Long time Madison residents took to South Park Street with signs and images of muddy runoff flowing into Monona Bay.
Steve Vanko has spent his whole life in Madison. He believes the construction site on Park Street is responsible for what he said were more than a dozen cases of polluted runoff, and he has the pictures to prove it.
Ghidorzi Companies out of Wausau has managed the site since July 2012. The City of Madison has come out a few times to clean up, but residents say it's not enough.
"The city comes out and says they're in compliance and that's it," Vanko said. "We get the runoff into our bay. We're not against this project at all. We're against 19 percent of phosphorous that goes into the bay that comes from construction sites."
"Our focus has been on compliance," said Margaret Ghidorzi, director of business development at Ghidorzi Companies. "Anything the governing bodies have asked, we've done."
Ghidorzi said the project has turned a dilapidated site into a Leadership in Energy and Environmental Design certified building that's in compliance with required regulations.
Tim Troester is a city engineer. He's heard their concerns and said Ghidorzi Companies has been cooperative by improving ground conditions.
"We do everything we can to minimize these situations within what we're allowed to do," Troester said. "We make the suggestions beyond what's required, but we can make them go beyond that set bar."
At this point, Vanko said they don't know what else they can do. They only know the runoff just adds to the challenges they bay has seen.
"The weeds have just clogged up. You can't even get your line out anymore." Vanko said.