City of Nashua Division of Public Works, Wastewater Department (Nashua WWTF, Sawmill Rd, and 9 CSOs)
CSO · New Hampshire · Nashua, Hudson
- NPDES permit
- NH0100170
- Outfalls
- 9 with coordinates in the registry
- Receiving waters
- Merrimack River; Nashua River
- Tracked waters
- Merrimack River, NH, Nashua River, NH
- Events tracked
- 731 discharges · latest Aug 3, 2026
- Volume reported
- 395,923,400 gallons across the 726 discharges that give a volume (5 without one)
Source: discharger record from the project's research and EPA ECHO (dischargers.json); counts from the 731 event records below, as of 2026-11-02 11:56 UTC.
How it tells the public
Banner on the Wastewater Department page https://www.nashuanh.gov/392/Wastewater-Department. The CSO page https://www.nashuanh.gov/842/Combined-Sewer-Overflows says: 'The City of Nashua's Wastewater web page will have a banner that will inform the public any time there is a Combined Sewer Overflow occurrence, as well as the location. This notification will stay up for 48 hours after the end of the overflow'. History PDF https://www.nashuanh.gov/DocumentCenter/View/11049 ('This data will be uploaded monthly'). CivicPlus Notify Me list 'Wastewater Department' (News Flash, https://www.nashuanh.gov/list.aspx) exists but is not CSO-specific. No CSO email or text list found.
Source: the project's research on each operator's notification channel (research/<state>/dischargers.json), checked by fetching the operator's pages.
Outfalls
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.
9 outfalls in the registry
- 002 Salmon Brook · CSO · Salmon Brook
- 003 Farmington Road · CSO · Merrimack River
- 004 Burke Street · CSO · Merrimack River
- 005 East Hollis Street · CSO · Merrimack River
- 006 Nashua River · CSO · Nashua River
- 007 Tampa Street · CSO · Nashua River
- 008 Broad Street · CSO · Nashua River
- 009 Lock Street · CSO · Nashua River
- 014 Screening Disinfection Facility · TCS · Merrimack River
Source: EPA ECHO CSO outfall inventory matched to waters (data/outfalls-ne.json).
Event history
| Start | End | Water | Outfall | Type | Volume | Source | Links |
|---|---|---|---|---|---|---|---|
| Aug 3, 2026 | ended, time not reported | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 006 Nashua River | Combined sewer overflow | 6.47 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-08-03:006, 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 | Nashua River, NH | 007 Tampa St. | Combined sewer overflow | 3.2 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-08-03:007, 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 166,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-08-03:008, 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 | Nashua River, NH | 009 Lock St. | Combined sewer overflow | 7,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-08-03:009, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 30, 2026 | ended, time not reported | Nashua River, NH | 006 Nashua River | Combined sewer overflow | 5,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-07-30:006, 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 30, 2026 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 13,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-07-30:008, 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 29, 2026 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-07-29:008, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, Jul 29, 2026 · Map |
| Jul 28, 2026 | ended, time not reported | Merrimack River, NH | 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 | Merrimack River, NH | 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 28, 2026 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 28,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-07-28:008, 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 | Merrimack River, NH | 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 |
| Jul 22, 2026 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-07-22:008, 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 |
| May 25, 2026 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 10,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-05-25:008, the source gives no report time, retrieved 2026-11-02 11:55 UTC · notice | Event: Combined sewer overflow, City of Nashua Wastewater Department, May 25, 2026 · Map |
| Apr 17, 2026 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 2,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-04-17:008, 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) | |||||||
| Apr 14, 2026 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 3,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2026-04-14:008, 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 28, 2025, 3:00 PM EST | Dec 28, 2025, 6:00 PM EST | Nashua River, NH | not stated | Sanitary sewer overflow | 22,000 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 NH0100170:7:1, reported Dec 29, 2025, 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) | |||||||
| Nov 10, 2025 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-11-10:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 47,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-10-20:008, 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 | Merrimack River, NH | 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) | |||||||
| Sep 6, 2025 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 17,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-09-06:008, 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 6, 2025 | ended, time not reported | Nashua River, NH | 009 Lock St. | Combined sewer overflow | 2,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-09-06:009, 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 19, 2025, 2:10 PM EDT | Sep 2, 2025, 10:46 PM EDT | “Cold Brook” (not placed) | not stated | Sanitary sewer overflow | 5.17 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 NH0100170:1:1, reported Sep 29, 2025, 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) | |||||||
| Aug 13, 2025 | ended, time not reported | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 006 Nashua River | Combined sewer overflow | 1.72 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-08-13:006, 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 | Nashua River, NH | 007 Tampa St. | Combined sewer overflow | 920,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-08-13:007, 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 | Nashua River, NH | 009 Lock St. | Combined sewer overflow | 10,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-08-13:009, 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 | Merrimack River, NH | 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 31, 2025 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-07-31:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 16,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-07-20:008, 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 | Nashua River, NH | 009 Lock St. | Combined sewer overflow | 5,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-07-20:009, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 10, 2025 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 19,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-10:008, 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 9, 2025 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 8,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-09:008, 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 8, 2025 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 48,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-08:008, 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 5, 2025 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 7,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-05:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 006 Nashua River | Combined sewer overflow | 323,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-04:006, 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 10,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-04:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 006 Nashua River | Combined sewer overflow | 144,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-03:006, 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 19,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-05-03:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 006 Nashua River | Combined sewer overflow | 4,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-17:006, 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 22,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-17:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 2,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-06:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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) | |||||||
| Mar 5, 2025 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 19,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-03-05:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 6,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2025-01-01:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 7,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-12-30:008, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 | Nashua River, NH | 006 Nashua River | Combined sewer overflow | 1.07 million gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-08-15:006, 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 | Nashua River, NH | 009 Lock St. | Combined sewer overflow | 13,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-08-15:009, 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 | Merrimack River, NH | 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 | Merrimack River, NH | 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 31, 2024 | ended, time not reported | Nashua River, NH | 009 Lock St. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-31:009, 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, 2024 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 4,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-29:008, 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 17, 2024 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 9,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-17:008, 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 17, 2024 | ended, time not reported | Nashua River, NH | 009 Lock St. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-17:009, 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 | Merrimack River, NH | 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 | Nashua River, NH | 006 Nashua River | Combined sewer overflow | 563,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-16:006, 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 27,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-16:008, 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 | Nashua River, NH | 009 Lock St. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-16:009, 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 | Merrimack River, NH | 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 13, 2024 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 3,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-13:008, 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 13, 2024 | ended, time not reported | Nashua River, NH | 009 Lock St. | Combined sewer overflow | 1,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-07-13:009, 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 | Merrimack River, NH | 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) | |||||||
| May 27, 2024 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 3,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-05-27:008, 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 10, 2024 | ended, time not reported | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 39,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-03-10:008, 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 | Nashua River, NH | 008 Broad St. | Combined sewer overflow | 68,000 gal | City of Nashua Wastewater Department (History of CSO Occurrences PDF) via nh-permittees, record nashua:2024-03-07:008, 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 | Merrimack River, NH | 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 | ended, time not reported | Merrimack River, NH | 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 | Merrimack River, NH | 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) | |||||||
Showing the newest 100 events of 731 events. See them all with filters.
History
- Discharge events, last 12 months21Dec 2025 to Nov 2026; partly covered or sparse source
- Days with a discharge, last 12 months9Dec 2025 to Nov 2026; partly covered or sparse source
- Hours under advisory, last 12 months75Dec 2025 to Nov 2026; on this discharger's reports; partly covered or sparse source
- 2026 season under advisory0.0%May to October, partly covered; 0 h
Discharge events per month
229 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 | 5 | 0 | 0 | 5 | Source records | |
| Feb 2022 | 6 | 0 | 0 | 6 | Source records | |
| Mar 2022 | 1 | 0 | 0 | 1 | Source records | |
| Apr 2022 | 7 | 0 | 0 | 7 | Source records | |
| May 2022 | 1 | 0 | 0 | 1 | Source records | |
| Jun 2022 | 1 | 0 | 0 | 1 | Source records | |
| Jul 2022 | 5 | 0 | 0 | 5 | Source records | |
| Aug 2022 | 4 | 0 | 0 | 4 | Source records | |
| Sep 2022 | 3 | 0 | 0 | 3 | Source records | |
| Oct 2022 | 4 | 0 | 0 | 4 | Source records | |
| Nov 2022 | 2 | 0 | 0 | 2 | Source records | |
| Dec 2022 | 2 | 0 | 0 | 2 | Source records | |
| Jan 2023 | 2 | 0 | 0 | 2 | Source records | |
| Feb 2023 | 0 | 0 | 0 | 0 | ||
| Mar 2023 | 0 | 0 | 0 | 0 | ||
| Apr 2023 | 4 | 0 | 0 | 4 | Source records | |
| May 2023 | 2 | 0 | 0 | 2 | Source records | |
| Jun 2023 | 13 | 0 | 0 | 13 | Source records | |
| Jul 2023 | 35 | 0 | 0 | 35 | Source records | |
| Aug 2023 | 8 | 0 | 0 | 8 | Source records | |
| Sep 2023 | 12 | 0 | 0 | 12 | Source records | |
| Oct 2023 | 4 | 0 | 0 | 4 | Source records | |
| Nov 2023 | 1 | 0 | 0 | 1 | Source records | |
| Dec 2023 | 9 | 0 | 0 | 9 | Source records | |
| Jan 2024 | 0 | 0 | 0 | 0 | ||
| Feb 2024 | 0 | 0 | 0 | 0 | ||
| Mar 2024 | 3 | 0 | 0 | 3 | Source records | |
| Apr 2024 | 0 | 0 | 0 | 0 | ||
| May 2024 | 1 | 0 | 0 | 1 | Source records | |
| Jun 2024 | 0 | 0 | 0 | 0 | ||
| Jul 2024 | 12 | 0 | 0 | 12 | Source records | |
| Aug 2024 | 7 | 0 | 0 | 7 | Source records | |
| Sep 2024 | 0 | 0 | 0 | 0 | ||
| Oct 2024 | 0 | 0 | 0 | 0 | ||
| Nov 2024 | 0 | 0 | 0 | 0 | ||
| Dec 2024 | 3 | 0 | 0 | 3 | Source records | |
| Jan 2025 | 3 | 0 | 0 | 3 | Source records | |
| Feb 2025 | 2 | 0 | 0 | 2 | Source records | |
| Mar 2025 | 10 | 0 | 0 | 10 | Source records | |
| Apr 2025 | 0 | 0 | 0 | 0 | ||
| May 2025 | 14 | 0 | 0 | 14 | Source records | |
| Jun 2025 | 1 | 0 | 0 | 1 | Source records | |
| Jul 2025 | 6 | 0 | 0 | 6 | Source records | |
| Aug 2025 | 7 | 1 | 0 | 8 | Source records | |
| Sep 2025 | 2 | 0 | 0 | 2 | Source records | |
| Oct 2025 | 4 | 0 | 0 | 4 | Source records | |
| Nov 2025 | 1 | 0 | 0 | 1 | Source records | |
| Dec 2025 | 0 | 1 | 0 | 1 | Source records | |
| Jan 2026 | 0 | 0 | 0 | 0 | ||
| Feb 2026 | 0 | 0 | 0 | 0 | ||
| Mar 2026 | 0 | 0 | 0 | 0 | ||
| Apr 2026 | 2 | 0 | 0 | 2 | Source records | |
| May 2026 | 1 | 0 | 0 | 1 | Source records | |
| Jun 2026 | 0 | 0 | 0 | 0 | ||
| Jul 2026 | 9 | 0 | 0 | 9 | Source records | |
| Aug 2026 | 8 | 0 | 0 | 8 | Source records | Partly covered or sparse source |
| Sep 2026 | 0 | 0 | 0 | 0 | Partly covered or sparse source | |
| Oct 2026 | 0 | 0 | 0 | 0 | Partly covered or sparse source | |
| Nov 2026 | 0 | 0 | 0 | 0 | Partly covered or sparse source |
Hours under advisory per month
Hours this discharger's reports put a water under an advisory, by the map's red rules.
- Advisory in effect
- Partly covered or sparse source
729 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. Official beach and cyanobacteria advisories are counted on water pages only. 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 | 0 | 0 | 672 | |
| Mar 2023 | 0 | 0 | 744 | |
| Apr 2023 | 0 | 0 | 720 | |
| May 2023 | 0 | 0 | 744 | |
| Jun 2023 | 0 | 0 | 720 | |
| Jul 2023 | 0 | 0 | 744 | |
| Aug 2023 | 0 | 0 | 744 | |
| Sep 2023 | 0 | 0 | 720 | |
| Oct 2023 | 0 | 0 | 744 | |
| Nov 2023 | 0 | 0 | 720 | |
| Dec 2023 | 0 | 0 | 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 | 298 | 298 | 744 | |
| Sep 2025 | 119 | 119 | 720 | |
| Oct 2025 | 0 | 0 | 744 | |
| Nov 2025 | 0 | 0 | 720 | |
| Dec 2025 | 75 | 75 | 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 | 0 | 0 | 744 | Partly covered or sparse source |
| Nov 2026 | 0 | 0 | 32 | Partly covered or sparse source |
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 | 4 | |
| Mar 2022 | 1 | |
| Apr 2022 | 5 | |
| May 2022 | 1 | |
| Jun 2022 | 1 | |
| Jul 2022 | 2 | |
| Aug 2022 | 4 | |
| Sep 2022 | 3 | |
| Oct 2022 | 4 | |
| Nov 2022 | 2 | |
| Dec 2022 | 1 | |
| Jan 2023 | 2 | |
| Feb 2023 | 0 | |
| Mar 2023 | 0 | |
| Apr 2023 | 4 | |
| May 2023 | 2 | |
| Jun 2023 | 6 | |
| Jul 2023 | 9 | |
| Aug 2023 | 3 | |
| Sep 2023 | 5 | |
| Oct 2023 | 1 | |
| Nov 2023 | 1 | |
| Dec 2023 | 4 | |
| Jan 2024 | 0 | |
| Feb 2024 | 0 | |
| Mar 2024 | 2 | |
| Apr 2024 | 0 | |
| May 2024 | 1 | |
| Jun 2024 | 0 | |
| Jul 2024 | 6 | |
| 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 | 6 | |
| Jun 2025 | 1 | |
| Jul 2025 | 2 | |
| Aug 2025 | 14 | |
| Sep 2025 | 3 | |
| Oct 2025 | 1 | |
| Nov 2025 | 1 | |
| Dec 2025 | 1 | |
| Jan 2026 | 0 | |
| Feb 2026 | 0 | |
| Mar 2026 | 0 | |
| Apr 2026 | 2 | |
| May 2026 | 1 | |
| Jun 2026 | 0 | |
| Jul 2026 | 4 | |
| Aug 2026 | 1 | Partly covered or sparse source |
| Sep 2026 | 0 | Partly covered or sparse source |
| Oct 2026 | 0 | Partly covered or sparse source |
| Nov 2026 | 0 | Partly covered or sparse source |
Discharge events per year, 2013 to 2026
731 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 | 116 | 0 | 0 | 116 | Partly covered or sparse source |
| 2014 | 52 | 0 | 0 | 52 | |
| 2015 | 31 | 0 | 0 | 31 | |
| 2016 | 27 | 0 | 0 | 27 | |
| 2017 | 23 | 0 | 0 | 23 | |
| 2018 | 68 | 0 | 0 | 68 | |
| 2019 | 75 | 0 | 0 | 75 | |
| 2020 | 36 | 0 | 0 | 36 | |
| 2021 | 74 | 0 | 0 | 74 | |
| 2022 | 41 | 0 | 0 | 41 | |
| 2023 | 90 | 0 | 0 | 90 | |
| 2024 | 26 | 0 | 0 | 26 | |
| 2025 | 50 | 2 | 0 | 52 | |
| 2026 | 20 | 0 | 0 | 20 | Partly covered or sparse source |
Reported volume per year
Gallons, summed from the 726 events that gave a number (5 did not).
- Partly covered or sparse source
5 of 731 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 | 41,568,000 | 112 | 4 | Partly covered or sparse source |
| 2014 | 50,834,000 | 52 | 0 | |
| 2015 | 4,612,000 | 31 | 0 | |
| 2016 | 10,692,000 | 26 | 1 | |
| 2017 | 9,614,000 | 23 | 0 | |
| 2018 | 42,508,000 | 68 | 0 | |
| 2019 | 45,666,000 | 75 | 0 | |
| 2020 | 11,360,300 | 36 | 0 | |
| 2021 | 49,812,000 | 74 | 0 | |
| 2022 | 4,495,100 | 41 | 0 | |
| 2023 | 52,101,000 | 90 | 0 | |
| 2024 | 11,024,000 | 26 | 0 | |
| 2025 | 38,169,000 | 52 | 0 | |
| 2026 | 23,468,000 | 20 | 0 | 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
729 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. Official beach and cyanobacteria advisories are counted on water pages only.
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 | 0 | 0.0% | |
| 2024 | 0 | 0.0% | |
| 2025 | 492 | 5.6% | |
| 2026 | 0 | 0.0% | 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 | 52 | 14 |
| Feb | 19 | 14 |
| Mar | 28 | 14 |
| Apr | 37 | 14 |
| May | 37 | 14 |
| Jun | 87 | 14 |
| Jul | 155 | 14 |
| Aug | 93 | 14 |
| Sep | 89 | 13 |
| Oct | 58 | 13 |
| Nov | 31 | 13 |
| Dec | 45 | 13 |
Discharge events by outfall
The 8 outfalls with the most events of 8, 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 | Events |
|---|---|
| 008 Broad St. | 184 |
| 005 East Hollis St. | 179 |
| 006 Nashua River | 91 |
| 004 Burke St. | 90 |
| 014 Bridge St. | 70 |
| 009 Lock St. | 61 |
| 003 Farmington Rd. | 46 |
| 007 Tampa St. | 8 |
| Outfall not stated | 2 |
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