Maintaining Safety And Pipeline Integrity
Both hazardous liquid and natural gas transmission pipeline operators are required to develop and implement comprehensive integrity management programs. An integrity management program is a set of safety management, analytical, operations, and maintenance processes that are implemented in an integrated and rigorous manner to assure operators provide protection for High Consequence Areas (HCAs). While the rules provide some flexibility for an operator to develop a program best suited for its pipeline system(s) and operations, there are certain required features – called “program elements” – which each integrity management program must have. The core integrity management program elements include:
- Identifying all locations where a pipeline failure might impact an HCA.
- Developing a risk-based plan (known as the Baseline Assessment Plan) to conduct integrity assessments on those portions of the pipeline. Integrity assessments are performed by in-line inspection (also referred to as “smart pigging”), hydrostatic pressure testing, direct assessment or other technology that the operator demonstrates can provide an equivalent understanding of the condition of the line pipe.
- Integrating the assessment results with other relevant information to improve the understanding of the pipe’s condition.
- Repairing pipeline defects identified through the integrated analysis of the assessment results.
- Conducting a risk analysis to identify the most significant pipeline threats in segments that can affect HCAs. Examples of pipeline threats include corrosion, excavation-induced damage, material defects, and operator errors.
- Identifying additional measures to address the most significant pipeline threats. These measures include actions to prevent and mitigate releases that go beyond repairing the defects discovered through integrity assessment.
- Regularly evaluating all information about the pipeline and its location-specific integrity threats to determine when future assessments should be performed and what methods should be selected to conduct those assessments.
- Periodically evaluating the effectiveness of the integrity management program and identifying improvements to enhance the level of protection.
- The Baseline Assessment Plan must identify the specific integrity assessment method(s) for each segment that can affect an HCA. These methods must be based on the identification of the most significant integrity threats for the specific segment. The Plan must also include a schedule indicating when the assessments of each segment will be performed. The schedule must be risk-based, meaning that higher-risk segments are scheduled before lower-risk segments. Operators must document the technical basis for the assessment methods they select and the risk analysis performed to establish the schedule.
Title 49 of the Code of Federal Regulations (CFR) Parts 195.452 and 192, Subpart O, have four basic objectives:
- Perform integrity assessments of pipeline where a pipeline failure could have significant consequences (HCAs)
- To improve operator management, analytical, and operational processes to manage pipeline integrity.
- To increase government's role in the oversight of operator integrity management programs and activities.
- To improve public confidence in pipeline safety.
High Consequence Areas
Although there are differences between natural gas and hazardous liquid pipelines for determining an HCA, the basics are similar. Both types of systems have rules in place to identify locations along their pipelines where a failure might impact an HCA. Natural gas transmission line HCAs are basically based upon population density, while hazardous liquid pipelines include urban areas, as well as environmental considerations such as commercially navigable waterways, drinking water, and ecological resources.
Pipeline operators invest significant time and capital maintaining the quality and integrity of their pipeline systems. Most active pipelines are monitored 24-hours a day via manned control centers. Pipeline companies also utilize aerial surveillance and/ or on-ground observers to identify potential dangers. Control center personnel continually monitor the pipeline system and assess changes in pressure and flow. They notify field personnel if there is a possibility of a leak. Automatic shut-off valves are sometimes utilized to isolate a leak.
Gas transmission and hazardous liquid pipeline operators have developed supplemental hazard and assessment programs known as Integrity Management Programs (IMPs). IMPs have been implemented for areas designated as HCAs in accordance with federal regulations. Specific information about an operator's program may be found on their company web site or by contacting them directly.