Construction is in progress on a pedestrian bridge that is part of Phase II of Metro’s Silver Line expansion, on July 26, in Herndon, Va. (Katherine Frey/The Washington Post)

Concrete panels for several of the new Silver Line stations do not meet safety or reliability standards and were made by a company that doctored testing records and used unapproved materials to mask the flaws, according to a whistleblower lawsuit unsealed Wednesday in federal court.

The suit, filed in the U.S. District Court for the Eastern District of Virginia, alleges officials at Universal Concrete Products, based in Stowe, Pa., knew the precast concrete panels they manufactured were defective and could be prone to cracking and water erosion that could affect structural integrity. When an employee in their quality assurance department flagged the problem, the suit alleges, he was told to ignore it and later instructed to fake test data to cover up the problems.

The company made more than 1,500 panels that were used to construct exterior walls at five of the six new Silver Line stations that are part of the extension to Dulles International Airport and into Loudoun County.

Virginia and the federal government announced on Wednesday that they were joining the suit over the project being managed by the Metropolitan Washington Airports Authority.

The whistleblower, Nathan ­Davidheiser, filed the suit in March 2016, claiming he was fired from his job as a quality control lab technician at Universal Concrete Products after he continued to question problems with the company’s manufacturing process. He filed his complaint under the federal False Claims Act, which allows whistleblowers to recover a portion of any money the government recovers on behalf of defrauded taxpayers.

Davidheiser’s allegations add uncertainty into the fate of the $5.8 billion rail project.

Officials at Universal Concrete did not reply Wednesday to phone calls and emails requesting comment. Universal was a subcontractor on the project, which is led by Capital Rail Constructors, a joint venture between Clark Construction Group and Kiewit Infrastructure. According to the lawsuit, Universal’s contract was valued at roughly $4 million.

The lawsuit indicates the problems are far more extensive that MWAA previously acknowledged in the wake of news accounts about the panels earlier this month.

Capital Rail Constructors said Wednesday the problems with the concrete affected only 20 percent of the 1,569 panels. CRC said earlier this month that a separate contractor would be hired to treat all remaining panels with a special sealant for an added layer of protection.

The suit alleges the combination of problems could present “a significant safety hazard” to riders and affect structural integrity because of water erosion and cracking. The allegations that problems went undetected for several years also raise questions about whether the project will meet its expected August 2019 deadline or need extensive repairs or concrete replacement in stations before they can open. It is expected to open for passenger service in 2020.

Officials at CRC did not identify problems with the concrete panels until April 2016.

Hours before the suit was unsealed Wednesday, MWAA’s board of directors, during its regular monthly board meeting, was assured by a CRC representative that concrete problems were being addressed and that the project would move forward on schedule and within budget.

“Corrective actions don’t impact CRC’s ability to deliver the product next year,” Keith Couch, who heads the project for CRC, told the board. “The safety, reliability and durability of the project is not compromised.”

Couch reiterated that all panels would be treated with sealant.

After the suit was unsealed: Couch said: “CRC is in the process of assessing the new information and it would be premature to comment.”

MWAA had no comment on the lawsuit.

The Silver Line rail project, seen by leaders in Northern Virginia as critical to the region’s economic growth, is one of the largest infrastructure projects under construction in the country. Its first phase, which included four stations in Tysons Corner and one in Reston, opened in 2014. The second phase, whose six stops include Dulles International Airport, is already 13 months behind schedule.

The filing unsealed Wednesday includes statements, text messages and email chains as part of its claim that there was an effort to cover up problems.

As part of his job, Davidheiser was responsible for testing the concrete for air content, a critical measure of the material because improper air ratios could cause water erosion “weakening the integrity of the structure potentially causing a collapse,” according to the suit. Another critical measure is the water-to-cement ratio, which, if higher than contractually required, “ultimately weakens the structure” and could cause cracks, according to the suit.

The suit alleges Davidheiser and his boss, Andrew Nolan, lacked the certifications to properly carry out required testing in Virginia. On several occasions, the lawsuit asserts, Davidheiser witnessed Nolan manipulating the water ratios.

Nolan could not be located for comment Wednesday.

“An improper water-to-cement ratio could lead to unanticipated degradation and impose upon Metro and its riders a significant safety hazard,” the suit says.

Text message threads included in the court filing indicate Davidheiser asked for data on the Silver Line materials — but because it was faulty or missing — was told by Nolan “we cannot give them the sheets with any testing data out of specs,” Nolan wrote, according to the text messages in the lawsuit. “They will reject those panels. We have to change the data and adjust our mix to achieve the specific conditions.”

“Just say the concrete was poured before [quality control] finished testing or something (if anyone asks) and that is why we have some bad data,” read a subsequent text allegedly from Nolan. “But we have to change it.”

Davidheiser eventually resigned from the company in 2016, the lawsuits says, after his concerns went unheeded.

Rep. Gerald E. Connolly (D-Va.), a Silver Line booster who advocated for the project as chairman of the Fairfax County Board of Supervisors, said the project must go forward, but Universal should pay the harshest penalty if the allegations are true.

“This is not a performance issue in terms of ‘Well, we didn’t quite meet the goal,’ or some technical glitch that ‘we just sold tiny [amount] shy of whatever standard,’ ” he said. “This is clearly blatant and willful and it needs to be treated as such — and that means they must make full restitution, they should be pursued in the court of law and they should be barred from future work on the project. That’s the penalty they’re going to pay.”