Environmental regulators in West Virginia ordered Energy Transfer Partners LP (NYSE: ETP) to again halt work on its Rover natural gas pipeline in the state due to permit violations, according to Reuters on March 14.

These are just the latest of numerous permit violations that the $4.2 billion Rover pipeline has racked up since ETP started building the project in the first-quarter of 2017.

Rover is the biggest gas pipe under construction in the U.S. It is designed to carry up to 3.25 billion cubic feet per day (Bcf/d) 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.

One Bcf of gas is enough to fuel about 5 million U.S. homes for a day.

The West Virginia Department of Environmental Protection (DEP) issued the order on March 5 following inspections in mid to late February.

The state said inspectors observed 14 permit violations, including problems with storm water and trash.

“We continue to work with ... the DEP to resolve any outstanding concerns,” ETP spokeswoman Alexis Daniel said.

This is not the first time West Virginia stopped ETP from work on Rover. The DEP ordered the company to halt some work from July 17 to August 9 due to violations of storm water rules.

In addition, the U.S. Federal Energy Regulatory Commission stopped ETP from horizontal drilling in Ohio from May 10 to September 18 after an estimated 2 million gallons of drilling fluid spilled into a wetland near the Tuscarawas River.

Energy companies use horizontal drilling to cross under obstacles such as rivers and highways.

Before those stop work orders, ETP expected to finish Rover in November. ETP said it still expects to complete the project by the end of the second-quarter of 2018. Rover has been partially in service since August and is now able to transport up to 1.7 Bcf/d.

Some analysts, however, said it would be difficult for ETP to complete Rover that soon.

“ETP has said in filings that it plans to conduct some horizontal drilling in April and May, making it more likely that they will not finish the project until the third quarter,” Peter Busk, a research analyst at energy research firm East Daley Capital, said.

Major producers that signed up to use Rover include units of privately held Ascent Resources Plc, Antero Resources Corp. (NYSE: AR), Range Resources Corp. (NYSE: RRC), Southwestern Energy Co. (NYSE: SWN), Eclipse Resources Corp. (NYSE: ECR) and EQT Corp. (NYSE: EQT).