A train approaches the Wiehle-Reston East station during a tour of the Silver Line in late 2013. (Matt McClain/The Washington Post)

With the announcement that work on the first phase of the Silver Line is complete, the much anticipated rail line inches a step closer to its ultimate goal: the beginning of passenger service.

Dulles Transit Partners, the contractor for the rail line, filed paperwork Wednesday saying its work on the Silver Line is complete. Officials at the Metropolitan Washington Airports Authority now have 15 days to verify that the contractor has met its obligations, including making some much-needed fixes that have contributed to multiple delays in getting the rail line up and running.

“We’re going to go through the process as expeditiously as we can to move things along,” said MWAA spokesman David Mould. “We are looking forward to the next step — being able to present the project to WMATA. We are optimistic that things will continue moving along well.”

MWAA’s sign-off on the contractor’s work is only the first in a series of steps that must take place before the Silver Line can begin carrying passengers.

Once MWAA gives its approval, it must negotiate a handoff to Metro officials, said Pat Nowakowski, executive director of the rail project. Nowakowski said MWAA officials hope to certify DTP’s work and hand the rail line to Metro simultaneously.

Metro then will have 90 days to test the system and train its personnel on the new rail line. During that period, Metro also will conduct emergency drills with first responders to familiarize them with the Silver Line. The Federal Transit Administration and the Tri-State Oversight Committee also will conduct their own safety reviews.

Earlier this week, Metro chief Richard Sarles told reporters that his commitment was that service on the line would start “within 90 days” of Metro assuming control of the Silver Line.

“We’ve watched the testing that MWAA has done and made sure we understood the results and worked with them when there is an issue,” he said.

Wednesday’s filing was Dulles Transit Partners’ second attempt at declaring its work on the project complete. An early try in February was rejected by officials at MWAA, who said DTP failed to meet seven of 12 requirements for completion, including securing proper permits and safety certifications for rail stations. MWAA’s review also found issues with escalators and elevators in the stations.

The filing signals that many of MWAA’s major concerns have been resolved. After the initial failed submission, Nowakowski said MWAA would work closely with DTP to ensure that the second filing would meet the standards.

Still, it is possible that MWAA could reject the submission — an action that would be a huge setback for a project already seven months overdue.

By filing Wednesday, DTP avoided the costly embarrassment of having to pay thousands in fines for delivering the project past the agreed upon date. Under the contract, DTP was required to finish the project by Sept. 9, 2013, but was given a grace period before financial penalties would be assessed. If DTP had failed to file paperwork Wednesday, it would have faced $25,000 a day in fines. If the delays stretched beyond three months, the fine would have escalated until the project was deemed complete.

Speculation on when the rail line will begin carrying passengers has become a parlor game for those who have monitored the Silver Line’s progress closely. Test trains have been running on the line since late 2012, and with the stations mostly complete, some people have been fooled into thinking the Silver Line is open for business. That has forced the contractors to bring in extra security to prevent trespassing.

Officials had originally hoped to begin passenger service in December, but a series of delays pushed the expected opening into 2014.

DTP was tasked with ripping out and reinstalling hundreds of speakers at five stations on the rail line that did not meet fire codes to move the project forward.

The Silver Line is the first new line to be added to the Metro system in more than two decades. It is also the first addition to the system that was not built by Metro, which added complexity to the project.

The addition to the Metro system is one of the largest infrastructure projects being built in the country. Northern Virginia leaders see it as key to the region’s economic development. This first phase will have five stops, four in Tysons Corner and one in Reston at Wiehle Avenue. Work on the second phase, which will have six stops, including one at Washington Dulles International Airport, has begun.

The majority of the rail line’s $5.6 billion cost is being paid by users of the Dulles Toll Road. But Fairfax and Loudoun counties, MWAA and the state of Virginia have also contributed to the project’s cost. The federal government contributed $900 million to the project’s first phase.

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