City to study sewer inflow and infiltration
By KATHRYN MARTINEZ news1@kilgorenewsherald.com

Several storms dumping more than 10 inches of rainfall in the Kilgore area last month caused the city waste water treatment plant to work beyond its intended capacity, city officials are intent on a study of sewer inflow and infiltration.

Infiltration is when rainwater finds its way into sanitary sewer lines through line breaks and loose joint connections. Inflow rainfall and standing water rushes through the lines after gaining access through sewer openings.

David Hackley, utilities superintendent, said the 10.24 inches of rainfall last month was the highest monthly accumulation in a long time.

"Up until May, we had a year-to-date rainfall of approximately 19 inches," Hackley said.

According to Hackley the waste water treatment plant was designed to carry a capacity of three million gallons per day. After the last big storm in May the plant processed 12 million gallons of water after six inches of rain fell over the course of 36 hours.

"It is apparent that inflow and infiltration is a problem," Hackley said. "We have studied some of our lines and plan to move ahead with a study of larger lines."

Hackley said the utilities department has utilized a sewer camera to check smaller lines for cracks, but a larger camera truck is needed to carry the + camera through the bigger lines. Many of which are 24 inches in diameter.

The camera is equipped with pan and tilt capabilities and uploads images to a computer, where cracks are noted for repair.

Until water levels lower and the city determines whether funds will be used to buy or rent the camera truck, the study is on a back burner.

Hackley suspects a feedline into a main trunk is one source of infiltration. He suspects much of the inflow is from manholes that have been underwater along Rabbit Creek and may be missing their covers.

"Right now the manholes along Rabbit Creek are inaccessible," Hackley said. "We have to wait for the area to dry out so brush can be cleared and we can get to the openings in question."

Jeff Howell, city manager, said the city's current plan recommends a complete study of sewer expansion needs and collection system improvements.

Hackley said it is in the city's best interest to invest in collection system improvements, since waste water treatment plant expansion could go as high as $9 million.