U.S. DOT/RSPA - Briefing Paper on Internal Corrosion

Page 1B riefing Paper August 24, 2006 Designing and constructing gas transmission pipelines to control internal corrosion Advisory Committee Action: Vote on proposed rule and cost-benefit analysis Project Contact: Barbara Betsock NTSB Recommendation: Revise 49 Code of Federal Regulations Part 192 to require that new or replaced pipelines be designed and constructed with features to mitigate internal corrosion. At a minimum, such pipelines should (1) be configured to reduce the opportunity for liquids to accumulate, (2) be equipped with effective liquid removal features, and (3) be able to accommodate corrosion monitoring devices at locations with the greatest potential for internal corrosion. Past PHMSA action and advisory committee consideration: • Following a briefing in June 2005, this committee generally supported the concept of a regulation responsive to the NTSB. Some members expressed concern that the regulation not be overbroad or limit protections to high consequence areas. • PHMSA issued a Notice of Proposed Rulemaking (NPRM). (70 Fed Reg 74262; December 15, 2005). The NPRM proposed to: - Require design to avoid liquid accumulation, to include liquid removal equipment, and to include monitoring. Apply the design requirement without regard to the anticipated operations of the line. - Include offshore pipelines and gathering lines. - Require an operator to examine downstream portions for internal corrosion impacts caused by changes to the upstream pipeline. - Require documentation, including engineering analysis, for every design decision with respect to internal corrosion control. • PHMSA presented the NPRM and cost benefit analysis to the committee for consideration and vote at the June 28, 2006 meeting. - At the meeting, PHMSA committed to clarify one concern raised by the committee with respect to a proposed requirement to analyze changes impacting downstream facilities. The final rule will clarify that only changes to configuration of the pipeline will require analysis. -The committee requested additional information and postponement of the vote. This paper and its attachments provide additional information for the meeting and vote on August 24. - Committee concerns unresolved at the June 28 meeting were: whether the committee was considering a proposed rule or a draft final rule; what type of record-keeping should apply to the regulation; and the degree of enforceability of the regulation. The additional information provided#

Page 2• This briefing paper includes a description of how PHMSA works with its advisory committees on consideration of proposed rules and cost-benefit analyses. • The description below of what PHMSA intends to do with the final rule outlines how we intend to address the major comments to the proposed rule. • The attached concept paper describes how we intend to approach record-keeping. • The attached summary of major comments includes an expanded description of comments on record-keeping, including approaches suggested by commenters. • The attached 5 pages of excerpts from the NTSB report on the Carlsbad, New Mexico, accident show how NTSB developed its recommendation on design and construction of gas transmission pipeline to address internal corrosion. Committee consideration of proposed rules and cost-benefit analyses • The pipeline safety law requires PHMSA to seek the advice of this committee on proposed rules and cost-benefit analyses. • In recent years, PHMSA has made an effort to provide this committee a summary of public comment on proposed rules and information about the position PHMSA is likely to take vis-à-vis the major comments. • PHMSA does not share the text of draft final rules with the committee since doing so could trigger a new round of public comment and delay the safety benefits of completing the rule. What PHMSA intends to do: • Consider carefully the comments and any advice this committee provides. Issue a final rule responsive to the NTSB recommendation. • We are considering issuing a final rule with the following changes from the NPRM: - Change focus from avoiding liquids to reducing risks of internal corrosion. Simplify the section to conform more closely to the NTSB recommendation. This change, which will be further explained in the preamble, will recognize the inability to avoid low spots in every case and the variety of pipeline environments. This change responds to comments by INGAA, AGA, individual pipeline companies, and the Iowa Utilities Board. Simplification will improve enforceability. - Except offshore pipelines from the regulation. This change responds to comments by INGAA and El Paso. - Keep the final rule with other corrosion control requirements in subpart I, but add a cross-reference in a design subpart of Part 192 and clarify the non-retroactive impact of the rule. This maximizes the safety benefit of integrated approaches to internal corrosion. - Simplify the recordkeeping provision. This responds to comments by INGAA, AGA, the Texas Pipeline Association, individual pipeline companies, and this committee.#

Page 3Concept for Addressing Record-keeping in Final Rule on Designing and constructing gas transmission pipelines to control internal corrosion Use the approach developed in negotiated rulemaking for operator qualification regulations. This two-fold approach would: 1. Require an operator generally to maintain records demonstrating compliance with the section; and 2. Add some specificity on the required records. For the specificity, allow an operator to use as-built drawings and other construction records or written procedures. Preamble language will provide examples. One example is a procedure on how an operator will address design following the contour of the land in design. To avoid accumulation of liquid in the low spots, the procedure might call for incorporating design feature to maintain gas velocity or turbulence or to remove liquids. The actual construction records or as-built drawings would show what an operator actually did. Another example might be a construction record showing the use of a filter or separator at the gate station of a distribution pipeline. Regardless of the choices in record-keeping an operator makes, the records must show circumstances justifying variance based on impracticability or lack of necessity. For example, if an operator does not provide features for effective liquid removal at low spots, the records must show why it is not necessary to do so.#

Page 4Summary of major comments and how we are addressing them Request for exceptions from regulation based on expected operations Many commenters requested an exception to the design and construction requirements if the operator believes liquids will not pose a problem in the line. The commenters suggested several variations, including: • except pipeline from the requirements where an operator confirms liquids will not present an uncontrolled threat (INGAA); • require design and construction actions only where corrosive gas is being transported (AGA); • except pipelines in areas without a history of internal corrosion (Iowa). Response: When an operator knows liquids in the pipeline are likely, relying on operation and maintenance actions alone to address internal corrosion misses the safety and economic benefit of advance planning for future needs. An operator cannot predict with any certainty the absence of corrosive gas in upset conditions. Planning for these upset conditions when making design and construction decisions makes sense from a safety perspective since it facilitates future operation and maintenance actions to address internal corrosion. For cost effectiveness, PHMSA is considering adding more flexibility to operators to select design and construction options fitting the relative risk that the pipeline will transport corrosive gas in the future. Other requested exceptions from regulation Commenters requested, without explanation, exceptions for the following pipeline facilities addressed by the proposed rule: • gathering lines (INGAA, El Paso); • offshore lines (INGAA, El Paso); and • compressor stations (Duke). Response: PHMSA agrees with an exception for offshore lines. Although these pipelines experience internal corrosion, the risk they pose to people and property is considerably less. In addition, the design and construction options are more limited. Gathering lines and compressor stations are different. Gathering lines are only regulated in populated areas. By their very nature, gathering lines regularly transport gas containing liquids. Both historically and in the new gathering line regulation, gathering lines are subject to the same design and corrosion regulations as transmission lines. Compressor stations do not operate well when there are liquids in the gas flow and liquid removal may result in liquid accumulation in compressor station piping. The incident statistics indicate the real risk of internal corrosion with respect to both gathering lines and compressor stations.#

Page 5Placement within Code Several commenters suggest Subpart I- Requirements for Corrosion Control is wrong place for the proposed rule. They suggest various combinations of Subpart C - Pipe Design, Subpart D - Design of Pipeline Components, and Subpart G - General Construction Requirements for Transmission Lines and Mains. Commenters give the following reasons: • These design and construction requirements should be in the non-retroactive section of the Code. • Subpart I requirements might be overlooked in design and construction. Response: Subpart I contains other design requirements, such as pipe coating. PHMSA believes consolidating corrosion control requirements strengthens the planning aspects of the regulation. To address concerns of commenters, PHMSA is considering adding language (such as a date) that clearly points to the non-retroactive effect of the regulation. PHMSA is also considering adding a cross reference to subpart I in subpart D to alert those designing pipelines of the need to look at corrosion requirements. Recordkeeping Many commenters expressed concern about the proposed recordkeeping requirements; some suggested alternative approaches: • As-built drawings and construction records provide sufficient information about an operator’s design and construction decisions in a less burdensome way. (Gas Piping Technology Committee) • Variances from specific requirements should be documented. (Duke Energy, Nicor, Gas Piping Technology Committee) Suggested language: When an operator makes an exception to paragraphs (a), (b), or (c) of this section, the operator must document the decisions related to the exception. • Documenting decisions with respect to all low spots would be costly and unnecessary (Kinder Morgan, INGAA, El Paso, Panhandle). • If an internal corrosion control program is in place, documenting procedures should be enough. (AGA, SoCal Gas, Southwest Gas, Paiute) Suggested language: An operator must have written procedures to implement the provisions of this section. • Broad general language would be more appropriate and consistent with existing regulations. (Texas Pipeline Association) Suggested language: An operator must maintain records demonstrating compliance with this section for the life of the pipeline. Response: The proposed recordkeeping requirements are overly burdensome. We are considering a general requirement to maintain records demonstrating compliance with the section. As-built drawings and other construction records operators normally maintain together with some additional explanation of variances will suffice. We have developed a concept paper discussing this.#

Page 6Redundancy Some commenters argued that other regulations on internal corrosion control make this proposed rule redundant. For example, commenters pointed to the requirement that new lines be “piggable” and hence capable of being cleaned. Others pointed to integrity management programs (AGA) which address internal corrosion. Response: The proposed rule is not redundant. Most rules cited by commenters are operation and maintenance requirements, not design standards, and thus do not address the NTSB concern. In addition, integrity management programs directly protect only high consequence areas. The piggability requirement is a design standard, but is not applicable to gathering lines.#