GREENWOOD — South Carolina authorities think an unidentified pollutant likely caused the deaths of thousands of fish, turtles and snails but are still trying to find an exact cause more than a month after residents first said fish were dying.
Officials are casting a wide net, even looking at earthquake data as they try to find exactly what killed so many animals on an 11,000-acre reservoir that fuels recreation and residential growth in a rural stretch of the Upstate.
While the exact cause remains unclear, the scope of the fish deaths on Lake Greenwood is becoming clearer, and the toll is much higher than the initial figure of 3,000 dead animals given out weeks ago.
“The kill was more extensive than previously reported to me with an estimated 15,000 – 25,000 aquatic animals affected,” state Rep. John McCravy said on social media after a legislative briefing from the Department of Natural Resources and Department of Environmental Services — the two state agencies investigating the fish deaths on Lake Greenwood.
McCravy, who represents many of those who live near the lake, shared in his post reports from the two agencies, which The Post and Courier has obtained from those agencies.
In one report, DNR concluded that “the event appears consistent with a pollutant or other contaminant being introduced into the lake, … although a definitive cause has not yet been confirmed.”
Reports of dead fish started April 13 near Cross Hill, about 50 miles south of Greenville. Most reports have been in the lower portion of the lake, below the lower train trestle. Officials said impacted species include crappie, yellow perch, flathead catfish, striped bass and bluegill.
Authorities have consistently said that fish kills can be common, with frequent causes including oxygen depletion, excessive algal blooms and high water temperatures. However, none of those common causes explain the fish deaths on Lake Greenwood.
The S.C. Department of Environmental Services is looking at a mothballed facility that for decades produced nylon fibers after thousands of fish died in nearby Lake Greenwood.
Matthew Hensley/Staff
In trying to pinpoint what substance might have caused the deaths, officials are conducting a broad search. They’ve scrutinized the long-polluted Ascend-Monsanto site and looked into empty industrial drums found just 20 feet from the lake’s 212 miles of shoreline, but so far have found no link.
DES is also monitoring the seven entities that are permitted to discharge treated wastewater upstream from the kill, but it hasn’t tied any to the deaths.
In its investigation, DES has even gotten earthquake data from DNR. The report with that detail did not specify why the agency sought the information, nor did the agency respond to a question on the topic.
A swarm of earthquakes was recorded last year near the lake, but the most recent quake was seven months ago — and six months before fish started mysteriously dying. A recent study, however, suggests that earthquakes can have a long-term impact on lake ecosystems.
DES says residents can share information with investigators using its online ReportIt! tool or by calling 803-898-3432.
A lakeside shelter at Lake Greenwood State Park sits empty Friday, May 8.
Matthew Hensley/Staff
Is it safe to swim and fish in Lake Greenwood?
A sign warns against swimming on a stretch of Lake Greenwood meant for boats near the state park. While state officials cautioned people against coming in contact with water in the wake of thousands of fish dying in the Upstate lake — guidance that has since been rescinded — no formal prohibition against fishing or swimming was ever put in place.
Matthew Hensley/Staff
In the wake of the fish kill, both environmental agencies urged people and pets to avoid coming in contact with water near the reported fish kills, releasing a map pinpointing affected areas, including along the shores of Irvines Landing and Black Gate communities, near Summerset Bay Road and at Lake Greenwood State Park.
That guidance — which was never a formal prohibition — has since been rescinded.
“Early in the investigation a general precaution was made to avoid contact with the water in areas where the fish kill had occurred, however, current water quality data do not indicate a concern for consuming fish or for recreating in the lake,” DES said in its latest update.
Greenwood County, which owns the lake, has reiterated that finding.
On May 8 — a Friday with blue skies and warm temperatures — The Post and Courier saw few boats on the lake, and just a small contingent of people visiting Lake Greenwood State Park.
Park officials, however, say the impact hasn’t greatly diminished attendance.
“While admissions and camping occupancy are slightly lower than previous years, many guests have chosen to transfer their stays rather than cancel, showing continued interest in visiting the park,” Daniel Bailey, senior ranger at Lake Greenwood State Park, said in an emailed statement.
Two Laurens County Water and Sewer Commission towers rise above surrounding trees in the rural Upstate community. The utility says its drinking water is safe after 15,000 to 25,000 aquatic animals died in Lake Greenwood, the reservoir it uses to supply residents with water.
Matthew Hensley/Staff
Is it safe to drink water from Lake Greenwood?
The lake is a source for Greenwood CPW and Laurens County Water and Sewer Commission, providing water for tens of thousands of residents across two counties.
Officials with both water systems have sought to ease concerns about safety.
“We want to reassure our customers that the water we treat and deliver meets all state and federal drinking water standards,” Jeff Meredith, Greenwood CPW general manager, said in a news release. “Our team closely monitors the raw water coming into our plant every day and adjusts our treatment process as needed to maintain consistent, high-quality drinking water.”
LCWSC offered similar assurances.
“Throughout this event, all finished water samples have remained within normal ranges, and LCWSC customers can feel confident in their drinking water,” said Max Hughes, LCWSC water production manager.
State officials have stressed that the fish kills were downstream from intakes for both water systems.