THREATS
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)
WATER QUALITY
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 ‘80’s, 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% betweeen 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.
WATER QUANTITY
IMPAIRED STREAMS / SECTIONS
FISH ADVISORIES
Lake
Oliver,
a source of drinking water for
Columbus has a fish advisory for catfish. (Willoughby)