U.S. designates Gulf of Mexico lightering areas

The U.S. Coast Guard has marked four areas in the Gulf of Mexico in which tankers may lighter cargoes of oil bound for coastal onshore terminals. The agency designated the lightering zones to wrap up a rulemaking process begun in late 1993 that also established three areas in the gulf where lightering will not be allowed.(74844 bytes) The Coast Guard issued the final rule as required by the Oil Pollution Act of 1990 (OPA 90), which sets strict environmental guidelines for oil and gas operations.
Sept. 4, 1995
3 min read

The U.S. Coast Guard has marked four areas in the Gulf of Mexico in which tankers may lighter cargoes of oil bound for coastal onshore terminals.

The agency designated the lightering zones to wrap up a rulemaking process begun in late 1993 that also established three areas in the gulf where lightering will not be allowed.(74844 bytes) The Coast Guard issued the final rule as required by the Oil Pollution Act of 1990 (OPA 90), which sets strict environmental guidelines for oil and gas operations.

Among other things, OPA 90 prevents single hull tankers taken under charter after June 30, 1990, or single hull tankers being phased out by the act from offloading oil destined for the U.S. anywhere in the U.S. Exclusive Economic Zone (EEZ). Exceptions are deepwater ports and designated lightering zones.

The first single hull vessel phaseout went into effect last Jan. 1.

The only deepwater U.S. oil port is the 1.4 million b/d Louisiana Offshore Oil Port in 115 ft of water 18 miles off Louisiana (OGJ, Aug. 21, p. 22).

The new lightering zones will allow single hull vessels an optional way of transshipping oil in the EEZ until 2015. After 2015, U.S. law bans all single hull tankers of 5,000 gross tons or more from operating in U.S. waters.

The final rule designating the lightering zones became effective upon publication Aug. 29 in the Federal Register. Coast Guard officials said enforcement of the requirements is to begin in less than 30 days.

Rule overview

The Coast Guard acknowledged that lightering is a well-established means of shipping oil into the U.S.

Officials estimate that about 2 million b/d of oil, or more than 25% of total U.S. daily crude oil imports, is lightered before entering the country.

Despite heavy reliance on lightering as a means of delivering oil to onshore marine terminals, companies involved in the operations have compiled a good environmental record.

Testimony in New Orleans during the lightering rule's comment period showed that only 15 accidental lightering spills occurred during 1980-90. The reported incidents released a combined 45 bbl of oil.

The Coast Guard's final rule demarks four lightering zones: Southtex, Gulfmex No. 2, Offshore Pascagoula No. 2, and South Sabine Point. The rule bans lightering in areas designated as Claypile, Flower Garden, and Ewing.

Flower Garden involves the Flower Garden Banks national marine sanctuary straddling the boundary between the gulf's western and central federal planning areas.

The rule also specifies weather conditions that will limit lightering operations. Tankers are not to attempt to moor alongside another vessel for light- ering if wind velocity exceeds 30 knots or wave heights exceed 10 ft. Lightering operations must cease if winds reach 44 knots or in seas greater than 15 ft.

The Coast Guard said setting up the lightering zones will not affect world tanker capacity for crude oil. If a shortage of tanker capacity occurred, however, the zones would help ease economic harm in the U.S.

Copyright 1995 Oil & Gas Journal. All Rights Reserved.

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