Annually, the South Granville Water and Sewer Authority (SGWASA) performs sanitary sewer system maintenance that includes jet-cleaning and televising of the gravity sanitary sewer lines. The SGWASA sanitary sewer system is comprised of 110 miles of gravity sewer pipe, 2,570 manholes, and 51 pump stations. The majority of the collection system's smaller diameter gravity mains are constructed of Vitrified Clay Pipe (VCP), Ployvinyl Chloride (PVC), and Ductile Iron Pipe (DIP).
Larger diameter gravity mains are predominately Reinforced Concrete Pipe (RCP) or Ductile Iron Pipe (DIP). SGWASA’s goal is to jet-clean and televise at least 10% of the total length of gravity sewer pipe annually.
The sanitary sewer maintenance is accomplished with in-house staff as well as through contracted staff. Traditionally, SGWASA spends approximately $66,000 annually on contracted sanitary sewer jet-cleaning and televising.
Why Jet-Clean and Inspect Sanitary Sewers?
Routine sanitary sewer cleaning is a vital component of maintaining the existing sewer system to its maximum effectiveness and capacity. According to the USEPA, “As sewer system networks age, the risk of deterioration, blockages, and collapses becomes a major concern. As a result, municipalities worldwide are taking proactive measures to improve performance levels of their sewer systems. Cleaning and inspecting sewer lines are essential to maintaining a properly functioning system; these activities further a community’s reinvestment into its wastewater infrastructure.”
The sanitary sewer cleaning and televising program helps SGWASA to evaluate pipes so that any necessary maintenance, repair or replacement can be scheduled to minimize unexpected problems and emergency repairs.
Jet-Clean & Televising Process
Sanitary Sewers are cleaned using high velocity jet equipment placed directly into the sewer through an upstream manhole. The extreme pressure of the water removes the dirt, sand, rocks and minor roots and pushes the debris to the downstream manhole.
Televising (TV) inspection is done with a camera that is placed directly into the sewer through a manhole. The camera can examine and televise the entire length of sewer between manholes. The cleaning and television program allow SGWASA to evaluate the sewer condition and identify deteriorated segments of the sewer main that need repair or replacement.
Schedule
Sewer cleaning and TV inspection projects occur year-round. The operation time of the projects varies from project to project; however, typical hours are from 8:00 AM to 4:00 PM weekdays.