VALDOSTA — Over the two day period of Feb. 22-27, 2013, the Valdosta area received 8 to 10 inches of rain. Inflow and infiltration of stormwater into the sanitary sewer collection system have caused high flow conditions at the wastewater treatment plants. The high flow at the Withlacoochee Water Pollution Control Plant (WPCP) caused a hydraulic overload of the secondary system with a resulting loss of secondary solids into the plant effluent. This condition is expected to continue until the Withlacoochee River drops below flood level.
The total suspended solids result from the effluent sample collected on Saturday, Feb. 25th was 467 milligrams per liter. This is greater than 1.5 times the seven day average allowed by the National Pollutant Discharge Elimination System (NPDES) permit, which constitutes a major spill. The volume of the major spill into the Withlacoochee River is the total flow for Feb. 25, which is 11,673,000 gallons. We expect the treatment plant to remain in violation until the River levels drop below flood conditions.
Some manholes along the Withlacoochee Interceptor line and trunk lines feeding the interceptor are now under flood water. Inflow from the flood will continue to cause high flow at the treatment plant until the flood waters recede.
The City of Valdosta is currently having a system of pump stations and force mains designed that will replace the existing 52” gravity main that runs along the river basin to deliver flow to the Withlacoochee WPCP. This will greatly reduce the effects of river flooding on the collection system. The city is also having a new headworks facility and equalization basin designed for the Withlacoochee WPCP that will reduce the effect of inflow and infiltration on the plant processes. Both of these designs are 60% complete.
During the federally declared disaster flood of 2009, one-third of the Withlacoochee facility was under flood waters. The City of Valdosta plans to move the facility to a higher elevation to prevent future flooding. This move will allow the plant to be completely redesigned and re-built.
These three projects should remove the potential for hydraulic overflow due to inflow and infiltration in the future. The City of Valdosta is currently seeking revenue sources to allow the completion of these necessary projects.
Upstream and downstream sampling of the Withlacoochee River has started. If you need further information please contact Environmental Manager John Waite at (229) 259-3592 or at email@example.com.