Early Water Monitoring
Spring 2009 - August 2010
Municipal Water Treatment Plants
The Kingston and Rockwood water treatment plants sampled untreated and treated water (or drinking water). Test results were compared to water quality standards established by TDEC. All samples met the applicable TDEC standards, which are different for treated and untreated water.
Kingston Water Treatment Plant
From December 2008 until August 2010, Kingston Water Treatment Plant sampled untreated and treated water daily and after heavy rainfall or high flows on the Emory River. TDEC also collected weekly samples.
All drinking water samples met TDEC criteria.
Rockwood Water Treatment Plant
TDEC collected weekly samples of untreated and treated water at the Rockwood Water Treatment Plant.
All drinking water samples met TDEC criteria.
Private Wells & Springs
In the three months following the ash release, TDEC sampled more than 100 private groundwater wells and springs within a four-mile radius of the ash release.
TDEC continues to sample selected wells quarterly and has reported no violations of drinking water standards.
Emory, Clinch, and Tennessee Rivers
Fixed Station Monitoring
TVA established eleven fixed surface water monitoring stations: five on the Emory River, four on the Clinch River and two on the Tennessee River. Their locations were strategically selected to monitor water quality and any potential movement of ash. After a few months of sampling three days a week, TVA began collecting samples each Monday and Friday until dredging was complete. TDEC independently collected samples at the same locations every Tuesday and Thursday. TVA and TDEC also sampled after heavy local rainfall and high flow on the Emory River, testing primarily for arsenic, total suspended solids, and ash-related materials.
Except for a few instances during dredging activities, high-flow events and immediately following the spill, samples met relevant water quality standards.
Results (link to graphs for each river)
In spring 2009, TVA placed five continuous monitors in the Emory River near dredging activity to measure turbidity (or muddiness). Daily average measurements were used to determine if dredging operations were meeting TDEC’s turbidity criteria. Three monitors were placed in permanent locations at Emory River miles 0.5 and 4.0 and at the Kingston Fossil Plant intake channel. Two mobile monitors were always positioned about 1/4 mile upstream and downstream of any dredging operation. Turbidity data was received in 15-minute intervals, allowing TVA to detect significant water quality changes quickly.
All daily average results met TDEC criteria. Monitoring was discontinued when dredging was complete.
Swan Pond Embayment
Runoff from the surrounding watershed naturally flows through Swan Pond Embayment and into the Emory River. A drainage system called the clean water ditch was built to intercept runoff before it reached ash in the embayment and direct it into the Emory River.
Another drainage ditch called the dirty water ditch was constructed to direct surface water that contacts ash in the embayment through a series of sediment basins. In these basins, the ash settles out before the water flows on to the clean water ditch and into the Emory River.
From June 2009 through summer 2010, samples were collected twice weekly from the sediment basins discharge point and the clean water ditch. The samples were tested primarily for arsenic, total suspended solids and ash-related materials. Heavy local rainfall exceeding 1/2 inch in a 24-hour period triggered additional sampling at these locations.
Results (link to graph for results in Swan Pond Embayment)
Ash produced by Kingston Fossil Plant and recovered from Emory River dredging operations were each pumped as a watery mix through a series of settling basins where ash separates from the water and settles to the bottom. The final settling basin is the stilling pond. Once ash settles out, water is discharged from the stilling pond back to the plant intake channel for reuse by the plant.
From March 2009 through summer 2010, TVA sampled daily where the stilling pond empties to the intake channel. The samples were tested primarily for arsenic, total suspended solids and ash-related materials.
Results (link to graph with stilling pond results)
While dredging in the Emory River, TVA deployed turbidity curtains around the work areas to reduce the movement of ash within the river. TVA also closely monitored dredge plumes, or suspended sediment in water as a result of dredging operations, daily to monitor the effectiveness of the curtains and the concentration of ash-related materials in the plumes.
Samples were analyzed primarily for arsenic, total and dissolved metals and total suspended solids. Plume samples also were collected periodically for acute toxicity tests. No toxicity was found. Plume monitoring was discontinued in June 2010 when dredging was completed.
Results (link, to graph of plume results)