Catawba Riverkeeper Sam Perkins doesn't have many words to describe this week's sewage spill in a creek winding its way into Lake Wylie.
If he had to pick a word, it would be "unprecedented."
Perkins was on site this week in the aftermath of Monday's spill near Oakdale Road in Charlotte. Perkins, whose job is responding to such incidents for testing and notification, couldn't recall a worse case.
Tuesday evening, Charlotte Water estimated the spill amount at 15.4 million gallons.
"That's quite a volume," Perkins said. "I get a lot of sewer overflow records for the basin. For the Catawba basin, going back about a decade, I don't recall having seen anything that large."
Charlotte Water crews responded Monday to reports of a broken sewage pipe. By 5:30 p.m., there were reports of a sewer odor and dead fish.
Crews found a 30-inch pipe broken near the point where Long and McIntyre creeks meet. Long Creek flows into the northern part of Lake Wylie, near the U.S. National Whitewater Center.
The spill stopped and cleanup started by 10:45 a.m. Tuesday.
Officials from North Carolina and South Carolina, including those south of the public water intakes in Belmont, N.C., and Rock Hill, were alerted.
Mecklenburg County announced a no-swim advisory Wednesday until further notice for the Catawba River and Lake Wylie on both sides of I-85, from north of the Whitewater Center to south of Wilkinson Boulevard. The map with that advisory includes the Whitewater Center, where paddling and water sports are common.
"It was necessary to close the areas to recreation because of the potential risk to human health," water quality program manager Rusty Rozzelle with Charlotte-Mecklenburg Storm Water Services said in the advisory release.
Efforts to obtain comment from the Whitewater Center on how the spill could affect business were unsuccessful.
Cities drawing water upstream and downstream of the spill say there's no indication drinking water has been impacted.
Chuck Flowers, utilities director for Belmont, said Wednesday morning that, soon after the spill, his staff began testing water near where Long Creek enters Lake Wylie. He said initially he "didn't see much difference" between water quality samples where Long Creek meets the lake and at the water intake.
"It's kind of hard to tell what we're seeing because of all the rain and runoff we're having," Flowers said.
From Sunday night to Wednesday morning, Belmont had 3.7 inches of rain. Turbidity, or the measure of how much solid material is in water, "increased incrementally overnight" and it could take some time before the full weight of the spill flows to Belmont, Flowers said.
The city is adding a pre-disinfectant to make sure the water remains clean for drinking and other uses.
"We'll probably do that, just as a precautionary measure, until next week," Flowers said. "We're making sure we're taking every precaution we can take."
Heavy rain muddying up testing after the spill also helped cause the spill, as storms washed away soil surrounding the failed pipe. According to Charlotte Water, storms caused trees to fall and erosion of the creek bank up to 50 feet in places. A downed tree re-routed the creek, eroding the land and exposing the pipe that broke because of its weight and fell into the creek.
"This is a very unique incident," Perkins said.
How it compares
Lake Wylie has had its share of environmental concerns. None, at least dating back a decade, match the volume of the most recent spill.
▪ Since the start of 2017, there have been 777 reported sewage spills in South Carolina. They combine for 5.2 million gallons.
▪ Tega Cay had sewage spill problems several years ago, frustrating residents to the point they demanded action from city leaders. After decades of discussion, the city bought what was then the private Tega Cay Water Service in 2014 for $5.85 million.
The tipping point was a six-spill day just before Christmas in 2013, followed by three more spills less than a week later.
Resident Linda Stevenson spearheaded a group calling for the city to buy the utility. City officials have since called the purchase of Tega Cay Water Service their biggest achievement in recent memory.
Reports of spills dwindled.
"All of the citizens have benefited tremendously from this buyout," Stevenson said two years after the sale.
State records showed in the 10 months leading up to the city's utility purchase, there were 42 spills. Three of every four spills in York County came from Tega Cay, which accounted for 7 percent of all spills statewide.
All those Tega Cay spills combined for 298,970 gallons.
▪ In August a sediment spill — it was disturbed soil, not sewage — had long-time lake experts calling it the worst of its kind they could recall. One witness to the spill, which crossed the state line near Tega Cay, said it raised the water level 6 to 8 inches in the nearest cove.
Residents poured into a Lake Wylie Marine Commission meeting about a week later in search of answers. They were told it could take a year or more for the soil to be dredged. Residents reported being able to walk across the cove on spilled soil.
"I saw the biggest mess I've ever seen on this lake," said Jim Allison, a resident of more than 60 years.
No estimate was given on how much soil spilled, though Allison said it was 3.5 acres of water that burst retention structures. Perkins, on site shortly after both incidents, said comparing a liquid to a solid spill is "comparing apples to TVs," but that even the massive soil spill couldn't match Monday's sewage spill.