New Hampshire / Reports /
New Hampshire sewage discharges in 2023
119 records of sewage discharges and water advisories in New Hampshire dated in 2023, newest first, 1 earlier version or duplicate included and marked. Each record keeps the source's own times and wording; a record from the last six months, or one still in effect, also has a page of its own.
By type: Combined sewer overflow (CSO)108 · Sanitary sewer overflow (SSO)6 · Treatment plant bypass4 · Treatment bypass1
By source: City of Nashua Wastewater Department (History of CSO Occurrences PDF)90 · City of Portsmouth DPW (CSO page, monthly summary table)15 · EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators)8 · Town of Exeter DPW (Combined Sewer & Sanitary Sewer Overflows page)6
2023 in other states: Connecticut, Maine, Massachusetts, New York, Pennsylvania, Rhode Island, Vermont.
Source: the agencies, sewer operators and EPA records named on each row and on the Sources page. Updated 2026-11-02 21:26 UTC.
| Start | Type | Water | Sewer operator | Outlet | Volume | Status and end | Source and record |
|---|---|---|---|---|---|---|---|
| Sanitary sewer overflow (SSO) | Merrimack River | HOOKSETT SANITARY SEWER SYSTEM | not provided | 3,000 gallons | Ended (as reported); Dec 18, 2023, 5:00 PM EST | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset, record NH0100129:3:1, reported Dec 20, 2023, 12:00 AM EST, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 50,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-12-18:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 004 Burke St. | 90,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-12-18:004, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 340,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-12-18:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 1.34 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-12-18:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 130,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-12-18:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 014 Bridge St. | 4.69 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-12-18:014, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 10,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-12-17:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO)Duplicate | Squamscott River | Town of Exeter DPW (Exeter WWTP, 13 Newfields Rd, and CSO 003) | 003 Tidal Gate of Clemson Pond | 14 gallons | Ended (as reported); Dec 12, 2023, 11:05 PM EST | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset, record NH0100871:2:1, reported Dec 14, 2023, 12:00 AM EST, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Squamscott River | Town of Exeter DPW | 003 Clemson Pond tide gate (CSO structures: Spring St, Water St) | 14,072 gallons | Ended (as reported); Dec 12, 2023, 11:05 PM EST | Town of Exeter DPW (Combined Sewer & Sanitary Sewer Overflows page) via History of CSO Occurrences PDF, record exeter:cso:2023-12-12:1, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Treatment plant bypass | Squamscott River | Town of Exeter WWTP | 001 WWTP outfall 001 | 9,646 gallons | Ended (as reported); end time not reported | Town of Exeter DPW (Combined Sewer & Sanitary Sewer Overflows page) via History of CSO Occurrences PDF, record exeter:bypass:2023-12-12:1, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 20,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-12-11:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 70,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-12-10:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 40,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-11-22:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 52,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-10-21:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 16,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-10-21:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 43,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-10-21:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 014 Bridge St. | 276,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-10-21:014, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 34,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-18:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 4,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-12:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 775,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-11:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 004 Burke St. | 747,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-11:004, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 3.09 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-11:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 5.58 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-11:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 70,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-11:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 009 Lock St. | 4,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-11:009, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 014 Bridge St. | 11.01 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-11:014, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 15,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-10:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 3,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-10:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 11,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-09-08:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10A Parrot Avenue | 2.4 million gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-09:10A, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10B Parrot Avenue | 21,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-09:10B, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 1,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-08-30:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 6,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-08-30:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 4,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-08-10:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 4,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-08-08:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 76,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-08-08:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 9,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-08-08:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 29,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-08-08:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 009 Lock St. | 1,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-08-08:009, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10A Parrot Avenue | 2.45 million gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-08:10A, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10B Parrot Avenue | 37,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-08:10B, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Piscataqua River | City of Portsmouth DPW Wastewater Division | 013 Deer Street | 59,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-08:013, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 62,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-29:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 004 Burke St. | 3,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-29:004, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 185,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-29:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 208,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-29:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 83,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-29:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 009 Lock St. | 5,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-29:009, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 014 Bridge St. | 1.49 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-29:014, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 16,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-24:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 74,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-24:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 13,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-24:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 014 Bridge St. | 527,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-24:014, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 71,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-21:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 004 Burke St. | 249,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-21:004, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 747,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-21:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 1.6 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-21:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 190,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-21:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 014 Bridge St. | 3.66 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-21:014, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 87,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-18:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 210,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-18:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 69,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-18:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 014 Bridge St. | 1.14 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-18:014, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Sanitary sewer overflow (SSO) | Merrimack River | City of Manchester DPW Environmental Protection Division (Manchester WWTF, 300 Winston St, and 15 CSOs) | not provided | volume not reported | Ended (as reported); Jul 16, 2023 | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset, record NH0100447:26:1, reported Jul 26, 2023, 12:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Sanitary sewer overflow (SSO) | Merrimack River | not stated | not provided | volume not reported | Ended (as reported); Jul 16, 2023 | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset, record NH0100129:2:1, reported Jul 17, 2023, 12:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 48,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-16:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 004 Burke St. | 428,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-16:004, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 714,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-16:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 1.84 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-16:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 51,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-16:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 009 Lock St. | 2,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-16:009, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 014 Bridge St. | 5.78 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-16:014, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 13,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-14:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 48,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-14:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 4,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-04:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 1,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-03:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 16,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-03:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 2,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-02:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 11,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-07-02:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10A Parrot Avenue | 826,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-07:10A, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10B Parrot Avenue | 3,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-07:10B, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Piscataqua River | City of Portsmouth DPW Wastewater Division | 013 Deer Street | 24,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-07:013, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 5,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-28:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 7,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-27:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 003 Farmington Rd. | 93,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-26:003, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 004 Burke St. | 167,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-26:004, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 379,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-26:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 006 Nashua River | 356,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-26:006, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 47,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-26:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 009 Lock St. | 1,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-26:009, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 014 Bridge St. | 2.55 million gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-26:014, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 1,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-16:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 23,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-14:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Nashua Wastewater Department | 005 East Hollis St. | 10,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-02:005, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 5,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-06-02:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Sanitary sewer overflow (SSO) | Baker River | PLYMOUTH SANITARY SEWER SYSTEM | not provided | 10,000 gallons | Ended (as reported); Jun 1, 2023, 10:00 AM EDT | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset, record NHG580242:4:1, reported Jun 2, 2023, 12:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10A Parrot Avenue | 14,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-06:10A, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Treatment plant bypass | Squamscott River | Town of Exeter WWTP | 001 WWTP outfall 001 | 4,720 gallons | Ended (as reported); end time not reported | Town of Exeter DPW (Combined Sewer & Sanitary Sewer Overflows page) via History of CSO Occurrences PDF, record exeter:bypass:2023-05-30:1, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 39,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-05-20:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Sanitary sewer overflow (SSO) | Pemigewasset River | PLYMOUTH SANITARY SEWER SYSTEM | not provided | 2,100 gallons | Ended (as reported); May 17, 2023, 11:33 AM EDT | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset, record NHG580242:3:1, reported May 19, 2023, 12:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 6,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-05-01:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10A Parrot Avenue | 2.19 million gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-05:10A, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 12,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-04-30:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 27,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-04-24:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 58,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-04-23:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Sanitary sewer overflow (SSO) | not linked to a mapped water | Town of Exeter DPW | 110 Front Street - Blockage in a sewer manhole | 100 gallons | Ended (as reported); end time not reported | Town of Exeter DPW (Combined Sewer & Sanitary Sewer Overflows page) via History of CSO Occurrences PDF, record exeter:sso:2023-04-20:1, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Treatment bypass | Connecticut River | not stated | not provided | 4 gallons | Ended (as reported); Apr 27, 2023, 10:30 AM EDT | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset, record NH0100765:2:1, reported May 3, 2023, 12:00 AM EDT, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 18,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-04-01:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10A Parrot Avenue | 634,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-04:10A, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Treatment plant bypass | Squamscott River | Town of Exeter WWTP | 001 WWTP outfall 001 | 2,000 gallons | Ended (as reported); end time not reported | Town of Exeter DPW (Combined Sewer & Sanitary Sewer Overflows page) via History of CSO Occurrences PDF, record exeter:bypass:2023-03-18:1, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10A Parrot Avenue | 71,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-03:10A, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Merrimack River | City of Manchester DPW Environmental Protection Division (Manchester WWTF, 300 Winston St, and 15 CSOs) | 044 Cemetery Brook | 16.43 million gallons | Ended (as reported); Feb 15, 2023, 7:15 AM EST | EPA ECHO Sewer Overflow and Bypass Event report (reported to regulators) via ECHO NPDES Sewer Overflow and Bypass Event Dataset, record NH0100447:19:1, reported Mar 6, 2023, 12:00 AM EST, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 22,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-01-26:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Treatment plant bypass | Squamscott River | Town of Exeter WWTP | 001 WWTP outfall 001 | 2,000 gallons | Ended (as reported); end time not reported | Town of Exeter DPW (Combined Sewer & Sanitary Sewer Overflows page) via History of CSO Occurrences PDF, record exeter:bypass:2023-01-23:1, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Nashua River | City of Nashua Wastewater Department | 008 Broad St. | 3,000 gallons | Ended (as reported); end time not reported | City of Nashua Wastewater Department (History of CSO Occurrences PDF), record nashua:2023-01-13:008, the source gives no report time, retrieved 2026-11-02 15:54 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10A Parrot Avenue | 4.17 million gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-01:10A, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Portsmouth Harbor | City of Portsmouth DPW Wastewater Division | 10B Parrot Avenue | 216,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-01:10B, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record | |
| Combined sewer overflow (CSO) | Piscataqua River | City of Portsmouth DPW Wastewater Division | 013 Deer Street | 140,000 gallons | Ended (as reported); end time not reported | City of Portsmouth DPW (CSO page, monthly summary table) via History of CSO Occurrences PDF, record portsmouth:2023-01:013, the source gives no report time, retrieved 2026-11-02 21:19 UTC · Original notice · Full record |