Pennsylvania / Reports /

Combined sewer overflow (CSO) reported — Allegheny County Sanitary Authority (ALCOSAN), Sep 16, 2026

Ended (as reported) · ALCOSAN sewer overflow advisories

Source: ALCOSAN sewer overflow advisories, record soak-20260916T0757, the source gives no report time, retrieved 2026-11-02 21:20 UTC · Read the original notice

Read the original notice · Report an error

1. Reported wastewater outlet

Operator named in the record: Allegheny County Sanitary Authority (ALCOSAN) (federal wastewater discharge permit, NPDES, PA0025984). Outlet: not stated. Location: not given in the report or in the outlet records.

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

2. Waters named in the notice

The notice names: “Allegheny, Monongahela and Ohio rivers (ALCOSAN service area, system-wide)”. DirtyWaterWatch links this report to Allegheny River, PA, Monongahela River, PA, Ohio River, PA. Match basis: the operator's listed receiving water; the report itself does not name the water.

3. Estimated downstream stretch

No downstream estimate is available for this report.

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When it happened and when it was reported

Event and notice times use Eastern Time (EST or EDT). Retrieval times use Coordinated Universal Time (UTC).

Started

Sep 16, 2026, 7:57 AM EDT

Ended

Sep 16, 2026, 8:24 AM EDT

Detail provided by the source

Times known to the minute

Reported to the source

not given

Published

not given

Source last updated

not given

Last retrieved by DirtyWaterWatch

2026-11-02 21:20 UTC

What and how much

Type

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

Status in the record

Ended (as reported)

Material

not stated

Volume

volume not reported (not stated whether estimated or measured)

Volume as reported

none

Advice from ALCOSAN sewer overflow advisories

“Overflows have ceased; Waterways may still be impaired.”

Advice period

48 hours

Basis

ALCOSAN advisory log (Dry = Out + 48 h)

Status history from this report

• Discharge or advisory reported Allegheny River: Discharge reported ongoing, Sep 16, 2026, 7:57 AM EDT to Sep 16, 2026, 8:24 AM EDT
• Discharge or advisory reported Allegheny River: Post-discharge period applies, Sep 16, 2026, 8:24 AM EDT to Sep 18, 2026, 8:24 AM EDT
• Caution Allegheny River: Within the caution period after the reported end, Sep 18, 2026, 8:24 AM EDT to Sep 19, 2026, 8:24 AM EDT
• Discharge or advisory reported Monongahela River: Discharge reported ongoing, Sep 16, 2026, 7:57 AM EDT to Sep 16, 2026, 8:24 AM EDT
• Discharge or advisory reported Monongahela River: Post-discharge period applies, Sep 16, 2026, 8:24 AM EDT to Sep 18, 2026, 8:24 AM EDT
• Caution Monongahela River: Within the caution period after the reported end, Sep 18, 2026, 8:24 AM EDT to Sep 19, 2026, 8:24 AM EDT
• Discharge or advisory reported Ohio River: Discharge reported ongoing, Sep 16, 2026, 7:57 AM EDT to Sep 16, 2026, 8:24 AM EDT
• Discharge or advisory reported Ohio River: Post-discharge period applies, Sep 16, 2026, 8:24 AM EDT to Sep 18, 2026, 8:24 AM EDT
• Caution Ohio River: Within the caution period after the reported end, Sep 18, 2026, 8:24 AM EDT to Sep 19, 2026, 8:24 AM EDT

Source: DirtyWaterWatch calculations using this report and the published status rules. Updated 2026-11-02 21:26 UTC.

Source and versions

Source

ALCOSAN sewer overflow advisories

Source record number

soak-20260916T0757

Original notice

Read the original notice

Earlier version

None: this is the first record

Later versions

None

{
  "entries": [
    {
      "alert_date": "September 17, 2026",
      "status": "Overflows are in effect; Minimize contact with waterways",
      "in": "09/16/2026 - 07:57 AM",
      "out": null,
      "dry": null,
      "stage": "effect"
    },
    {
      "alert_date": "September 17, 2026",
      "status": "Overflows have ceased; Waterways may still be impaired.",
      "in": "09/16/2026 - 07:57 AM",
      "out": "09/16/2026 - 08:24 AM",
      "dry": null,
      "stage": "ceased"
    }
  ],
  "stage": "ceased",
  "dry_at": null,
  "time_corrections": [],
  "entry_problems": [],
  "system_wide": true,
  "water_basis": "The SOAK log is one system-wide status for the ALCOSAN service area, not per outfall; the three rivers at Pittsburgh are inferred from that scope.",
  "timezone_note": "The log states no time zone; times are read as America/New_York.",
  "alert_dates_note": "Alert dates are the posting days (day only); overnight changes are posted at 8 a.m."
}