BOISE -- Crews working on the new Esther Simplot Park have made a potentially harmful discovery.
The City of Boise says the construction workers started finding industrial products last week, about 20 feet below ground.
"Obviously the materials we did find were not conducive for the use we want for it," said Mike Journee, spokesperson for the City of Boise.
The city says the materials include construction debris, petroleum, and even a half dozens drums of waste.
"As soon as we discovered there was an issue we reported it right away, we're working with the contractor to get it cleaned up and do the right thing as far as that goes," said Journee.
As of Tuesday, crews had removed 22,234 tons of the unsuitable material, and are hauling off more than 6,000 tons per day. They're taking the materials to a local disposal site.
The city called the Department of Environmental Quality and have been working ever since to test the items, and the groundwater to make sure nothing has been contaminated.
The city says so far, there has been no negative environmental impact.
"There's no indication at all that this has moved beyond a very localized place where those materials were found," said Journee.
The city says the materials are there because the property used to be home to a concrete plant and asphalt plant decades ago.
"The whole Boise River corridor was an industrial zone for many, many years going back, and just up until the 60s and 70s did that start getting cleaned up," said Journee.
The city is still unsure how much this will set them back, but say they're focused on clearing out what doesn't belong on park property.
"It's going to be a beautiful park at the end of the day and we're really excited about what's going to happen," said Journee.
Tuesday night, the City Council unanimously approved the money to pay for the added cleanup expense.
The resolution says current equipment costs are nearly $40,000 a day, and disposal of the debris could cost up to $2.5 million.
The city says a Capitol Contingency Fund will cover the costs.
The city owns the property where the 55-acre park will be built, but the Simplot Foundation is paying for the park construction.
The park is scheduled to be complete by the spring of 2016.
