DEQ Determines There is a Significant AVF in the Otter Creek Drainage -

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DEQ Determines There is a Significant AVF in the Otter Creek Drainage

Tuesday, November 7, 2017/Categories: Department of Environmental Quality/Tags:

HELENA – Department of Environmental Quality officials have completed the process for determining the presence, extent and significance of an Alluvial Valley Floor for Tract 2 of the Otter Creek Coal Tracts. DEQ originally began the AVF determination in 2013 as part of the permit application review for the proposed Otter Creek Coal mine.


An Alluvial Valley Floor, or AVF, determination focuses on defining the presence, absence, extent and significance of the AVF to the associated agricultural operations within the valley. An AVF must have stream-laid alluvial deposits and agricultural activities supported by either flood and/or subirrigation. An AVF determination is a part of the coal permitting process because there are specific protections for an AVF from coal mining impacts.


DEQ determined the presence, absence, and extent of the AVF in February of 2016. DEQ has now completed determinion that it is a significant AVF because of its relative importance to the associated agricultural operations.


DEQ has moved forward on the work of the AVF determination because the data were available to complete the AVF significance determination, there was a potential future need for the information, and there was a request from Great Northern Properties to complete the significance determination.


Arch Coal suspended permitting activities on the Otter Creek permit application in early 2016 and DEQ has not continued work on any other aspect of the permitting process for the Otter Creek Coal Mine.  

The significance determination can be found here:


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