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	USDA Forest Service 1400 Independence Avenue SW Washington, D.C. 20250-0003 (202) 205-8333

Hoover Wilderness

General Information

State(s): California

County(s): Mono

Forest Service Administrative Unit(s):
Intermountain Region (Region 4) -- Toiyabe National Forest; Pacific Southwest Region (Region 5) -- Inyo National Forest

Size: 48601 acres

Elevation Range: 7,640 - 12,446 feet

Image(s): http://www.wilderness.net/images/

Detailed wilderness information: http://www.wilderness.net

GIS Map/Official Boundary: http://www.wilderness.net/NWPS/

Webcam(s): Hoover (Gallery)

Data:

Wet Deposition (NADP)
Dry Deposition (CASTNET)
- Sequoia NP - Lookout Pt
- Yosemite NP - Turtleback Dome
Visibility (IMPROVE) - Hoover

Links

HOME
Hoover Wilderness
Map
Alphabetical Area Listing

Resource Concern Thresholds

AQRV Type: VISIBILITY
Sensitive Receptor	Sensitive Receptor Indicator	Thresholds
Natural Visibilty		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 %ile change in light extinction is <5% for each year modeled, when compared to the 20% best natural background values.
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	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	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	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, a long-term reduction of ANC of 5-10 ueq/l results in the condition class "Significant".
Lakes with Low Anc	Acid Neutralizing Capacity	For lakes with low acid neutralizing capacity, a long-term reduction of ANC of less than 10 ueq/l results in the condition class "No Change".
Lakes with Low Anc	Acid Neutralizing Capacity	For lakes with low acid neutralizing capacity, no more than a 10% change in ANC is acceptable.
Lakes with Low Anc	Acid Neutralizing Capacity	For lakes with low acid neutralizing capacity, a reduction of ANC to near 0 ueq/l during and immediately following hydrologic events results in the condition class "Severe".
Perennial Streams	Acid Neutralizing Capacity	For perennial streams with low acid neutralizing capacity, a reduction of ANC to near 0 ueq/l during and immediately following hydrologic events results in the condition class "Severe".
Perennial Streams	Acid Neutralizing Capacity	For perennial streams with low acid neutralizing capacity, a long-term reduction of ANC of 5-10 ueq/l results in the condition class "Significant".
Perennial Streams	Acid Neutralizing Capacity	For perennial streams with low acid neutralizing capacity, a long-term reduction of ANC of less than 10 ueq/l results in the condition class "No Change".

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 0.005 kg/ha/yr. kilograms/hectare/year.
Q (Sum of SO2+NOx+PM10+H2SO4)	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, 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.
Sulfur	EXCEEDANCE	The Deposition Analysis Threshold for sulfur deposition below which estimated impacts from a source are considered negligible is 0.005 kg/ha/yr.
	CHANGE	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.
	EXCEEDANCE	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.
	CHANGE	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.
	CHANGE	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.
	EXTINCTION	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.
	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 %ile change in light extinction is <5% for each year modeled, when compared to the 20% best natural background values.

Natural Background Visibility

Site Specific Rayleigh scattering coefficient: 9	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)	353	312	173	105	266	197
Haze Index (dv)	0.07	1.44	7.71	12.87	3.16	6.33
For more information on these numbers, click here.