Smell Gas? What to Do, and When a Plumber Can Help

What should you do right now?

1. Leave. Get everyone, including pets, out of the building. If it is quick and on your way, open doors and windows as you go, but do not stay inside to do it.
2. Do not create a spark. No light switches, no unplugging, no lighters, matches or candles, no starting the car in an attached garage, and no phone calls from inside.
3. Move to a safe distance. Go well away from the building, upwind if you can.
4. Call 911, then the gas utility. For Washington Gas, call 844-WASHGAS (844-927-4427) and select option 1. If you call from somewhere else, give the address and a callback number so crews can get in.
5. Stay out until responders or the utility say it is safe to go back in.

Fairfax County's emergency guidance adds two points worth remembering: do not try to find the leak yourself, and only shut off the gas if authorities or the utility tell you to.

What does a gas leak smell, sound and look like?

Natural gas has no smell of its own. Washington Gas adds an odorant called mercaptan so leaks can be noticed, and it describes the result as sulfur or rotten eggs. Smell is the most reliable sign, but not the only one:

• A hissing or blowing sound near a gas line, meter or appliance, usually with an odor.
• A patch of dead grass or plants in an otherwise green yard, or a dry spot in wet ground.
• Bubbles rising in a puddle or standing water.
• Dirt or dust being blown into the air near the ground.

Any one of these is reason to leave and call. Do not wait to see whether the smell fades.

Which gas company should you call?

Most homes in the District and the nearby Maryland and Virginia suburbs are served by Washington Gas, but not all. The utility that owns the pipes is printed on your gas bill. It is worth checking now, before you ever need it, and saving the number in your phone.

Some homes and apartment buildings are all-electric and have no gas service at all. If you smell something like rotten eggs in an all-electric home, still leave and call 911; the fire department can find the source. Readers in Laurel, Manassas and Herndon should double-check which company is on the bill, because neighboring streets can differ.

What if you live in an apartment, condo or rowhouse?

Shared walls change the details but not the order. Fairfax County's advice is to get everyone out of the building, so leave your unit and the building, and warn neighbors on your way out by knocking rather than using a doorbell or intercom. Once outside and at a distance, make the calls and tell the dispatcher it is a multi-unit building. If a property manager or building engineer is on site, let them know too, but do not wait for them before calling 911 and the utility. Rowhouses on many District blocks share party walls and sometimes basements that connect, so a smell next door is worth reporting even if your own home seems fine.

Renters should still call the utility directly. Let the landlord or manager know once you are safe; they arrange the repair to the house piping afterward.

What if the smell is faint or comes and goes?

Treat it the same way. You cannot judge from a smell how much gas has built up, especially in a basement or a closet with a water heater or furnace. Washington Gas's advice does not change with the strength of the odor: leave and call. The utility's crew has instruments that measure gas in the air and can tell you whether the source is on their side of the meter or yours. Calling about a faint smell that turns out to be minor is far better than waiting on one that is not.

If the crew traces a small leak to a fitting or valve inside your house, they may shut off the affected appliance or the service until it is repaired. That is the point where you need a plumber.

Where does the utility's job end and a plumber's begin?

Washington Gas states that the meter at your home, inside or outside, belongs to the utility, and tampering with it is illegal. The utility responds to leaks and maintains its distribution system. The piping that runs from the meter to your range, dryer, water heater, furnace or fireplace is house piping, and repairing it is work for a plumber or gas fitter you hire. Typical jobs after a leak call include:

• Finding and repairing a leaking fitting, valve or flexible connector.
• Replacing corroded or outdated pipe.
• Pressure-testing the system after repairs so service can be restored.
• Capping a line left behind when an appliance was removed.

After service is restored following a repair, Washington Gas says its personnel or contractors relight customer appliances. A gas line repair in the District or a Fairfax gas piping job follows the same pattern: the leak is made safe first, then the house piping is fixed and tested.

Is a permit needed for gas piping work?

Usually, and the office depends on where you live. In the District, the DC Department of Buildings issues plumbing and gas permits, and the application is signed by a Master Plumber or Gas Fitter. In Montgomery and Prince George's counties, WSSC Water issues plumbing and gasfitting permits, and gas work, including gas water heater and furnace replacements, must be done by a plumber or gasfitter holding a WSSC Water license. In Fairfax County, new gas piping needs a Residential Plumbing permit, and even a like-for-like gas water heater replacement needs a Household Appliance permit. Ask who will pull the permit before work begins.

Is carbon monoxide the same danger?

No. Carbon monoxide has no smell, so the rotten-egg odor will not warn you. It forms when a gas appliance burns without enough air or does not vent properly. Washington Gas warns against installing gas furnaces, water heaters or dryers in a small enclosed space such as a closet without the air openings code requires, and notes that kitchen, bath and attic exhaust fans can pull combustion gases back into the house. Fairfax County recommends working smoke and carbon monoxide alarms in every home. If an appliance shows soot, a lazy yellow flame or signs of poor venting, turn it off, air out the house and have it checked. A plumbing inspection can include gas appliance connections, and a failing heater may point toward replacing the water heater.

Planning to dig in the yard?

Damage from digging is a leading cause of gas emergencies. Call 811 at least two full working days before you dig, not counting weekends and holidays, so buried lines are marked. That applies to fence posts and garden beds as much as to a sewer line replacement.

Is this a plumbing emergency?

A gas smell is a 911 call first, not a plumber call. Once the utility has made the house safe, finding a plumber for the repair is urgent but rarely a midnight job, especially if the gas is off and the house is otherwise safe. The guide to when a plumbing problem can wait helps sort the rest, and the DC emergency plumber page connects you with an independent local plumber when it cannot.