Heavy rains result in more sewer spills

A deluge Sunday caused three sewer spills here, according to city of Cairo officials.
All three were due to hydraulic overload from excessive storm water entering the city’s sanitary sewer system.
The first spill reported occurred between 7:45 a.m. until 9:45 a.m. at the city’s wastewater treatment plant in southwest Cairo. City officials report that an estimated 9,600 gallons of sewage were discharged into Parker’s Mill Creek.
The two other spills occurred at sewer liftstations on Sixth Street S.E. and Seventh Avenue S.E. and both began at approximately 8:15 a.m. and lasted until 9:30 a.m.
At the Sixth Street liftstation about 1,875 gallons of sewage were discharged into a tributary of Little Tired Creek.
The 5,625 gallons of sewage discharged from the Seventh Avenue liftstation spilled on the ground there and at the treatment plant, but did not discharge into Parker’s Mill Creek.
The Georgia Department of Natural Resources Environmental Protection Division ordered the city in 2010 to produce a plan to prevent future spills.
Since then, city crews have been working to identify sources for the inflow and infiltration of storm water into the sewer system and flowing into the treatment plant.
City officials met last year with officials of Siemens, the builder of the city’s new treatment plant, and at company expense Siemens replaced undersized pumps at the plant.
Gauges were added last March to measure the actual amount of influent coming into the plant. Previously, the city only had a gauge to measure the affluent, which is all that is required by EPD.
Cairo City Manager Chris Addleton said this week that the new gauges show that during heavy rain events, there is in excess of eight million gallons of water per day entering the plant.
The new wastewater treatment plant is designed to accommodate eight million gallons per day even though the city is permitted to discharge three million gallons of treated wastewater per day.
“We had suspicions that the plant was not handling the amount it was designed to handle, but the new gauges show that it was designed properly. It just cannot handle more than eight million gallons per day,” Addleton said.
The city, according to Addleton, has been successful in making repairs to correct inflow issues around the city, but the more difficult problem is addressing the infiltration of groundwater into the wastewater treatment system.
“We have a lot of old terra-cotta pipe and during heavy rains the groundwater is seeping into the joints of the pipes,” Addleton said.
“We have made an impact with all of our smoke testing, but the infiltration issue is much more difficult to correct,” the city manager said.
The city has over 90 miles of sewer to maintain in addition to 1,500 manholes and 19 pump stations.
Addleton said the state is requiring the city to complete smoke testing of its entire sewer system over four years. The city is in the second year of the state mandate and, according to Addleton, has met all of the benchmarks set by EPD.

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