AIR | ABOUT US |  CONTACT US |  FAQ'S | NEWSROOM
Logo of the US Forest Service, Caring for the Land and Serving the People Logo of the US Forest Service, Caring for the Land and Serving the People

Forest Service Home
Employment
Fire & Aviation
International
Just for Kids
Maps & Brochures
Passes & Permits
Photo & Video Gallery
Projects & Policies
Pubs, Regs & Manuals
Recreational Activities
Research & Development
Safety & Occupational Health
State & Private Forestry
 
Air Resource Management Home
Program Spotlight
Wilderness Air Quality
Who We Are
Our Partners
Monitoring and Data
Air Pollution
Law and Policy
Manager's Portal
   
   

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

Egov: My Government. My Terms -- The President's E-government Intitatives.

USA dot Gov: The U.S. Government's Official Web Portal.
   

Presidential Range-Dry River Wilderness

Home > PSD Limits > Map, List > Presidential Range-Dry River Wilderness

General Information

Image of Presidential Range-Dry River Wilderness

State(s): New Hampshire

County(s): Carroll, Coos

Forest Service Administrative Unit(s):
Eastern Region (Region 9) -- White Mountain National Forest

Size: 27380 acres

Elevation Range: 880 - 5,413 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
Aquatic Organisms Chemistry Total sulfur plus 20% of nitrogen deposition at levels exceeding 16 kg/ha-yr may cause ANC loss that would impact aquatic organisms. Levels below 7 kg/ha-yr are not expected to significantly impact aquatic organisms.
Aquatic Organisms Chemistry Sulfur deposition may significantly impact aquatic organisms at levels above 14 kg/ha/yr. Levels below 6 kg/ha-yr are not expected to significantly impact aquatic organisms.
Perennial Lakes and Streams Chronic Acid Neutralizing Capacity To maintain healthy biological functioning in perennial lakes and streams, the chronic acid neutralizing capacity must be >= 25 ueq/l. ANC's below 10 ueq/L (the red line) are expected to cause adverse effects.
Perennial Lakes and Streams Episodic Acid Neutralizing Capacity To maintain healthy biological functioning in perennial lakes and streams, the episodic acid neutralizing capacity must be >= 0 ueq/l.
Pollutant Exposure Concern Thresholds
Pollutant Exposures Level Name Thresholds
N EXCEEDANCE The Deposition Analysis Threshold for nitrogen deposition is 0.010 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 0.01 kg/ha/yr. Below this, estimated impacts from a source greater than 50km from a FLM Class I Area are considered negligible.
S DEPOSITION Sulfur deposition may significantly impact aquatic organisms at levels above 14 kg/ha/yr. Levels below 6 kg/ha-yr are not expected to significantly impact aquatic organisms.
S20PctN DEPOSITION Total sulfur plus 20% of nitrogen deposition at levels exceeding 16 kg/ha-yr may cause ANC loss that would impact aquatic organisms. Levels below 7 kg/ha-yr are not expected to significantly impact aquatic organisms.

Natural Background Visibility

Site Specific Rayleigh scattering coefficient: 11 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) 289 191 122 40 203 101
Haze Index (dv) 3.73 7.66 11.99 22.82 7.07 13.77
For more information on these numbers, click here.