Relations are increasingly strained between the California Public Utilities Commission (CPUC) and Pacific Gas and Electric Co. (PG&E) after coming to a head Tuesday over the utility's latest plans to verify operating pressures for hundreds of miles of natural gas transmission pipeline in highly populated areas.
The head of the CPUC's Consumer Protection and Safety Division (CPSD), Richard Clark, pushed back against PG&E's plans by insisting that the San Francisco-based utility hydrostatically test up to 705 miles of pipeline in high-consequence areas (HCA).
"We will be working with the commission to better understand the impacts this may have on PG&E's operations, as well as to the natural gas transmission industry as a whole," a PG&E spokesperson told NGI Thursday. "Meanwhile, we have already taken many steps to further enhance the safety of our system, including an aggressive plan to hydrostatically test or replace 152 miles of gas pipeline in 2011, etc."
If the staff's proposal is approved by the five-member CPUC, the added hydro-testing could cost an estimated $350 million over a five-year period during which significant disruption of service might also result.
A source of friction is the National Transportation Safety Board's (NTSB) standard for "traceable, verifiable and complete" records on the pressure testing of every section of pipeline traversing HCAs (see Daily GPI, Jan. 5). Increasingly, the CPUC safety staff has criticized PG&E for trying to skirt the standard in terms of the total miles of pipe tested and the thoroughness of the tests.
"CPSD staff has become increasingly uncomfortable with PG&E's proposal to use assumptions to populate its pipeline features list as an integral part of verifying the maximum allowable pipeline pressure of particular segments of its HCA pipeline segments that do not have 'traceable, verifiable and complete' records of all the components of each segment," Clark said.
Clark said both NTSB and the CPUC are requiring PG&E to provide "direct evidence" of the material condition of all sections of its transmission pipelines. The CPUC wants pressure testing or replacement of all pipe sections for which PG&E used assumptions to validate maximum allowable operating pressure. It does not want substitutes used for hydrostatic testing of these segments.
PG&E has attempted in some cases to use other measures -- x-ray, camera inspections or automated ball indentation -- in place of the hydro-testing. Clark said the other measures can help in prioritizing pipeline segments for hydro-testing, but they cannot be used as a replacement.
In other instances, according to Clark's letter, PG&E has proposed using inline inspection (ILI) tools for pipelines with various welded seams that were installed before 1970. The CPUC does not that think that is sufficient testing since the San Bruno, CA, segment that ruptured last September was found to have a similar welded seam, although PG&E records indicated that it was "seamless."
"Inline inspection tools, as advanced as they are, are not without the possibility of missing certain defects when run through the pipeline," Clark said. "While hydro-testing also has its limitations and concerns, CPSD believes these concerns can be addressed through properly designing and performing the tests as PG&E intends to do for the 152 miles of pipeline it intends to hydro-test in 2011."
From Clark's latest communication with the utility, it appeared that the CPUC thinks that complete pressure test records should include all elements that were required by the regulations in effect at the time the pipelines were constructed. In addition, the state regulators are mindful that requiring hydro-testing of 705 miles of HCA pipelines will be both costly and disruptive to PG&E gas utility operations.
Thus, the CPUC will work with PG&E to provide enough time and flexibility, and ultimately "to assure that these activities can be prioritized so as to minimize the possibility of outages," Clark said.
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