The federal government will investigate all of the Pegasus Pipeline — an ExxonMobil line that has leaked oil twice in the past few weeks, a federal spokeswoman said.

“We are looking at the entire Pegasus line,” said Patricia Klinger, a spokeswoman for the Pipeline and Hazardous Materials Safety Administration, in email Thursday.

On Wednesay, the pipeline that ruptured in Arkansas on March 29 and dumped about 5,000 barrels of thick, black crude into a Mayflower community sprang another leak in Ripley County, Missouri. A photo from Exxon shows black oil oozing up from the ground.

“Although the pipeline was not in service, it leaked crude oil that remained in other sections of the pipe following the March failure,” Klinger wrote. 

The spill in Missouri is small, officials said. Exxon spokesman Michael Kontos said the leak in Missouri is not related to the one in Arkansas.

“Preliminary indications are that the damage that caused the one-barrel leak in Doniphan was third-party related, but we are still investigating the causes of both incidents,” he said in email.

Before the line restarts, the entire length of the line — about 850 miles — will be inspected, Kontos said. Pegasus was inspected in 2006 and 2010, as required by PHMSA.

“Immediately prior to the incident, the pipeline met all requirements as outlined by PHMSA for operating under normal pressure and flow conditions,” Kontos said.

The pipeline’s integrity is not predicted by age, Kontos said.

“Each pipeline is evaluated and managed based on its type of service, the results of ongoing inspections and other relevant data,” he wrote. “ExxonMobil manages its pipelines with a detailed and systematic integrity management program, consistent with the requirements outlined by the federal regulators. This includes, among other activities, cathodic protection, corrosion monitoring, internal inspections, hydrotesting, ground and air surveillance and the use of internal cleaning devices.”

After the investigation is finished, Exxon will develop a plan for restarting the line, Kontos said.  

“We will not restart the pipeline until both the relevant government authorities and we are convinced it is safe to do so,” Kontos said.

In an accident report filed with the federal government April 26, Exxon said it estimated it would spend $13.6 million toward the emergency response to the oil spill in Mayflower. Kontos said the company estimates about $1.3 million will be spent on temporary housing. The company would not release information on the amount paid in general claims, citing privacy concerns.

Exxon also lost $500,000 in oil and suffered about $1 million in property damage and repairs.

The document also estimates about 2,000 barrels of oil reaching water or released in it. Exxon has said no oil is in Lake Conway, but has said oil is in the cove and marsh areas around the lake. 

The cause of the accident has yet to be determined, Exxon wrote in its report.

Meanwhile the state attorney general is continuing its own investigation and reviewing the documents Exxon provided, spokesman Aaron Sadler said in email Thursday.

“We can’t speculate as to what happened in Missouri, but our focus now is on making sure the pipeline is safe and well-maintained in Arkansas,” Sadler wrote. “This incident in another state further demonstrates the need for a thorough investigation of the condition of the entire Pegasus pipeline.”

The company completed repairs on the Pegasus pipeline in Doniphan, Mo., where about one barrel of oil leaked from the line, by Friday afternoon. 

“Work crews will begin to backfill the site today, weather permitting,” Kontos said. “The company is working with regulators to investigate the cause of the incident.”

The pipeline remains out of service.