# CONOCOPHILLIPS — Hazardous liquid — incident on 2011-08-27

**Citation:** PHMSA Report 20110363  
**Type / status:** incident / historical  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2011-08-27  
**Published:** 2011-09-26

Hazardous liquid incident in BYRON, CONTRA COSTA County, CA. Reported cause: EXCAVATION DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 56 CRUDE OIL released, $20,000 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

Hazardous liquid incident in BYRON, CONTRA COSTA County, CA. Reported cause: EXCAVATION DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 56 CRUDE OIL released, $20,000 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: 20110363.

Operator ID: 31684.

Reported incident date: 8/27/2011 5:50.

Location detail: C-23

Cause detail: EXCAVATION DAMAGE BY THIRD PARTY

Cause detail: MISCELLANEOUS ROOT CAUSES

Cause detail: ROOT CAUSE NOT LISTED (COMMENT REQUIRED)

Cause detail: 3RD PARTY DIGGING OVER LINE NC-21 APPROXIMATELY 3 MILES DOWNSTREAM FROM BYRON PUMP STATION JUST WEST OF VASCO ROAD STRUCK OUR LINE CAUSING A RELEASE OF 56 BARRELS OF RODEO REFINERY COKER MIX. THE CONTROL CENTER SHUT THE LINE DOWN ON LOW PRESSURE ALARM FOR PLM. THE TRACY OFFICE PERSONNEL RESPONDED.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EXCAVATION DAMAGE — THIRD PARTY EXCAVATION DAMAGE.

PHMSA indexed costs: $1,275,040 reported total cost, $683,873.287 in 1984 dollars, $1,684,169.434 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/1d547e17-2be1-4a32-9958-a1d5a946ade9?download=true&filename=Hazardous%20Liquid%20Accident%20Data%20-%20January%202010%20to%20present.zip>
- Source ID: `phmsa-pipeline-incidents`
- SHA-256: `cfcfd53c7364bf9afe04a07366329c25c377ca9eec5ed0134d95765b30de1d1c`
- Retrieved: 2026-08-20T03:30:32.010Z
- Exported: 2026-08-25T04:13:22.087Z
- Document slug: `phmsa-incident-a5b49f24c6577a929fa9e91d`

### Source metadata

```json
{
  "recordKind": "pipeline_incident",
  "datasetType": "hazardous_liquid",
  "datasetLabel": "Hazardous liquid",
  "datasetPeriod": "January 2010 to present",
  "report": {
    "number": "20110363",
    "supplementalNumber": "16351",
    "type": "SUPPLEMENTAL FINAL",
    "receivedDate": "2011-09-26",
    "receivedDateRaw": "9/26/2011"
  },
  "operator": {
    "id": "31684",
    "name": "CONOCOPHILLIPS"
  },
  "incident": {
    "date": "2011-08-27",
    "dateRaw": "8/27/2011 5:50"
  },
  "location": {
    "city": "BYRON",
    "county": "CONTRA COSTA",
    "state": "CA",
    "postalCode": "94514",
    "latitude": 37.795178,
    "longitude": -121.672381,
    "type": "PIPELINE RIGHT-OF-WAY",
    "details": {
      "DESIGNATED_NAME": "C-23"
    },
    "facilityName": "LINE 200"
  },
  "cause": {
    "category": "EXCAVATION DAMAGE",
    "details": {
      "CAUSE_DETAILS": "EXCAVATION DAMAGE BY THIRD PARTY",
      "ROOT_CAUSE_CATEGORY": "MISCELLANEOUS ROOT CAUSES",
      "ROOT_CAUSE_TYPE": "ROOT CAUSE NOT LISTED (COMMENT REQUIRED)",
      "NARRATIVE": "3RD PARTY DIGGING OVER LINE NC-21 APPROXIMATELY 3 MILES DOWNSTREAM FROM BYRON PUMP STATION JUST WEST OF VASCO ROAD STRUCK OUR LINE CAUSING A RELEASE OF 56 BARRELS OF RODEO REFINERY COKER MIX. THE CONTROL CENTER SHUT THE LINE DOWN ON LOW PRESSURE ALARM FOR PLM. THE TRACY OFFICE PERSONNEL RESPONDED."
    }
  },
  "consequences": {
    "fatalities": 0,
    "injuries": 0,
    "commodity": "CRUDE OIL",
    "release": "56",
    "propertyDamage": 20000,
    "estimatedOperatorCost": 0,
    "estimatedEmergencyCost": 250000,
    "estimatedEnvironmentalCost": 1000000,
    "ignition": "NO",
    "explosion": "NO",
    "evacuated": 0,
    "raw": {
      "FATAL": "0",
      "INJURE": "0",
      "UNINTENTIONAL_RELEASE_BBLS": "56",
      "EST_COST_PROP_DAMAGE": "20000",
      "PRPTY": "1275040"
    }
  },
  "provenance": {
    "viewId": "27nc-rsge",
    "viewUrl": "https://data.transportation.gov/api/views/27nc-rsge",
    "assetId": "1d547e17-2be1-4a32-9958-a1d5a946ade9",
    "archiveFilename": "Hazardous Liquid Accident Data - January 2010 to present.zip",
    "archiveSha256": "5aaa1a31834a0503acfdfc82172d9ff3483b480019cec1605ebb8e15d0040f0d",
    "memberPath": "accident_hazardous_liquid_jan2010_present.txt",
    "memberSha256": "2af519107224bbd22874e67c65f6aa526073a297b2b30104b711d071680488a4",
    "rowNumber": 5272,
    "rowSha256": "18ad962fb30ce4275811ddacccd31e91ba2e344a67c5e04f680ef85eef8adfda"
  },
  "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": "EXCAVATION DAMAGE",
      "sevenSubcategory": "THIRD PARTY EXCAVATION DAMAGE",
      "eightCategory": "EXCAVATION DAMAGE",
      "eightSubcategory": "THIRD PARTY EXCAVATION DAMAGE"
    },
    "costs": {
      "reported": 1275040,
      "in1984Dollars": 683873.2871690424,
      "currentYearDollars": 1684169.4338085537
    },
    "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": "hl2010toPresent.xlsx",
      "sheet": "hl2010toPresent",
      "rowNumber": 573,
      "rowSha256": "b6236c21cbcc348c645000f2d1f7172aec1c1f8f5703ec6731157a176153332b"
    }
  },
  "jurisdiction": "US",
  "operatorName": "CONOCOPHILLIPS"
}
```