, 2:29 PM EDT | Oct 13, 2025, 9:14 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 1.04 million gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 894507d9-6d84-4a2f-bc20-3535168983ed, published Nov 12, 2025, 8:47 AM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 13, 2025, 2:29 PM EDT | Oct 13, 2025, 9:14 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 9d8d78b7-ac0f-4c93-96ce-4f42d51cfaf7, published Oct 14, 2025, 8:06 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 9, 2025, 7:00 PM EDT | Oct 9, 2025, 9:45 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflow | 11,000 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record c6bb5f9a-b134-42f1-b533-f9ebd4974fce, published Nov 14, 2025, 4:52 PM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 9, 2025, 7:00 PM EDT | Oct 9, 2025, 9:45 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 8de129b7-14b6-4fb7-b89f-6602b9c98dbf, published Oct 10, 2025, 9:54 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 8, 2025, 10:30 AM EDT | Oct 8, 2025, 10:45 AM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflow | 40,000 gal | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 08adc1c7-dd73-4487-9c2e-28b58120e6f0, published Nov 12, 2025, 8:43 AM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 8, 2025, 10:25 AM EDT | Oct 8, 2025, 10:45 AM EDT | CITY OF SOMERVILLE | SOM007A/MWR205A SOUTH BANK OF MYSTIC RIVER AT INT OF ASSEMBLY SQ DR & 28 | Combined sewer overflowrevised | not reported | CITY OF SOMERVILLE (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 6b1b25dd-c6fd-4b93-997b-abce5c9af848, published Oct 8, 2025, 3:54 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 8, 2025, 9:10 AM EDT | Oct 8, 2025, 6:45 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflow | 1.58 million gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record fb2d9148-c247-472f-af19-96092600eae1, published Nov 18, 2025, 10:31 AM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 8, 2025, 9:10 AM EDT | Oct 8, 2025, 6:45 PM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 71f05f21-7cfc-4b39-9894-5e10ab2e42de, published Oct 10, 2025, 10:06 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 8, 2025, 9:05 AM EDT | Oct 8, 2025, 8:25 AM EDT | CITY OF CHELSEA | CHE004 PEARL ST | Combined sewer overflowrevised | not reported | CITY OF CHELSEA (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 0e0e8cb1-9a6a-46cc-ad7b-37087ff47989, published Oct 31, 2025, 10:31 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 8, 2025, 8:58 AM EDT | Oct 8, 2025, 10:46 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 1.71 million gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record ff130865-cd4c-4ef3-8f41-9f29c995dcc0, published Nov 12, 2025, 8:41 AM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 8, 2025, 8:55 AM EDT | Oct 8, 2025, 10:46 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record f5a13362-7dc2-47cf-83de-1b7688450a22, published Oct 8, 2025, 3:52 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 8, 2025, 8:20 AM EDT | Oct 8, 2025, 8:25 AM EDT | CITY OF CHELSEA | CHE004 PEARL ST | Combined sewer overflow | 269 gal | CITY OF CHELSEA (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 0e7d8191-ba81-4ff5-96da-71dda0d75a52, published Nov 3, 2025, 4:28 PM EST, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 25, 2025, 10:05 AM EDT | Sep 25, 2025, 10:15 AM EDT | CITY OF CHELSEA | CHE004 PEARL ST | Combined sewer overflow | 6,017 gal | CITY OF CHELSEA (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record ed0cb619-6b0c-41e9-944a-f411f9c0a17d, published Oct 2, 2025, 3:16 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 25, 2025, 10:05 AM EDT | Sep 25, 2025, 10:15 AM EDT | CITY OF CHELSEA | CHE004 PEARL ST | Combined sewer overflowrevised | not reported | CITY OF CHELSEA (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 4bd8a18d-ebef-4007-ba4c-4eca8c65a134, published Sep 25, 2025, 2:12 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 25, 2025, 10:00 AM EDT | Sep 25, 2025, 10:45 AM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflow | 20,000 gal | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record b9bee524-e5fa-43b9-bec1-a13e145c1813, published Oct 14, 2025, 4:36 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 25, 2025, 10:00 AM EDT | Sep 25, 2025, 10:45 AM EDT | BOSTON WATER & SEWER COMMISSION | BOS010 WEST OF BORDER ST ON EAST BANK BOS INNER HRBR | Combined sewer overflowrevised | not reported | BOSTON WATER & SEWER COMMISSION (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 6a802cf5-c499-40b2-ab6b-dc44a5e8a6aa, published Sep 25, 2025, 3:36 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 25, 2025, 9:32 AM EDT | Sep 25, 2025, 12:04 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 1.97 million gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record ba013e31-f127-4e43-807d-d47a13f3d775, published Oct 20, 2025, 4:51 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 25, 2025, 9:32 AM EDT | Sep 25, 2025, 12:04 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 65cc77d1-277e-4c67-bc7e-6a13f902f980, published Sep 26, 2025, 7:55 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 18, 2025, 3:28 AM EDT | Sep 18, 2025, 4:05 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 450,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record c95bdf2f-1971-4fe3-b5c0-ecee639eafce, published Oct 20, 2025, 4:49 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 18, 2025, 3:28 AM EDT | Sep 18, 2025, 4:05 AM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 18321db7-ea1c-4426-8af4-bb67894682a3, published Sep 18, 2025, 12:32 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 7, 2025, 11:05 AM EDT | Sep 7, 2025, 1:07 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 360,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record d76a73de-9e11-437d-aca4-bb4da3f3c3ed, published Oct 20, 2025, 4:48 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 7, 2025, 11:05 AM EDT | Sep 7, 2025, 1:07 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 3c39d50c-57c8-4194-9db1-a9cdc9d68011, published Sep 7, 2025, 9:40 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 6, 2025, 6:15 PM EDT | Sep 6, 2025, 6:25 PM EDT | CITY OF CHELSEA | CHE004 PEARL ST | Combined sewer overflow | 1,711 gal | CITY OF CHELSEA (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 4924f29d-3808-459b-8f02-e13dca78c019, published Sep 9, 2025, 5:00 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 6, 2025, 6:15 PM EDT | Sep 6, 2025, 6:25 PM EDT | CITY OF CHELSEA | CHE004 PEARL ST | Combined sewer overflowrevised | not reported | CITY OF CHELSEA (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record a4740635-6fe1-47cc-a5fe-0f6c609fef73, published Sep 8, 2025, 8:24 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 6, 2025, 5:47 PM EDT | Sep 6, 2025, 7:41 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 690ab939-194e-4e2f-a808-119645f33539, published Sep 7, 2025, 11:19 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 6, 2025, 5:46 PM EDT | Sep 6, 2025, 7:41 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 3.74 million gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record b9ab83cd-48ea-493c-9ad6-ef440ba113a7, published Oct 20, 2025, 4:43 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 14, 2025, 6:42 PM EDT | Aug 14, 2025, 7:27 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record c4035618-356e-475f-8f80-c64441fa8204, published Aug 15, 2025, 9:14 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 14, 2025, 6:41 PM EDT | Aug 14, 2025, 7:27 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 30,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 37d037e8-3cf2-4974-9dbb-b20e90cbf401, published Sep 11, 2025, 7:05 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 31, 2025, 5:48 PM EDT | Jul 31, 2025, 6:43 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 990,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record d79e8c41-cab5-47eb-a0a4-cd6ff2ba34aa, published Aug 14, 2025, 11:22 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 31, 2025, 5:48 PM EDT | Jul 31, 2025, 6:43 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflowrevised | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 0c561431-75b4-44af-8dac-321393728a5c, published Aug 1, 2025, 8:48 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 21, 2025, 7:45 PM EDT | ended, time not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record aeab3ea6-6948-493a-afb0-5b5564d8c54d, published Jul 20, 2025, 9:52 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 20, 2025, 7:45 PM EDT | Jul 20, 2025, 8:09 PM EDT | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | 320,000 gal | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record bd18259b-26e3-4a36-b651-947577d90b5a, published Aug 14, 2025, 10:58 AM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 11, 2025, 11:45 AM EDT | ended, time not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY | MWR205 EAST BNK MYSTIC 150 FT SW OF MDC LOCKS | Combined sewer overflow | not reported | MASSACHUSETTS WATER RESOURCES AUTHORITY (MassDEP sewage notification portal) via MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/), record 3d728374-6633-4507-bc4f-39f29a226f3a, published Jul 10, 2025, 8:16 PM EDT, retrieved 2026-11-02 10:58 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
Showing the newest 100 events of 425 events. See them all with filters.
Outfalls on this water
No outfall in the registry is matched to this water.
Dischargers: Boston Water and Sewer Commission, City of Chelsea, City of Somerville DPW, Massachusetts Water Resources Authority.
Launches
Source: OpenBoatLaunch launch records (public agency data and OpenStreetMap, ODbL). · Mystic River on OpenBoatLaunch
Sources covering this water
- ECHO Effluent Charts REST services (per-permit DMR data incl. monthly CSO event counts, duration, volume per outfall) · updating · last answered Nov 2, 2026, 6:54 AM EST
- ECHO NPDES Sewer Overflow and Bypass Event Dataset (eRule Phase 2, current versions) · updating · last answered Nov 2, 2026, 6:54 AM EST
- MassDEP CSO API behind the portal (eeaonline.eea.state.ma.us/dep/CSOAPI/api/) · updating · last answered Nov 2, 2026, 6:54 AM EST
425 events placed on this water in this build.