The safety of our customers, employees and the public is our highest priority and a core value of Liberty Utilities.
Liberty Utilities has a long history of safely operating natural gas pipelines and liquefied natural gas (LNG) and propane storage facilities. For the past 45 years our three LNG facilities have provided safe and reliable service to our customers in New Hampshire. While smaller than Granite Bridge, these facilities function, and must be monitored and maintained, in much the same way as the Granite Bridge LNG storage facility.
Properly constructed and maintained LNG storage facilities have excellent safety track records. Design and construction is strictly regulated and the monitoring of proper maintenance is overseen by the New Hampshire Public Utilities Commission (NH PUC) and the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration (PHMSA).
LNG has been safely used and transported for over 70 years. LNG is not explosive or flammable in its liquid state. If exposed to the environment, LNG would rapidly warm to its gaseous state and evaporate, leaving no residue on water or soil.
There are currently 43 LNG facilities located in 28 towns serving customers in New England. In New Hampshire there are three LNG storage facilities, located in Manchester, Tilton and Concord. At present, there are 113 LNG facilities located in the United States.
In 2016 we completed a project to upgrade an existing high pressure natural gas distribution line in Loudon, which brings natural gas from Concord to customers in the Lakes Region. This project involved installing a new 12-inch natural gas line within the NHDOT right-of-way along Route 106, the construction methods and work required for Granite Bridge would be very similar to this project.
SAFETY THROUGHOUT PROJECT DESIGN, CONSTRUCTION AND OPERATION
Full x-ray of all pipeline joint welds
On-site inspections at pipeline fabrication mill to ensure proper manufacture
New coated, 1/2 inch thick, steel pipe
Pipeline buried 48” underground, completely within NHDOT right-of-way
Safety warning tape place 1' above infrastructure to mitigate potential 3rd party damage
Full pipeline route inspections would exceed federal requirements
Full containment LNG storage tank (tank within a tank), most robust design
Impoundment areas designed to help contain liquid, in unlikely event of a release
Facility located within 140 acre parcel, set down in an abandoned abandoned quarry
On-site fire suppression and safety systems
24/7 on-site and remote (Londonderry) monitoring & control of storage facility and pipeline
Coordination and training with first responders
LNG Itself Does Not Burn
Unless oxygen is present, LNG is not flammable. As LNG warms, it begins to vaporize.
A very specific set of circumstances - an exact ratio of gas to air and a source of ignition - would have to be present for these vapors to burn.
FULL-CONTAINMENT LNG TANK
A full containment LNG storage tank system is a free standing inner tank surrounded by a second free standing tank, designed to hold the entire liquid capacity of the inner tank. It is the most robust storage tank design.
Essentially, a full containment storage tank system is a tank housed within another tank.
This ensures the highest level of safety and adds an additional layer of complete containment, in the unlikely event of an LNG release.
The tank would be located in an abandoned quarry with 30’ high walls that would create an additional level containment, in the unlikely event of a release from both the inner and outer tanks.
Granite Bridge will be reviewed, inspected and must be approved by several state and federal agencies, including the NHPUC Safety Division, the Pipeline and Hazardous Materials Safety Administration (PHMSA) and the NH Site Evaluation Committee.