Substandard concrete was used in drainage inlets installed during construction on the Woodrow Wilson Bridge, a man who supplied the flawed material admitted in pleading guilty to federal charges late Monday.

Frederick Precast Concrete also sold concrete used in improvements to Interstate 70 and other projects in Maryland.

“This particular concrete had no bearing whatsoever on the structural integrity of the Wilson Bridge or I-70,” said Valerie ­Burnette-Edgar, director of the Maryland State Highway Administration. “Everything they supplied was inspected and either replaced or deemed safe.”

Frederick Precast Concrete’s director of quality control pleaded guilty to three counts of making false statements, federal officials said Tuesday.

Santos Eliazar Rivas, 32, of Hagerstown was responsible for overseeing manufacture of the company’s precast products and ensuring compliance with state regulations.

“Santos Eliazar Rivas falsely certified that his company was delivering the precast concrete the government was paying for, and the government relied on that certification,” Maryland U.S. Attorney Rod J. Rosenstein said. “Although the inferior quality of the concrete was concealed, a cracked structure led to an investigation that exposed a pattern of misrepresentations.”

The bad concrete was discovered when cracks appeared in a precast piece delivered in 2007 to the I-70 job site, federal documents said. Inspection revealed that the material contained two layers of steel rebar rather than the three layers specified, and that the steel was of a weaker gauge than required.

That led investigators to other projects, including the Wilson Bridge, for which contractors bought materials from Frederick Precast. They found several instances in which the wrong number or gauge of steel rebar was used, documents said.

“We replaced six drainage structures and 40 manhole covers on I-70,” Burnette-Edgar said. “We replaced six structures at the Wilson Bridge, and we went back three years on all projects to inspect for anything used elsewhere.”

She said the replacements were paid for by the contractors who purchased from Frederick Precast.

It was not the first time that Frederick Precast, which was originally based in Maryland but moved to Pennsylvania in 2002, ran afoul of the state. In 1998 it was suspended by the SHA for 60 days, and in 1999 it received a one-year suspension from supplying state projects, according to federal documents. State officials were not immediately sure of the reasons for the suspensions.

A woman who answered the phone at a number for Frederick Precast said the company no longer does business under that name. She said Rivas was not employed there.

Rosenstein said federal agents found numerous occasions when Rivas signed off on precast structures whose concrete mix either had not been tested or had been tested and failed to meet specifications. He said the state paid three prime contractors $131,410 for the deficient materials, who then paid Frederick Precast.

Rivas could face five years in prison and a $250,000 fine on each of the three counts. He is scheduled to be sentenced in U.S. District Court on Dec. 19.