Pipeline

Where will the Granite Bridge pipeline be located?


The Granite Bridge pipeline would connect two existing natural gas pipelines and would be buried completely within the New Hampshire Department of Transportation’s (NHDOT) right-of-way along Route 101, from Exeter to Manchester. In 2016, the New Hampshire Legislature passed a law designating Route 101 as one of the state’s Energy Infrastructure Corridors. The Granite Bridge pipeline would utilize this Energy Infrastructure Corridor. To view a map of the proposed route, click here. To view town maps, click here.




What would be the size and pressure of the Granite Bridge pipeline?


The Granite Bridge pipeline would be 16 inches in diameter, with a Maximum Allowable Operating Pressure (MAOP) of 950 pounds per square inch (psi), The typical operating pressure would be much lower, approximately 750 psi. Prior to being placed into service, the entire pipeline would be tested to 150% of its MAOP to ensure that the pipeline is constructed properly and that it will operate safely.




Would any of part of the Granite Bridge pipeline be located on private property?


No. The Granite Bridge pipeline would be buried exclusively within the NHDOT right-of-way along Route 101. The metering stations would be located on property owned by Liberty Utilities, or located within the NHDOT right-of-way.




Will eminient doman be used for any part of this project?


No.




Do natural gas pipes make any noise? If so, how much?


There would not be any noise from the pipeline's normal operation. Some low-level noise would be generated from the metering stations, but these noise levels would be within applicable standards, and lower than the sound of traffic along Route 101. The metering equipment is housed in buildings, each roughly the size of a detached garage, designed to reduce noise.




How will traffic impacts be managed during the pipeline's construction?


Route 101 is a well-traveled, busy highway that many people use to commute to and from work. We would take every measure to ensure minimal traffic disruption and we would hire uniformed police details to ensure public safety during the construction of the Granite Bridge pipeline. Throughout the construction of the Granite Bridge pipeline, both lanes of Route 101 would remain open during high-traffic commuting times. We would adhere to all of the NHDOT’s traffic mitigation standards and work closely with the NHDOT on coordinating the construction schedules to ensure minimal disruption. We will work diligently to minimize traffic impacts. Some night work may be required in certain areas.




Would compressor stations be constructed along the pipeline?


No. There would not be any compressor stations required to move the natural gas through the Granite Bridge pipeline.




Will the Granite Bridge pipeline be safe?


Yes. The safety of our customers, employees and the public is our highest priority and a core value of Liberty Utilities. The design and construction of natural gas infrastructure is strictly regulated and the monitoring of proper maintenance is overseen by the New Hampshire Public Utilities Commission (NHPUC) and the U.S. Department of Transportation (DOT) Pipeline and Hazardous Materials Safety Administration (PHMSA). The Granite Bridge pipeline would be thoroughly inspected and tested prior being placed into service. Every weld would be x-rayed to ensure strength and proper bonding and the entire pipeline would be tested to 150% of its Maximum Allowable Operating Pressure (MAOP) to ensure proper construction and safe operation. We would also conduct inspections at the pipe fabrication mill to ensure that before the pipe is delivered it has been property manufactured and free of defects. Liberty Utilities has a long history of safely operating natural gas pipelines. We work diligently to adhere to regulatory standards and we operate our own maintenance and safety systems. In addition to our own emergency response systems, we work with local, state and federal officials to ensure that the First Responder community is property trained and regularly updated with the latest safety information.




How will the pipeline cross bodies of water such as the Lamprey River?


When we encounter a body of water, or sensitive environmental area, we would directionally drill deep under the area to mitigate any potential environmental impacts that may occur from the construction. Directional drilling under bodies of water is a safe, well developed and frequently used process to ensure minimal disruption. The depth of these directional drillings would depend on the specific geology and location of each crossing, but typically the drilling would be 20 to 50 feet below the bottom of the riverbed, which would mitigate disruption to the natural environment. In 2016, we completed a very similar project, installing a 12-inch pipe under the Soucook River along Route 106 in Loudon. We would employ the same methods, and work with environmental scientists to mitigate the disturbance of environmentally sensitive areas along Route 101.




How deep will the Granite Bridge pipeline be buried?


The Granite Bridge pipeline would be buried at least four feet underground, with warning tape placed one foot above the pipe, to mark its location. There are several areas where the pipeline would be buried at greater depth. These areas would include locations where the pipeline crosses underneath a river or sensitive environmental area. In these cases, we would utilize directional drillings, which would go deep under the area, so as to prevent disruption to the environment.




What is the Granite Bridge pipeline?


The Granite Bridge pipeline is an infrastructure project, proposed by Liberty Utilities, designed to bring additional natural gas supply to residents and businesses in southern and central New Hampshire in order to supply the growing needs of customers who are seeking a clean, safe and economic alternative to their existing fuel source.




How would Liberty Utilities ensure the Granite Bridge pipeline is built and installed correctly?


We would take many preventative measures to ensure that the pipeline is properly constructed and maintained, including conducting inspections at the pipe fabrication mill, testing the entire pipeline to 150% of its MAOP, x-raying all the connection welds to ensure proper bonding, coating the pipe and applying cathodic protection to prevent corrosion, burying the pipe at least four feet underground, backfilling the trench with sand to prevent damage from rocks and other debris, adding warning tape one foot above the pipe and ensuring that the NHDOT has accurate engineering designs showing the exact location of the pipe. All inspectors, technicians, welders and other pipeline workers would be fully trained with up-to-date certifications.




Will the project impact Lake Massabesic?


No. At its closest point, Lake Massabesic is approximately 700 feet from Route 101. We have proposed constructing the Granite Bridge pipeline on the far side of Route 101 from the lake. The Granite Bridge pipeline would be completely buried at least four feet underground, completely within the NHDOT right-of-way, a designated Energy Infrastructure Corridor. Unlike other heating fuels, which are transported by truck along Route 101, natural gas is lighter than air and non-toxic. In the unlikely event that the pipeline is damaged and releases natural gas, it would disperse into the air and not leave any residue on the ground or in the water. We would take many preventative measures to ensure that the pipeline is properly constructed and maintained, including testing the entire pipeline to 150% of its maximum allowable operating pressure before placing it into service, conducting inspections at the pipe fabrication mill to ensure proper manufacturing, x-raying all the connection welds to ensure proper bonding, coating the pipe and applying protection to prevent corrosion, backfilling the trench with sand to prevent damage from rocks and other debris, adding warning tape one foot underground above the pipe location and ensuring that the NHDOT has accurate engineering designs showing the precise location of the pipe. In addition, pressures on the Granite Bridge pipeline would be monitored continuously and trained personnel would inspect the entire route four times a year with special detection equipment, to ensure the line is operating properly.





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