Document ID: EPA-HQ-OW-2016-0694-0025
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2019-05-01T04:00Z

Fifth Percentile Estimates for Level III Ecoregions in Oregon 
Level III Ecoregion
                                 Stream Order
                                Calcium (mg/L)
                               Magnesium (mg/L)
                                 Sodium (mg/L)
                               Potassium (mg/L)
                               Alkalinity (mg/L)
                                Chloride (mg/L)
                                Sulfate (mg/L)
                                  DOC (mg/L)
                                1. Coast Range
                                    SO 1-3
                                      4.9
                                      0.7
                                      1.2
                                      0.1
                                     36.6
                                      0.5
                                      1.0
                                      0.4
                                       
                                    SO 4-6
                                      3.1
                                      0.8
                                      1.8
                                      0.2
                                     12.6
                                      0.9
                                      1.6
                                       
                                       
                                    SO 7-9
                                     11.2
                                      3.2
                                      4.0
                                      0.7
                                     52.1
                                      2.0
                                      5.9
                                       
                             3. Willamette Valley
                                    SO 1-3
                                      4.5
                                      1.6
                                      3.2
                                      0.5
                                     26.0
                                      2.2
                                      1.0
                                      0.4
                                       
                                    SO 4-6
                                      2.4
                                      1.0
                                      2.4
                                      0.4
                                     24.0
                                      3.1
                                      0.5
                                       
                                       
                                    SO 7-9
                                      4.7
                                      1.5
                                      3.3
                                      0.6
                                     20.0
                                      2.4
                                      2.1
                                       
                                  4. Cascades
                                    SO 1-3
                                      0.9
                                      0.1
                                      1.7
                                      0.1
                                       -
                                      0.3
                                      0.2
                                      0.2
                                       
                                    SO 4-6
                                      3.3
                                      0.9
                                      2.8
                                      0.4
                                     15.5
                                      0.7
                                      0.5
                                       
                                       
                                    SO 7-9
                                     12.5
                                      3.3
                                      3.3
                                      0.9
                                     49.9
                                      1.5
                                      5.7
                                       
                   9. Eastern Cascades Slopes and Foothills
                                    SO 1-3
                                      6.0
                                      1.2
                                      2.5
                                      0.5
                                     35.0
                                      0.2
                                      1.0
                                      0.3
                                       
                                    SO 4-6
                                      5.2
                                      0.8
                                      2.2
                                      0.5
                                     20.0
                                      0.5
                                      2.1
                                       
                                       
                                    SO 7-9
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       
                             10. Columbia Plateau
                                    SO 1-3
                                     16.8
                                      4.8
                                      6.4
                                      1.3
                                     43.4
                                      3.2
                                      6.5
                                      0.6
                                       
                                    SO 4-6
                                      7.6
                                      2.4
                                      3.2
                                      0.7
                                     25.9
                                      0.9
                                      2.4
                                       
                                       
                                    SO 7-9
                                      4.1
                                      0.9
                                      1.9
                                      0.6
                                     14.1
                                      0.5
                                      2.0
                                       
                              11. Blue Mountains
                                    SO 1-3
                                      8.6
                                      3.2
                                     49.0
                                      3.7
                                     169.0
                                     11.0
                                     24.0
                                      0.7
                                       
                                    SO 4-6
                                      3.3
                                      0.7
                                      1.3
                                      0.7
                                     13.6
                                      0.2
                                      0.4
                                       
                                       
                                    SO 7-9
                                      7.4
                                      1.1
                                      2.8
                                      0.7
                                     27.2
                                      0.6
                                      3.7
                                       
                             12. Snake River Plain
                                    SO 1-3
                                     11.9
                                      1.6
                                      4.5
                                      0.6
                                     32.5
                                      0.9
                                      1.7
                                      1.2
                                       
                                    SO 4-6
                                     11.0
                                      1.8
                                      4.2
                                      0.9
                                     33.0
                                      1.4
                                      3.1
                                       
                                       
                                    SO 7-9
                                     23.3
                                      8.1
                                     11.0
                                      1.9
                                     109.9
                                      8.9
                                     22.1
                                       
                             78. Klamath Mountains
                                    SO 1-3
                                      5.4
                                      5.1
                                      4.9
                                      0.3
                                       -
                                      2.1
                                      1.8
                                      0.5
                                       
                                    SO 4-6
                                      7.3
                                      3.0
                                      3.7
                                      0.5
                                     30.8
                                      1.7
                                      1.9
                                       
                                       
                                    SO 7-9
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       
                         80. Northern Basin and Range
                                    SO 1-3
                                      6.1
                                      1.0
                                      3.0
                                      1.0
                                     23.0
                                      0.2
                                      1.9
                                      0.9
                                       
                                    SO 4-6
                                     16.8
                                      5.9
                                      3.6
                                      0.6
                                     42.0
                                      1.3
                                      7.3
                                       
                                       
                                    SO 7-9
                                      8.9
                                      2.4
                                      7.7
                                      2.1
                                       -
                                      2.1
                                      5.1
                                       
Twenty-fifth Percentile Estimates for Level III Ecoregions in Oregon 
Level III Ecoregion
                                 Stream Order
                                Calcium (mg/L)
                               Magnesium (mg/L)
                                 Sodium (mg/L)
                               Potassium (mg/L)
                               Alkalinity (mg/L)
                                Chloride (mg/L)
                                Sulfate (mg/L)
                                  DOC (mg/L)
                                1. Coast Range
                                    SO 1-3
                                      8.5
                                      1.1
                                      1.8
                                      0.2
                                     50.9
                                      0.8
                                      2.7
                                      0.9
                                       
                                    SO 4-6
                                      5.7
                                      1.3
                                      3.0
                                      0.5
                                     19.0
                                      2.7
                                      3.8
                                       
                                       
                                    SO 7-9
                                     13.9
                                      3.9
                                      4.9
                                      0.9
                                     62.0
                                      2.9
                                      7.7
                                       
                             3. Willamette Valley
                                    SO 1-3
                                     10.6
                                      3.8
                                      5.9
                                      1.5
                                     42.0
                                      4.7
                                      3.2
                                      0.6
                                       
                                    SO 4-6
                                      8.0
                                      2.8
                                      5.2
                                      0.9
                                     33.0
                                      4.0
                                      3.0
                                       
                                       
                                    SO 7-9
                                      5.7
                                      1.9
                                      4.1
                                      0.7
                                     22.8
                                      3.1
                                      2.9
                                       
                                  4. Cascades
                                    SO 1-3
                                      2.5
                                      0.8
                                      2.0
                                      0.4
                                       -
                                      0.6
                                      0.3
                                      0.4
                                       
                                    SO 4-6
                                      4.0
                                      1.1
                                      3.0
                                      0.5
                                     16.5
                                      1.2
                                      1.1
                                       
                                       
                                    SO 7-9
                                     15.9
                                      4.1
                                      4.5
                                      1.0
                                     58.3
                                      2.2
                                      8.7
                                       
                   9. Eastern Cascades Slopes and Foothills
                                    SO 1-3
                                     14.5
                                      8.0
                                     23.0
                                      3.5
                                     35.0
                                      0.5
                                      3.2
                                      0.6
                                       
                                    SO 4-6
                                      6.9
                                      1.7
                                      3.5
                                      0.6
                                     31.0
                                      0.9
                                      2.9
                                       
                                       
                                    SO 7-9
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       
                             10. Columbia Plateau
                                    SO 1-3
                                     31.2
                                     12.2
                                     18.8
                                      2.8
                                     113.0
                                      7.8
                                     24.0
                                      1.4
                                       
                                    SO 4-6
                                     13.0
                                      4.9
                                      7.0
                                      1.7
                                     54.0
                                      2.6
                                      6.1
                                       
                                       
                                    SO 7-9
                                     14.5
                                      4.0
                                      2.4
                                      0.8
                                     20.0
                                      1.2
                                      7.7
                                       
                              11. Blue Mountains
                                    SO 1-3
                                     12.4
                                      6.2
                                     49.0
                                      3.7
                                     169.0
                                     11.0
                                     24.0
                                      1.2
                                       
                                    SO 4-6
                                      5.0
                                      1.4
                                      2.1
                                      1.0
                                     23.0
                                      0.5
                                      0.9
                                       
                                       
                                    SO 7-9
                                     15.0
                                      2.9
                                      5.7
                                      1.0
                                     55.3
                                      1.5
                                      7.8
                                       
                             12. Snake River Plain
                                    SO 1-3
                                     21.3
                                      3.7
                                     11.2
                                      2.3
                                     41.0
                                      3.4
                                     10.1
                                      1.4
                                       
                                    SO 4-6
                                     21.9
                                      5.9
                                      9.4
                                      1.9
                                     65.3
                                      4.4
                                      7.9
                                       
                                       
                                    SO 7-9
                                     41.8
                                     13.0
                                     19.7
                                      3.3
                                     138.5
                                     18.8
                                     38.0
                                       
                             78. Klamath Mountains
                                    SO 1-3
                                     17.4
                                      8.2
                                      5.0
                                      0.4
                                       -
                                      2.5
                                      4.4
                                      0.6
                                       
                                    SO 4-6
                                      8.8
                                      3.9
                                      4.6
                                      0.7
                                     39.0
                                      2.8
                                      3.4
                                       
                                       
                                    SO 7-9
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       
                         80. Northern Basin and Range
                                    SO 1-3
                                      7.2
                                      1.7
                                      6.7
                                      2.8
                                     27.0
                                      0.7
                                      3.3
                                      1.3

                                    SO 4-6
                                     44.0
                                      9.4
                                      4.1
                                      0.8
                                     137.8
                                      2.5
                                     10.2
                                       

                                    SO 7-9
                                      8.9
                                      2.4
                                      7.7
                                      2.1
                                       -
                                      2.1
                                      5.1