2021 Sewer Improvements

The City of Watertown started undertaking a sanitary sewer improvement project in fall 2021 as part of its Inflow and Infiltration (I & I) program.

Project Background

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The work includes installation of approximately 32,000 feet of cured-in-place sewer pipe. This is commonly known as sewer lining. This process allows the contractor to reconstruct certain sections of badly deteriorated sewer “in place” rather than the traditional disruptive method of excavating and replacing the existing pipes.  Instead of digging up and replacing the old sewer pipes, the sewer lining process provides for the insertion of a special lining inside the pipe, creating a new smooth-surfaced, long-lasting pipe within the old sewer.

Contract 21-01S Construction Plans

As part of the sewer lining process, a flexible liner is then placed into the existing sewer. Heated water or steam is forced into the liner, causing it to be pushed tightly against the walls of the existing sewer pipe. The heat from the steam or heated water causes the liner material to harden (cure), thus creating a new pipe inside the existing sewer walls.

The sewer lining process restores the integrity of the pipe and also reduces the amount of infiltration into the Town’s sewer system. 

In some areas, preparatory work, involving spot repairs of the sewer system requiring excavation of the sewer pipes, are also required.

Why is the City coming into my neighborhood to replace or rehabilitate the sewer pipes?

The project scheduled for your neighborhood is part of the City's proactive program to inspect and maintain the sewer system. Many of the City’s pipes are older and need to be repaired because of their age, a history of sewer back-ups, pipe breaks or other problems.

How will I be notified of the work?

Crews will place door hangers approximately one-week before work is scheduled at each affected building. An additional notice will be provided the day before work is performed.

Please note that you may see preparatory work, such as video inspection or vacuum cleaning trucks on your street.  After work is completed you may see additional crews performing post-installation inspection or other cleanup activities. These activities do not interrupt sewer service and the City does not provide advanced notification for them.

How are sewer mains being repaired?

Sewer mains are being repaired using a process called Cured-In-Place-Pipe (CIPP), a process used to repair about 50 percent of all water pipes in the United States and also used extensively to repair sanitary sewer and storm water pipes. Watertown has used this process for several years to rehabilitate sewer and drain lines throughout the Town to ensure residents have safe and reliable sanitary sewer services.

What is the CIPP process?

The CIPP process is a cost-effective and non-invasive process that involves inserting a soft plastic liner inside a host pipe and then curing (hardening) the liner with pressurized steam. There will be no digging or trenching through this process and once your sewer is lined, the process should never need to be repeated.

Are the chemicals used in the CIPP process safe?

The CIPP process uses a styrene monomer resin to rehabilitate the pipes. Styrene is widely used and can be found in items such as consumer electronics, medical supplies, packaging, etc. In addition, foods such as coffee, strawberries and cinnamon naturally contain styrene. Styrene has a very distinct odor that is noticeable at a threshold of 0.1 parts per million (ppm). The US Occupational Safety and Health Administration (OSHA) has established a safe exposure standard for styrene of 50 parts per million (ppm) over an eight hour day. Exposure levels from the CIPP process are significantly below this.

How long will my sewer service be interrupted when a sewer main is being repaired?

If your home or business is connected to the sewer line being rehabilitated, your sewer service will be temporarily blocked off from the sewer mainline once the liner is inflated. This will prevent any water leaving your home or business from flowing into the sewer main while the liner is curing.

The process only takes a few hours. During this time your water service is not shut off and you can continue using it for drinking, cooking and other purposes, but residents are asked to limit water use. You should avoid taking showers or baths, running your dishwasher and washing machine, and also be sure to turn off all sump pumps connected to your sewer service. Flush your toilets sparingly.  Using small amounts of water to wash your hands or brush your teeth is okay.

Immediately after the CIPP liner has been installed, crews robotically reinstate all sewer lateral connections to restore sewer service to individual buildings. Once crews are complete, residents can resume using water and the process should never need to be repeated.

Can the steam enter my home or business?

You may notice steam emitting from manholes while the work is taking place. This steam may produce odors in the outside environment, but it is still possible that odors from the process may enter your home.

Keeping your windows closed and sealing off any neutral vents will help ensure outside odors do not enter your home or business. If you do experience odors in your home or building, open windows to help ventilate the area.

If odor is entering your home, it is likely through private plumbing defects such as cracks in pipe, dry floor drains and sinks.  You can help prevent odors from entering your home or building by pouring water down all floor drains, sinks, and tubs to help ensure a water barrier is maintained in each drain’s P-trap.

Will there be road closures or other impacts during the work?

While a CIPP project is taking place, you may experience minor traffic interruptions and parking restrictions. Every effort will be made to maintain driveway access.  For your safety and the safety of the workers, please avoid driving in construction areas. As with any construction project, stay clear of work zones and adhere to signs and safety barriers.

During CIPP work, homes and businesses near the work area can expect noise impacts from various types of equipment necessary to complete the work, such as generators, boilers, and heavy equipment.