Metro has told Montgomery County it will not operate the Silver Spring Transit Center as planned because construction and design flaws plaguing the $120 million facility have made it too expensive to maintain.

Under the terms of a 2008 agreement, the Washington Metropolitan Area Transit Authority is supposed to take control of the three-level bus-and-train hub from the county after completion. Metro would operate the center, which is adjacent to its Silver Spring station, as a part of its regional system.

The opening of the center is more than two years behind schedule because of concerns about the strength of the concrete and the adequacy of steel supports in some areas. WMATA has said several times that it would not accept the facility unless it was satisfied with the repairs, which are expected to get underway this summer. But A. Robert Troup, Metro’s deputy general manager of operations, told county officials in an April 12 letter that the building falls short of standards outlined by the agency in the agreement.

The issues are of a “magnitude and severity,” Troup said, that even if repaired “would unnecessarily place an inordinate maintenance burden onto WMATA.”

Troup said WMATA would still operate Metrobus service from the center after the county completes repairs. But he said the agency would no longer pursue plans for inter-city bus operations from the center.

Concrete issues at the Silver Spring Transit Center

The agency’s position only deepens an expensive and embarrassing predicament for Montgomery. The project, envisioned as a critical cog in the urbanization of downtown Silver Spring, has been bedeviled since the beginning by problems that have left it tens of millions of dollars over budget. These include trouble sinking caissons into bedrock on the construction site, cracked and inadequately strengthened concrete and missing steel supports.

A study commissioned by the county from KCE Structural Engineers concluded that “errors and omissions” by designer Parsons Brinckerhoff, general contractor Foulger-Pratt and inspections and materials testing firm Robert B. Balter Co. had left the center unusable and “a significant safety hazard.”

The contractors have disputed many aspects of the report.

David Dise, director of the county’s Department of General Services, said Thursday that WMATA’s stance was “a hugely bad idea” and that the agency was questioning “a design for a facility that they reviewed and approved.”

He also said he considered it to be an opening gambit for negotiations.

“Frankly, we believe that it’s an initial position,” Dise said. “We don’t believe that it is a final position. For that to be a final position poses a tremendous number of challenges. We are proceeding with the approach that they are our partner.”

Dise spent much of Thursday afternoon in a meeting with all the major contractors on the transit center, who sat down with state and county officials for the first time since issuance of the KCE report to devise a repair plan. Dise said he is optimistic that the fixes can be completed before the winter.

WMATA was invited to the meeting but did not attend, according to Dise.

Dise said that if WMATA broke the agreement, it would create a fresh thicket of legal and financial issues that could further delay the opening of the facility. Most pressing is the question of who would the pay operating costs that were to be covered by WMATA.

It’s unclear who would operate the center if Metro backs out.

But County Executive Isiah Leggett (D) has said that taxpayers will not bear any new costs connected to project repairs.

“We would seek that money from the contractors,” Dise said. “We would look for that from the contractors, the consultants, whoever played a role in this.”

Meeting minutes and other project documents show that WMATA has expressed concerns about the safety and durability of the center ever since cracks began appearing in the concrete in 2010. As early as last July, agency officials raised the idea of modifying its memorandum of understanding with Montgomery to make the county responsible for maintenance.

According to KCE, Parsons Brinckerhoff’s design for the building did not meet WMATA’s criteria. These include specific requirements for “curing” or hardening concrete; adequate quantities of anti-corrosion agents in the concrete to protect steel supports; “slip joints” to accommodate movement by some concrete slabs; adequate concrete covering certain beams and girders; design drawings that delineate a requirement for steel supports in certain areas; and proper fireproofing of certain parts of the structure.

Jerry Jannetti, Parsons Brinckerhoff’s vice president and area manager, did not return a phone message seeking comment.