Pipeline Replacement Frequently Asked Questions
Why Does Atlanta Gas Light Need to Replace Pipelines?
A small portion of Atlanta Gas Light pipe being replaced dates as far back as the 1860s and is a testament to the engineering skills of the day. Tests show that some of that old cast iron pipe had retained up to 80 percent of its original integrity. However, over time, corrosion and age may have weakened the pipes’ integrity.
What Exactly Will Atlanta Gas Light Be Doing?
We are replacing the majority of cast iron and older steel distribution system piping with new plastic piping. For our Inner-Belt renewal project (which is higher pressure, larger diameter pipe), we will be replacing the old pipe with 12” and 16” steel pipe. The replacement of our pipe will involve working mainly in the public right of way.
When it first began, the pipeline replacement program operated on the concept of replacing the “worst first”: Segments were identified by their leak history through Atlanta Gas Light’s extensive records of its entire pipeline system and comprehensive data on leaks. Regular leak surveys are conducted to constantly monitor the condition of the bare steel and cast iron pipe. First to be replaced were the segments of pipeline determined to have the worst leak history. By the end of the fifth year, the number of leaks on the Atlanta Gas Light system had dropped dramatically, by 50 percent. (Please note that because of the periodic leak surveys, the leaks found are generally extremely small and do not create a hazard).
Although the number of leaks has declined, the company still uses leak data to assist in determining the order in which segments are replaced. Segments range from as short as 500 feet to as long as 70 miles. Some segments are in rural areas, but most are in congested urban areas where construction can be disruptive to the public. In every instance, the company has tried to be sensitive to neighborhood concerns. Atlanta Gas Light is coordinating with the City of Atlanta water and sewer replacement program and the Department of Public Works street repairing to minimize aggregate neighborhood impacts.
What Is the Planning Process?
It takes about 12 months to design and engineer each phase of this pipeline replacement program, as Atlanta Gas Light coordinates around existing utility and roadway infrastructure. At the end of the 15 year process, we will have replaced more than 2,600 miles of older cast iron and steel pipe in Georgia.
Can This Work Be Delayed/Rescheduled?
As Atlanta Gas Light is required to meet certain required milestones as part of the PRP mandated by the Georgia Public Service Commission, work can not be rescheduled. The nature of this large pipeline replacement also requires that the work be done in sequence to upgrade the Inner-Belt line that essentially circles Atlanta. When completed, the replacement will improve the system’s reliability and safety and reduce leaks.