In March 2008, the Georgia Environmental Protection Division (EPD) established a continuous monitoring station on the Chattahoochee River at Capps Ferry Road (River Mile 269.32). This station was established to monitor dissolved oxygen concentrations in the River to verify that reduced releases from Buford Dam to achieve a flow of 650 cubic feet per second would not adversely impact water quality. The station was established at Capps Ferry because it is near the point at which EPD’s RIV1 hydrodynamic model predicts minimum dissolved oxygen levels will occur downstream from discharges to the River from the metropolitan Atlanta wastewater treatment facilities. The programmable in-situ water quality monitor recorded the dissolved oxygen levels at the station every hour and data from the monitor was collected manually from the monitor once per week. This webpage contains all dissolved oxygen information collected at the station.
The Georgia Environmental Protection Division (GAEPD) has discontinued the continuous monitor that measured in-situ water quality in the Chattahoochee River at Capps Ferry Road. GAEPD has done analyses and has concluded that the water quality data collected by the U.S. Geological Survey at the location Chattahoochee River near Fairburn, Ga. (USGS 02337170) is a reasonable and appropriate substitute for the data previously collected at the Capps Ferry Road site. These data can be found at USGS Station 02337170.
The above graph shows what the EPD RIV1 hydrodynamic model predicted dissolved oxygen would be at Capps Ferry between March and August 2008 plotted against actual dissolved oxygen measurements at Capps Ferry during the same period. In making this prediction, the model was run using March through August 2008 conditions which includes meteorological information, streamflow data, wastewater treatment facility water quality monitoring data, water withdrawal permit data, tributary flow data, and instream water quality data. Major discrepancies between modeled and measured dissolved oxygen values, represented by sudden dips in measure values, are attributable to major precipitation events that cannot be predicted by the model. The data gaps in measured dissolved oxygen results indicate periods where problems were experienced with one of the sampling probes deployed at Capps Ferry being clogged by silt in the River. This problem has been corrected with the use of a probe that is less prone to silting and moving the probe to a location on the bridge at Capps Ferry that is more representative of flow conditions in the River. With the exception of dips caused by major precipitation events and data gaps resulting from sampling problems, dissolved oxygen measurements at Capps Ferry showed good correlation with what the model predicted would occur. Therefore the model serves as an accurate tool for predicting dissolved oxygen concentrations in the River.
Uncorrected and Corrected Daily Data
The above graph displays the most recent seven days’ worth of dissolved oxygen data measured at Capps Ferry. This graph is updated every fifteen minutes. The corrected dissolved oxygen data is available for download below as a .pdf file, and will be updated approximately monthly as conditions warrant.
Please direct any questions regarding this project to Brandon Moody (Brandon.Moody"at" dnr.state.ga.us) of the Georgia EPD - Watershed Planning and Monitoring Program.