# PACIFIC GAS & ELECTRIC CO — Gas transmission and gathering — incident on 2017-10-28

**Citation:** PHMSA Report 20170105  
**Type / status:** incident / historical  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2017-10-28  
**Published:** 2017-11-16

Gas transmission and gathering incident in PAICINES, SAN BENITO County, CA. Reported cause: INCORRECT OPERATION. Reported consequences: 0 fatalities, 0 injuries, 28500 NATURAL GAS released, $0 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings. PHMSA trend classification: significant incident, not serious.

## Document text

Gas transmission and gathering incident in PAICINES, SAN BENITO County, CA. Reported cause: INCORRECT OPERATION. Reported consequences: 0 fatalities, 0 injuries, 28500 NATURAL GAS released, $0 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20170105.

Operator ID: 15007.

Reported incident date: 10/28/2017 14:45.

Location detail: 436.85

Cause detail: PIPELINE OR EQUIPMENT OVERPRESSURED

Cause detail: ON 10/28/17 AT 14:45, RELIEF VALVE M AT PRESSURE-LIMITING STATION 6AB ON L300A MP 436.85 ACTIVATED AND BEGAN VENTING GAS. THE RELIEF VALVE CLOSED AT 15:53. THE MAOP OF THIS SECTION OF L300A IS 631 PSIG AND THE RELIEF VALVE OPENED AT 602 PSIG. THE FIRE DEPARTMENT RESPONDED TO THE RELIEF VALVE ACTIVATION. THE INITIAL INVESTIGATION DETERMINED THE RELIEF VALVE ACTIVATED BELOW THE SET POINT OF 615 PSIG. THIS INCIDENT IS BEING REPORTED DUE TO THE EARLY ACTIVATION OF THE RELIEF VALVE AND UNINTENTIONAL RELEASE OF GAS OVER 3MMCF. THE INCIDENT WAS DUE TO OPERATOR ERROR. THE OPERATOR INPUT A REGULATION SET POINT MEANT FOR PLS4 INTO PLS6 CAUSING THE PRESSURE TO RISE AND THE OVER PRESSURE PROTECTION RELIEF VALVE TO ACTIVATE.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: INCORRECT OPERATION — PIPELINE/EQUIPMENT OVERPRESSURED.

PHMSA indexed costs: $85,500 reported total cost, $81,183.894 in 1984 dollars, $99,681.49 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.

## Provenance

- Official: Yes
- Source: <https://data.transportation.gov/api/views/27nc-rsge/files/2b05c2d8-d14a-4c56-ac1c-7d23a4bc31c8?download=true&filename=Gas%20Transmission%20%26%20Gathering%20Incident%20Data%20-%20January%202010%20to%20present.zip>
- Source ID: `phmsa-pipeline-incidents`
- SHA-256: `8ea4ee687d1550d17b24946fa75c10dc25e601b4596c4d0c8159d31fad3d181b`
- Retrieved: 2026-08-20T03:30:32.010Z
- Exported: 2026-08-24T10:01:00.880Z
- Document slug: `phmsa-incident-85286320c3eef5817980863d`

### Source metadata

```json
{
  "recordKind": "pipeline_incident",
  "datasetType": "gas_transmission_gathering",
  "datasetLabel": "Gas transmission and gathering",
  "datasetPeriod": "January 2010 to present",
  "report": {
    "number": "20170105",
    "supplementalNumber": "30189",
    "type": "SUPPLEMENTAL FINAL",
    "receivedDate": "2017-11-16",
    "receivedDateRaw": "11/16/2017"
  },
  "operator": {
    "id": "15007",
    "name": "PACIFIC GAS & ELECTRIC CO"
  },
  "incident": {
    "date": "2017-10-28",
    "dateRaw": "10/28/2017 14:45"
  },
  "location": {
    "city": "PAICINES",
    "county": "SAN BENITO",
    "state": "CA",
    "postalCode": "95075",
    "latitude": 36.70052,
    "longitude": -121.21127,
    "type": "OPERATOR-CONTROLLED PROPERTY",
    "details": {
      "DESIGNATED_NAME": "436.85"
    },
    "facilityName": "L300A"
  },
  "cause": {
    "category": "INCORRECT OPERATION",
    "details": {
      "CAUSE_DETAILS": "PIPELINE OR EQUIPMENT OVERPRESSURED",
      "NARRATIVE": "ON 10/28/17 AT 14:45, RELIEF VALVE M AT PRESSURE-LIMITING STATION 6AB ON L300A MP 436.85 ACTIVATED AND BEGAN VENTING GAS. THE RELIEF VALVE CLOSED AT 15:53. THE MAOP OF THIS SECTION OF L300A IS 631 PSIG AND THE RELIEF VALVE OPENED AT 602 PSIG. THE FIRE DEPARTMENT RESPONDED TO THE RELIEF VALVE ACTIVATION. THE INITIAL INVESTIGATION DETERMINED THE RELIEF VALVE ACTIVATED BELOW THE SET POINT OF 615 PSIG. THIS INCIDENT IS BEING REPORTED DUE TO THE EARLY ACTIVATION OF THE RELIEF VALVE AND UNINTENTIONAL RELEASE OF GAS OVER 3MMCF. THE INCIDENT WAS DUE TO OPERATOR ERROR. THE OPERATOR INPUT A REGULATION SET POINT MEANT FOR PLS4 INTO PLS6 CAUSING THE PRESSURE TO RISE AND THE OVER PRESSURE PROTECTION RELIEF VALVE TO ACTIVATE."
    }
  },
  "consequences": {
    "fatalities": 0,
    "injuries": 0,
    "commodity": "NATURAL GAS",
    "release": "28500",
    "propertyDamage": 0,
    "estimatedOperatorCost": 0,
    "estimatedEmergencyCost": 0,
    "estimatedEnvironmentalCost": null,
    "ignition": "NO",
    "explosion": "NO",
    "evacuated": 0,
    "raw": {
      "FATAL": "0",
      "INJURE": "0",
      "UNINTENTIONAL_RELEASE": "28500",
      "EST_COST_PROP_DAMAGE": "0",
      "PRPTY": "85500"
    }
  },
  "provenance": {
    "viewId": "27nc-rsge",
    "viewUrl": "https://data.transportation.gov/api/views/27nc-rsge",
    "assetId": "2b05c2d8-d14a-4c56-ac1c-7d23a4bc31c8",
    "archiveFilename": "Gas Transmission & Gathering Incident Data - January 2010 to present.zip",
    "archiveSha256": "fe0b136ca4b00ac987a8bc2e195098accf910d97512c5fc3b59e62d9da5f674e",
    "memberPath": "incident_gas_transmission_gathering_jan2010_present.txt",
    "memberSha256": "b435f2a25718cf54c54e00294e6788c4f9c6860e02fb86355e75d294c243c4dd",
    "rowNumber": 1040,
    "rowSha256": "68fbd6f63bfa2e99b7619accc32526a3821c4f7bb92597088a5dff14f6d70971"
  },
  "caveat": "Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.",
  "operatorReported": true,
  "finalAgencyFinding": false,
  "flaggedAnalysis": {
    "dataAsOf": "2026-07-31",
    "flags": {
      "fireFirst": null,
      "significant": true,
      "serious": false
    },
    "standardizedCause": {
      "sevenCategory": "INCORRECT OPERATION",
      "sevenSubcategory": "PIPELINE/EQUIPMENT OVERPRESSURED",
      "eightCategory": "INCORRECT OPERATION",
      "eightSubcategory": "PIPELINE/EQUIPMENT OVERPRESSURED"
    },
    "costs": {
      "reported": 85500,
      "in1984Dollars": 81183.89423076923,
      "currentYearDollars": 99681.49038461539
    },
    "caveat": "PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.",
    "provenance": {
      "sourceUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/data_statistics/pipeline/PHMSA_Pipeline_Safety_Flagged_Incidents.zip",
      "landingPageUrl": "https://www.phmsa.dot.gov/data-and-statistics/pipeline/pipeline-incident-flagged-files",
      "catalogUrl": "https://data.transportation.gov/Pipelines-and-Hazmat/Pipeline-Incident-Flagged-Files/qdme-9bbm",
      "retrievalMode": "official_live",
      "archivedAt": null,
      "archiveSha256": "317e6a3e16d60b9b677efe391dc40258b5dd7ead83fb8bea74cb553cedfbbdec",
      "workbook": "gtggungs2010toPresent.xlsx",
      "sheet": "gtggungs2010toPresent",
      "rowNumber": 949,
      "rowSha256": "68c739cc445c7cf7753e6d1999bcabd6d4d5a7fca9a6a53d69b1cbbf6f75e93e"
    }
  },
  "jurisdiction": "US",
  "operatorName": "PACIFIC GAS & ELECTRIC CO"
}
```