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HISTORY
In
the late 70's the Environmental Protection Division felt there
was a need to mandate the improvement of wastewater treatment
in the Upper Ocmulgee River Basin due to the environmental conditions
affecting Jackson Lake. Recognizing this need, the City of Covington
and the Newton County Water & Sewerage Authority (NCWSA)
undertook a joint venture project resulting in the construction
of the existing 4.8 million gallon per day Land Application
Facility. The engineering firm of Welker & Associates of
Marietta, GA. planned and designed the project that was completed
in 1985 at a cost of nearly $7 million dollars. |
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DESCRIPTION
The
864-acre land application facility receives effluent from
two secondary activated sludge plants. A 3.0 million gallon
per day plant operated by the City of Covington and a 1.8
million gallon per day plant operated by the NCWSA both pump
their treated wastewater to a storage pond at the land application
site. This pond is 18 acres in size, has a capacity of 72
million gallons, and is home to a variety of fish, snakes,
turtles, ducks and other wildlife.
The irrigation system
consists of 54 miles of underground pipe with nearly 5000
sprinklers. It is distributed throughout a forested system
of pines and hardwoods. It is designed with eight sprayfields
that comprise a total of 617 irrigated acres. Irrigation lines
are 85 feet apart and sprinklers are spaced every 60 feet
on the lines. Drain valves are provided on each line to prevent
freeze damage.
Required buffer zones
are 300 feet from residential dwellings, 150 feet from public
roads, and 100 feet from any surface waters. With these minimum
requirements, the land application process should virtually
go unnoticed to the public and its neighbors.
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MONITORING
The
Georgia Environmental Protection Division issued and renews
the permit for the Covington/Newton County Land Application
Facility. According to this permit, certain pretreatment and
monitoring requirements must be met. It is important that the
secondary plants send a quality effluent to the storage pond
for irrigation. An industrial pretreatment program is also required
to monitor industrial discharge strengths into the sewerage
collection system. Within the Land Application Facility, routine
monitoring takes place on the soil, groundwater quality, and
upstream and downstream points of Dried Indian Creek. Monitoring
data and irrigation amounts are all submitted to the Georgia
E.P.D. in a monthly report. |
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After years
of success, the Environmental Protection Division strongly
encourages the construction of land treatment systems
over direct stream discharges.
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OPERATION
AND MAINTENANCE
One
of the eight designed sprayfields can be irrigated for up to
12 hours per day. The field is then allowed to dry and re-aerate
6-7 days before being irrigated again. A maximum of 2.25 inches
of effluent is allowed to be sprayed over each field in a seven
day period.
As the treated wastewater is irrigated,
the trees and vegetation take up the available nutrients contained
within the irrigated water. Specifically, these nutrients are
nitrogen and phosphorous, which are two of the three basic components
in a commercial fertilizer. After the plants use these nutrients
for growth, the soil then acts as a filtering device for the
remaining nutrients.When this process is complete, a quality
effluent is delivered to the groundwater table.
Routine maintenance is required
to ensure proper operation. Keeping lateral lines clear of windblown
and fallen debris, and mowing the vegetative cover are necessary
to allow quick inspections and access to the irrigation system.
Maintenance of the irrigation site also includes cleaning sprinkler
nozzles, pipe repair, keeping a sufficient ground cover crop,
and controlling any erosion that may occur.
Maintenance requires the use of
low ground pressure equipment and must be scheduled according
to the soil moisture conditions in each field. |
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COSTS
The
Covington/Newton County Land Application Facility has operated
with relatively low operations and maintenance costs. Though
the initial investment costs were significant, the O&M costs
associated with tertiary land treatment are much lower than
the more intensive physical and chemical treatments required
for a stream discharge. Of the annual budget amount, approximately
50% is applied toward salaries and benefits. Personnel is made
up of four employees : two operators, one equipment operator,
and one manager. Utilities (pumping costs), maintenance, supplies
and materials make up the remaining 50% of the budget. |
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REVENUES
Land
application also offers the benefit of harvesting a byproduct
crop. By using a forested system for the uptake of nutrients,
periodic harvesting is necessary to maintain an efficient uptake
of nutrients.As these forested cells reach their efficiency
maximum the timber is then sold and harvested. Revenue received
from this sale of timber is deposited into an account designated
for capital improvements at the Land Application Facility.
Significant purchases of capital
items, such as tractors, have all been purchased through this
account.
After the timber is harvested, the site is then replanted. A
management plan has been established in order to maintain a
healthy balance between mature and younger stands of timber.
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FOR MORE INFORMATION
PLEASE CONTACT :
CITY OF
COVINGTON
LAND APPLICATION FACILITY
11085 FLAT SHOALS ROAD
COVINGTON, GA. 30016
770/385-2048 (OFFICE)
770/385-6828 (FAX)
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