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Studies and Monitoring

Olympic National Park

Olympic National Park (NP), Washington, has its own unique environmental concerns based on its particular ecology. Air quality studies and monitoring programs at Olympic NP focus on toxic air contaminants, nitrogen deposition, and visibility. Click on the tabs below to review air quality studies and key scientific references at Olympic NP, as well as to access information on air quality monitoring in the park.

  • Studies & Projects
  • Monitoring & Data
  • Key References

Ongoing research in Olympic NP, Washington:

Centralia: A Source of Nitrogen, Sulfur, and Mercury Pollution at Olympic NP

Located approximately 90 km from Olympic NP in Centralia, WA, TransAlta’s Centralia Power Plant is one of the largest stationary sources of atmospheric nitrogen, sulfur, and mercury in the region. These pollutants are emitted through the coal-burning process used to generate electricity at the power plant. Retrofit technologies have been installed to better control sulfur dioxide and nitrogen oxide emissions, and reductions in sulfate have followed. Control of mercury emissions is currently achieved via existing controls for sulfur dioxide and nitrogen oxides. The National Park Service currently requests better nitrogen oxide emission controls and continues discussions with other agencies and the owners of Centralia Power Plant.

Airborne Toxic Contaminants Impacts

Air currents transport contaminants such as pesticides, industrial pollutants, and heavy metals from their sources, and deposit these toxics in rain, snow, and dryfall at Olympic NP. The Western Airborne Contaminants Assessment Project found airborne contaminants in air, vegetation, fish, snow, and sediment samples from the park. Mercury concentrations in some park fish exceeded human and wildlife health thresholds (Landers et al. 2010; Landers et al. 2008; Schwindt et al. 2008). Further, logging practices in the Lake Ozette basin have led to high levels of mercury in bass from this coastal park lake (Furl et al. 2009). Supplementary research found changes in metabolic, endocrine, and immune-related genes in fish from contaminated lakes, as compared to fish from uncontaminated lakes (Moran et al. 2007). The Pacific Northwest Contaminants Workshop addressed regional concerns regarding contaminant distribution and effects. Additional research is examining whether contaminants disrupt reproductive organs in park fish. Contaminant effects upon amphibian populations at the park are currently unknown.

Nitrogen & Sulfur Impacts

Nitrogen emissions in the Pacific Northwest remain a concern for park managers (Fenn et al. 2003 [pdf, 895 KB]). Nitrogen deposition exceeds the critical load for lichen community composition in some polluted areas of the Pacific Northwest. In the Columbia River Gorge and the Willamette Valley, for example, sensitive lichen species important to wildlife have declined and been replaced by pollution-tolerant species (Geiser and Neitlich 2007; Geiser et al. 2010). However, surveyed lichen sites at the park were among the least polluted sites in the study region and do not exceed the critical load. These sites are strongly dominated by pollution-sensitive lichen species. Nevertheless, nitrogen deposition from adjacent sources (urban, agricultural, marine vessel) could affect high elevation alpine vegetation and surface waters on the park’s east side (Eilers et al. 1994 [pdf, 520 KB]).

Visibility Impacts

The PREVENT (Pacific Northwest Regional Visibility Experiment Using Natural Tracers) study found that sulfur is the largest contributor to reduced visibility reduction at Olympic NP, a result largely of power plants and urban emissions. Nitrates contributed about 10% of the visibility reduction at the park, and mostly result from nitrogen oxide emissions from pulp and paper mills or lime-kiln activity, fires, power plants, and transportation (Malm et al. 1994).

Air quality monitoring information and data access:

Air Pollutant/Impact

Monitoring Program

Sites and Data Access

Mercury NADP/MDN
Other Toxics & Mercury WACAP
Visibility IMPROVE
Nitrogen & Sulfur Wet deposition NADP/NTN
Dry deposition CASTNet

Abbreviations in the above table:

    CASTNet: EPA Clean Air Status and Trends Network
    GPMP: Gaseous Pollutant Monitoring Program
    IMPROVE: Interagency Monitoring of Protected Visual Environments
    MDN: Mercury Deposition Network
    NADP: National Atmospheric Deposition Program
    NOAA: National Oceanic and Atmospheric Administration
    NPS: National Park Service
    NTN: National Trends Network
    VIEWS: Visibility Information Exchange Web System
    WACAP: Western Airborne Contaminants Assessment Project

For more information regarding monitoring and data assessments conducted by the National Park Service, link to the NPS Air Quality Monitoring Program or to the NPS Air Quality Monitoring History Database for a history of active and inactive monitoring sites at Olympic NP.

Key air quality related references from Olympic NP, Washington:

Barna, M., Lamb, B., O’Neill, S., Westberg, H., Figueroa-Kaminsky, C. Otterson, S., Bowman, C., and DeMay, J. 2000. Modeling Ozone Formation and Transport in the Cascadia Region of the Pacific Northwest. Journal of Applied Meteorology 39: 349–366.

Bohm, M. 1992. Air Quality and Deposition. In: Olson, R. K., Binkley, D. and Bohm, M. (eds). The Response of Western Forests to Air Pollution. Springer-Verlag: New York, NY. pp. 63–152.

Brace, S., Peterson, D. L., and Bowers, D. 1999. A guide to ozone injury in vascular plants of the Pacific Northwest. Gen. Tech. Rep. PNW-GTR—446. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 63 pp.

Eilers, J. M., Rose, C. L., Sullivan, T. J. 1994. Status of Air Quality and Effects of Atmospheric Pollutants on Ecosystems in the Pacific Northwest Region of the National Park Service. NPS Final Report. 255 pp. Available at (pdf, 520 KB).

Fenn, M., Geiser, L., Peterson, J., Waddell, E., and Porter, E. 2003. Why Federal Land Managers in the Northwest are Concerned about Nitrogen Emissions. National Park Service. 18 pp. Available at (pdf, 895 KB).

Frenzel, R. W., Witmer, G. W. and Starkey, E. E. 1990. Heavy metal concentrations in a lichen of Mt. Rainier and Olympic National Parks, Washington, USA. Bulletin of Environmental Contamination and Toxicology 44 (1): 158–164.

Furl, C. V., Colman, J. A., Bothner, M. H. 2009. Mercury Sources to Lake Ozette and Lake Dickey: Highly Contaminated Remote Coastal Lakes, Washington State, USA. Water Air Soil Pollut 208: 275–286.

Geiser, L. H., Jovan, S. E., Glavich, D. A., Porter, M. K. 2010. Lichen-based critical loads for atmospheric nitrogen deposition in Western Oregon and Washington Forests, USA. Environmental Pollution 158: 2412–2421.

Geiser, L. and Neitlich, P. 2007. Air pollution and climate gradients in western Oregon and Washington indicated by epiphytic macrolichens. Environmental Pollution 145: 203–218.

Hageman, K. J., Simonich, S. L., Campbell, D. H., Wilson, G. R., Landers, D. H. 2006. Atmospheric deposition of current-use and historic-use pesticides in snow at national parks in the Western United States. Environmental Science & Technology 40: 3174–3180.

[IMPROVE] Interagency Monitoring of Protected Visual Environments. 2010. Improve Summary Data. Available at

Jaffe, D., McKendry, I., Anderson, T., Price, H. 2003. Six ‘new’ episodes of trans-Pacific transport of air pollutants. Atmos. Envir. 37: 391–404.

Landers, D. H., Simonich, S. M., Jaffe, D., Geiser, L., Campbell, D. H., Schwindt, A., Schreck, C., Kent, M., Hafner, W., Taylor, H. E., Hageman, K., Usenko, S., Ackerman, L., Schrlau, J., Rose, N., Blett, T., Erway, M. M. 2010. The Western Airborne Contaminant Assessment Project (WACAP): An Interdisciplinary Evaluation of the Impacts of Airborne Contaminants in Western U.S. National Parks. Environmental Science and Technology 44: 855–859.

Landers, D. H., S. L. Simonich, D. A. Jaffe, L. H. Geiser, D. H. Campbell, A. R. Schwindt, C. B. Schreck, M. L. Kent, W. D. Hafner, H. E. Taylor, K. J. Hageman, S. Usenko, L. K. Ackerman, J. E. Schrlau, N. L. Rose, T. F. Blett, and M. M. Erway. 2008. The Fate, Transport, and Ecological Impacts of Airborne Contaminants in Western National Parks (USA). EPA/600/R—07/138. U.S. Environmental Protection Agency, Office of Research and Development, NHEERL, Western Ecology Division, Corvallis, Oregon. Available at

Malm, W. C., Gebhart, K. A., Molenar, J., Eldred, R., Harrison, H. 1994. Pacific Northwest Regional Visibility Experiment Using Natural Tracers—PREVENT. National Park Service Final Report. Available at

Moran P. W., Aluru, N., Black, R. W., Vijayan, M. M. 2007. Tissue contaminants and associated transcriptional response in trout liver from high elevation lakes of Washington. Environ Sci Technol. 41(18): 6591–6597.

Schwindt, A. R., Fournie, J. W., Landers, D. H., Schreck, C. B., Kent, M. 2008. Mercury Concentrations in Salmonids from Western U.S. National Parks and Relationships with Age and Macrophage Aggregates. Environmental Science & Technology 42 (4): 1365–1370.

Sullivan, T. J., McDonnell, T. C., McPherson, G. T., Mackey, S. D., Moore, D. 2011a. Evaluation of the sensitivity of inventory and monitoring national parks to nutrient enrichment effects from atmospheric nitrogen deposition: main report. Natural Resource Report NPS/NRPC/ARD/NRR—2011/313. National Park Service, Denver, Colorado. Available at

Sullivan, T. J., McDonnell, T. C., McPherson, G. T., Mackey, S. D., Moore, D. 2011b. Evaluation of the sensitivity of inventory and monitoring national parks to nutrient enrichment effects from atmospheric nitrogen deposition: North Coast and Cascades Network (NCCN). Natural Resource Report NPS/NRPC/ARD/NRR—2011/330. National Park Service, Denver, Colorado. Available at (pdf, 7.4 MB).

Trudell, S. A. and Edmonds, R. L. 2004. Macrofungus communities correlate with moisture and nitrogen abundance in two old-growth conifer forests, Olympic National Park, Washington, USA. Canadian Journal of Botany-Revue Canadienne de Botanique 82 (6): 781–800.

Featured Content

Impacts icon

Pollutants including mercury, fine particles, nitrogen, and ozone affect resources such as streams, soils, and scenic vistas. Find out how on our Olympic NP Air Pollution Impacts web page.

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Last Updated: January 03, 2017