Middle Prong Wilderness lies west of Shining Rock Wilderness. The Wilderness is made of steep and rugged high-elevation ridges. Elevations range from 3,200 feet at the west fork of Pigeon River to Richland Balsam. The west fork and middle prong of the Pigeon River are born amid the high valleys of this Wilderness and are fed by numerous streams.
The Middle Prong Wilderness is designated as Class II air quality under the Clean Air Act Amendments of 1977. The 1984 North Carolina Wilderness Act created the 7,460-acre Middle Prong Wilderness.
Air Quality Related Values (AQRV)
Water
Numerous high quality streams dissect the wilderness and provide habitat for native brook trout as well as enhance the recreation experience. Although there are about 2000 miles of trout streams in western North Carolina only a few sustain native brook trout populations. The streams in Middle Prong Wilderness are unique in providing habitat for these native species. The streams are cold, clean and free of situation and pollution. These qualities plus the beauty of the fast moving water over the rocks are enjoyed by wilderness users.
Air Quality Related Values (AQRV) and Sensitive Receptor Indicators
| AQRV Type: FLORA | ||||||
|---|---|---|---|---|---|---|
| Sensitive Receptor | Sensitive Receptor Indicator |
Concern Thresholds |
Upper Limit |
Lower Limit |
Units | Comments |
| Ozone Sensitive Species | Foliar Symptoms | Visible Symptoms | 30 | Percent | observed from 6 feet away | |
| AQRV Type: VISIBILITY | ||||||
|---|---|---|---|---|---|---|
| Sensitive Receptor | Sensitive Receptor Indicator |
Concern Thresholds |
Upper Limit |
Lower Limit |
Units | Comments |
| Representative Site | Haziness | Change | 0.5 | Deciviews | from natural background | |
| AQRV Type: WATER | ||||
|---|---|---|---|---|
| Sensitive Receptor | Sensitive Receptor Indicator |
Concern Thresholds |
Lower Limit |
Units |
| Perennial Streams | Acid Neutralizing Capacity | Measurable Decrease | <0.1 | Microequivalents Per Liter |
| Perennial Streams | Chronic Acid Neutralizing Capacity | Maintain Biological Function | >25 | Microequivalents Per Liter |
| Perennial Streams | Chronic pH | Maintain Biological Function | >6 | pH |
| Perennial Streams | Episodic Acid Neutralizing Capacity | Maintain Biological Function | >0 | Microequivalents Per Liter |
| Perennial Streams | Episodic pH | Maintain Biological Function | >5.5 | pH |
| Perennial Streams | pH | Measurable Decrease | <0.01 | pH |
Pollutant Exposures
| Pollutant Exposures | Level Name | Comments | Upper Limit | Lower Limit | Units | Pollutant Averaging | AQRV | Sensitive Receptor | Sensitive Receptor Indicator |
|---|---|---|---|---|---|---|---|---|---|
| Nitrogen | Deposition | SCREENING VALUES | 10 | 3 | Kilograms Per Hectare - Year | Annual | Flora | Soils | Soil Chemistry |
| Ozone | N100 Metric | Number of hours greater than or equal to 0.100 ppm. | 4 | Hours | April-September | Flora | Ozone Sensitive Species | Biomass Reduction | |
| Ozone | W126 Ppm Metric | Weighting of ozone concentrations in a biologically meaningful way | 14.5 | Parts per Million-Hours | April-September | Flora | Ozone Sensitive Species | Biomass Reduction | |
| Sulfur | Deposition | SCREENING VALUES | 20 | 5 | Kilograms Per Hectare - Year | Annual | Flora | Soils | Soil Chemistry |
updated: 9/26/2006