July 11, 2003
TO:Missouri Natural Gas Distribution Operators with operations prior to 1985.
(Letter A to operators who reported older Aldyl A pipe installations.)
Letter B to operators who did not report older Aldyl A pipe installations, but did report older PE pipe.
(Letter C to operators who did not report any older PE pipe.)
SUBJECT:Information Request in Follow-up to OPS Advisory Bulletins ADB-02-7 and ADB-99-02
Note: With few exceptions, only one copy of this correspondence is sent per operator. Please forward to the appropriate person(s).
The U.S. DOT–RSPA-Office of Pipeline Safety (OPS) issued Advisory Bulletin ADB-02-7 last year and it was published in the Federal Register on November 26, 2002 (see attached). To call attention to ADB-02-7, the Staff sent a copy to you as an attachment to the All Operators Letter dated January 17, 2003. ADB-02-07 results from brittle-like cracking observed in some older polyethylene (PE) pipe, and specifically mentions the following pipe material as being more susceptible than current materials: Century Utility Products, Inc. products; PE 3306 pipe; and certain “Aldyl A” pipe manufactured before 1973. In addition to advising operators about this older plastic pipe, OPS recommends that all operators implement 6 practices (listed at end of the advisory bulletin) for all polyethylene systems.
OPS also issued Advisory Bulletin ADB-99-02 and it was published in the Federal Register on March 11, 1999 (see attached). The purpose was to advise natural gas distribution line operators of the need to determine the susceptibility to brittle-like cracking of plastic pipe installed between 1960 and the early 1980s.
On May 14, 1997, the Staff sent an All Operators Letter with a survey on older PE pipe. The survey asked if operators had any Century Pipe or Flying “W” piping and requested information regarding any PE pipe installed prior to 1980. No operators responded that they had Century or Flying “W” in their Missouri gas systems. Several operators provided information about PE pipe that was installed prior to 1980, including a few operators who had installed “Aldyl A” pipe.
To follow up on ADB-02-07, ADB-99-02 and the 1997 survey, the Staff is sending correspondence to all operators that operated Missouri gas systems prior to 1985. There are three versions of this correspondence. Letter A is being sent to operators who replied to the 1997 survey and indicated they installed “Aldyl A” prior to 1980. Letter B is being sent to other operators who reported other types of older PE pipe. Letter C is being sent to all other operators with gas systems prior to 1985.
Letter B
Within 20 days of this letter, please reply to the following questions or contact the Staff to request a later reply date.
1)Do you have any Century Utility Products, Inc. products or PE 3306 polyethylene pipe in your Missouri gas systems? If so, please indicate the footage of main and number of service lines for each.
2)Please find attached your response to the 1997 survey on older PE pipe. Please verify the accuracy of the survey answers and provide any corrections.
3)Your survey indicates that you did not install “Aldyl A” pipe prior to 1980. Please verify that this is correct.
4)In ADB-02-07, OPS recommended that all operators implement 6 practices for all PE piping systems to identify brittle-like cracking problems and take appropriate action, including replacement. The first recommended practice is to:
Review system records to determine if any known susceptible materials have been installed in the system. Both engineering and purchasing records should be reviewed. Based on the available records, identify the location of the susceptible materials. More frequent inspection and leak surveys should be performed on systems that have exhibited brittle-like cracking failures of known susceptible materials.
ADB-02-07 identifies “known susceptible materials” as Century Utility Products, Inc. products, “Aldyl A” piping manufactured before 1973, and PE 3306 pipe. Please indicate if your City or Company has implemented this first recommended practice. If so, please provide results and indicate what actions are planned. If not, please indicate if and when this practice will be implemented.
5)Please provide any plans or results related to the implementation of recommended practices 2 through 6 in ADB-02-07.
6)In ADB-99-02, OPS recommended that all owners and operators of natural gas distribution systems:
Identify all pre-1982 plastic pipe installations, analyze leak histories, and evaluate any conditions that may impose high stresses on the pipe. Appropriate remedial action, including replacement, should be taken to mitigate any risks to public safety.
Please indicate if your City or Company has implemented this recommendation. If so, please provide results and indicate what remedial actions have been taken or planned. If not, please indicate if and when this recommendation will be implemented.
7)If you have PVC mains or service lines in your Missouri gas systems, please provide information regarding your leak history with PVC, including how many leaks involved a crack or fracture?
8)Please provide any other actions or programs that are in place or planned by your City or Company related specifically to the “known susceptible materials” that have been identified by OPS in ADB-02-07; and in general for older PE pipe and/or PVC pipe.
If you have any questions concerning this topic, please contact me at 573/751-3456.
Sincerely,
Robert R. Leonberger
Assistant Manager – Gas Safety/Engineering
JK; RRL
Attachments