Defining gas gathering lines–Part 2

By Joseph C. Caldwell
Contributing Editor

After studying all the information and comments collected from all interested parties, OPS believed the potential for harm of some onshore gathering lines was too low to warrant DOT regulation. These lines generally are of small diameter, and operate at low pressures in remote or secluded areas.
For other lines, OPS agreed with commentators that the level of regulation should increase as risk increased by operating pressure and proximity to people. Under this approach, the highest-risk lines would have the most regulation. This approach is consistent with the statutory directive on determining which rural gathering lines warrant regulation.
In 1999, in furtherance of the still open gathering line proceeding and Congress action on gathering lines, OPS opened a website for public discussion of the definition problem, and the need to regulate rural gathering lines.
The comments mainly foc-used on the comprehensive work by the American Petroleum Institute (API), later published as API Recommended Practice 80, “Guidelines for the Definition of Onshore Gas Gathering Lines” (API RP 80). API RP 80 defines onshore gas gathering lines through a series of definitions, descriptions, and diagrams intended to represent the varied and complex nature of production and gathering lines in the United States. Although industry commentators spoke favorably about the API RP 80 gathering line definition, the National Association of Pipeline Representatives (NAPSR), a nonprofit association of State pipeline safety officials, objected to the use of certain “furthermost downstream” end points to mark the beginning and end of gathering.
NAPSR’s concern was that if the definition was included in Part 192, operators would have an incentive to establish or move the endpoints further downstream to reduce the amount of regulated pipelines. While considering its next step, OPS published an Advisory Bulletin to remind operators it was regulating gathering lines according to court precedents, and its prior interpretations.
In deciding what safety rules to apply according to risk, OPS favored the tiered models two commentators suggested. Tiers are a reasonable way to pair safety regulations with lines posing different levels of risk. However, considering the need for practicality in both compliance and enforcement, OPS created a model with only two tiers or types of lines.
To determine if a pipeline is an onshore gathering line, an operator must use API RP 80 (which has been incorporated by reference). The determination is subject to the following limitations.

For type “A”:

• Pipe feature–metallic, and the MAOP produces a stress of 20% or more of SMYS. If the stress level is unknown, the operator must determine the stress level according to the applicable provisions in Subpart C–“Pipeline Design” of 192.
• Non-metallic, and the MAOP is more than 125 psig.
• Area of operation-Class 2,3,or 4 location (see 192.5)
• Safety buffer zone–none.

For type “B”:

• Pipe feature–metallic, and the MAOP produces a hoop stress of less than 20% of SMYS. If the stress level is unknown, an operator must determine the stress level according to the applicable provisions of Subpart C of 192.
• Non-metallic, and the MAOP is 125 psig or less.
• Area of operation:

º Area 1. Class 3 or 4 location
º Area 2. An area within a Class 2 location the operator determines by using any of the following three methods:

(a) A Class 1 location
(b) An area extending 150 ft on each side of the centerline of any continuous one mile of pipeline, and including more than 10 but fewer than 46 dwellings
(c) An area extending 150 ft on each side of the centerline of any continuous 1000 ft of pipeline, and including five or more dwellings.

• Safety buffer zone–If the gathering line is in area 2(b) or 2(c), the additional length of line extending upstream and downstream from the area to a point where the line is 150 ft from the nearest dwellings in 2(b) or 2(c) qualifies a line as Type B, the type B classification ends 150 ft from the nearest dwelling in the cluster.

This regulation is an attempt to resolve a very complex and long-standing void in the Part 192 of the Pipeline Safety Regulations. In its attempt to solve the problem, the OPS may have over-reacted in its attempt to satisfy all the stakeholders (the Congress, state regulators, code-making organizations and industry). These regulations are very complex, and may be difficult to comply with and enforce. Time will tell.