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Welcome To Washington Gas

For more than 165 years Washington Gas has been distributing natural gas to customers in the District of Columbia, Maryland and Virginia. We bring natural gas to your home or business safely and reliably.

Interruptible Customer Profile

Interruptible customers are large commercial and industrial customers who, in addition to using natural gas, have the ability to operate their mechanical equipment utilizing an alternate fuel source. This ability to switch to an alternate fuel source when interruptions or curtailments are in effect is what sets Interruptible customers apart from other natural gas customers.

Interruptible customers are a diverse group that cut across many sectors. They include but are not limited to:


Property Management companies: Companies that generally maintain a portfolio of properties, both large and small office and apartment complexes and coordinate their energy needs.


  • Hospitals

  • Universities

  • Schools

  • Hotels

  • Governmental complexes

  • Laundries

  • Asphalt plants

To qualify as an interruptible customer, you must be able to meet a minimum level of annual natural gas consumption and have alternate fuel capability. The annual gas consumption varies by jurisdiction:

20,000 therms per year

District of Columbia
60,000 therms per year

60,000 therms per year

Interruptions and curtailments, in general, occur during the cold months of winter when demand for natural gas is very high. While weather conditions are not the only reason for natural gas service interruption or curtailment, using weather forecasts can be helpful in predicting interruptions and curtailments.

Frequently Asked Questions

Q. What is unique about an Interruptible Customer?

A. The distinction between an interruptible customer and a firm customer is the ability of the interruptible customer to operate mechanical systems independently on two or more fuel sources. Interruptible customers enjoy lower rates than firm commercial customers by maintaining the ability to discontinue their natural gas usage by switching to an alternate fuel during periods of interruption or curtailment.

Q. What is meant by interruption or curtailment?

A. Due to weather or market conditions, interruptible customers may be required to interrupt their use of natural gas (switch to their alternate fuel source) or curtail their use of natural gas (make certain they have an adequate supply of natural gas to match their needs for a given time period or switch to their alternate fuel source). In periods of curtailment, it is critical that interruptible customers communicate with their third-party suppliers to ensure that adequate supplies of natural gas are delivered or to avoid unauthorized gas usage penalties, switch to your alternate fuel source.

Q. How can I become an Interruptible Customer?

A.  The initial requirement for an interruptible customer is they must have alternate fuel capabilities. For example, a customer's mechanical system must be able to operate solely on #2 fuel oil. Additionally, in the District of Columbia and Virginia, a customer must consume 60,000 therms and, in Maryland, 20,000 therms on an annual basis. These natural gas consumption numbers are equivalent to using 45,000 and 14,500 gallons, respectively, of #2 fuel oil on an annual basis.

Q. Can an Interruptible Customer switch to become a firm (consumer of only natural gas) customer?

A. Contact your Washington Gas Account Manager to begin the assessment process to determine whether Washington Gas infrastructure is adequate to accommodate your request. If the infrastructure is adequate to meet your needs, you may operate your facilities under Washington Gas' firm tariff. Please remember that a customer may switch once during a twelve-month period from one tariff rate to another. All decisions are based on whether the Washington Gas infrastructure can accommodate such a request.

Q. What is a natural gas supplier?

A. A natural gas supplier is an entity which arranges to purchase natural gas (the commodity) for natural gas customers. Any customer may purchase gas from a natural gas supplier, however, you must make arrangements with Washington Gas to deliver your supplier's purchase of natural gas. The natural gas supplier and Washington Gas will assist you through this process.

Q. Can I monitor my gas supply and usage?

A. If you are an interruptible customer, you can monitor your natural gas usage on a daily basis. If you have internet access you can sign up for Washington Gas' Bulletin Board Service. This service will provide updated daily information on your supplier's activities, actual natural gas usage for your property and any inventories of natural gas your account may have accumulated.   Please submit your account number, telephone number and email address to