Great Sand Dunes National Park & Preserve Air Quality Information
Overview
Both local and distant air pollution sources affect air quality in Great Sand Dunes NP&P. Power plants, cement kilns, automobiles, and other sources in Colorado, New Mexico, and other Southwestern states, all contribute pollutants to the monument and preserve.
The air quality related values (AQRVs) of Great Sand Dunes NP&P are those resources that are potentially sensitive to air pollution, and include vegetation, wildlife, water quality, soils, and visibility. At present, visibility has been identified as the most sensitive AQRV in the monument and preserve; other AQRVs may also be very sensitive, but have not been sufficiently studied. Although visibility in the area is still superior to that in many parts of the country, visibility is often impaired by light-scattering pollutants (haze).
The U.S. Environmental Protection Agency’s Regional Haze regulations require States to establish goals for each Class I air quality area to improve visibility on the haziest days and ensure no degradation occurs on the clearest days. As part of the Interagency Monitoring of Protected Visual Environments (IMPROVE) network, visual air quality in Great Sand Dunes NP&P has been monitored using an aerosol sampler (1988-present) and an automatic camera (1987-1995). An analysis of 1990-1999 data from the site indicates that visibility in the area is improving somewhat on the clearest days and staying about the same on the haziest days.
Certain surface waters and soils in Great Sand Dunes NP&P, particularly those at higher elevations, may be sensitive to atmospheric deposition of sulfur and nitrogen compounds. Sensitive waters may experience chronic or episodic acidification.
Soils, vegetation, and water in the park may be sensitive to nutrient enrichment from nitrogen deposition. In some parts of the country, nitrogen deposition has altered soil nutrient cycling and vegetation species composition; native plants that have evolved under nitrogen-poor conditions have been replaced by invasive species better able to utilize nitrogen. Tundra plant communities and sensitive aquatic ecosystems in Rocky Mountain National Park are experiencing subtle changes because of nitrogen deposition; similar communities in Great Sand Dunes NP&P may also be vulnerable to such changes.
Atmospheric deposition is not monitored in Great Sand Dunes NP&P. Wet deposition is monitored in nearby Alamosa by the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). The site ID is CO00. Although deposition rates from that monitor are relatively low, they are elevated above natural conditions. From 1980-2002, sulfur deposition decreased at the site, while nitrogen deposition increased. There are no dry deposition monitors near Great Sand Dunes NP&P.
Several plant species that occur in Great Sand Dunes NP&P are known to be sensitive to ozone, including Pinus ponderosa (ponderosa pine), Populus tremuloides (quaking aspen), and Rhus trilobata (skunkbush). Tropospheric (ground-level) ozone concentrations were monitored from 1988-1991; in addition, current estimates of ozone concentrations can be found on the NPS Air Atlas website. The monitored and estimated concentrations are in ranges that would not be expected to induce vegetation injury. If ozone increases in the area, the risk to vegetation could increase.
Additional information on in-park emissions at Gread Sand Dunes NP is available in 2001 Air Emissions Inventory- Great Sand Dunes National Monument (October 2003).
Additional information relative to air quality and air quality related values at Great Sand Dunes NP&P is available in D. Binkley et al. 1997. Status of Air Quality and Related Values in Class I National Parks and Monuments of the Colorado Plateau. National Park Service. Denver, CO.