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Pennsylvania / Sewer operators /

ALCOSAN SEW SYS

Sewer utility with combined sewers · Pennsylvania · Pittsburgh City

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. Square boat markers mark boat launches listed by OpenBoatLaunch.

Federal wastewater discharge permit (NPDES)
PA0025984
Wastewater outlets
None with locations in our records (the state's records list 254)
Waters listed as receiving wastewater
Allegheny River; Monongahela River; Ohio River; Chartiers Creek; Saw Mill Run; Turtle Creek; Thompson Run
Tracked waters
Allegheny River, PA, Monongahela River, PA, Ohio River, PA
Discharge records counted
134 records · latest
Total reported volume in these records
20,000,000 gallons across the 1 record that give a volume (133 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 02:43 UTC.

Public notices and alerts

Get alerts from ALCOSAN SEW SYS

Pages where ALCOSAN SEW SYS or the state publishes its notices:

Source: ALCOSAN SEW SYS'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

Combined sewer overflow (CSO): sewage mixed with rainwater spills from a shared sewer system.

Reports linked to ALCOSAN SEW SYS, newest first
WhenReportStatus
to 9:32 AMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 12:31 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to Sep 22, 1:44 AMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 3:38 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 4:12 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 8:24 AMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 9:03 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 5:51 AMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 5:37 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to Sep 10, 1:48 AMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to Sep 4, 2:12 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 8:49 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 9:46 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 8:19 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 6:16 AMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 4:31 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 12:08 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 5:41 AMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 1:23 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 1:58 AMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 10:01 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 5:38 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 10:47 AMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
to 8:48 PMAllegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended
Allegheny River, Monongahela River, Ohio River · CSO · volume not reported report · notice · mapended

Sources: ALCOSAN Sewer Overflow Advisory Key (SOAK) online overflow log, retrieved 2026-11-02 21:20 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 25 records of 134 records.See them all with filters.

All reports in Pennsylvania by year: 2026 (66 from ALCOSAN SEW SYS) · 2025 (66 from ALCOSAN SEW SYS) · 2024 (2 from ALCOSAN SEW SYS)

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
    1 report: Allegheny River 1
    Show records

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

  • Discharge or advisory reported: to
    1 report: Allegheny River 1
    Show records

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

  • Caution: to
    1 report: Allegheny River 1
    Show records

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

  • Discharge or advisory reported: to
    1 report: Allegheny River 1
    Show records

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

  • Caution: to
    2 reports: Allegheny River 2
    Show records

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

  • Discharge or advisory reported: to
    3 reports: Allegheny River 3
    Show records

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

  • Caution: to
    1 report: Allegheny River 1
    Show records

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

  • Discharge or advisory reported: to
    1 report: Allegheny River 1
    Show records

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

  • Caution: to
    2 reports: Allegheny River 2
    Show records

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

  • Discharge or advisory reported: to
    3 reports: Allegheny River 3
    Show records

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

  • Caution: to
    1 report: Allegheny River 1
    Show records

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

  • Discharge or advisory reported: to
    1 report: Allegheny River 1
    Show records

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

  • Caution: to
    1 report: Allegheny River 1
    Show records

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

  • Discharge or advisory reported: to
    1 report: Allegheny River 1
    Show records

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

  • Caution: to
    1 report: Allegheny River 1
    Show records

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

  • Discharge or advisory reported: to
    2 reports: Allegheny River 2
    Show records

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

  • Caution: to
    2 reports: Allegheny River 2
    Show records

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

  • Discharge or advisory reported: to
    3 reports: Allegheny River 3
    Show records

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

  • Caution: to
    3 reports: Allegheny River 3
    Show records

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

  • Discharge or advisory reported: to
    9 reports: Allegheny River 9
    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 02:43 UTC.

Reported discharges over time

  • Discharges reported by Allegheny County Sanitary Authority (ALCOSAN), last 12 months66December 2025 to November 2026Verified reports where available, else notices; revisions and duplicates counted once.
  • Days with a discharge reported by Allegheny County Sanitary Authority (ALCOSAN), last 12 months54December 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 Allegheny County Sanitary Authority (ALCOSAN)'s reports, last 12 months2,244December 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 (Allegheny County Sanitary Authority (ALCOSAN))42%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.

Reported discharges per month

134 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 September 2024.

Source: pa-alcosan. Records cover October 6, 2024 to November 2, 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 September 2024. 1 discharge report has no end time and is not marked ongoing; under DirtyWaterWatch rules it shows caution, not a discharge or advisory status, and adds no hours here. Official beach and cyanobacteria (harmful blue-green algae) advisories are counted on water pages only.

Source: pa-alcosan. Records cover October 6, 2024 to November 2, 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 September 2024.

Source: pa-alcosan. Records cover October 6, 2024 to November 2, 2026.

Show table

Reported volume per year

Gallons (axis: K thousand, M million), summed from the 1 report that gave a volume as a number (133 did not).

  • Incomplete source coverage
Limited records

133 of 134 discharge reports gave no volume as a number; only numbers are summed.

Source: pa-alcosan. Records cover October 6, 2024 to November 2, 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

1 discharge report has no end time and is not marked ongoing; under DirtyWaterWatch rules it shows caution, not a discharge or advisory status, and adds no hours here. Official beach and cyanobacteria (harmful blue-green algae) advisories are counted on water pages only.

Source: pa-alcosan. Records cover October 6, 2024 to November 2, 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
  • Season with incomplete source coverage

Seasons with incomplete source coverage: 2024. The share is of the hours a source covered. 1 discharge report has no end time and is not marked ongoing; under DirtyWaterWatch rules it shows caution, not a discharge or advisory status, and adds no hours here. Official beach and cyanobacteria (harmful blue-green algae) advisories are counted on water pages only.

Source: pa-alcosan. Records cover October 6, 2024 to November 2, 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.

Source: pa-alcosan. Records cover October 6, 2024 to November 2, 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.

  • pa-alcosan: records from October 6, 2024 to the latest update