New Hampshire / Waters /
Merrimack River
River in New Hampshire · near Allenstown, Bedford, Boscawen, Bow, Canterbury
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 an unknown time: unresolved, no end reported · City of Manchester DPW Environmental Protection Division · downstream path not modeled · since Nov 1, 2026, 7:23 AM EST
Source: City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14033, reported Oct 18, 2026, 8:23 AM EDT, retrieved 2026-11-02 11:55 UTC · notice
As of Nov 2, 2026, 6:56 AM EST.
Events behind the colour
- Unresolved: no end reported Combined sewer overflow · City of Manchester DPW Environmental Protection Division · outfall not stated · not reported (reported Oct 18, 2026, 8:23 AM EDT) to Oct 17, 2026, 8:23 PM EDT · not reported · Unresolved: no end reported, until Nov 17, 2026, 7:23 AM EST
Source: City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14033, reported Oct 18, 2026, 8:23 AM EDT, retrieved 2026-11-02 11:55 UTC · notice
- Unresolved: no end reported Combined sewer overflow · City of Manchester DPW Environmental Protection Division · outfall not stated · not reported (reported Oct 12, 2026, 1:53 PM EDT) to Oct 12, 2026, 1:53 AM EDT · not reported · Unresolved: no end reported, until Nov 11, 2026, 12:53 PM EST
Source: City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14023, reported Oct 12, 2026, 1:53 PM EDT, retrieved 2026-11-02 11:55 UTC · notice
- Unresolved: no end reported Combined sewer overflow · City of Manchester DPW Environmental Protection Division · outfall not stated · not reported (reported Oct 7, 2026, 5:22 AM EDT) to Oct 6, 2026, 5:22 PM EDT · not reported · Unresolved: no end reported, until Nov 6, 2026, 4:22 AM EST
Source: City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14013, reported Oct 7, 2026, 5:22 AM EDT, retrieved 2026-11-02 11:55 UTC · notice
- Unresolved: no end reported Combined sewer overflow · City of Manchester DPW Environmental Protection Division · outfall not stated · not reported (reported Oct 3, 2026, 11:38 PM EDT) to Oct 3, 2026, 11:38 AM EDT · not reported · Unresolved: no end reported, until Nov 2, 2026, 10:38 PM EST
Source: City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14011, reported Oct 3, 2026, 11:38 PM EDT, retrieved 2026-11-02 11:55 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 Merrimack River
No discharge colours a modeled reach on this water now.
Traced outfall paths
- No current report NH0100170 outfall 002 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100170 outfall 003 · 39.203 km traced · Model stops here: tidal below this point
- No current report NH0100170 outfall 004 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100170 outfall 005 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100170 outfall 014 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 011 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 018 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 031 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 043 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 044 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 045 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 046 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 047 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 050 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 051 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 052 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 053 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 054 · 40 km traced · Model stops here: 40 km cap
- No current report NH0100447 outfall 055 · 40 km traced · Model stops here: 40 km cap
Source: paths traced by DirtyWaterWatch on the USGS NLDI / NHDPlus network from each outfall to the head of tide, the first lake or the distance cap; statuses from the events on them.
The last 90 days
- Unresolved: no end reported: Nov 1, 2026, 8:00 AM EST to now · set by event 1, event 2, event 3, event 4
- Caution: Oct 20, 2026, 9:00 PM EDT to Nov 1, 2026, 8:00 AM EST · set by event 1, event 2, event 3
- Advisory in effect: Oct 12, 2026, 3:00 PM EDT to Oct 20, 2026, 9:00 PM EDT · set by event 1, event 2
- Caution: Sep 29, 2026, 11:00 AM EDT to Oct 12, 2026, 3:00 PM EDT · set by event 1, event 2, event 3, event 4
- Unresolved: no end reported: Aug 17, 2026, 12:00 AM EDT to Sep 2, 2026, 12:00 AM EDT · set by event 1, event 2, event 3, event 4, event 5, event 6, event 7, event 8, event 9, event 10, event 11, event 12, event 13, event 14, event 15, event 16, event 17
- Caution: Aug 4, 2026, 8:00 AM EDT to Aug 17, 2026, 12:00 AM EDT · set by event 1, event 2, event 3, event 4, event 5, event 6, event 7, event 8, event 9, event 10, event 11, event 12, event 13, event 14, event 15, event 16, event 17
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 months15Dec 2025 to Nov 2026; partly covered or sparse source
- Days with a discharge, last 12 months14Dec 2025 to Nov 2026; partly covered or sparse source
- Hours under advisory, last 12 months197Dec 2025 to Nov 2026; partly covered or sparse source
- 2026 season under advisory6.5%May to October, partly covered; 197 h
Discharge events per month
106 events, Jan 2022 to Nov 2026.
- Combined sewer overflow
- Sanitary sewer overflow
- Bypass, blended or other
- Partly covered or sparse source
EPA ECHO sewer overflow records are sparse (only what permittees file with EPA). NH permittees publish on their own pages; each discharger's record begins on a different date.
Sources: EPA ECHO sewer overflow events; NH permittee notices (Nashua, Manchester, Portsmouth, Exeter). Covered 2022-01-01 to 2026-11-02.
Show table
| Month | Combined sewer overflow | Sanitary sewer overflow | Bypass, blended or other | Total | Counted from | Coverage |
|---|---|---|---|---|---|---|
| Jan 2022 | 3 | 0 | 0 | 3 | Source records | |
| Feb 2022 | 2 | 0 | 0 | 2 | Source records | |
| Mar 2022 | 0 | 0 | 0 | 0 | ||
| Apr 2022 | 2 | 0 | 0 | 2 | Source records | |
| May 2022 | 0 | 0 | 0 | 0 | ||
| Jun 2022 | 0 | 0 | 0 | 0 | ||
| Jul 2022 | 2 | 0 | 0 | 2 | Source records | |
| Aug 2022 | 0 | 0 | 0 | 0 | ||
| Sep 2022 | 0 | 0 | 0 | 0 | ||
| Oct 2022 | 0 | 0 | 0 | 0 | ||
| Nov 2022 | 0 | 0 | 0 | 0 | ||
| Dec 2022 | 1 | 0 | 0 | 1 | Source records | |
| Jan 2023 | 0 | 0 | 0 | 0 | ||
| Feb 2023 | 1 | 0 | 0 | 1 | Source records | |
| Mar 2023 | 0 | 0 | 0 | 0 | ||
| Apr 2023 | 0 | 0 | 0 | 0 | ||
| May 2023 | 0 | 0 | 0 | 0 | ||
| Jun 2023 | 5 | 0 | 0 | 5 | Source records | |
| Jul 2023 | 20 | 2 | 0 | 22 | Source records | |
| Aug 2023 | 3 | 0 | 0 | 3 | Source records | |
| Sep 2023 | 5 | 0 | 0 | 5 | Source records | |
| Oct 2023 | 2 | 0 | 0 | 2 | Source records | |
| Nov 2023 | 0 | 0 | 0 | 0 | ||
| Dec 2023 | 4 | 1 | 0 | 5 | Source records | |
| Jan 2024 | 0 | 0 | 0 | 0 | ||
| Feb 2024 | 0 | 0 | 0 | 0 | ||
| Mar 2024 | 1 | 0 | 0 | 1 | Source records | |
| Apr 2024 | 0 | 0 | 0 | 0 | ||
| May 2024 | 0 | 0 | 0 | 0 | ||
| Jun 2024 | 0 | 0 | 0 | 0 | ||
| Jul 2024 | 3 | 0 | 0 | 3 | Source records | |
| Aug 2024 | 5 | 0 | 0 | 5 | Source records | |
| Sep 2024 | 0 | 0 | 0 | 0 | ||
| Oct 2024 | 0 | 0 | 0 | 0 | ||
| Nov 2024 | 0 | 0 | 0 | 0 | ||
| Dec 2024 | 2 | 0 | 0 | 2 | Source records | |
| Jan 2025 | 2 | 0 | 0 | 2 | Source records | |
| Feb 2025 | 2 | 0 | 0 | 2 | Source records | |
| Mar 2025 | 6 | 0 | 0 | 6 | Source records | |
| Apr 2025 | 0 | 0 | 0 | 0 | ||
| May 2025 | 6 | 0 | 0 | 6 | Source records | |
| Jun 2025 | 1 | 0 | 0 | 1 | Source records | |
| Jul 2025 | 3 | 0 | 0 | 3 | Source records | |
| Aug 2025 | 4 | 0 | 0 | 4 | Source records | |
| Sep 2025 | 0 | 0 | 0 | 0 | ||
| Oct 2025 | 3 | 0 | 0 | 3 | Source records | |
| Nov 2025 | 0 | 0 | 0 | 0 | ||
| Dec 2025 | 0 | 0 | 0 | 0 | ||
| Jan 2026 | 0 | 0 | 0 | 0 | ||
| Feb 2026 | 0 | 0 | 0 | 0 | ||
| Mar 2026 | 0 | 0 | 0 | 0 | ||
| Apr 2026 | 0 | 0 | 0 | 0 | ||
| May 2026 | 0 | 0 | 0 | 0 | ||
| Jun 2026 | 0 | 0 | 0 | 0 | ||
| Jul 2026 | 4 | 0 | 0 | 4 | Source records | |
| Aug 2026 | 4 | 0 | 0 | 4 | Source records | Partly covered or sparse source |
| Sep 2026 | 1 | 0 | 0 | 1 | Source records | Partly covered or sparse source |
| Oct 2026 | 6 | 0 | 0 | 6 | Source records | |
| 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
- Partly covered or sparse source
390 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. EPA ECHO sewer overflow records are sparse (only what permittees file with EPA). NH permittees publish on their own pages; each discharger's record begins on a different date.
Sources: EPA ECHO sewer overflow events; NH permittee notices (Nashua, Manchester, Portsmouth, Exeter). Covered 2013-01-10 to 2026-11-02.
Show table
| Month | Hours under advisory | From discharge windows | Hours in month | Coverage |
|---|---|---|---|---|
| Jan 2022 | 0 | 0 | 744 | |
| Feb 2022 | 0 | 0 | 672 | |
| Mar 2022 | 0 | 0 | 744 | |
| Apr 2022 | 0 | 0 | 720 | |
| May 2022 | 0 | 0 | 744 | |
| Jun 2022 | 0 | 0 | 720 | |
| Jul 2022 | 0 | 0 | 744 | |
| Aug 2022 | 0 | 0 | 744 | |
| Sep 2022 | 0 | 0 | 720 | |
| Oct 2022 | 0 | 0 | 744 | |
| Nov 2022 | 0 | 0 | 720 | |
| Dec 2022 | 0 | 0 | 744 | |
| Jan 2023 | 0 | 0 | 744 | |
| Feb 2023 | 236 | 236 | 672 | |
| Mar 2023 | 0 | 0 | 744 | |
| Apr 2023 | 0 | 0 | 720 | |
| May 2023 | 0 | 0 | 744 | |
| Jun 2023 | 0 | 0 | 720 | |
| Jul 2023 | 96 | 96 | 744 | |
| Aug 2023 | 0 | 0 | 744 | |
| Sep 2023 | 0 | 0 | 720 | |
| Oct 2023 | 0 | 0 | 744 | |
| Nov 2023 | 0 | 0 | 720 | |
| Dec 2023 | 79 | 79 | 744 | |
| Jan 2024 | 0 | 0 | 744 | |
| Feb 2024 | 0 | 0 | 696 | |
| Mar 2024 | 0 | 0 | 744 | |
| Apr 2024 | 0 | 0 | 720 | |
| May 2024 | 0 | 0 | 744 | |
| Jun 2024 | 0 | 0 | 720 | |
| Jul 2024 | 0 | 0 | 744 | |
| Aug 2024 | 0 | 0 | 744 | |
| Sep 2024 | 0 | 0 | 720 | |
| Oct 2024 | 0 | 0 | 744 | |
| Nov 2024 | 0 | 0 | 720 | |
| Dec 2024 | 0 | 0 | 744 | |
| Jan 2025 | 0 | 0 | 744 | |
| Feb 2025 | 0 | 0 | 672 | |
| Mar 2025 | 0 | 0 | 744 | |
| Apr 2025 | 0 | 0 | 720 | |
| May 2025 | 0 | 0 | 744 | |
| Jun 2025 | 0 | 0 | 720 | |
| Jul 2025 | 0 | 0 | 744 | |
| Aug 2025 | 0 | 0 | 744 | |
| Sep 2025 | 0 | 0 | 720 | |
| Oct 2025 | 0 | 0 | 744 | |
| Nov 2025 | 0 | 0 | 720 | |
| Dec 2025 | 0 | 0 | 744 | |
| Jan 2026 | 0 | 0 | 744 | |
| Feb 2026 | 0 | 0 | 672 | |
| Mar 2026 | 0 | 0 | 744 | |
| Apr 2026 | 0 | 0 | 720 | |
| May 2026 | 0 | 0 | 744 | |
| Jun 2026 | 0 | 0 | 720 | |
| Jul 2026 | 0 | 0 | 744 | |
| Aug 2026 | 0 | 0 | 744 | Partly covered or sparse source |
| Sep 2026 | 0 | 0 | 720 | Partly covered or sparse source |
| Oct 2026 | 197 | 197 | 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.
- Partly covered or sparse source
Sources: EPA ECHO sewer overflow events; NH permittee notices (Nashua, Manchester, Portsmouth, Exeter). Covered 2022-01-01 to 2026-11-02.
Show table
| Month | Days with a discharge | Coverage |
|---|---|---|
| Jan 2022 | 1 | |
| Feb 2022 | 1 | |
| Mar 2022 | 0 | |
| Apr 2022 | 1 | |
| May 2022 | 0 | |
| Jun 2022 | 0 | |
| Jul 2022 | 1 | |
| Aug 2022 | 0 | |
| Sep 2022 | 0 | |
| Oct 2022 | 0 | |
| Nov 2022 | 0 | |
| Dec 2022 | 1 | |
| Jan 2023 | 0 | |
| Feb 2023 | 8 | |
| Mar 2023 | 0 | |
| Apr 2023 | 0 | |
| May 2023 | 0 | |
| Jun 2023 | 2 | |
| Jul 2023 | 8 | |
| Aug 2023 | 2 | |
| Sep 2023 | 2 | |
| Oct 2023 | 1 | |
| Nov 2023 | 0 | |
| Dec 2023 | 1 | |
| Jan 2024 | 0 | |
| Feb 2024 | 0 | |
| Mar 2024 | 1 | |
| Apr 2024 | 0 | |
| May 2024 | 0 | |
| Jun 2024 | 0 | |
| Jul 2024 | 2 | |
| Aug 2024 | 2 | |
| Sep 2024 | 0 | |
| Oct 2024 | 0 | |
| Nov 2024 | 0 | |
| Dec 2024 | 1 | |
| Jan 2025 | 1 | |
| Feb 2025 | 2 | |
| Mar 2025 | 3 | |
| Apr 2025 | 0 | |
| May 2025 | 2 | |
| Jun 2025 | 1 | |
| Jul 2025 | 1 | |
| Aug 2025 | 1 | |
| Sep 2025 | 0 | |
| Oct 2025 | 1 | |
| Nov 2025 | 0 | |
| Dec 2025 | 0 | |
| Jan 2026 | 0 | |
| Feb 2026 | 0 | |
| Mar 2026 | 0 | |
| Apr 2026 | 0 | |
| May 2026 | 0 | |
| Jun 2026 | 0 | |
| Jul 2026 | 3 | |
| Aug 2026 | 1 | Partly covered or sparse source |
| Sep 2026 | 1 | Partly covered or sparse source |
| Oct 2026 | 9 | |
| Nov 2026 | 0 |
Discharge events per year, 2013 to 2026
396 events, 2013 to 2026.
- Combined sewer overflow
- Sanitary sewer overflow
- Bypass, blended or other
- Partly covered or sparse source
EPA ECHO sewer overflow records are sparse (only what permittees file with EPA). NH permittees publish on their own pages; each discharger's record begins on a different date.
Sources: EPA ECHO sewer overflow events; NH permittee notices (Nashua, Manchester, Portsmouth, Exeter). Covered 2013-01-10 to 2026-11-02.
Show table
| Year | Combined sewer overflow | Sanitary sewer overflow | Bypass, blended or other | Total | Coverage |
|---|---|---|---|---|---|
| 2013 | 76 | 0 | 0 | 76 | Partly covered or sparse source |
| 2014 | 33 | 0 | 0 | 33 | |
| 2015 | 23 | 0 | 0 | 23 | |
| 2016 | 17 | 0 | 0 | 17 | |
| 2017 | 17 | 0 | 0 | 17 | |
| 2018 | 30 | 0 | 0 | 30 | |
| 2019 | 44 | 0 | 0 | 44 | |
| 2020 | 15 | 0 | 0 | 15 | |
| 2021 | 35 | 0 | 0 | 35 | |
| 2022 | 10 | 0 | 0 | 10 | |
| 2023 | 40 | 3 | 0 | 43 | |
| 2024 | 11 | 0 | 0 | 11 | |
| 2025 | 27 | 0 | 0 | 27 | |
| 2026 | 15 | 0 | 0 | 15 | Partly covered or sparse source |
Reported volume per year
Gallons, summed from the 387 events that gave a number (9 did not).
- Partly covered or sparse source
9 of 396 events gave no volume as a number; only numbers are summed.
Sources: EPA ECHO sewer overflow events; NH permittee notices (Nashua, Manchester, Portsmouth, Exeter). Covered 2013-01-10 to 2026-11-02.
Show table
| Year | Gallons | Events with a number | Events without | Coverage |
|---|---|---|---|---|
| 2013 | 22,300,000 | 76 | 0 | Partly covered or sparse source |
| 2014 | 20,332,000 | 33 | 0 | |
| 2015 | 4,169,000 | 23 | 0 | |
| 2016 | 6,826,000 | 17 | 0 | |
| 2017 | 7,795,000 | 17 | 0 | |
| 2018 | 33,692,000 | 30 | 0 | |
| 2019 | 37,937,000 | 44 | 0 | |
| 2020 | 9,095,300 | 15 | 0 | |
| 2021 | 40,073,000 | 35 | 0 | |
| 2022 | 3,959,100 | 10 | 0 | |
| 2023 | 56,104,000 | 41 | 2 | |
| 2024 | 9,219,000 | 11 | 0 | |
| 2025 | 29,606,000 | 27 | 0 | |
| 2026 | 13,570,000 | 8 | 7 | Partly covered or sparse source |
Hours under advisory per year
Hours under advisory each year; 2026 to date.
- Advisory in effect
- Partly covered or sparse source
390 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.
Sources: EPA ECHO sewer overflow events; NH permittee notices (Nashua, Manchester, Portsmouth, Exeter). Covered 2013-01-10 to 2026-11-02.
Show table
| Year | Hours under advisory | Share of the year | Coverage |
|---|---|---|---|
| 2013 | 0 | 0.0% | Partly covered or sparse source |
| 2014 | 0 | 0.0% | |
| 2015 | 0 | 0.0% | |
| 2016 | 0 | 0.0% | |
| 2017 | 0 | 0.0% | |
| 2018 | 0 | 0.0% | |
| 2019 | 0 | 0.0% | |
| 2020 | 0 | 0.0% | |
| 2021 | 0 | 0.0% | |
| 2022 | 0 | 0.0% | |
| 2023 | 411 | 4.7% | |
| 2024 | 0 | 0.0% | |
| 2025 | 0 | 0.0% | |
| 2026 | 197 | 2.7% | Partly covered or sparse source |
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.
Sources: EPA ECHO sewer overflow events; NH permittee notices (Nashua, Manchester, Portsmouth, Exeter). Covered 2013-01-10 to 2026-11-02.
Show table
| Month | Events | Years of records |
|---|---|---|
| Jan | 38 | 14 |
| Feb | 14 | 14 |
| Mar | 16 | 14 |
| Apr | 18 | 14 |
| May | 19 | 14 |
| Jun | 42 | 14 |
| Jul | 80 | 14 |
| Aug | 48 | 14 |
| Sep | 43 | 14 |
| Oct | 33 | 14 |
| Nov | 16 | 14 |
| Dec | 29 | 13 |
Discharge events by outfall
The 5 outfalls with the most events of 5, all years.
EPA ECHO sewer overflow records are sparse (only what permittees file with EPA). NH permittees publish on their own pages; each discharger's record begins on a different date.
Sources: EPA ECHO sewer overflow events; NH permittee notices (Nashua, Manchester, Portsmouth, Exeter). Covered 2013-01-10 to 2026-11-02.
Show table
| Outfall | Discharger | Events |
|---|---|---|
| 005 East Hollis St. | City of Nashua Wastewater Department | 179 |
| 004 Burke St. | City of Nashua Wastewater Department | 90 |
| 014 Bridge St. | City of Nashua Wastewater Department | 70 |
| 003 Farmington Rd. | City of Nashua Wastewater Department | 46 |
| 044 Cemetery Brook | City of Manchester DPW Environmental Protection Division (Manchester WWTF, 300 Winston St, and 15 CSOs) | 1 |
| Outfall not stated | 10 |
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)
- NH permittee notices (Nashua, Manchester, Portsmouth, Exeter): 2013-01-10 to 2026-08-03
- NH permittee notices (Nashua, Manchester, Portsmouth, Exeter): 2026-09-29 to now
Every event on Merrimack River
| Start | End | Discharger | Outfall | Type | Volume | Source | Links |
|---|---|---|---|---|---|---|---|
| not reported (reported Oct 18, 2026, 8:23 AM EDT) | Oct 17, 2026, 8 PM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflowrevised | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14032, reported Oct 18, 2026, 8:23 AM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Oct 18, 2026, 8:23 AM EDT) · Map |
| not reported (reported Oct 18, 2026, 8:23 AM EDT) | Oct 17, 2026, 8:23 PM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflow | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14033, reported Oct 18, 2026, 8:23 AM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Oct 18, 2026, 8:23 AM EDT) · Map |
| not reported (reported Oct 14, 2026, 12:08 AM EDT) | Oct 17, 2026, 8 PM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflow | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14026, reported Oct 14, 2026, 12:08 AM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Oct 14, 2026, 12:08 AM EDT) · Map |
| not reported (reported Oct 12, 2026, 3:04 PM EDT) | Oct 17, 2026, 8 PM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflow | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14024, reported Oct 12, 2026, 3:04 PM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Oct 12, 2026, 3:04 PM EDT) · Map |
| not reported (reported Oct 12, 2026, 1:53 PM EDT) | Oct 12, 2026, 1:53 AM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflow | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14023, reported Oct 12, 2026, 1:53 PM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Oct 12, 2026, 1:53 PM EDT) · Map |
| not reported (reported Oct 11, 2026, 9:21 PM EDT) | Oct 12, 2026, 1 AM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflowrevised | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14022, reported Oct 11, 2026, 9:21 PM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Oct 11, 2026, 9:21 PM EDT) · Map |
| not reported (reported Oct 7, 2026, 5:22 AM EDT) | Oct 6, 2026, 5:22 PM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflow | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14013, reported Oct 7, 2026, 5:22 AM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Oct 7, 2026, 5:22 AM EDT) · Map |
| not reported (reported Oct 3, 2026, 11:38 PM EDT) | Oct 3, 2026, 11:38 AM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflow | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14011, reported Oct 3, 2026, 11:38 PM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Oct 3, 2026, 11:38 PM EDT) · Map |
| not reported (reported Oct 3, 2026, 11:39 AM EDT) | Oct 3, 2026, 11 AM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflowrevised | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14010, reported Oct 3, 2026, 11:39 AM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Oct 3, 2026, 11:39 AM EDT) · Map |
| not reported (reported Sep 29, 2026, 11:39 AM EDT) | Sep 28, 2026, 11:39 PM EDT | City of Manchester DPW Environmental Protection Division | not stated | Combined sewer overflow | not reported | City of Manchester EPD (CSO Discharge Notification page) via nh-permittees, record manchester:Item14000, reported Sep 29, 2026, 11:39 AM EDT, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Manchester DPW Environmental Protection Division, not reported (reported Sep 29, 2026, 11:39 AM EDT) · Map |
| Aug 3, 2026 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 208,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-08-03:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, Aug 3, 2026 · Map |
| Aug 3, 2026 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 1.04 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-08-03:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, Aug 3, 2026 · Map |
| Aug 3, 2026 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 1.89 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-08-03:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, Aug 3, 2026 · Map |
| Aug 3, 2026 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 10.3 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-08-03:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, Aug 3, 2026 · Map |
| Jul 30, 2026 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 13,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-07-30:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, Jul 30, 2026 · Map |
| Jul 28, 2026 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 117,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-07-28:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, Jul 28, 2026 · Map |
| Jul 28, 2026 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-07-28:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, Jul 28, 2026 · Map |
| Jul 22, 2026 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 2,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-07-22:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, Jul 22, 2026 · Map |
| Oct 20, 2025 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-10-20:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 20, 2025 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 31,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-10-20:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 20, 2025 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 221,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-10-20:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 13, 2025 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 59,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-08-13:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 13, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 608,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-08-13:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 13, 2025 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 1.37 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-08-13:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 13, 2025 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 7.39 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-08-13:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 20, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 139,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-07-20:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 20, 2025 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 38,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-07-20:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 20, 2025 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 396,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-07-20:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jun 6, 2025 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 4,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-06-06:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| May 4, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 1.43 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-04:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| May 4, 2025 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 165,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-04:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| May 4, 2025 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 8.08 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-04:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| May 3, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 395,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-03:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| May 3, 2025 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 81,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-03:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| May 3, 2025 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 1.17 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-03:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Mar 17, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 1.03 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-17:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Mar 17, 2025 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 58,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-17:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Mar 17, 2025 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 2.53 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-17:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Mar 6, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 324,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-06:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Mar 6, 2025 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 305,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-06:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Mar 5, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 4,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-05:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Feb 5, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 203,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-02-05:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Feb 4, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 89,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-02-04:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jan 1, 2025 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 2.4 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-01-01:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jan 1, 2025 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 1.07 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-01-01:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 30, 2024 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 3.71 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-12-30:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 30, 2024 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 1.65 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-12-30:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 15, 2024 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 18,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-08-15:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 15, 2024 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 74,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-08-15:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 15, 2024 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 385,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-08-15:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 15, 2024 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 1.96 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-08-15:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 4, 2024 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 233,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-08-04:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 16, 2024 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 135,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-16:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 16, 2024 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 404,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-16:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 3, 2024 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 163,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-03:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Mar 7, 2024 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 493,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-03-07:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 18, 2023, 10:00 AM EST | Dec 18, 2023, 5:00 PM EST | HOOKSETT SANITARY SEWER SYSTEM | not stated | Sanitary sewer overflow | 3,000 gal | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset (eRule Phase 2, current versions), record NH0100129:3:1, reported Dec 19, 2023, 7:00 PM EST, retrieved 2026-11-02 11:54 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 18, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 50,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-12-18:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 18, 2023 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 90,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-12-18:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 18, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 340,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-12-18:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 18, 2023 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 4.69 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-12-18:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 21, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 52,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-10-21:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Oct 21, 2023 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 276,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-10-21:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 11, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 775,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-09-11:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 11, 2023 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 747,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-09-11:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 11, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 3.09 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-09-11:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 11, 2023 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 11.01 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-09-11:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Sep 10, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 15,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-09-10:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 30, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-08-30:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 8, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 4,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-08-08:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Aug 8, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 76,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-08-08:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 29, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 62,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-29:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 29, 2023 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 3,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-29:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 29, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 185,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-29:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 29, 2023 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 1.49 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-29:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 24, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 16,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-24:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 24, 2023 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 527,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-24:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 21, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 71,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-21:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 21, 2023 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 249,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-21:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 21, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 747,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-21:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 21, 2023 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 3.66 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-21:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 18, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 87,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-18:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 18, 2023 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 1.14 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-18:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 16, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 48,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-16:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 16, 2023 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 428,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-16:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 16, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 714,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-16:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 16, 2023 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 5.78 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-16:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 15, 2023 | Jul 15, 2023 | City of Manchester DPW Environmental Protection Division (Manchester WWTF, 300 Winston St, and 15 CSOs) | not stated | Sanitary sewer overflow | not reported | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset (eRule Phase 2, current versions), record NH0100447:26:1, reported Jul 25, 2023, 8:00 PM EDT, retrieved 2026-11-02 11:54 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 15, 2023 | Jul 15, 2023 | not stated | not stated | Sanitary sewer overflow | not reported | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset (eRule Phase 2, current versions), record NH0100129:2:1, reported Jul 16, 2023, 8:00 PM EDT, retrieved 2026-11-02 11:54 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 14, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 13,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-14:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 14, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 48,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-14:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 3, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-03:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jul 2, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 2,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-07-02:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jun 26, 2023 | ended, time not reported | City of Nashua Wastewater Department | 003 Farmington Rd. | Combined sewer overflow | 93,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-06-26:003, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jun 26, 2023 | ended, time not reported | City of Nashua Wastewater Department | 004 Burke St. | Combined sewer overflow | 167,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-06-26:004, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jun 26, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 379,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-06-26:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jun 26, 2023 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 2.55 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-06-26:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Jun 2, 2023 | ended, time not reported | City of Nashua Wastewater Department | 005 East Hollis St. | Combined sewer overflow | 10,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2023-06-02:005, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Feb 8, 2023, 11:00 AM EST | Feb 15, 2023, 7:15 AM EST | City of Manchester DPW Environmental Protection Division (Manchester WWTF, 300 Winston St, and 15 CSOs) | 044 Cemetery Brook | Combined sewer overflow | 16.43 million gal | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset (eRule Phase 2, current versions), record NH0100447:19:1, reported Mar 5, 2023, 7:00 PM EST, retrieved 2026-11-02 11:54 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
| Dec 23, 2022 | ended, time not reported | City of Nashua Wastewater Department | 014 Bridge St. | Combined sewer overflow | 53,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2022-12-23:014, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | record below · Map |
Full record (older than 180 days, so no page of its own) | |||||||
Showing the newest 100 events of 399 events. See them all with filters.
Outfalls on this water
No outfall in the registry is matched to this water.
Dischargers: City of Manchester DPW Environmental Protection Division (Manchester WWTF, 300 Winston St, and 15 CSOs), City of Nashua Division of Public Works, Wastewater Department (Nashua WWTF, Sawmill Rd, and 9 CSOs), NH Medium WWTF General Permit facilities (21 POTWs) - SSO/unauthorized discharge web notices.
Launches
- Amoskeag Canoe Launch
- Arms Park
- Bedford Scenic Easement
- Boscawen Town Park
- Depot St Reeds Ferry Boat Ramp
- Exchange Street Site
- Ferry Street Boat Ramp
- Greeley Boat Ramp
- Institute Drive Boat Ramp
- Intervale Road Canoe Access
- Kiwanis River Front Park
- Lambert Park
- Merrimack County Boat Launching Facility
- Merrimack River East Concord
- Merrimack River Boat Access Facility Sewalls 1
- Psnh Boat Launch
- Riverside Park Hooksett
- Sewalls Falls Multi Use Recreation Area 2
- Stark Landing
- Thorntons Ferry Boat Launch
Source: OpenBoatLaunch launch records (public agency data and OpenStreetMap, ODbL). · Merrimack 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
- nh-permittees · updating · last answered Nov 2, 2026, 6:55 AM EST
399 events placed on this water in this build.