The middle Chattahoochee between Morgan Falls and West Point contains extensive riverine (unimpounded) habitat but with degraded water quality. The low diversity of riverine fishes in this section is attributed to decades of industrial and municipal dishcharges and NPS run-off. (Corps 98 ACF Report)
The Georgia Department of Natural Resources reported that 218 miles (30%) of rivers and streams in the Chattahoochee River Basin were only partially meeting water quality standards. They also reported that 49 miles were fully failing to meet water quality standards and other use criteria. The other 610 watershed miles in the basin were supporting their designated uses. There are many fish consumption advisories in the basin.
Goat Rock Lake, Lake Oliver, Walter F. George, and Lake Andrews are only partially meeting water quality standards because of impacts from urban and nonpoint source runoff. Fecal coliforms and metals are the primary parameters exceeding criteria. All 4 lakes as well as Lake Harding have fish consumption advisories.
West Point Lake and Lake Harding fail to meet their water quality standards. Sufficient flow for wastewater assimilation in the Chattahoochee is most critical in the reach between Atlanta and West Point Lake. A minimum flow of 750 cfs must be met to provide for wastewater assimilation and compliance with the Clean Water Act. West Point has nutrient problems associated with these point source loadings to the lake. To address these problems, Georgia adopted nutrient standards in 1995. A phosphorous reduction was aided by a 1990 statewide ban on high phosphate detergents in Georgia. This action along with reductions of phosphorous at WWTP has resulted in significant reductions in phosphorous loadings in the lake.
Wastewater discharges from the six largest metropolitan Atlanta treatment facilities increased by about 50% from 1980 to 1995. However, the phosphorous load from these facilities decreased by about 83% from the largest load in 1988. Phosphorous loads from non-point sources continues to increase.
Alabama lists West Point Lake and Lake Harding as impaired due to contaminated sediments. Chlordane, a termiticide was used extensively through the 80s, and PCBs are both found in West Point. High metals concentrations in sediments from historical urban and industrial activity affect West Point, Lake Harding and Walter F. George.
Urban tributaries and the Chattahoochee downstream from Atlanta were among the most degraded sites evaluated by NAWQA (National Water Quality Assessment) during 1992-95.
Aquatic life criteria for bed sediment was exceeded downstream from Atlanta in West Point Lake (chlordane and PCBs)
The natural quality of groundwater from all aquifers in the ACF basin is acceptable for public supply.
Impacts to water quality as a result of possible changes in water allocation.
Low DO is predicted for discharges from four of the seven reservoirs in the lower Chattahoochee, with a substantial number of days with DO less than 5 mg/L above West Point and above Bartlett’s Ferry. No low DO’s predicted at Columbus.
The average percent of stream flow that is made up of wastewater discharges in the summer is expected to increase by 25 to 30 % from 1995 to 2050.
Chloryphyll a is expected to increase with most significant increases occurring in West Point Lake (12% between 1995-2050). Other reservoirs should change less than 5%.
Phosphorous loadings are predicted to rise most significantly in Goat Rock and George Andrews, yet these loadings are modest.
WWTP face potential tighter discharge limits in order to preserve water quality under low flow conditions.
Continued incremental instream flow reductions are likely to have cumulative negative effects on fish and aquatic resources. Low flow conditions may also allow for the accumulation of sediments due to reduced frequency of flushing.
IMPAIRED STREAMS / SECTIONS
Lake Oliver, a source of drinking water for Columbus has a fish advisory for catfish. (Willoughby)