Sanitary Sewer Cleaning Notice

The Allenstown Sewer Department and our qualified contractor are scheduled to clean and inspect sanitary sewer mains in your neighborhood the week of October 21st 2019. A map of the proposed cleaning schedule is provided as an attachment.  As the work progresses sewer mains may be added or removed as determined by the Sewer Department.

The sanitary sewer lines are cleaned using high performance sewer cleaning equipment. A cleaning nozzle is propelled from one manhole to the next using water under high pressure. The nozzle is then pulled back to the starting manhole. As the nozzle is pulled back, water scours the inside of the sanitary sewer pipe.  Any debris in the pipe is pulled back with the water. The debris is removed from the manhole with a vacuum. After the cleaning process the pipe is inspected through video surveillance. This process is repeated on every sewer line cleaned.

During cleaning of sanitary sewer lines, air occasionally vents into a home through the sanitary sewer service line and ventilation system. When this happens, water in the toilet bowl or floor drains, can bubble or surge or, in rare instances, splash out of the bowl or drain. We remind you that the water that could come from this type of incident is from the bowl or drain, and is non-hazardous. During the scheduled cleaning period it would be beneficial to make sure to keep the lid of your toilet bowl down to minimize the water splashing from your toilet, and cover any drains connected to the sanitary sewer.

The common causes of air venting into homes during sanitary sewer cleaning are: air movement from normal cleaning operations, the use of higher pressure needed when cleaning sanitary sewer lines that have a steep slope, sewer lines running close to the building, a plugged roof vent, and the size and complexity of the home’s waste and ventilation system. To minimize water splashing out of your toilet bowl, keep the lid down.

If you have any further questions, please contact the Allenstown Sewer Department at 603-485-5600.