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Maryland / Sewer operators /

Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs)

Sewer utility · Maryland · Baltimore

Map sources: water outlines and launches from OpenBoatLaunch and OpenStreetMap contributors (Open Database License); wastewater outlets from EPA and state records; downstream estimates by DirtyWaterWatch using U.S. Geological Survey maps and flow data. Base map: OpenFreeMap and OpenMapTiles.

No outlet locations are in our records for this operator. Dashed river stretches are estimates of where a discharge travels. Square boat markers mark boat launches listed by OpenBoatLaunch.

Federal wastewater discharge permit (NPDES)
MD0021555, MD0021601
Wastewater outlets
None with locations in our records (the state's records list 4)
Waters listed as receiving wastewater
Jones Falls; Gwynns Falls; Herring Run; Back River; Bear Creek; Patapsco River; Stony Run; Western Run; Middle Branch; Northwest Harbor; Colgate Creek
Tracked waters
Northwest Harbor, MD, middle-branch-patapsco-river-md, Patapsco River, MD, Back River, MD, Bear Creek, MD, lake-roland-md, Dead Run, MD, Stony Run, MD, Gwynns Falls, MD, Herring Run, MD, Jones Falls, MD, Chinquapin Run, MD, Moores Run, MD, Western Run, MD, Maidens Choice Run, MD, Tiffany Run, MD, Biddison Run, MD, Whitemarsh Run, MD, Gwynns Run, MD, Colgate Creek, MD, Curtis Creek, MD
Discharge records counted
1,087 records · latest
Total reported volume in these records
1,295,546,752 gallons across the 1,075 records that give a volume (12 without one)

These totals reflect the records we track. Missing volumes and gaps in reporting limit comparisons between operators.

Sources: EPA ECHO and the operator and state sources linked below. Counts use the discharge records on this page. Updated 2026-11-03 08:50 UTC.

Public notices and alerts

Pages where Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs) or the state publishes its notices (check them for an alert sign-up):

Source: Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs)'s public notice and alert pages and the state's notification records.

Report a missing notice or error

Wastewater outlets

Outfall: a pipe or outlet where wastewater enters a water body.

Reports and advisories

Sanitary sewer overflow (SSO): sewage spills from a sewer meant to carry sewage separately from rainwater.

Reports linked to Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs), newest first
WhenReportStatus
Water not mapped · 920 braddish ave · SSO · volume not reported report · notice · mapreported
to 7:00 PMWater not mapped · 2 N Wheeler Ave · SSO · 180 gallons report · notice · mapended
Dead Run · 619 Nottingham Rd · SSO · 5 gallons report · notice · mapto Nov 15, 3:50 PM
to 11:00 PMWater not mapped · SSO · 2 gallons report · noticeended
to 9:00 PM“None” · 3915 Stokes Drive · SSO (earlier version) · 2 gallons report · noticeended
to 10:36 PMWater not mapped · 3915 Stokes Dr · SSO · 448 gallons report · notice · mapended
Water not mapped · 2025 N Bentalou St · SSO · 2 gallons report · notice · mapreported
to Oct 28, 7:26 PMStony Run · 500 W University Pkwy · SSO · 28,520 gallons in all mapended
Water not mapped · 1205 Ashland Ave · SSO · 1 gallons report · notice · mapreported
to 1:30 PMGwynns Falls · 2801 Frederick Ave · SSO · 6,000 gallons in all mapended
to Oct 23, 10:30 AM“Maidens Choice Creek” · 1104 Joh Ave · SSO · 4,110 gallons in all mapended
to 11:06 PMGwynns Falls · 1510 Mosher St · SSO · 401 gallons report · notice · mapended
to Oct 22, 12:03 AMPatapsco River · 1510 Mosher Street · SSO (earlier version) · 125 gallons report · notice · mapended
to 6:00 PMWater not mapped · 6205 Pimlico Rd · SSO · 440 gallons report · notice · mapended
Northwest Harbor · 700 S Caroline St · SSO · 2 gallons report · notice · mapto Nov 18, 8:12 AM
Water not mapped · 703 N Carey St · SSO · 3 gallons report · notice · mapreported
to Oct 16, 6:47 PMHerring Run · 2708 Grindon Ave · SSO · 3,298 gallons in all mapended
Northwest Harbor · 700 S Caroline St · SSO · 5 gallons report · notice · mapto Nov 14, 10:22 AM
Northwest Harbor · 700 S Caroline St · SSO · 2 gallons report · notice · mapto Nov 12, 8:25 AM
Water not mapped · 2004 South Rd · SSO · 2 gallons report · notice · mapreported
to Oct 14, 9:54 AMGwynns Falls · N Hilton St & Edmondson Ave · SSO · 15,176 gallons in all mapended

Sources: Baltimore City DPW Sewer Overflow Map (SSO_Points2 map service), retrieved 2026-11-03 08:17 UTC; MDE Reported Sewer Overflows (New for 2023), Maryland Open Data Portal (Socrata stgj-u72u), retrieved 2026-11-03 08:17 UTC. A report's record id and times show when you hover or focus its "report" link.

Download these reports as CSV

Showing the latest 26 records of 1,191 records.See them all with filters.

All reports in Maryland by year: 2026 (370 from Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs)) · 2025 (414 from Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs)) · 2024 (268 from Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs)) · 2023 (139 from Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs))

Other sewer operators on these waters

The last 90 days

Last 90 days, hour by hour. Red: discharge or advisory reported. Amber: caution. Hatched amber: end not confirmed. Grey: no current status on the water outline. Purple hatching: source update overdue.
  • Caution: to the latest update
    5 reports: Northwest Harbor 2, Dead Run 1, Gwynns Falls 1, Stony Run 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Stony Run 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    4 reports: Northwest Harbor 3, Gwynns Falls 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Gwynns Falls 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    4 reports: Northwest Harbor 3, Gwynns Falls 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Gwynns Falls 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    6 reports: Northwest Harbor 3, Gwynns Falls 2, Herring Run 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Herring Run 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    4 reports: Gwynns Falls 2, Northwest Harbor 2
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    3 reports: Gwynns Falls 2, Jones Falls 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    4 reports: Jones Falls 2, Chinquapin Run 1, Northwest Harbor 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    3 reports: Jones Falls 2, Chinquapin Run 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    5 reports: Northwest Harbor 3, Moores Run 1, Stony Run 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Stony Run 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    5 reports: Northwest Harbor 3, Jones Falls 1, Moores Run 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Northwest Harbor 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    4 reports: Northwest Harbor 2, Jones Falls 1, Moores Run 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Jones Falls 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    6 reports: Gwynns Falls 2, Northwest Harbor 2, Jones Falls 1, Moores Run 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Northwest Harbor 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    3 reports: Gwynns Falls 2, Jones Falls 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Jones Falls 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    2 reports: Gwynns Falls 2
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Gwynns Falls 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    5 reports: Jones Falls 3, Gwynns Falls 2
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Jones Falls 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    3 reports: Jones Falls 2, Gwynns Falls 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    1 report: Gwynns Falls 1
    Show records

    The records are also in the report table on this page.

  • Caution: to
    5 reports: Herring Run 2, Jones Falls 2, Northwest Harbor 1
    Show records

    The records are also in the report table on this page.

  • Discharge or advisory reported: to
    8 reports: Herring Run 3, Jones Falls 2, Dead Run 1, Gwynns Falls 1, Northwest Harbor 1
    Show records

    The records are also in the report table on this page.

Source: DirtyWaterWatch calculations using the reports named above and the published status rules. Updated 2026-11-03 08:50 UTC.

Reported discharges over time

  • Discharges reported by Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs), last 12 months351December 2025 to November 2026Verified reports where available, else notices; revisions and duplicates counted once.
  • Days with a discharge reported by Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs), last 12 months246December 2025 to November 2026A day counts once however many discharges were under way on it. Verified reports where available, else notices; revisions and duplicates counted once.
  • Hours with a discharge or advisory status from Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs)'s reports, last 12 months4,199December 2025 to November 2026Red hours by the map's rules: each discharge to its reported end plus the state's post-discharge period; overlapping hours count once.
  • 2026 season with a discharge or advisory status (Baltimore City Department of Public Works (separate sanitary system; Back River and Patapsco WWTPs))51%May to October 2026Share of May 1 to October 31 hours with red status by the map's rules, of the hours a source covered.

Combined sewer overflow (CSO): sewage mixed with rainwater spills from a shared sewer system. Sanitary sewer overflow (SSO): sewage spills from a sewer meant to carry sewage separately from rainwater. Treatment bypass: wastewater skips one or more treatment steps. Blended discharge: wastewater that skipped some treatment is mixed with treated wastewater. Outfall: a pipe or outlet where wastewater enters a water body.

Reported discharges per month

1,087 reported discharges, January 2022 to November 2026.

  • Combined sewer overflow
  • Sanitary sewer overflow
  • Treatment bypass, blended or other
  • No tracked source for this period
  • Incomplete source coverage
No tracked source

No tracked source covers January 2022 to December 2022.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Hours with a discharge or advisory status per month

Hours when a water had a discharge or advisory status from this sewer operator's reports, under DirtyWaterWatch rules.

  • Discharge or advisory reported
  • No tracked source for this period
  • Incomplete source coverage
No tracked source

No tracked source covers January 2022 to December 2022. 59 discharge reports have no end time and are not marked ongoing; under DirtyWaterWatch rules they show caution, not a discharge or advisory status, and add no hours here. 14 discharges reported to last more than 31 days are counted as 31 days. Official beach and cyanobacteria (harmful blue-green algae) advisories are counted on water pages only.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Days with a reported discharge per month

A day counts when any counted discharge was under way on it, from its start to its reported end in Eastern Time; a report with no end counts its start day.

  • No tracked source for this period
  • Incomplete source coverage
No tracked source

No tracked source covers January 2022 to December 2022.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Reported volume per year

Gallons (axis: K thousand, M million), summed from the 1,075 reports that gave a volume as a number (12 did not).

  • Incomplete source coverage
Limited records

12 of 1,087 discharge reports gave no volume as a number; only numbers are summed.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Hours with a discharge or advisory status per year

Hours with a discharge or advisory status each year under DirtyWaterWatch rules; 2026 to date.

  • Discharge or advisory reported
  • Incomplete source coverage
Limited records

59 discharge reports have no end time and are not marked ongoing; under DirtyWaterWatch rules they show caution, not a discharge or advisory status, and add no hours here. 14 discharges reported to last more than 31 days are counted as 31 days. Official beach and cyanobacteria (harmful blue-green algae) advisories are counted on water pages only.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Share of the May to October season with a discharge or advisory status

Share of the hours from May 1 to October 31 with a discharge or advisory status under DirtyWaterWatch rules.

  • Discharge or advisory reported

59 discharge reports have no end time and are not marked ongoing; under DirtyWaterWatch rules they show caution, not a discharge or advisory status, and add no hours here. 14 discharges reported to last more than 31 days are counted as 31 days. Official beach and cyanobacteria (harmful blue-green algae) advisories are counted on water pages only.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Reported discharges by calendar month, all years

Every counted discharge report, by the calendar month it began.

Months are summed over every year a tracked source covers; the table gives the number of years behind each month.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table

Reported discharges by wastewater outlet

Wastewater outlets with the most tracked discharge records: 10 of 844, all years. Counts depend on reporting coverage and do not measure legal compliance or harm.

Sources: md-baltimore-sso; md-mde-overflows. Records cover January 4, 2023 to November 3, 2026.

Show table
How these charts are counted

We count each discharge once. Where a source publishes notices and confirmed reports, we use confirmed reports for an operator's month when available; otherwise we use notices. We combine revisions and exclude duplicate state reports copied by the U.S. Environmental Protection Agency (EPA). Monthly and yearly totals appear separately. Status hours follow this site's rules. Shaded gaps mean missing coverage, not zero discharges.

  • md-baltimore-sso: records from June 23, 2024 to the latest update
  • md-mde-overflows: records from January 4, 2023 to the latest update