| 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 |
| Aquatic Organisms |
Chemistry |
Effective sulfur deposition may significantly impact aquatic organisms at levels above 11 kg/ha/yr. |
| Aquatic Organisms |
Chemistry |
Total sulfur plus 20% of nitrogen deposition at levels exceeding 14 kg/ha-yr may cause ANC loss that would 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 |
Chronic Acid Neutralizing Capacity |
Adverse effects to the functioning of perennial lakes and streams are likely below 10 ueq/L. |
| 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. |
| Perennial Streams |
Acid Neutralizing Capacity |
The target load for sulfur deposition is 0 kg/ha/yr. |
| 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. |
| 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. |
| 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 |
The target load for sulfur deposition is 0 kg/ha/yr. |
| Sulfur |
DEPOSITION |
Effective sulfur deposition may significantly impact aquatic organisms at levels above 11 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. |
|
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. |
|
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 |
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. |
|
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. |
|
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. |
|
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. |
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