A statement of claim filed in May on behalf of the partners behind the nearly complete arena alleges more than two dozen errors and omissions in the design by HOK and 360 Architecture, a firm purchased by HOK, according to the Edmonton Journal.

EAC and the city claim it cost $4.7 million to correct the alleged design flaws that it would have taken steps to offset if it had known about the cost overruns. The 20,734-capacity Rogers Place, under construction since 2014, and the overall complex with a pedway, community rink and Light Rail Transit station is expected to cost about $606 million, the paper said.

Accusations in the statement of claim include failure to specify the type of backfill used between the arena and the rail station, which was redone, and failure to include a stipulation for a natural gas refueling station for Zambonis and forklifts, the Journal said. A joint statement from the parties said that the legal action was necessary but downplayed the significance.

“Within the context of a project in excess of $600 million, a claim in the amount of ($4.7 million) is in no way unusual,” the Journal reported. “As part of managing this project, the project team exercised the additional diligence of placing project insurance to cover this very kind of claim. “The project team continues to be diligent to ensure we receive the level of quality for which the owners contracted and the construction of Rogers Place remains on time and on budget. We will be opening Rogers Place in September 2016 as planned.”