It’s predicting it will cost approximately $640,000 to dispose of the feces, some sitting there since the bridge was first completed in the 1960s.
There are three dozen cavities sitting beneath the bridge deck which has become home to 1,500 pigeons and the city said there are about five decades of excrement in those cavities.
“You look at the river and they look quite small. They look like these little rectangle holes. What happens is there are 36 of these cavities and each cavity is about 10 feet wide by 30 feet deep. So it works out to be 10,800 square feet of real estate that’s been accumulating feces,” said Todd Grabowski, the city’s manager of asset preservation for bridges.
All of the extra weight – which the city said works out to 230 mid-sized vehicles – could compromise the bridge’s structure, even creating cracks on the bridge.
It’s also bringing more than a bad smell.
“The feces is corrosive to steel and also is bad for the concrete as well. So there’s been some known studies that it can cause some damage to structures. It is near critical components of the structure,” Grabowski said.
The cavities are located beneath the bridge deck, which makes it hard for people to access.
Special scaffolding is needed so equipment can reach into the cavity.
The city said crews are using jackhammers to create a hole in the asphalt so their vacuum is able to pull up the excrement into a container before shipping it to be disposed of.
Grabowski said the first cavity took four days to clean and expects the entire cleansing to take two to three months.
The city also started a project to humanly euthanize between 50 to 70 per cent of the pigeons who nest around the bridge.
It will also be taking some preventative measures, like putting up a fence so birds won’t nest there, to make sure this doesn’t become a problem in the future.