{"operation":"document","citation":"PI-73-012","title":"West Virginia Public Service Commission — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1973-12-14","effective_on":null,"summary":"PI-73-012 response to West Virginia Public Service Commission concerning 192.457.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-73-012-1973-12-14.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-73-012-1973-12-14.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-73-012-1973-12-14","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/Pipeline/1973/g73-12-14_Spalding_192.457-nlmx.pdf","body":"<<<PAGE 1>>>\n\nPI-73-0120\nDecember 14, 1973\nMr. T. K. Spalding\nDirector\nGas Pipeline Safety Division\nWest Virginia Public Service Commission\nCharleston, WV 25305\nDear Mr. Spalding:\nIn your letter of November 29, 1973, you forwarded questions submitted to you by a local operator. These questions\nwith our comments are as follows:\nQuestion 1\nDo the minimum standards require the cathodic protection of the section of a bare, welded transmission line where it\ncrosses a public highway, or makes a parallel encroachment on the right-of-way, if both the transmission line and the\nhighway are in a Class 1 location?\nOPS Comment\nRegardless of class or location (such as at a highway crossing), a transmission operator must comply with section\n192.457(b)(1) which requires cathodic protection in areas in which active corrosion is found. As required by Section\n192.457(b), the operator shall determine areas of active corrosion by electrical survey, or where electrical survey is\nimpractical, by the study of corrosion and leak history records, by leak detection survey, or by other means. Specifically,\nif tests do no indicate the presence of active corrosion at a highway crossing, then cathodic protection is not necessary.\nQuestion 2\nOn a bare transmission or distribution line do you consider a soil resistivity survey to be an electrical survey, as required\nby 192.457(b), for determining hot spot protection?\nOPS Comment\nA soil resistivity survey consists of electrical measurements which are helpful in determining those portions of a pipeline\nsystem in which corrosion is more likely to occur than in other portions. Following this survey, an electrical survey, such\nas pipe-to-soil potential measurements or surface potential measurements, is normally made in areas of low resistivity\nso that cathodic protection can be provided first in those areas that need it most.\nOn a transmission pipeline, an electromagnetic survey could be made in lieu of soil resistivity and pipe-to-soil potential\nsurveys.\nIf an operator plans to cathodically protect an entire portion of bare transmission pipeline or distribution system, a soil\nresistivity survey is sufficient. If the operator plans to provide cathodic protection only in areas of active corrosion as\nrequired by Section 192.457(b), a soil resistivity survey by itself will not pinpoint areas of active corrosion. For this\nreason, a combination of soil resistivity survey and, for example, pipe-to-soil potential survey is necessary.\nI trust this answers your questions. If not, please let us know.\nSincerely,\nJoseph C. Caldwell\nDirector\nOffice of Pipeline Safety\n\n<<<PAGE 2>>>\n\nState of West Virginia\nPublic Service Commission\nCharleston, 25305\nNovember 29, 1973\nMr. Joseph C. Caldwell, Director\nOffice of Pipeline Safety\nDepartment of Transportation\nWashington, D.C. 20590\nDear Sir:\nThe following questions were submitted to me by a local operator and I will appreciate your answer:\n1. Do the minimum standards require the cathodic protection of the section of a bare, welded\ntransmission line where it crosses a public highway, or makes a parallel encroachment on the right-of- way, if\nboth the transmission line and the highway are in a Class 1 location?\n2. On a bare transmission or distribution line do you consider a soil resistivity survey to be an electrical\nsurvey, as required by 192.457(b), for determining hot spot protection?\nYours very truly,\nT.K. Spalding, Director\nGas Pipeline Safety Division","truncated":false,"body_characters":3460}