700,000+ gallons of sewage spilled in Columbia in ’17 — but that’s a big improvement

Nasty, poorly treated sewage remains a threat to Columbia rivers, but city officials and a riverkeeper group are encouraged by data showing the volume of spills was down last year.

For the first time in five years of compiling sewage spill data, the Congaree Riverkeeper says spills dropped below 1 million gallons in 2017. The group reports that utilities, led by the city of Columbia, released 758,000 gallons of untreated wastewater.

The hot spot for sewage leaks was again Crane Creek, a tributary of the Broad River in north Columbia.

About $16 million in sewage system improvements have been made in the area, according to the city of Columbia. And they appear to be paying off.

“The city of Columbia completed a multi-year sewer line replacement project along the creek in 2017, and there has not been a significant spill reported there since April,’’ the Congaree Riverkeeper said on its website.

State records compiled by the riverkeeper show sewage spills reached a five-year peak in 2015 at 5.6 million gallons, likely because of torrential flooding that overwhelmed sewer lines, Congaree Riverkeeper Bill Stangler said.

The drop to 758,000 gallons this year is encouraging, he added. “This is a positive, and we want to keep that positive momentum going.’’

Stangler said some of the improvements result from the U.S. Environmental Protection Agency ordering the city to fix its leak-prone sewage system.

Joey Jaco, Columbia’s utilities director, said drier weather in 2017 also may have helped reduce spills.

The city’s ongoing work also is making a difference, Jaco said. “As we continue with improvements, this (downward trend) is going to continue.’’

The city of Columbia operates the state’s largest wastewater treatment plant, a 60 million gallon-a-day facility on the Congaree River. It also has 1,100 miles of sewage lines.