Algonquin Gas Transmission is performing a maintenance activity on one of its pipelines under Southford Road in Southbury.  The work started yesterday and is being done Mondays through Saturday round the clock.  Only one lane of alternating traffic will get by during construction.  Southbury Police say Algonquin will be taking measures to minimize sound when working outside the daylight hours. At this time, Algonquin anticipates that the work will be completed by the Labor Day weekend. The interstate natural gas transmission company maintains and operates pipelines in the mid-Atlantic and New England States. Part of the system crosses under Route 67 near 623 Southford Road.  Algonquin has been coordinating with local officials to ensure awareness and provide information on the maintenance project.