This usually involves an unauthorized person removing a manhole cover and dropping objects into the manhole and obstructing the flow. This has occasionally resulted in a back up into a building, but generally results in a manhole overflowing.
The stoppage is caused because the main is broken and/or full of roots at the service line connection from a building. Service connections are the responsibility of the property owners. When a connection is determined to be in need of repair, the property owner is notified that repairs are needed. The Sewer Utility is not responsible for repairing service connections.
Obstructions in a manhole or main may be due to structural failure, roots, or a buildup of grease, rags or grit. These problems can be identified and corrected by the Sewer Utility.
The type and priority of preventive maintenance following an obstruction is dependent on various factors.
Obstructions which caused a sewer backup into a business or residence are classified as top priority for investigative and follow-up preventive maintenance measures. This priority is given to assure that a subsequent obstruction does not occur due to the same source. Corrective measures may include routine cleaning on an established frequency or dig-up and repair if warranted.
Obstructions which caused wastewater to overflow from a manhole and do not cause personal property damage, are placed on a lower priority repair schedule, or on a routine cleaning/inspection schedule.
This is not an obstruction, but the result of heavy or prolonged rainfall causing the sanitary sewer main to fill due to infiltration and inflow (I&I) of storm water. Much work has been done to eliminate I&I from sanitary sewers but there are still areas where this is a problem. However, there are measures a property owner can take to prevent backups from a surcharged main.