Appendix B: Detailed Methods The main text of this report, “Groundwater-Dependent Biodiversity and Associated Threats: A Statewide Screening Methodology and Spatial Assessment of Oregon,” is available online at http://conserveonline.org. Contents: I. OVERVIEW OF APPROACH: ...........................................................................................3 II. MAPPING GROUNDWATER-DEPENDENT ECOSYSTEMS AND SPECIES: ................3 A. SPRINGS: ....................................................................................................................3 1. Data sources: ............................................................................................................3 2. Mapping springs:.......................................................................................................4 3. Determining potential groundwater dependence:......................................................4 B. WETLANDS: ................................................................................................................4 1. Data used:.................................................................................................................4 2. Mapping wetlands: ....................................................................................................4 3. Determining potential groundwater dependence:......................................................5 C. RIVERS:.......................................................................................................................6 1. Data used:.................................................................................................................6 2. Mapping rivers:..........................................................................................................6 3. Determining potential groundwater dependence:.....................................................6 a. Permeability of surficial geologic deposits: ............................................................7 b. Flow gaging data: ..................................................................................................7 D. LAKES:.........................................................................................................................8 1. Data used:.................................................................................................................8 2. Mapping lakes: ..........................................................................................................8 3. Determining potential groundwater dependence:......................................................8 E. SUBTERRANEAN AREAS:..........................................................................................9 F. SPECIES AND ECOLOGICAL COMMUNITIES OF CONSERVATION CONCERN: ...9 1. Data sources: ............................................................................................................9 2. Mapping species and communities of conservation concern: ...................................9 3. Determining groundwater dependence: ....................................................................9 a. Vascular plants: .....................................................................................................9 b. Non-vascular plants: ............................................................................................10 c. Amphibians and Reptiles: ....................................................................................11 d. Beetles:................................................................................................................11 e. Birds: ...................................................................................................................11 f. Butterflies:.............................................................................................................12 g. Caddisflies: ..........................................................................................................12 h. Dragonflies, mayflies, and stoneflies: ..................................................................12 i. Fish: ......................................................................................................................12 j. Mollusks:...............................................................................................................12 k. Bats:....................................................................................................................13 l. Other species:.......................................................................................................13 m. Ecological communities: .....................................................................................13 III. SUMMARIZING THE DISTRIBUTION OF GDEs IN OREGON:....................................14 IV. THREATS TO GROUNDWATER QUANTITY: .............................................................14 A. KNOWN WATER TABLE DECLINES ................................................................................. 14 B. CURRENT THREATS:........................................................................................................... 15 Table of Contents B-1 C. FUTURE THREATS:..................................................................................................16 1. Large wells: ............................................................................................................16 2. Small wells: ............................................................................................................16 V. THREATS TO GROUNDWATER QUALITY: .................................................................17 A. KNOWN GROUNDWATER CONTAMINATION:........................................................17 1. Nutrients:.................................................................................................................17 a. Draft Groundwater Management Areas: ..............................................................17 b. Groundwater quality data:....................................................................................17 2. Pesticides:...............................................................................................................18 3. Other toxic contaminants:........................................................................................18 B. THREAT OF GROUNDWATER CONTAMINATION — NUTRIENTS: .......................19 1. Nitrates:...................................................................................................................19 a. Agricultural fertilizer use and septic system density:............................................19 b. Concentrated Animal Feeding Operations:..........................................................21 c. Underground Injection Control sites for septic systems: ......................................21 2. Phosphorus: ............................................................................................................21 a. Agricultural fertilizer use: .....................................................................................22 b. Urban fertilizer use:..............................................................................................22 C. THREAT OF GROUNDWATER CONTAMINATION — PESTICIDES: ......................22 1. Urban use:...............................................................................................................22 2. Agricultural use:.......................................................................................................23 D. THREAT OF GROUNDWATER CONTAMINATION — OTHER TOXIC CONTAMINANTS: ..........................................................................................................28 1. Leaking underground storage tanks:.......................................................................28 2. Underground Injection Control wells:.......................................................................28 3. Hazardous waste spills:...........................................................................................29 4. Specific land use activities: .....................................................................................29 E. THREAT OF ALTERED THERMAL REGIME – HOT SPRINGS:...............................31 VI. THREAT SYNTHESIS: .................................................................................................31 REFERENCES:..................................................................................................................32 Tables: 1: Criteria used to identify HUC6s in which GDEs occur in Oregon ...................................14 2: Criteria for identifying HUC6s with a threat of altered groundwater quantity ..................14 3: Criteria for identifying HUC6s with threats of altered groundwater quality due to known groundwater contamination.................................................................................17 4: Criteria for identifying HUC6s with threats of altered groundwater quality due to potential contamination by nitrates................................................................................................19 5: Use codes used to identify irrigated areas from the points of use data in the OWRD water rights database. ....................................................................................................20 6: Criteria for identifying HUC6s with threats of altered groundwater quality due to potential contamination by phosphorus ..........................................................................22 7: Criteria used to