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Pasayten Wilderness

Home > PSD Limits > Map, List > Pasayten Wilderness

General Information

Image of Pasayten Wilderness

State(s): Washington

County(s): Okanogan, Whatcom

Forest Service Administrative Unit(s):
Pacific Northwest Region (Region 6) -- Mt. Baker - Snoqualmie National Forest, Okanogan National Forest

Size: 529477 acres

Elevation Range: 2,600 - 9,066 feet

Data:

Documents

Resource Concern Thresholds

AQRV Type: VISIBILITY
Sensitive Receptor Sensitive Receptor Indicator Thresholds
Natural Visibilty For sources generally further than 50 km from a Class I area, the visibility threshold for concern is not exceeded if the 98th %ile 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 Higher level near-field screening and 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 Absolute Contrast 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 Plume blight near-field 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.
Plume Blight Color Difference Index 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.

AQRV Type: WATER
Sensitive Receptor Sensitive Receptor Indicator Thresholds
Lakes with Low Anc Acid Neutralizing Capacity For lakes with low acid neutralizing capacity, the condition class of "Severe Deterioration" applies if there is deterioration below ANC of 0 ueq/l.
Lakes with Low Anc Acid Neutralizing Capacity For lakes with low acid neutralizing capacity, the condition class of "Significant Deterioration" applies if there is greater than or equal to a 20% decline in ANC.
Lakes with Low Anc Acid Neutralizing Capacity For lakes with low acid neutralizing capacity, the condition class of not significant applies if there is less than a 20% decline in ANC.
Lakes with Low Anc pH For lakes with low acid neutralizing capacity, the condition class of "Severe Deterioration" applies if pH levels are below 5.3.
Lakes with Low Anc pH For lakes with low acid neutralizing capacity, the condition class of "Not Significant" applies if pH levels are above 6.0.
Lakes with Low Anc pH For lakes with low acid neutralizing capacity, the condition class of "Significant Deterioration" applies if pH levels are between 5.3-6.0.
Streams Acid Neutralizing Capacity For streams that have an initial acid neutralizing capacity of 25-100 ueq/l, the condition class of "Not Significant" applies if there is less than a 25% change in ANC from baseline.
Streams Acid Neutralizing Capacity For streams that have an initial acid neutralizing capacity of greater than 100 ueq/l, the condition class of "Significant Deterioration" applies if ANC levels are between 15-25 ueq/l.
Streams Acid Neutralizing Capacity For streams that have an initial acid neutralizing capacity of greater than 100 ueq/l, the condition class of "Not Significant" applies if there is less than a 50% change in ANC from baseline.
Streams Acid Neutralizing Capacity For streams that have an initial acid neutralizing capacity of 25-100 ueq/l, the condition class of "Significant Deterioration" applies if ANC levels are between 15-25 ueq/l.
Streams Acid Neutralizing Capacity For streams that have an initial acid neutralizing capacity of less than 25 ueq/l, the condition class of "Severe Deterioration" applies if there is any change from baseline.
Streams Acid Neutralizing Capacity For streams that have an initial acid neutralizing capacity of greater than 100 ueq/l, the condition class of "Severe Deterioration" applies if ANC levels are less than 15 ueq/l.
Streams Acid Neutralizing Capacity For streams that have an initial acid neutralizing capacity of less than 25 ueq/l, the condition class of "Not Significant" applies if there is no change from baseline.
Streams Acid Neutralizing Capacity For streams that have an initial acid neutralizing capacity of 25-100 ueq/l, the condition class of "Severe Deterioration" applies if ANC levels are less than 15 ueq/l.
Pollutant Exposure Concern Thresholds
Pollutant Exposures Level Name Thresholds
N EXCEEDANCE The Deposition Analysis Threshold for nitrogen deposition is 0.005 kg/ha/yr. Below this, estimated impacts from a source greater than 50km from a FLM Class I Area are considered negligible.
Q QOverD For new or modified sources locating greater than 50 km from a Class I area, its impacts will be considered negligible with respect to Class I AQRVs if its total SO2, NOx, PM25, PM10, and H2SO4 annual emissions in tons/yr, based on 24-hr maximum allowable emissions, divided by the distance (km ) from the Class I area (Q/D) is 10 or less. For sources operating less than a year, the emissions must be adjusted to reflect what the emissions would be if the source operated year-round.
S EXCEEDANCE The Deposition Analysis Threshold for sulfur deposition is 0.005 kg/ha/yr. Below this, estimated impacts from a source greater than 50km from a FLM Class I Area are considered negligible.

Natural Background Visibility

Site Specific Rayleigh scattering coefficient: 10 Clearest 20% Natural Clearest 20% 2000-2004 Baseline Haziest 20% Natural Haziest 20% 2000-2004 Baseline Average Annual Natural Annual Average 2000-2004 Baseline
Standard Visual Range (km) 348 298 171 85 263 177
Haze Index (dv) 1.16 2.73 8.25 15.23 3.97 7.93
For more information on these numbers, click here.