[Federal Register Volume 64, Number 153 (Tuesday, August 10, 1999)]
[Notices]
[Pages 43422-43423]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-20539]


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DEPARTMENT OF TRANSPORTATION

Research and Special Programs Administration
[Docket No. RSPA-99-5442; Notice 2]


Chevron Pipe Line Company; Grant of Waiver

AGENCY: Research and Special Programs Administration, DOT.

ACTION: Notice.

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    Chevron Pipe Line Company (CPL) petitioned the Research and Special 
Programs Administration (RSPA) for a waiver from compliance with 49 CFR 
19.612(b)(3), which requires that gas pipeline facilities in the Gulf 
of Mexico found to be exposed on the seabed or constituting a hazard to 
navigation be reburied so that the top of the pipe is 36 inches below 
the seabed.
    CPL proposed to install concrete mesh blanket units to protect the 
pipeline from damage in lieu of the 36 inches of cover required by 
(192.612(b)(3)). Each concrete mesh blanket unit is a 20-foot by 8-foot 
by 9-inch section constructed from 160 individually cast 17-inch by 17-
inch by 9-inch beveled concrete briquettes inter-connected with \3/4\-
inch polypropylene UV stabilized line.
    On May 27, 1999 we published a notice of petition for waver with 
request for comments in the Federal Register (60 FR 27809 May 25, 
1995). We received two comments. The first commenter opined that the 
alternative to cover the line with a 9'' concrete mat did not appear to 
provide equal protection to the pipeline to that of 36'' of natural 
cover. The commenter further stated that the mat would produce a hump 
on the gulf floor which may create further safety risk. The second 
commenter expressed interest in the proposal to require a rock shield. 
The commenter believed that a pipe of the diameter would have been 
concrete coated before installation thus negating the need for any 
further protection of the pipe from the concrete mesh blanket units.
    We have considered the concerns expressed by the commenter and 
agree that the concrete mat could under some circumstances pose a 
hazard to navigation by reducing the water depth by 9-inches. However, 
the potential for adverse consequences of a vessel striking the mat is 
less than the potential for adverse consequence for a vessel striking 
and rupturing a high pressure natural gas pipeline. As evidenced by 
repeated surveys in this area, the gulf floor consists of sugar sands 
which are highly susceptible to erosion. Although the concrete mats

[[Page 43423]]

would reduce the depth of water by 9-inches, the mats provide 
consistent penetration resistance and are designed to promote the 
collection of bottom silt and vegetative growth. This silt-in process 
is achieved by particulates dropping out of the water column as a 
result of reduced current flow across the mesh blankets and will add 
stability to the installation while building cover over the pipeline. 
The concrete blanket will consistently protect the line to an equal or 
greater degree as will 36-inches of soft, unstable natural cover.
    We agree with the second commenter that the rock shield would be 
unnecessary if the pipeline is concrete coated. CPL confirms that the 
pipeline was concrete coated. Therefore we will not require a rock 
shield to be installed.
    In consideration of the forgoing we find that the requested waiver 
of compliance with Sec. 192.612(c)(3) is not inconsistent with pipeline 
safety. Therefore the request for waiver is granted.

FOR FURTHER INFORMATION CONTACT: L.E. Herrick by telephone at 202-366-
5523, by fax at 202-366-4566, by mail at U.S. Department of 
Transportation, RSPA, DPS-10, 400 Seventh Street, SW, Washington, DC 
20590, or via e-mail to [email protected] regarding the subject 
matter of this notice.

    Authority: 49 U.S.C. 60118(c); 49 CFR 1.53.

    Issued in Washington, DC, on August 5, 1999.
Richard B. Felder,
Associate Administrator for Pipeline Safety.
[FR Doc. 99-20539 Filed 8-9-99; 8:45 am]
BILLING CODE 4910-60-P