All rankings
Maryland · Maryland (MDE)
Patapsco WWTP
Permit N/A
—
No waterway impact reported
Reported events
1,608
Total volume
641.2M gal
Reached waterways
0 (0%)
Reporting since
2005
What caused the overflows
Grease / FOG
282
Other / Unknown
269
Root Intrusion
180
Rainfall / Flooding
163
Equipment Failure
106
Reported overflow events (showing 200 of 1,608)
| Date | Volume | Cause | Reached water | Receiving water |
|---|---|---|---|---|
| May 24, 2026 | — | Other / Unknown | — | Not going into receiving waters. |
| May 6, 2026 | 10K gal | Other / Unknown | — | none |
| May 5, 2026 | 210K gal | Other / Unknown | — | no |
| Apr 29, 2026 | 6.7M gal | Other / Unknown | — | none |
| Apr 9, 2026 | 6.8M gal | Other / Unknown | — | none |
| Apr 7, 2026 | 10K gal | Other / Unknown | — | none |
| Apr 5, 2026 | 6.8M gal | Other / Unknown | — | Patapsco River, but all flow has been disinfected |
| Mar 23, 2026 | 8.4M gal | Other / Unknown | — | — |
| Mar 20, 2026 | 150K gal | Other / Unknown | — | none |
| Mar 15, 2026 | — | Other / Unknown | — | none |
| Mar 12, 2026 | 10.7M gal | Other / Unknown | — | none |
| Mar 10, 2026 | 4.7M gal | Other / Unknown | — | none |
| Mar 3, 2026 | 19.6M gal | Other / Unknown | — | none |
| Feb 20, 2026 | 40K gal | Other / Unknown | — | none |
| Feb 15, 2026 | 4.4M gal | Other / Unknown | — | Storm drain on a private road within the facility, ultimately draining to Patapsco River. |
| Jan 12, 2026 | 4K gal | Other / Unknown | — | In the plant overflowed out of the pump station into the main hole and storm drain |
| Dec 15, 2025 | — | Other / Unknown | — | none |
| Oct 30, 2025 | 200K gal | Other / Unknown | — | Patapsco River |
| Oct 4, 2025 | 6K gal | Other / Unknown | — | Patapsco River |
| Aug 20, 2025 | 1.7M gal | Other / Unknown | — | none |
| Jul 14, 2025 | 1.6M gal | Other / Unknown | — | Patapsco River/Baltimore Harbor |
| Jul 8, 2025 | 200 gal | Other / Unknown | — | Entered storm drain. |
| Jul 1, 2025 | 26.0M gal | Other / Unknown | — | Patapsco River |
| Jun 11, 2025 | 4.0M gal | Other / Unknown | — | Patapsco River |
| May 30, 2025 | 42.0M gal | Other / Unknown | — | N/A |
| May 29, 2025 | 200 gal | Other / Unknown | — | None. |
| May 28, 2025 | 800 gal | Other / Unknown | — | Spilled onto the grass next to the structure. |
| May 24, 2025 | 40.0M gal | Other / Unknown | — | None. |
| May 21, 2025 | 19.6M gal | Other / Unknown | — | Patapsco River |
| May 21, 2025 | — | Other / Unknown | — | Patapsco River |
| May 14, 2025 | 24.0M gal | Other / Unknown | — | Patapsco River |
| May 9, 2025 | 509 gal | Other / Unknown | — | none |
| Apr 13, 2025 | 525 gal | Other / Unknown | — | N/A |
| Mar 5, 2025 | 25.8M gal | Other / Unknown | — | unknown (under investigation) |
| May 23, 2024 | 0 gal | Other / Unknown | — | Storm drain |
| Apr 22, 2024 | 24.1M gal | Other / Unknown | — | none |
| Mar 23, 2024 | 76.2M gal | Other / Unknown | — | Patapsco River |
| Mar 21, 2024 | 0 gal | Other / Unknown | — | Multiple receiving waters according to the permit. |
| Mar 8, 2024 | 30.0M gal | Other / Unknown | — | Patapsco River |
| Mar 2, 2024 | 257.5M gal | Other / Unknown | — | Patapsco River |
| Dec 1, 2020 | — | Rainfall / Flooding | — | — |
| Nov 30, 2020 | — | Rainfall / Flooding | — | — |
| Jun 8, 2020 | — | Other / Unknown | — | — |
| Jul 24, 2018 | — | Rainfall / Flooding | — | — |
| Oct 31, 2013 | — | Grease / FOG | — | — |
| Oct 30, 2013 | — | Equipment Failure | — | — |
| Oct 24, 2013 | — | Equipment Failure | — | — |
| Oct 24, 2013 | — | Other / Unknown | — | — |
| Oct 14, 2013 | — | Grease / FOG | — | — |
| Oct 14, 2013 | — | Grease / FOG | — | — |
| Oct 11, 2013 | — | Rainfall / Flooding | — | — |
| Oct 11, 2013 | — | Rainfall / Flooding | — | — |
| Oct 11, 2013 | — | Rainfall / Flooding | — | — |
| Oct 11, 2013 | — | Rainfall / Flooding | — | — |
| Oct 10, 2013 | — | Rainfall / Flooding | — | — |
| Oct 6, 2013 | — | Equipment Failure | — | — |
| Sep 30, 2013 | — | Grease / FOG | — | — |
| Sep 19, 2013 | — | Other / Unknown | — | — |
| Sep 16, 2013 | — | Root Intrusion | — | — |
| Aug 30, 2013 | — | Other / Unknown | — | — |
| Aug 23, 2013 | — | Grease / FOG | — | — |
| Aug 22, 2013 | — | Other / Unknown | — | — |
| Aug 20, 2013 | — | Other / Unknown | — | — |
| Aug 19, 2013 | — | Root Intrusion | — | — |
| Aug 15, 2013 | — | Other / Unknown | — | — |
| Aug 9, 2013 | — | Grease / FOG | — | — |
| Aug 2, 2013 | — | Other / Unknown | — | — |
| Jul 29, 2013 | — | Root Intrusion | — | — |
| Jul 27, 2013 | — | Equipment Failure | — | — |
| Jul 22, 2013 | — | Grease / FOG | — | — |
| Jul 19, 2013 | — | Equipment Failure | — | — |
| Jul 18, 2013 | — | Grease / FOG | — | — |
| Jul 17, 2013 | — | Equipment Failure | — | — |
| Jun 30, 2013 | — | Other / Unknown | — | — |
| Jun 20, 2013 | — | Root Intrusion | — | — |
| Jun 16, 2013 | — | Equipment Failure | — | — |
| Jun 16, 2013 | — | Root Intrusion | — | — |
| Jun 14, 2013 | — | Other / Unknown | — | — |
| Jun 14, 2013 | — | Grease / FOG | — | — |
| Jun 13, 2013 | — | Rainfall / Flooding | — | — |
| Jun 13, 2013 | — | Other / Unknown | — | — |
| Jun 13, 2013 | — | Rainfall / Flooding | — | — |
| Jun 11, 2013 | — | Root Intrusion | — | — |
| Jun 10, 2013 | — | Rainfall / Flooding | — | — |
| Jun 10, 2013 | — | Rainfall / Flooding | — | — |
| Jun 10, 2013 | — | Rainfall / Flooding | — | — |
| Jun 10, 2013 | — | Rainfall / Flooding | — | — |
| Jun 10, 2013 | — | Rainfall / Flooding | — | — |
| Jun 10, 2013 | — | Rainfall / Flooding | — | — |
| Jun 10, 2013 | — | Rainfall / Flooding | — | — |
| Jun 5, 2013 | — | Equipment Failure | — | — |
| May 25, 2013 | — | Grease / FOG | — | — |
| May 23, 2013 | — | Rainfall / Flooding | — | — |
| May 21, 2013 | — | Root Intrusion | — | — |
| May 20, 2013 | — | Other / Unknown | — | — |
| May 12, 2013 | — | Root Intrusion | — | — |
| May 12, 2013 | — | Grease / FOG | — | — |
| May 11, 2013 | — | Grease / FOG | — | — |
| May 9, 2013 | — | Root Intrusion | — | — |
| May 7, 2013 | — | Grease / FOG | — | — |
| May 6, 2013 | — | Root Intrusion | — | — |
| May 5, 2013 | — | Equipment Failure | — | — |
| May 3, 2013 | — | Grease / FOG | — | — |
| May 1, 2013 | — | Other / Unknown | — | — |
| May 1, 2013 | — | Other / Unknown | — | — |
| May 1, 2013 | — | Root Intrusion | — | — |
| Apr 30, 2013 | — | Other / Unknown | — | — |
| Apr 29, 2013 | — | Root Intrusion | — | — |
| Apr 27, 2013 | — | Equipment Failure | — | — |
| Apr 27, 2013 | — | Other / Unknown | — | — |
| Apr 24, 2013 | — | Other / Unknown | — | — |
| Apr 24, 2013 | — | Root Intrusion | — | — |
| Apr 23, 2013 | — | Other / Unknown | — | — |
| Apr 21, 2013 | — | Grease / FOG | — | — |
| Apr 19, 2013 | — | Rainfall / Flooding | — | — |
| Apr 17, 2013 | — | Other / Unknown | — | — |
| Apr 16, 2013 | — | Other / Unknown | — | — |
| Apr 15, 2013 | — | Grease / FOG | — | — |
| Apr 15, 2013 | — | Grease / FOG | — | — |
| Apr 14, 2013 | — | Grease / FOG | — | — |
| Apr 11, 2013 | — | Other / Unknown | — | — |
| Apr 9, 2013 | — | Root Intrusion | — | — |
| Apr 8, 2013 | — | Equipment Failure | — | — |
| Apr 5, 2013 | — | Other / Unknown | — | — |
| Apr 5, 2013 | — | Grease / FOG | — | — |
| Apr 4, 2013 | — | Root Intrusion | — | — |
| Apr 4, 2013 | — | Equipment Failure | — | — |
| Apr 4, 2013 | — | Other / Unknown | — | — |
| Apr 4, 2013 | — | Root Intrusion | — | — |
| Apr 4, 2013 | — | Root Intrusion | — | — |
| Mar 31, 2013 | — | Grease / FOG | — | — |
| Mar 29, 2013 | — | Grease / FOG | — | — |
| Mar 27, 2013 | — | Equipment Failure | — | — |
| Mar 24, 2013 | — | Root Intrusion | — | — |
| Mar 23, 2013 | — | Root Intrusion | — | — |
| Mar 22, 2013 | — | Other / Unknown | — | — |
| Mar 16, 2013 | — | Root Intrusion | — | — |
| Mar 15, 2013 | — | Root Intrusion | — | — |
| Mar 14, 2013 | — | Other / Unknown | — | — |
| Mar 13, 2013 | — | Other / Unknown | — | — |
| Mar 12, 2013 | — | Rainfall / Flooding | — | — |
| Mar 12, 2013 | — | Rainfall / Flooding | — | — |
| Mar 10, 2013 | — | Grease / FOG | — | — |
| Mar 10, 2013 | — | Grease / FOG | — | — |
| Mar 9, 2013 | — | Grease / FOG | — | — |
| Mar 9, 2013 | — | Grease / FOG | — | — |
| Mar 7, 2013 | — | Grease / FOG | — | — |
| Mar 7, 2013 | — | Root Intrusion | — | — |
| Mar 7, 2013 | — | Other / Unknown | — | — |
| Mar 7, 2013 | — | Root Intrusion | — | — |
| Mar 6, 2013 | — | Other / Unknown | — | — |
| Mar 5, 2013 | — | Other / Unknown | — | — |
| Mar 5, 2013 | — | Other / Unknown | — | — |
| Mar 5, 2013 | — | Other / Unknown | — | — |
| Mar 4, 2013 | — | Grease / FOG | — | — |
| Mar 2, 2013 | — | Other / Unknown | — | — |
| Mar 2, 2013 | — | Other / Unknown | — | — |
| Mar 2, 2013 | — | Root Intrusion | — | — |
| Feb 28, 2013 | — | Other / Unknown | — | — |
| Feb 28, 2013 | — | Grease / FOG | — | — |
| Feb 27, 2013 | — | Other / Unknown | — | — |
| Feb 27, 2013 | — | Root Intrusion | — | — |
| Feb 26, 2013 | — | Rainfall / Flooding | — | — |
| Feb 26, 2013 | — | Grease / FOG | — | — |
| Feb 26, 2013 | — | Rainfall / Flooding | — | — |
| Feb 26, 2013 | — | Other / Unknown | — | — |
| Feb 25, 2013 | — | Grease / FOG | — | — |
| Feb 22, 2013 | — | Other / Unknown | — | — |
| Feb 22, 2013 | — | Other / Unknown | — | — |
| Feb 21, 2013 | — | Other / Unknown | — | — |
| Feb 11, 2013 | — | Equipment Failure | — | — |
| Feb 10, 2013 | — | Grease / FOG | — | — |
| Feb 5, 2013 | — | Grease / FOG | — | — |
| Feb 1, 2013 | — | Root Intrusion | — | — |
| Jan 31, 2013 | — | Rainfall / Flooding | — | — |
| Jan 31, 2013 | — | Grease / FOG | — | — |
| Jan 31, 2013 | — | Rainfall / Flooding | — | — |
| Jan 31, 2013 | — | Rainfall / Flooding | — | — |
| Jan 30, 2013 | — | Rainfall / Flooding | — | — |
| Jan 30, 2013 | — | Rainfall / Flooding | — | — |
| Jan 30, 2013 | — | Rainfall / Flooding | — | — |
| Jan 30, 2013 | — | Rainfall / Flooding | — | — |
| Jan 30, 2013 | — | Rainfall / Flooding | — | — |
| Jan 30, 2013 | — | Rainfall / Flooding | — | — |
| Jan 28, 2013 | — | Grease / FOG | — | — |
| Jan 27, 2013 | — | Grease / FOG | — | — |
| Jan 24, 2013 | — | Root Intrusion | — | — |
| Jan 23, 2013 | — | Equipment Failure | — | — |
| Jan 23, 2013 | — | Grease / FOG | — | — |
| Jan 23, 2013 | — | Root Intrusion | — | — |
| Jan 22, 2013 | — | Other / Unknown | — | — |
| Jan 20, 2013 | — | Other / Unknown | — | — |
| Jan 20, 2013 | — | Other / Unknown | — | — |
| Jan 19, 2013 | — | Other / Unknown | — | — |
| Jan 16, 2013 | — | Other / Unknown | — | — |
| Jan 15, 2013 | — | Rainfall / Flooding | — | — |
| Jan 14, 2013 | — | Other / Unknown | — | — |
| Jan 13, 2013 | — | Other / Unknown | — | — |
| Jan 11, 2013 | — | Equipment Failure | — | — |
| Jan 8, 2013 | — | Grease / FOG | — | — |
Source: Maryland (MDE). Volumes are utility-reported estimates. Some events lack precise coordinates or volumes.