City Begins Blasting At Construction Site
by Joel Young, Meteorologist/Reporter
January 17, 2013 5:23 PM
The flood of 2010 took its toll on the sewer system in Sioux Falls. As crews work to relocate and rebuild the sanitary sewer line, they found something standing in their way.
The city rang in the new year by starting on another phase of the Sioux River South Interceptor Improvements project, which basically involves relocating an existing sanitary sewage line from the south side of Yankton Trail Park to the north side.
“We’re trying to increase the size of the sewer pipe and move it away from the river so that we have more capacity and a tighter system to keep some of that extraneous water out of the system,” says Trent Lubbers of Sioux Falls Public Works.
However, that’s a task that sounds easier than it actually is.
“There’s a lot of bedrock, existing rock in the ground, and it’s higher than the depth that we need to put the sewer,” says Lubbers.
That's where the blasting comes into play. Over 15,000 cubic yards of Sioux Quartzite bedrock must be removed over the next few months.
First, they drill a 3-inch hole about 23 feet into the ground. Then, they put the explosives inside the hole before filling it with material to contain the explosives.
Shortly thereafter, they blow a series of horns signaling the go ahead. Following the blast, they will blow one more horn signaling the site is all clear.
City officials say it's a method that is absolutely necessary in order to complete the project.
“The explosive method is the best way for us to fracture that rock so they can get it out of the way to install the new pipes,” says Lubbers.
Of course, it’s all being done very carefully to ensure the safety of everyone around.
City officials plan to have part of the project completed by the end of March in time for soccer season. It should be completely wrapped up by June 7, 2013.