Pipeline Safety

Understanding Gas 

Hawai‘i Gas distributes three types of gas to consumers: synthetic natural gas (SNG); renewable natural gas (RNG); and propane (liquefied petroleum gas, or LPG). Gas is naturally nontoxic, colorless, odorless, and flammable. The type of gas you use depends primarily on your area, and in some cases, the purposes for which you use gas. 

SNG is made from a byproduct (naptha) of the oil refining product and recycled water. It is primarily composed of methane, the simplest and cleanest of all carbon-based fuels, along with up to 15% hydrogen. SNG is mixed with locally produced RNG. SNG is lighter than air, and tends to rise and dissipate rapidly if released. On O‘ahu, SNG is transported to our utility customers through 1,000 miles of underground distribution pipelines. 

LPG, or propane, is usually liquefied and bottled, making it convenient for delivery and storage in a variety of containers (e.g., cylinders for your barbeque grill). We deliver propane to utility and non-utility customers on every island, including propane distribution locations. Propane gas is heavier than air; it tends to move along the surface toward low ground if released. Utility customers receive propane gas through underground distribution pipelines.

Because gas is odorless, Hawaiʻi Gas adds a distinctive odor to its Natural Gas, Synthetic Natural Gas (SNG) and Liquefied Petroleum Gas (LPG) as a safety precaution to assist in the detection of leaks. This odorant gives gas its recognizable “rotten egg” smell.

‍

Prevent Pipeline Damage

If you are planning to dig within your property, call the Hawaiʻi One Call Center at least five (5) working days before you dig by dialing 811. 

Give them the address and location of the cross street(s) nearest where you plan to dig. The Hawaiʻi One Call Center will contact all local utilities to mark or identify the location of underground utilities, at no cost to you.

Always call to locate underground gas and utility lines before beginning any excavation activity, even when conducting minor excavation. 

‍

For Contractors

Safety is everyone’s responsibility. Any excavation in public rights-of-way (land over which facilities such as highways, power lines, or utilities are built) or on private property not exclusively owned by the excavator must adhere to the following procedure:

Have an excavation permit issued by the County or the State, depending on jurisdiction, with approved clearances from all affected utility companies.

Call the Hawaiʻi One Call Center at 811 at least five (5) working days before you dig.

Hawaiʻi Gas will provide approximate locations of gas lines in the area of your dig site. It is the responsibility of the excavator to determine the exact location (i.e. alignment and depth) of the pipes. Look for the presence of gas meters or vaults to aid your search.

To determine the exact location of the pipes, carefully hand dig until the gas line is exposed. Do NOT use power equipment until the gas line has been exposed. Use suitable, rock-free material for backfill to avoid damage to the pipe or pipe coating.

Excavation in or near public rights-of-way can affect public safety. If you are aware of any unauthorized digging or construction in public rights-of-way or if you notice any suspicious activity in the vicinity of gas pipelines, contact the Hawaiʻi One Call Center at 811.

‍

For Homeowners

Like contractors, homeowners are encouraged to call the Hawaiʻi One Call Center at 811 at least five (5) working days before they start any type of project involving excavation, including planting a hedge or installing a mailbox, fence, sprinkler system, deck, or pool, etc.

Recognizing Gas Pipelines

Hawaiʻi Gas’ pipelines are made of steel or high-density polyethylene, and are as large as 16 inches and as small as 1/4-inch in diameter. Wherever possible, Hawaiʻi Gas buries pipes with yellow warning tape; however, all underground facilities should be treated with caution. Never assume a pipe is abandoned. On O‘ahu, Hawaiʻi Gas posts yellow warning signs along our high-pressure transmission pipeline from Kapolei to Pier 38.

‍

Maps and Records

For general information on the location of Hawai‘i Gas high pressure pipelines and other underground pipelines in your neighborhood, visit the National Pipeline Mapping System’s website at www.npms.phmsa.dot.gov.  

To learn about proper cover requirements for gas pipelines as well as all other underground gas pipeline locations, information is available on O‘ahu by visiting our Maps and Records Department at 515 Kamakee Street (open Monday –⁠ Friday, 7:30am –⁠ 3:30pm), or by calling 808-535-5933 ext. 4. On the Neighbor Islands, contact your local Hawaiʻi Gas office.

‍

Damage to Hawaiʻi Gas Facilities 

No matter how small, even a slight gouge, scrape or minor dent in a gas pipeline could eventually result in a rupture or leak. Damage to the locating wire used for polyethylene gas pipes could make it difficult to locate pipes in the future. 

If you suspect a leak, stop all work and check for the smell, sound and other signs of escaping gas. Call the Hawai‘i Gas emergency line, or contact 911. Do not attempt to repair the pipeline or backfill the area until Hawai‘i Gas has inspected for and repaired any damage. 

Residential customers should have their piping checked once every five years and commercial customers should check their piping annually.

Hawaiʻi Gas customers should maintain 3’ (SNG) or 5’ (LPG) of clearance to Meter Set Assemblies from sources of ignition (i.e. electrical outlets, water heaters, air conditioners) and building openings (i.e. doors, windows, vents). 

Hawaiʻi Gas utilizes anodeless risers at customer meter sets. Anodeless risers can be identified by a red sticker marked “Do Not Bury Above This Line”. Customers should maintain the surface elevation at meter sets with anodeless risers such that the sticker does not become buried underground.