Cottonwood Integrated Weed Treatment Program ENVIRONMENTAL ASSESSMENT Coeur d’AleneCoeur District, Idaho Dalmation toadflax biological control release site Cottonwood Field Office 9015 DOI-BLM-ID-C020-2011-0017-EA January 2012 It is the mission of the Bureau of Land Management to sustain the health, diversity, and productivity of the public lands for the use and enjoyment of present and future generations. Cottonwood Field Office 1 Butte Drive Cottonwood, ID 83522 208-962-3245 Cover Photo: Dalmation toadflax biological control site; Photo by Lynn Danly Cottonwood Integrated Weed Treatment Program Contents 1 PURPOSE OF AND NEED FOR ACTION ........................................................................... 1 1.1 Introduction ...................................................................................................................... 1 1.2 Type of Action ................................................................................................................. 1 1.3 Location of Proposed Action ........................................................................................... 1 1.4 Background ...................................................................................................................... 1 1.5 Purpose of and Need for Action ....................................................................................... 3 1.6 Land Use Plan Conformance............................................................................................ 4 1.7 Relationship to Statutes, Regulations or Other Plans ....................................................... 5 1.8 Incorporation by Reference and Tiering .......................................................................... 7 2 PROPOSED ACTION AND ALTERNATIVES ................................................................... 8 2.1 Elements Common to All Action Alternatives ................................................................ 8 2.2 Proposed Action ............................................................................................................. 10 2.3 Alternative 1 – 18 Active Ingredient List....................................................................... 18 2.4 Alternative 2 – No Aerial Application ........................................................................... 19 2.5 Alternative 3 – No Herbicide or Exotic Biological Control .......................................... 19 2.6 Alternative 4 – No Action .............................................................................................. 20 2.7 Alternatives Considered but not Analyzed in Detail ...................................................... 20 2.8 Alternative Comparison ................................................................................................. 21 3 AFFECTED ENVIRONMENT ............................................................................................ 23 3.1 General Setting ............................................................................................................... 23 3.2 Affected Resources ........................................................................................................ 23 3.2.1 Special Designation Areas ........................................................................................... 23 3.2.2 Vegetation .................................................................................................................... 25 3.2.3 Water Quality ............................................................................................................... 32 3.2.4 Fisheries and Special Status Fish ................................................................................. 34 3.2.5 Wildlife and Special Status Wildlife............................................................................ 40 3.2.6 Soils.............................................................................................................................. 43 3.2.7 Native American Tribal Uses....................................................................................... 44 3.2.8 Cultural Resources ....................................................................................................... 44 3.2.9 Human Health/Recreation Use .................................................................................... 45 4 ENVIRONMENTAL EFFECTS .......................................................................................... 46 4.1 Special Designation Areas ............................................................................................. 46 4.1.1 Proposed Action ........................................................................................................... 46 4.1.2 Alternative 1 – 18 Active Ingredient List .................................................................... 49 4.1.3 Alternative 2 – No Aerial Application ......................................................................... 49 4.1.4 Alternative 3 – No Herbicide or Exotic Biological Control ........................................ 50 4.1.5 Alternative 4 – No Action ............................................................................................ 50 4.2 Vegetation ...................................................................................................................... 51 4.2.1 Proposed Action ........................................................................................................... 51 4.2.2 Alternative 1 – 18 Active Ingredient List .................................................................... 62 4.2.3 Alternative 2 – No Aerial Application ......................................................................... 63 4.2.4 Alternative 3 – No Herbicide or Exotic Biological Control ........................................ 65 4.2.5 Alternative 4 – No Action ............................................................................................ 68 Environmental Assessment (January 2012) Page i Cottonwood Integrated Weed Treatment Program 4.3 Water Quality ................................................................................................................. 70 4.3.1 Proposed Action ........................................................................................................... 70 4.3.2 Alternative 1 – 18 Active Ingredient List ................................................................... 73 4.3.3 Alternative 2 – No Aerial Application ......................................................................... 74 4.3.4 Alternative 3 – No Herbicide or Exotic Biological Control ........................................ 74 4.3.5 Alternative 4 – No Action ............................................................................................ 75 4.4 Fisheries and Special Status Fish ................................................................................... 75 4.4.1 Proposed Action ........................................................................................................... 75 4.4.2 Alternative 1 – 18 Active Ingredient List .................................................................... 82 4.4.3 Alternative 2 – No Aerial Application ......................................................................... 83 4.4.4 Alternative 3 – No Herbicide or Exotic Biological Control ........................................ 84 4.4.5 Alternative 4 – No Action ............................................................................................ 85 4.5 Wildlife and Special Status Wildlife .............................................................................. 85 4.5.1 Proposed Action ........................................................................................................... 85 4.5.2 Alternative 1 – 18 Active Ingredient List .................................................................... 94 4.5.3 Alternative 2 – No Aerial Application ......................................................................... 94 4.5.4 Alternative 3 – No Herbicide or Exotic Biological Control ........................................ 95 4.5.5 Alternative 4 – No Action ............................................................................................ 97 4.6 Soils ................................................................................................................................ 97 4.6.1 Proposed Action ........................................................................................................... 97 4.6.2 Alternative 1 – 18 Active Ingredient List .................................................................... 99 4.6.3 Alternative 2 – No Aerial Application ......................................................................... 99 4.6.4 Alternative 3 – No Herbicide or Exotic Biological Control ...................................... 100 4.6.5 Alternative 4 – No Action .......................................................................................... 100 4.7 Native American Tribal Uses ....................................................................................... 100 4.7.1 Proposed Action ......................................................................................................... 100 4.7.2 Alternative 1 – 18 Active Ingredient List .................................................................. 101 4.7.3 Alternative 2 – No Aerial Application ....................................................................... 101 4.7.4 Alternative 3 – No Herbicide or Exotic Biological Control .....................................