Who builds and owns an offsite gas line extension?

The utility does. Southwest Gas Rule No. 6 says the utility "will construct, own, operate and maintain service and main line extensions." That covers the main in the street and the service line from the main to the meter. The owner does not hire a contractor to build the utility's pipe or to trench in the public right-of-way for it.

The rule also sets some conditions on the applicant:

1. 1Gas service lines will be of suitable capacity from the utility's main to "a meter location on the property of the applicant that is satisfactory to the Utility." The utility has a say in where the meter goes.
2. 2Main extensions run along public streets and roads where the utility has legal right to be, and across private property only where rights-of-way "satisfactory to the Utility, may be obtained without cost or condemnation." Easements across private land are expected at no cost to the utility, so plan for that in your site and lease documents.

Rule No. 6 says all service and main extensions are made "on the basis of economic feasibility," calculated by the Incremental Contribution Method. In general terms, the utility compares the revenue it expects from the new customer with the cost to serve, and it builds at its own expense up to an "allowable investment."

When the numbers do not reach that level, the tariff lets the utility extend anyway if the customer signs an extension agreement and advances part of the cost, or agrees to pay a nonrefundable facility charge, enough to make the extension economically feasible. Advances are refunded without interest under the tariff's refund method, and the tariff describes an annual review of refunds over a ten-year period for line extensions built under the incremental method.

What does that mean for a commercial project? A large load, such as a restaurant kitchen, a laundry or a boiler plant, can improve the utility's math. A small load at the end of a long run may require an advance. The practical step is to send the utility your expected gas load early, so the feasibility study starts before your schedule depends on it. Rate schedules and rules are revised by the Arizona Corporation Commission from time to time, and the sheets we reviewed carry revision dates from 2017 to 2021, so ask for the current terms.

At the point of delivery. The tariff defines it as the point where the customer's pipes connect to the utility's pipes, or the outlet side of the meter, whichever is further downstream. Three related definitions matter:

• The service line is the pipe from the main to the point of delivery.
• The customer piping system is everything from the point of delivery to the outlets of the appliance shutoff valves.
• Rule No. 7 says meters, regulators and service pipe that the utility owns on the customer's premises "shall continue to be the property of the Utility," and the utility keeps them in safe operating condition.

Southwest Gas states the split in plain words on its customer brochure: the utility owns the piping up to and including the meter, and the customer owns the piping from the meter to the structure and to outdoor gas appliances. That buried piece is called customer buried piping.

Rule No. 7 puts it in one sentence. The customer shall, at the customer's "sole risk and expense," furnish, install and keep in good, safe and leak-free condition a customer piping system and the appliances and apparatus beyond the point of delivery. The utility runs a leak check on the customer's piping when it turns the gas on, will deny service while any hazardous leak remains, and may refuse service until a certificate from an authorized public official or a licensed plumber is issued.

On a commercial site, the owner-side scope usually includes the piping from the meter set to the building, the regulators and piping inside, the appliance connections and the pressure test the inspector expects. The permit path for that work is covered in our page on gas line permits and who can install in Arizona, and the test itself in gas line pressure test.

Yes, and it is one of the few choices an owner has. The Southwest Gas brochure says a meter set at the property line may leave a long run of customer-owned buried pipe. If the meter is relocated next to the building at the customer's expense, that pipe "greatly" shrinks, because the utility owns everything up to and including the meter. For a new building, agree on the meter location during design. The tariff gives the utility a say, so the answer is a negotiation, not a right.

If the proposed customer piping crosses another parcel, have the designer and local authority verify the permitted route and any easement requirements. An older city amendment is not a substitute for the current code and an approved site plan.

Get out first, then call. The Southwest Gas brochure tells you to exit the building, leave doors open, and from a safe place call 911 and Southwest Gas at 877-860-6020, day or night. Do not use switches, lighters or anything that can spark, and do not start an engine. Our page on what to do if your house smells like gas covers the steps in more detail.

1. 1Contact the gas utility with your expected load, your schedule and the site plan, so the feasibility review and the meter location are settled early.
2. 2Ask in writing where the point of delivery will be, and mark it on your plans.
3. 3Have your engineer or plumbing designer size the customer piping to the load the utility approved.
4. 4Budget for an advance or facility charge only if the utility asks for one, and get its terms in a signed agreement.
5. 5Hire a licensed contractor for the owner-side piping, and pull the permit before work starts.

HQ Plumbing & Air handles the owner-side gas piping, from the meter to your appliances, with a free estimate and the price up front. We do not build the utility's main or service line. Tariffs and codes change, so confirm current terms with your gas utility and your building department before you begin.