By Kate Petersen, CNN
(CNN) — A massive fish kill on the Chattahoochee River west of Atlanta was reported Friday by environmental protection non-profit, Chattahoochee Riverkeeper. Chattahoochee Riverkeeper executive director Jason Ulseth told CNN he discovered the dead fish when he embarked on a river patrol Friday morning.
Ulseth estimates thousands of fish, some weighing 20 to 30 pounds, are dead along a roughly 20-mile stretch of river on the western border of Fulton County. He found spotted bass, catfish, carp, shad and striped bass — floating, strewn along banks and caught in debris piles and low-hanging tree branches.
An unidentified, foul-smelling black substance has also coated the river banks, according to Ulseth.
“To see everything dead was just catastrophic,” Ulseth said.
The die-off followed an intense thunderstorm that dumped three inches of rain per hour on the Atlanta metro area Wednesday, which also flooded area streets resulting in flash flooding.
Investigations into the cause of the fish kill are ongoing by Chattahoochee Riverkeeper and the City of Atlanta’s Department of Watershed Management. Both entities believe drought and heat played a role in the die-off.
Due to prolonged drought, the river was running very low when the storm arrived. There simply wasn’t enough cool water to moderate the influx of significantly warmer stormwater, heated by urban infrastructure.
“Once the heavy rainfall event hit the downtown urban core, the river had little buffer capacity to absorb nutrients and thermal loads. The flow on the Chattahoochee River was very low, while the urban streams were very high flowing into the river. The elevated temperature and time of day may have contributed to the creation of additional thermal load and stress on aquatic life,” Lena Hardy, a spokesperson for the City of Atlanta Department of Watershed Management, told CNN.
But Chattahoochee Riverkeeper believes stormwater and sewage discharge from an underground tunnel system built to hold excess wastewater likely also contributed to the incident.
“At this time, Chattahoochee Riverkeeper believes low flows in the river due to drought, massive polluted stormwater flows from Peachtree Creek, a discharge of untreated combined sewage from the City of Atlanta into Peachtree Creek, and additional treated discharges from wastewater facilities into the Chattahoochee River created the conditions for the fish kill,” the organization said in a Saturday press release.
Ulseth said he found condoms, menstrual products and wet wipes in the river, which he says strongly suggest sewage contamination. Other litter, more consistent with stormwater flows, have also accumulated with the dead fish, he said.
Moreover, the affected stretch of river begins where an overflow structure associated with the tunnel system drains into the river, according to Ulseth.
Hardy said that, as of Monday, “preliminary water quality data indicates the tunnel system operated as designed and within permitted water quality standards. However, all laboratory tests have not been completed, and DWM is still investigating the impact to the river and the relationship to the fish die off.”
Ulseth says litigation over sewage contamination in the Chattahoochee River dates back to the 1990s and is ongoing.
CNN also reached out Georgia Environmental Protection Division and Georgia Department of Natural Resources. The natural resource agency directed CNN to the Georgia Environmental Protection Division.
The-CNN-Wire
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