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Sanitary sewer overflow (SSO) reported — San Mateo City, Oct 28, 2026

Ended (as reported) · California State Water Resources Control Board (CIWQS Sanitary Sewer System Database)

Source: California State Water Resources Control Board (CIWQS Sanitary Sewer System Database) via State Water Board CIWQS Sanitary Sewer System spill data: Cat1-2-3-Spills.txt (nightly flat file), record 908748, the source gives no report time, retrieved 2026-11-05 15:08 UTC · Read the original notice

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1. Reported wastewater outlet

Operator named in the record: San Mateo City (federal wastewater discharge permit, NPDES, 2SSO10183). Outlet: “[house number removed] Flores St.”. Location: 37.54303, -122.30728; location source: given in the source record.

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

2. Waters named in the notice

The notice names: “San Mateo Creek”. DirtyWaterWatch links this report to San Mateo Creek, CA. Match basis: the water named in the report.

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

Oct 28, 2026, 11:48 AM PDT

Ended

Oct 28, 2026, 12:20 PM PDT

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

2026-11-05 15:08 UTC

What and how much

Type

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

Status in the record

Ended (as reported)

Material

“untreated sewage”

Volume

170 gallons (estimated)

Volume as reported

“170 gallons spilled (estimated total leaving the sewer system); 150 gallons reached surface water; 20 gallons recovered”

Advice from California State Water Resources Control Board (CIWQS Sanitary Sewer System Database)

This report includes no advice. Check current local health notices.

Advice period

This report does not state a period. See the rule DirtyWaterWatch applies and its source.

Basis

not stated

Status history from this report

• Discharge or advisory reported San Mateo Creek: Discharge reported ongoing, Oct 28, 2026, 11:48 AM PDT to Oct 28, 2026, 12:20 PM PDT
• Caution San Mateo Creek: Within the caution period after the reported end, Oct 28, 2026, 12:20 PM PDT to Oct 31, 2026, 12:20 PM PDT

Source: DirtyWaterWatch calculations using this report and the published status rules. Updated 2026-11-06 09:03 UTC.

Source and versions

Source

State Water Board CIWQS Sanitary Sewer System spill data: Cat1-2-3-Spills.txt (nightly flat file)

Source record number

908748

Original notice

Read the original notice

Earlier version

None: this is the first record

Later versions

None

{
  "region": "2",
  "wdid": "2SSO10183",
  "enrollee_status": "Active",
  "system_name": "San Mateo CIty CS",
  "agency_name": "San Mateo City",
  "spill_event_id": "908748",
  "version": "1.1",
  "spill_status": "Work In Progress",
  "draft_submitted_on": null,
  "first_certified_on": null,
  "final_certified_on": null,
  "spill_type": "Category 1 Spill",
  "location_name": "[house number removed] Flores St.",
  "enrollee_notified_at": "10/28/2026 11:48",
  "crew_arrival_at": "10/28/2026 12:05",
  "start_at": "10/28/2026 11:48",
  "caloes_notified_at": null,
  "caloes_control_number": null,
  "technical_report_on": null,
  "lat": "37.54303",
  "lon": "-122.30728",
  "appearance_points": "Manhole",
  "volume_total_gal": "170",
  "reached_drainage_system": "Y",
  "volume_recovered_from_drainage_gal": "20",
  "volume_left_in_drainage_gal": "150",
  "volume_to_surface_water_gal": "150",
  "volume_recovered_gal": "20",
  "destinations": "Drainage Conveyance System that discharges to surface water",
  "destination_points_given": "Y",
  "end_at": "10/28/2026 12:20",
  "causes": "Debris from Construction; Fats, Oil and Grease (FOG)",
  "failure_location": "Gravity Mainline",
  "storm_event": "N",
  "response_completed_at": "10/28/2026 12:20",
  "receiving_water": "San Mateo Creek",
  "receiving_water_type": "Stream/Creek",
  "public_access_impact": "Other (specify below)",
  "closing_entity": "none",
  "days_closed_or_restricted": "0",
  "within_1000_ft_of_intake": "N",
  "samples_collected": "N",
  "spill_category": "1",
  "reached_water": true,
  "destination_points": [
    {
      "lat": 37.542,
      "lon": -122.306
    }
  ]
}