By Seth Schmidt
Enormous volumes of clear storm water continue to overload Tracy’s sanitary sewer system during and after periods of heavy rain.
After nearly five and a half inches of rain soaked Tracy over four days last week, volumes of effluent flowing to city sewage ponds reached 4.5 million gallons a day, according to Public Works Director Shane Daniels. That’s about ten times the normal volume.
Because of the large flows,Tracy Public Works Dept. and fire dept. members pumped out overloaded sewer mains Thursday to prevent sewage from backing up into homes and businesses.
“There is a lot of clear water entering the sanitary sewer,” Daniels told the city council Monday.
Improper connections between the city’s storm sewer and sanitary sewer systems, he indicated, account for the bulk of the storm water inflow. Those inter-mingled connections, he said, include footing and roof tiles and sump pump discharges tapping into the sanitary sewer. Co-joined sanitary and storm sewers and deteriorating service lines also contribute to the problem.
Sewage flow to the ponds declined to just over 1 million gallons per day on Saturday, two days after the rain stopped, Daniels said.
“That’s still a lot,” Daniels said, but gave some idea how great peak flows were on Thursday.
Prior to the heavy Sept. 17-20 precipitation, Daniels said the flows to the ponds were about 456,000 gallons per day. That figure, he noted, is greater than the volume of water being pumped from the city’s water treatment plant, evidence that storm water is continually getting into the sanitary system.
For more on this article, see this week’s Headlight-Herald.