This Indy 500 race weekend, there was more than just the smell of excitement in the air.Downtown Indianapolis office workers complained about a strong, unpleasant odor permeating the regional business district."Sewage -- that's the best I can do to describe it. It's just nasty sewage," said one woman who works at the One America building.Another downtown office worker said that the smell of raw sewage occurs frequently, RTV6s Jack Rinehart said."You can go out in the alley behind Fifth Third Bank and you can really smell it," she said.Citizens Energy spokeswoman Sarah Holsapple said thousands of miles of sewers were to blame for the smell."When it's this dry and this warm, and you have as many sewers as we do in the downtown area, that odor tends to rise up," Holsapple said. Over the last couple of days, we've been getting complaints from business owners or people in downtown complaining about an odor in the air.Over the past two days, utility workers have opened fire hydrants downtown to help dilute the concentration of sewage and flush the system, and some Hoosiers said it has helped.(The flushing) must have taken care of it because it smells like a beautiful day," one worker said.