Know what's below: Excess Flow Valves

What is an Excess Flow Valve (EFV)? An EFV is a device that automatically restricts the flow of natural gas if an underground pipe is punctured or severed. Such damage may result from excavation. The EFV is installed underground on the service pipeline that runs between the natural gas main (usually located near the street, alley, or easement) and the Avista meter on the customer’s property. Generally, the EFV is installed as close as possible to the natural gas main.

EFVs have been installed on most new and replaced natural gas customer services since 2008, however, since April 2017, existing natural gas customers without an EFV on their natural gas service may elect to have one installed at the customer’s request and expense. Installation costs vary greatly due to different conditions within our service territory. Customers will be billed for actual labor and materials costs associated with the installation. Estimates for cost and timeframe for construction will be provided as requested on a case-by-case basis. There is no ongoing maintenance cost for the customer.

Whether you have an EFV installed or not on your service line, you need to call 811 to have all underground utility lines properly marked at least two business days before starting any projects that require digging.

If you would like to pursue having an EFV installed in your service line or if you would like to find out if you already have an EFV, please call us at (800) 227-9187 or email us at

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  1. Natural Gas
  2. Safety