Guidance on Determining High Consequence Areas and on Carrying out Requirements in the Integrity Management Rule
I. Guidance on Determining a High Consequence Area
To determine which segments of an operator's transmission pipeline system are covered for purposes of the integrity management program requirements, an operator must identify the high consequence areas. An operator must use the methods defined in paragraphs (1) or (2) of subdivision (f) of section 255.903 of this Part to identify a high consequence area. An operator may apply one method to its entire pipeline system, or an operator may apply one method to individual portions of the pipeline system. (Refer to Figure 1 below for a diagram of a high consequence area.)
FIGURE 1
II. Guidance on Assessment Methods and Additional Preventive and Mitigative Measures for Transmission Pipelines
(a) Table 1 below gives guidance to help an operator implement requirements on additional preventive and mitigative measures for addressing time dependent and independent threats for a transmission pipeline operating below 30 percent SMYS not in a High Consequence Area (i.e., outside of potential impact circle) but located within a Class 3 or Class 4 Location.
(b) Table 2 below gives guidance to help an operator implement requirements on assessment methods for addressing time dependent and independent threats for a transmission pipeline in a high consequence area.
(c) Table 3 below gives guidance on preventive and mitigative measures addressing time dependent and independent threats for transmission pipelines that operate below 30 percent SMYS, in high consequence areas.
Table 1
Preventive and Mitigative Measures for Transmission Pipelines Operating Below 30% SMYS not in HCAs but in Class 3 and 4 Locations
For Cathodically Protected Transmission Pipeline: • Performs semi-annual leak surveys. For Unprotected Transmission Pipelines or for Cathodically Protected Pipe where Electrical Surveys are Impractical: • Perform quarterly leak surveys
• Participation in state one-call system • Use of qualified operator employees and contractors to perform marking and locating of buried structures and in direct supervision of excavation work, AND • Either monitoring of excavations near operator's transmission pipelines, or bi-monthly patrol of transmission pipelines in class 3 and 4 locations. Any indications of unreported construction activity would require a follow up investigation to determine if mechanical damage occurred.
Table 2
Assessment Requirements for Transmission Pipelines in HCAs (Re-assessment intervals are the maximum allowed)
Re-Assessment Requirements (see Note 3)
At or Above 50% SMYS
At or Above 30% SMYS up to 50% SMYS
Below 30% SMYS
Baseline Assessment Method (See Note 3)
Max Re-Assessment Interval
Assessment Method
Max Re-Assessment Interval
Assessment Method
Max Re-Assessment Interval
Assessment Method
7
CDA
7
CDA
Pressure
10
Pressure
Preventive and
Testing
Test or ILI or DA
Ongoing
Mitigative (P&M)
Measures
Repeat inspection cycle every 10 years
15 (See Note 1)
Pressure Test or ILI or DA (See Note 1)
(See Table 3), (See Note 2)
Repeat inspection
20
Pressure Test or ILI or DA
cycle every 15 years
Repeat inspection cycle every 20 years
7
CDA
7
CDA
In-Line
10
ILI or DA
Preventive and
Inspection
or Pressure Test
Ongoing
Mitigative (P&M)
Measures
Repeat inspection cycle every 10 years
15 (See Note 1)
ILI or DA or Pressure Test (See Note 1)
(See Table 3), (See Note 2)
Repeat inspection
20
ILI or DA or Pressure Test
cycle every 15 years
Repeat inspection cycle every 20 years
7
CDA
7
CDA
Direct
10
DA or ILI or
Preventive and
Assessment
Pressure Test (see Note 1)
Ongoing
Mitigative (P&M)
Measures
Repeat inspection cycle every 10 years
15 (See Note 1)
DA or ILI or Pressure Test (See Note 1)
(See Table 3), (See Note 2)
Repeat inspection
20
DA or ILI or Pressure Test
cycle every 15 years
Repeat inspection cycle every 20 years
Operator may choose to utilize CDA at year 14, then utilize ILI, Pressure Test, or DA at year 15 as allowed under ASME B31.8S
Operator may choose to utilize CDA at year 7 and 14 in lieu of P&M
Operator may utilize "other technology that an operator demonstrates can provide an equivalent understanding of the condition of line pipe"
Table 3
Preventive and Mitigative Measures Addressing Time Dependent and Independent Threats for Transmission Pipelines that Operate Below 30% SMYS, in HCAs
For Cathodically Protected Transmission Pipelines: • Perform an electrical survey (i.e. indirect examination tool/method) at least every 7 years. Results are to be utilized as part of an overall evaluation of the CP system and corrosion threat for the covered segment. Evaluation shall include consideration of leak repair and inspection records, corrosion monitoring records. exposed pipe inspection records, and the pipeline environment. For Unprotected Transmission Pipelines or Cathodicallv Protected pipe where Electrical Surveys are Impracticable: • Conduct Quarterly leak surveys AND • Every 1½ years, determine areas of active corrosion by evaluation of leak repair and inspection records. corrosion monitoring records, exposed pipe inspection records, and the pipeline environment.
• Obtain and review gas analysis data each calendar year for corrosive agents from transmission pipelines in HCAs • Periodic testing of fluid removed from pipelines. Specifically, once each calendar year from each storage field that may affect transmission pipelines in HCAs. AND • At least every 7 years, integrate data obtained with applicable internal corrosion leak records, incident reports, safety related condition reports, repair records, patrol records, exposed pipe reports, and test records.
• Participate in state one-call system. • Use of qualified operator employees and contractors to perform marking and locating of buried structures and in direct supervision of excavation work. AND • Either monitoring of excavations near operator's transmission pipelines, or bi-monthly patrol of transmission pipelines in HCAs or class 3 and 4 locations. Any indications of unreported construction activity would require a follow up investigation to determine if mechanical damage occurred.
