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  • NorthWestern Continues Spill Cleanup Work in Cut Bank

    Jan 21, 2015

    Butte, Mont. – Jan. 21, 2015 – NorthWestern Energy continues work cleaning up a spill of mercaptan, which is a non-toxic substance added to natural gas to give it a distinctive odor. Because natural gas is colorless and odorless, adding mercaptan to gas is a way to help detect the presence of natural gas or a gas leak. It can be smelled at very low concentrations and has been described as smelling like a skunk or rotten eggs.

    The spill occurred on NorthWestern Energy property near Cut Bank, Mont., on Nov. 13, 2014. NorthWestern estimates that 1,200 gallons of mercaptan was released. The spill caused intermittent natural gas odors and reports of gas leaks in and around Cut Bank. Area residents are to be thanked for reporting the smell.

    NorthWestern reported the spill shortly after the incident and has been working the Montana Department of Environmental Quality and others to monitor and clean-up the spill. Wells have been installed to monitor groundwater and the spill area has been capped to minimize odors.  A vapor extraction system has been installed under the cap and will be used to vacuum up odors and help remove the mercaptan from the soil.

    NorthWestern Energy reminds area residents to remain vigilant to possible natural gas leaks and not assume any natural gas smell is coming from the spill site.

    At any time, if you smell gas, take these precautions:

    • Don’t smoke, light matches, turn electrical switches on or off, use the telephone or cell phone, or do anything that might create a spark.
    • Evacuate everyone in your home or building, and stay out until someone from the utility company tells you it is safe to return.
    • Keep others away from the area.
    • Call 911 and your local natural-gas provider once you are a safe distance from the structure.

    NorthWestern customers with questions about natural-gas safety or any aspect of their service can contact us at (888) 467-2669. Bear in mind that your natural-gas provider may be a company other than NorthWestern Energy.

    To keep abreast of outages and other NorthWestern Energy events, follow us on Facebook and on Twitter (@NorthWestern__MT).

    About NorthWestern Energy (NYSE: NWE)
    NorthWestern Energy provides electricity and natural gas in the Upper Midwest and Northwest, serving approximately 678,200 customers in Montana, South Dakota and Nebraska. More information on NorthWestern Energy is available on the company's website at

    Media Contact:
    Butch Larombe
    (866) 622-8081


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