Fifty years of debris was dragged from sewer lines in buckets as the Macon Water Authority repaired sewer pipes that run through Central City Park and underneath the Macon levee. Now the work, which began in September after a pipe crumbled at the foot of the Macon levee, is mostly complete, Macon Water Authority Director Tony Rojas said.
The pipe collapse caused a sinkhole which threatened the levee and caused the authority to shut off pumps that moved sewage through the line. As a result, the authority calculates that about 37.5 million gallons of sewage spilled onto the Ocmulgee Heritage Trail and at the Ocmulgee National Monument.
The authority bored under the levee to install a new pipe, cleaned and lined 700 feet of 52-inch pipe, and fixed two manholes as part of the project, Rojas said.
A force main was installed to keep sewage moving in the pipe all the time so gases from decomposition would not cause corrosion as they did in the pipe that failed, Rojas said.
The whole project cost $1.4 million, Rojas said.
The pipes that run through Central City Park had not been cleaned in half a century, Rojas said. “The bottom of the pipe was two feet of hardened sediment. ... We had to put people in the pipe with hammers and chisels.”
He said workers had to use a boom to remove a huge amount of rope-type mop material that had been dumped in the pipe decades ago.
Rojas said the authority is now paying a contractor $60,000 to use sonar to check the pipe between the park and Lower Poplar sewage treatment plant for obstructions, and the authority plans to continue that every two years.
Rojas said some sidewalk repair and grassing still needs to be completed in the park, but the work is otherwise done.
In a related issue, in September the U.S. Army Corps of Engineers asked the water authority to evaluate whether an abandoned sewer line could destabilize the levee. If the old line remains open inside, it could cause soil in the levee to shift.
Rojas said the authority plans to investigate that and grout the pipe full if necessary, but not immediately.
“We have told the corps we’ll fill in the pipe over time, that we’ll program it into our spending year by year,” Rojas said. “They basically said they could work with that.”