From time to time, SoCalGas® may need to interrupt natural gas service to its customers. The tariff provisions governing the process of service interruption or “curtailment” are set forth in Tariff Rule 23, “Continuity of Service and Interruption of Delivery”.
(Note: While SoCalGas exercises reasonable diligence and care to furnish and deliver service to its customers, it is not liable for damages resulting from any failure to deliver natural gas or provide service, which failure results from breakage of its facilities, operating limitations or other conditions beyond its reasonable control.)
The situations requiring curtailment vary but generally fall into these categories:
- System Curtailment
- Localized Curtailment
- Emergency Curtailment
- Planned Maintenance Curtailment
The purpose of this overview is to help you better understand the general provisions of curtailment. It is not intended to be a substitute for Rule 23 or the other tariff schedules SoCalGas has on file with the California Public Utilities Commission (CPUC). All of these tariffs can be reviewed online.
Rule 23 was updated on November 1, 2016. Please see the revised tariffs and proceeding (A.15-06-020) documents for complete information about the new curtailment rules and procedures.
- Frequently Asked Questions regarding Updates to Rule 23
- History of Curtailments at SoCalGas
- Detailed descriptions of Local Service Zones
Order of Curtailment
In the event of a system curtailment, SoCalGas shall curtail service according to Rule 23:
- In the event of a curtailment being called based on day-ahead forecasts of peak electric generation load, all Dispatchable Electric Generation not currently forecasted to be operating at the time the curtailment order is effective. In the event of a curtailment being called based on real-time demand, all Dispatchable Electric Generation not operating when a curtailment is issued.
- Up to 60 percent of Dispatched Electric Generation load during November through March and up to 40 percent of Dispatched Electric Generation load during April through October.
- Up to 100 percent of non-electric generation noncore and noncore cogeneration usage on a pro rata basis, except for pre-established refinery minimum usage requirements.
- Up to 100 percent of remaining refinery load not curtailed in step 3.
- Up to 100 percent of remaining Dispatched Electric Generation load not curtailed in step 2.
- All Priority 2A service on a pro rata basis.
- All Priority 1 non-residential service on a pro rata basis.
- All Priority 1 residential service on a pro rata basis.
System Curtailment may occur in a large area of our service territory when the system cannot maintain adequate pressure. In such an event, curtailment of service to customers in the affected area will generally be made based on the order of curtailment shown above (and specified in Section C.1 of Tariff Rule 23). However, this order will be followed only to the extent it is operationally feasible to do so. Unbundled as-available and firm storage withdrawal service may not be available for deliveries to customers whose service is restricted as a result of a system curtailment.
Localized curtailment occurs when a specific area of our service territory is impacted by intrastate capacity restrictions or emergencies. Curtailment of service to customers in the affected area will generally be made based on the order of curtailment shown above (and specified in Section C.1 of Tariff Rule 23). However, this order will be followed only to the extent it is operationally feasible to do so. Unbundled as-available and firm storage withdrawal service may not be available for deliveries to customers whose service is restricted as a result of a localized curtailment.
SoCalGas may need to curtail service on an emergency basis. This occurs at times where there is a threatened or actual shortage creating an emergency condition for a short duration in our ability to meet the demands of core customers. During such an emergency, we may curtail service to all or some of our customers in the most reasonable and practicable manner possible. In such an emergency, we have the right to shut off, discontinue, re-establish or continue service to such customers, irrespective of the priority or preference set forth in its tariff schedules, contracts, or rules and regulations applicable to such service.
Planned Maintenance Curtailment
A Planned Maintenance Curtailment may occur to complete safety or maintenance work on the pipeline. Under a Planned Maintenance Curtailment, the customer is provided with advance notice through an electronic bulletin board, Envoy®, that interruptible and/or firm service will be reduced or unavailable during a specified period. SoCalGas makes every attempt to minimize customer impacts during a Planned Maintenance Curtailment. Rules regarding planned maintenance curtailment are outlined in Rule 30.
The customer's transportation service priority shall be established in accordance with the provisions of Rule No. 23, Continuity of Service and Interruption of Delivery.
The Utility shall have the right, without liability, to interrupt the acceptance or redelivery of gas whenever it becomes necessary to test, alter, modify, enlarge or repair any facility or property comprising the Utility's system or otherwise related to its operation. When doing so, the Utility will try to cause a minimum of inconvenience to the customer. Except in cases of unforeseen emergency, the Utility shall give a minimum of ten (10) days advance written notice of such activity.
The Curtailment Transfer Process
Customers may make arrangements to transfer or “trade” curtailment requirements. Through such an arrangement, responsibility for a specified curtailment level can be transferred from one customer (who otherwise would be required to curtail) to another customer (who would not otherwise be required to curtail).
Customers who reach mutual agreement on a transfer of curtailment requirements must execute a “Notice of Intrastate Curtailment Transfer” (Form No. 6600) and submit this form to SoCalGas. The form must indicate the customer facilities involved in the trade and must specify the amount of curtailment to be transferred between each. Transfer arrangements are not valid until the required form is accepted and agreed to by SoCalGas. Accordingly, customers should submit their curtailment trades as early as possible. A copy of the transfer form may be obtained by contacting your account representative.
Contact your account representative if you have any questions regarding transfers.
SoCalGas shall provide notification of a curtailment to the contact personnel indicated on the Personnel Notification Form most recently submitted by the customer. Curtailment notification shall be provided by any one or more of the following means: notification posting on ENVOY, verbally by telephone or in person; in writing via email, fax or overnight postal delivery; or by text message sent via an alphanumeric pager system. SoCalGas will attempt to provide advance notice of a curtailment but only to the extent it is practical to do so. In some situations, SoCalGas may need to curtail service immediately upon notification of the curtailment. In this event, the customer shall be required to curtail or will be found in violation of curtailment.