Index
- Introduction
- Vegetation
- Surface Water
- AQRV Type VISIBILITY
- AQRV Type WATER
- Pollutant Exposure Concern Thresholds
- General Information
Introduction
Rainbow Lake Wilderness is a densely vegetated, primitive forest landscape containing 15 undeveloped lakes that are 5 acres or larger in size, and nine ponds. All the lakes and ponds are landlocked; there are no streams. Six miles of the North Country National Scenic Trail traverse the area. Old logging roads provide access to other parts of the wilderness.
Air Quality Related Values
Vegetation
The vegetation contributes significantly to the scenic beauty, variety, and richness of the wilderness. Northern hardwood forest is the dominant vegetation. Maple, white pine, balsam fir, aspen, and paper birch are dominant tree species within the wilderness. Visitors in the spring and summer experience a lush, green, northern hardwood forest, colorful wildflowers, and small kettle lakes of the hummocky terrain. Autumn presents a dazzling array of colors and, as the leaves fall, the hummocky topography created by ancient glaciers is more easily seen.
Surface Water
The Rainbow Lake Wilderness is noted for its beautiful lakes, which provide a rich habitat for fish, furbearers, and aquatic plants. The lakes provide recreation opportunities for anglers, naturalists, and canoeists. The wilderness contains 22 kettle lakes that range in size from 1 to 33 acres. Water enters these landlocked lakes by way of direct precipitation and underground flow from the watershed and leaves by subsurface seepage and evaporation at the surface. The lake water is extremely soft and low in nutrients and dissolved minerals. Visitors to the wilderness gain access to 18 of the lakes along upland shorelines and are able to see several feet into the clear or light brown water. Four of the lakes have a rich, dark stain due to peatlands. Fishing for bass, perch, trout, and bluegill is a popular wilderness use.
Resource Concern Thresholds
| AQRV Type: VISIBILITY | ||
|---|---|---|
| Sensitive Receptor | Sensitive Receptor Indicator | Thresholds |
| Natural Visibility | Light Extinction | In specific Class I areas to maintain consistency with Regional Haze implementation plans or BART, the visibility threshold for concern is not exceeded if the 98th percentile change in light extinction is <5% for each year modeled, when compared to the 20% best natural background values. |
| Natural Visibility | Light Extinction | For sources generally further than 50 km from a Class I area, the visibility threshold for concern is not exceeded if the 98th percentile change in light extinction is <5% for each year modeled, when compared to the annual average natural condition value for that Class I area. |
| Plume Blight | Absolute Contrast | Screening Analysis: For near field sources (within 50 km of a Class I area), no additional analysis will be requested if screening analysis of a new or modified source can demonstrate that its emissions will not cause a plume with hourly estimates of DeltaE (color difference index) greater than or equal to 2.0 or the absolute value of the contrast greater than or equal to 0.05 when modeled against natural conditions. |
| Plume Blight | Absolute Contrast | Refined Analysis: No further analysis will likely be requested if a new or modified source can show that impacts from a new or modified source will stay with the threshold of DeltaE <1.0 and |C| <0.02 modeled against natural conditions. |
| Plume Blight | Color Difference Index | Screening Analysis: For near field sources (within 50 km of a Class I area), no additional analysis will be requested if screening analysis of a new or modified source can demonstrate that its emissions will not cause a plume with hourly estimates of DeltaE (color difference index) greater than or equal to 2.0 or the absolute value of the contrast greater than or equal to 0.05 when modeled against natural conditions. |
| Plume Blight | Color Difference Index | Refined Analysis: No further analysis will likely be requested if a new or modified source can show that impacts from a new or modified source will stay with the threshold of DeltaE <1.0 and |C| <0.02 when modeled against natural conditions. |
| AQRV Type: WATER | ||
|---|---|---|
| Sensitive Receptor | Sensitive Receptor Indicator | Thresholds |
| Aquatic Organisms | Chemistry | Effective sulfur deposition may significantly impact aquatic organisms at levels above 11 kg/ha/yr. Total sulfur plus 20% of nitrogen deposition at levels exceeding 14 kg/ha/yr may cause ANC loss that would impact aquatic organisms. |
| Perennial Streams | Chronic Acid Neutralizing Capacity | To maintain healthy biological functioning in perennial streams, the chronic acid neutralizing capacity must be >= 25 ueq/l. Acid neutralizing capacity below 10 ueq/L (the red line) are expected to cause adverse impacts. |
| Perennial Streams | Episodic Acid Neutralizing Capacity | To maintain healthy biological functioning in perennial streams, the episodic acid neutralizing capacity must be >= 0 ueq/l. |
| Perennial Streams | Metals (Hg) Concentration | In perennial lakes and streams, the concern threshold for mercury in fish tissue is .05 parts per million mercury in wet weight, skin-on filet. |
| Pollutant Exposure Concern Thresholds | ||
|---|---|---|
| Pollutant Exposures | Level Name | Thresholds |
| Nitrogen | EXCEEDANCE | The Deposition Analysis Threshold for nitrogen deposition below which estimated impacts from a source are considered negligible is 0.010 kg/ha/yr. |
| S+20%N | DEPOSITION | Total sulfur plus 20% of nitrogen deposition at levels exceeding 14 kg/ha/yr may cause ANC loss that would impact aquatic organisms. |
| Sulfur | DEPOSITION | Total sulfur deposition at levels below 30 kg/ha/yr is not expected to significantly impact aquatic organisms. |
| Sulfur | EXCEEDANCE | The Deposition Analysis Threshold for sulfur deposition below which estimated impacts from a source are considered negligible is 0.010 kg/ha/yr. |
| Sulfur | EXCEEDANCE | The Deposition Analysis Threshold for sulfur deposition below which estimated impacts from a source are considered negligible is 0.010 kg/ha/yr. |
| General Information | |
|---|---|
| State(s): | Wisconsin |
| County(s): | Bayfield |
| Forest Service Administrative Unit(s): | Northern Region (Region 9) – Chequamegon-Nicolet National Forest |
| Size: | 6388 acres |
| Elevation Range: | 1,100 - 1,325 feet |
| Image(s): | https://www.wilderness.net/images/ |
| Detailed wilderness information: | https://www.wilderness.net |
| GIS Map/Official Boundary: | https://www.wilderness.net/NWPS/ |
updated: 02/28/13