Investigation of Atlanta fish kill continues

CRK’s investigation indicates a combination of factors contributed to the fish kill.

The City of Atlanta’s West Area Tunnel, part of the combined sewer system, overflowed into Peachtree Creek. This emergency overflow of untreated water mixed with the polluted stormwater in Peachtree Creek and then entered the Chattahoochee River. The City of Atlanta has indicated that they did not follow all their standard operating procedures for management of the combined sewer overflow system. Due to drought conditions, the Chattahoochee River was flowing at a very low level – approximately 750 cubic feet per second. The U.S. Army Corps of Engineers – the entity responsible for managing the river’s flow – was only maintaining minimum flows at this critical waterway junction due to the drought.

Significant stormwater flows in Peachtree Creek carried high levels of pollutants. After hitting pavement on a warm day, the stormwater temperatures would have been higher than the creek’s typical temperature. Additionally, due to a lack of rain, the stormwater flows carried a high load of additional pollutants that had built-up on the roads into Peachtree Creek and the Chattahoochee River.

CRK collected samples of the material and await the test results from a private laboratory. Based on reports from neighbors who observed the overflow of the tunnel, we believe the black material came from inside the tunnel.

On June 2, 2026, CRK met with representatives of the City of Atlanta Department of Watershed Management (DWM), the Georgia Environmental Protection Division (EPD), and the U.S. Environmental Protection Agency (EPA). Details from that meeting and a review of permits, city operating procedures, flow and rain gauges, CRK hotline reports, and other evidence indicate that a combination of factors contributed to this event.

City of Atlanta Department of Watershed Management (DWM) – Evaluating internal operations and conducting water quality and sediment testing. The city continues to submit reports and assessments to EPD. DWM has publicly committed to hiring a third-party engineering firm to conduct a thorough review of the event and make any necessary changes to operating procedures and implement any technological upgrades to ensure a fish kill event like this one does not happen again. 

Georgia Dept. of Natural Resources (DNR) – After collecting data on water quality along with the number, species, and sizes of dead fish on May 22, 2026, the agency’s Wildlife Resources Division (WRD) investigators concluded in their report that 44, 509 fish were killed in a 16-mile stretch of the river and placed a value on the fish killed: $838,603.96. DNR concluded: “Given the [City of Atlanta Department of Watershed Management’s] statement, eyewitness account, presence of dead fish within the affected river reach, the data collected at the Fairburn USGS gauge, and WRD field staff observations during the investigation, WRD Fisheries can reasonably conclude that the fish kill was the result of the development of hypoxic conditions in the Chattahoochee River following the [West Area Tunnel’s] wastewater discharge on 5/20/26.” To CRK’s knowledge, this is the biggest fish kill in Georgia since the 2011 Ogeechee River incident when 38,000 fish over 77 miles with $125,000 value died. 

CRK anticipates that Georgia EPD will fine the City of Atlanta for the value of the dead fish. 

U.S. Environmental Protection Agency (EPA) – Oversees the City of Atlanta Consent Decree for their Combined Sewer System.  

At the time of the fish kill, the Southeast region had been in a drought with minimal rainfall for months. Streams and the Chattahoochee River have been flowing at near-historical lows. On April 27, the Georgia Environmental Protection Division announced Drought Response Level 1, the first time since 2017. 

This event demonstrates that warmer temperatures and changing rainfall patterns due to climate change – combined with high pollutant loads, overwhelmed infrastructure, and inadequate flows – stressed the river to the point of breaking. 

This event did not occur within the Chattahoochee River National Recreation Area. Subsequent rainfall events and non-point source pollution predictably elevated E. coli levels in the river unrelated to the fish kill. Always exercise caution when coming into contact with the river for 48 hours after it rains and the river is high and muddy. You can view real-time bacteria estimates online at bacterialert.org.

Since May 22, CRK only observed dead fish on the stretch of river from Peachtree Creek in Atlanta to the city of Chattahoochee Hills. We did not observe any impacts to water quality, fish, or other wildlife in West Point Lake or further downstream in Columbus.