FAIRFIELD — A gas main replacement in beach neighborhoods began this week.

The Southern Connecticut Gas Company is working to upgrade the existing natural gas mains along the beach neighborhoods.

The existing gas mains in the beach neighborhood areas are more than 70 years old, SCG said. The mains are low pressure and are made of cast iron pipes, which can be brittle. SCG will replace the old mains with higher pressure, smaller diameter pipes.

The new gas mains will improve performance and reliability.

Excavations are required for this project. Fairfield Public Works Department will oversee the excavation and any temporary and permanent pavement restoration work related to this project.

Fairfield Police Department will oversee traffic control during all the construction work.

Reef Road is expected to be the first road under construction during the week of June 11. The work on these roadways are expected to continue throughout the year. In some cases, final paving projects will wrap up in the spring of 2019.

SCG has tentative plans for another project in 2019 for similar work in the beach neighborhoods.

Roads that are expected to be worked on during this current project:

Carlton Street.

Catherine Terrace.

Charles Street.

Cummings Avenue.

Dwight Street.

Eastlawn Street.

Forest Avenue.

Fox Street.

Hollis Street.

Howard Street.

Jarvis Court.

Lind Street.

Longdean Road.

Mellow Street.

Millard Street.

Mona Terrace.

Oldfield Drive.

Paulding Street (from Millard Street to Dwight Street).

Pratt Street.

Quincy Street (from Reef Road to Rowland Road).

Reef Court.

Reef Road (from Oldfield Road to Richard White Way).

Sandy Way.

Smith Street.

Sullivan Place.

Veres Street.

Whetstone Hill Court.