WASHINGTON — Phase I of Metro’s Silver Line turns two years old next week, but the project isn’t done. There may be up to 1,600 construction-related problems yet to be resolved.

“There’s a disagreement between [the Metropolitan Washington Airports Authority] and VDOT in terms of what’s in that punch list, what’s valid – what’s not,” said Mark Canale, Dulles Rail Project manager for Fairfax County’s Department of Transportation.

Virginia’s Department of Transportation estimates that resolving all the issues would cost $34 million, but Canale said MWAA rejects the list and the cost. Some problems in dispute include missing and cracked drain pipes under Route 7.

“Also, a lot of these structures don’t meet the VDOT minimum standard requirements,” Canale said.

Another wrinkle in the dispute involves Dulles Transit Partners disagreeing with VDOT about whether some work is actually deficient, and/or whether it should be considered under warranty.

The potential for an impasse on this was brought up at a Federal Transit Administration meeting last week, Canale said.

“There’s talk about trying to get an arbitrator in, escalating it up. And maybe bringing in a professional third party to evaluate the MWAA and VDOT position so we can get this thing moved forward,” he said.