The Columbia River Crossing says an error of more than $3 million was the reason project officials gave the Federal Transit Administration an inaccurate operating cost estimate for at least two years.When the CRC provided its most recent financial summary to the FTA as part of a grant application process, it listed the project’s annual future operating cost related to light rail at $12.81 million as of November 2012. That appeared to be a significant jump from the 2011 figure provided to FTA, which was $8.35 million.But a CRC representative said this week that the 2011 number was given in error, and should have been reported as $11.6 million. The same mistake also led to an inaccurate number in 2010, according to the project.So what happened? “The wrong cell in the spreadsheet was selected for the report,” CRC spokeswoman Mandy Putney said in an email. The most recent figure is correct, and the earlier mistakes weren’t repeated elsewhere, she said.Each of those figures, revised yearly, refer to the predicted operating cost of light rail in 2030. The number has grown due to inflation and an uptick in expected maintenance costs, Putney said.