Interpretation Response #PI-18-0013

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date: 11/05/2018

Company Name: Michigan PSC

Individual Name: Mr. David J. Chislea

Location State: MI Country: US

View the Interpretation Document

Response text:

Mr. David J. Chislea
Manager of Gas Operations
Michigan Public Service Commission
7109 W. Saginaw Highway
Lansing, MI 48917

Dear Mr. Chislea:

In a May 16, 2018, letter to the Pipeline and Hazardous Materials Safety Administration (PHMSA), you requested an interpretation of 49 CFR Part 192. Specifically, you requested interpretation for external corrosion remedial measures to "hot-spot" protected pipelines under § 192.483(c). You provided a summary of PHMSA issued interpretations and requested response for the following questions. PHMSA's responses follow each question.

Question 1. An operator experiences a corrosion leak on an electrically-continuous unprotected steel distribution pipeline. The operator then installs a leak clamp and an anode at this location. Does the operator have to comply with the monitoring requirements in 49 CFR 192.465 and the level of cathodic protection criteria in 49 CFR 192.463?

PHMSA Response 1. Yes, at a "hot-spot" location, an anode must be installed on an otherwise cathodically-unprotected pipeline. Installation of an anode at this spot makes it cathodically protected. Therefore, as stated in § 192.465(a), unless tests at those intervals are impractical, each pipeline that is under cathodic protection must be tested at least once each calendar year, but with intervals not exceeding 15 months, to determine whether the cathodic protection meets the requirements of § 192.463.

In addition, under § 192.465(e), after the initial evaluation required by §§ 192.455(b) and (c) and 192.457(b), each operator must, not less than every 3 years at intervals not exceeding 39 months, reevaluate its unprotected pipelines (in this case, “hot spots”) and cathodically protect them in accordance with this subpart in areas in which active corrosion is found.

PHMSA prepares guidance to assist its stakeholders and the public to understand how it interprets it regulations. Guidance documents describe the practices used by PHMSA pipeline safety investigators and other enforcement personnel in undertaking their compliance, inspection, and enforcement activities. PHMSA's Corrosion Enforcement Guidance, explains that PHMSA's regulations require that short sections of separately protected coated and "hot spot" protected bare (ineffectively coated) sections of pipeline be surveyed on an annual 10 percent basis with a different 10 percent checked each subsequent year so that all these sections are tested in each 10-year period. If the "hot spot" is included in the 3-year monitoring program, transmission operators who are electrically monitoring their entire bare (ineffectively coated) sections of pipeline on a one-third per year basis would not have to include their "hot spot" protected sections of pipeline in a 10 percent monitoring program (https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/Corrosion_Enforcement_Guidance_Part192_12_7_2015.pdf).

Question 2. An operator experiences external corrosion that did not result in a leak on an electrically continuous unprotected steel distribution pipeline. The operator recoats the pipeline at this location and installs an anode. Does the operator have to comply with the monitoring requirements in 49 CFR 192.465 and the level of cathodic protection criteria in 49 CFR 192.463?

PHMSA Response 2. Yes, similar to the answer to Question 1, cathodically protected pipelines must comply with §§ 192.463 and 192.465 requirements.

Question 3. If so, at what interval does the operator have to monitor the "hot-spot?"

PHMSA Response 3. Please refer to response to question 1.

Question 4. Does the operator's threat assessment prioritization through the distribution integrity management plan [DIMP] have an impact on how this would be enforced if these "hot spot" areas are identified and ranked as a corrosion threat? Could the operator's increased corrosion threat identification in a hot spot area through the integrity management program potentially eliminate the monitoring requirements in 49 CFR 192.465 and the level of cathodic protection criteria in § 192.463?

PHMSA Response 4. While these requirements are complimentary, an operator is required to comply with both regulations. It is a pipeline operator's responsibility to prioritize its pipeline system assessment for safety threats. However, the operator must comply with these sections as well as the DIMP requirements.

As to your second question, integrity management cannot be used to eliminate the requirements in §§ 192.465 and 192.463. Relief from those regulations may only be granted under a waiver/special permit according to § 190.341, and would involve alternative safety measures. In 49 CFR, Part 192, subpart P, Gas Distribution Integrity Management outlines in § 192.1007 how to identify, evaluate and implement measures to address risks. Implementation of additional measures to eliminate threats and risks from unprotected "hot spot" areas would not allow the operator to avoid complying with the monitoring requirements in 49 CFR § 192.465 and the level of cathodic protection in 49 CFR § 192.463.

Question 5. Are "hot-spot" protected areas on electrically continuous pipeline considered "separately protected?"

PHMSA Response 5. Yes, a "hot-spot" is a location where a leak clamp and an anode has been installed on an otherwise cathodically-unprotected pipeline and the "hot spot" must comply with §§ 192.463 and 192.465 requirements. Other examples of pipelines considered separately protected would be steel pipelines connected to other pipe materials such as cast iron and a plastic.

Question 6. Why were the interpretations in Numbers 4, 5, and 6 removed from PHMSA's website?

PHMSA Response 6. The October 28, 1996, PHMSA interpretation was removed because of a regulatory change to § 192.465(e). The September 17, 1976, letter may have been removed during changes to the PHMSA public website. We are looking into the status of this interpretation. The July 15, 1993, letter (PI-93-035) is posted on the PHMSA website, available at https://www.phmsa.dot.gov/regulations/title49/b/2/1/list?filter=Pipelines.

If we can be of further assistance, please contact Tewabe Asebe at 202-366-5523.

Sincerely,

John A. Gale
Director, Office of Standards
and Rulemaking

Regulation Sections