Feb 6 (Reuters) - The U.S. Federal Energy Regulatory Commission on Tuesday authorized Energy Transfer Partners LP to recommence a horizontal drill under the Tuscarawas River in Ohio as the company works to complete its Rover natural gas pipeline by the end of the first quarter.
FERC said in a filing it allowed Rover to start drilling again after the company provided a revised drilling plan for the second pipe under the Tuscarawas River on Sunday and some analysis on Monday of residential water wells in the vicinity of the drill.
Rover will monitor the quality of the water in the wells during and for a period of time after the drill.
FERC ordered Rover to cease drilling of the second pipe under the river on Jan. 24 and asked the company to evaluate alternatives to the drill after Rover lost some drilling fluid - a mixture of clay and water - in the hole.
Those alternatives included completing the current drilling, finding another location to cross under the river or go with just one pipe across the river.
ETP said in a letter to FERC last week that it was not unusual for some fluid to be lost and that none has returned to the surface or caused any harm.
The $4.2 billion Rover project is designed to carry up to 3.25 billion cubic feet per day of gas from the Marcellus and Utica shale fields in Pennsylvania, Ohio and West Virginia to the U.S. Midwest and Canada's Ontario province.
ETP already has one pipe in service under the Tuscarawas, with more than 1.1 bcfd of gas flowing through it. One bcfd of gas is enough for about 5 million U.S. homes.
While drilling that first pipe, the company spilled about 2 million gallons of drilling fluid into a wetland in April. That spill led FERC in May to ban Rover from horizontal drilling temporarily.
Energy companies use horizontal drilling to cross under obstacles like highways and rivers.
ETP said on Monday it was still on track to complete the project by the end of the first quarter. Some analysts, however, have said completion of the project would probably be delayed into the second quarter, at least.
Major producers that signed up to use Rover include units of privately held Ascent Resources, Antero Resources Corp, Range Resources Corp, Southwestern Energy Co, Eclipse Resources Corp and EQT Corp. (Reporting by Scott DiSavino; Editing by James Dalgleish)