Urban Visibility Measurements in Fort Collins, Colorado

摘要

The urban visibility standard developed by the CDPHE has been in effect for communities along the Front Range in Colorado since 1995. Methods to develop the Denver standard have been used in other municipalities, and the standard has also been used as part of the basis for a proposed US EPA secondary standard for PM_(2.5) addressing urban visibility impacts. Long term measurements in Fort Collins indicate that visibility is improving, and continuing measurements could support a goal of continued improvement. Because the standard was developed using images and measurements in downtown Denver, it may be useful for the City of Fort Collins to examine the range of acceptable conditions specific to the judgment of Fort Collins residents for Fort Collins views. If a secondary PM_(2.5) visibility standard is implemented by the EPA, continued continuous transmissometer monitoring will also be a useful supplement to any future speciated PM_(2.5) compliance monitoring efforts, providing a long term record that can be measured against a standard specific to the clear air values and expectations of Fort Collins residents.