Office of Pipeline Safety Incident and Accident Reports
(Data are collected from the entire population of interest)
Data Scope
Data includes leaks of natural gas or petroleum/petroleum by-products
that meet reporting requirements as outlined in CFR 49, Parts 191, 192
and 195.
Data Collection
Methods - Data are entered on a form designed for the particular
system involved; i.e. natural gas transmission, natural gas distribution,
and hazardous liquid transmission. The forms are mailed in.
Schedule - Reports are required to be submitted by the responsible
operators within 30 days of the incident or face penalties for non-compliance.
Response Rates - As best as can be determined, most incidents
that meet reporting requirements are submitted. A response percentage cannot
be calculated as the actual population of reportable incidents cannot be
precisely determined.
Non-sampling Errors
Non-sampling errors are attributable to several reasons, primarily the
following:
-
Incident/Accidents are not under OPS jurisdiction.
-
The operator does not submit a report.
-
The operator does not have all required reporting information or only preliminary
information by the time the report is due.
-
The information originally submitted is not accurate and no updates have
been forwarded. Quality control and edit procedures are in place to reduce
errors attributable to data entry personnel.
Non-entry Error - Missing records occur in three possible ways:
1) it may not be determined within the reporting period if the incident/accident
was reportable or not, and there was no follow up on the part of the operator;
2) the responsible party cannot be identified, and 3) the operator judges
a reportable incident/accident as non-reportable or non-jurisdictional
to OPS. OPS routinely cross-checks incident/accident reports against other
sources of data, such as the telephonic reporting system for incidents
requiring immediate notification provided to the National Response Center
(NRC),
Duplicate Entry Error - Duplicates occasionally occur when operators
submit updates to records already entered and the updates are entered as
a new report; or a copy of the incident/accident is submitted to the state
regulatory agency, which forwards it to OPS at a later date, and that report
is entered as a new report. Quality assurance procedures designed to identify
duplicates are constantly invoked and duplicates are subsequently removed.
Some reports may seem to be duplicates, but the incidents/accidents actually
occurred on loop lines or in different locations within the same system
on the same day.
Missing Data Error - Since the operators must submit reports
within 30 days, not all of the required data may be available within that
time. Some missing data errors may result from data entry errors that are
missed during the quality review process, although QA procedures conducted
by the OPS data entry personnel show that such errors are rare.
Response/Measurement Error - Determining if the data provided
is correct depends on how responsible and accurate the operator is in reporting
and submitting updates. OPS does not update reports from operators unless
the operator submits updates. OPS does conduct reviews of the more severe
incidents/accidents and request updates from the operator as required.
Coding/Recording Error - The only item coded on the report is
the operator ID. This is researched carefully before the coding is done.
Non-coverage Error - Members of the population are missing because
they do not meet reporting requirements or are not under the jurisdiction
of OPS.
Verification and Validation
Validation of the data is conducted through field checks and pick lists
in the data entry application. The data are reviewed after entry for accuracy
of entry. Possible duplicates are investigated before data entry and again
after data entry. Once a month, incident/accident reports are transmitted
to the OPS regions for review of their completeness and accuracy.
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