Strategies to Assess Mercury Impacts and Minimize Their Effects in Colorado and Beyond

Mark McMillan
Manager, Mercury Program, Colorado Department of Public Health and Environment, Denver, CO

Koren Nydick
Director of Research & Education, Mountain Studies Institute, Durango, CO


Mercury is the most frequently listed substance for fish consumption advisories in the United States. In Colorado, at least sixteen (16) water bodies have these advisories, often thought to be due in part to atmospheric deposition of mercury. Mercury concentrations in sport fish from several Colorado reservoirs have exceeded the 0.5 microg/g action level, resulting in mercury fish consumption advisories for McPhee, Narraguinnep, Navajo, Sanchez and Vallecito Reservoirs. Sediment core analysis for Narraguinnep Reservoir show that mercury fluxes increased by approximately a factor of two after about 1970. Total mercury in wet deposition has been monitored at Mesa Verde National Park since 2002 as part of the Mercury Deposition Network (MDN). Results show mercury concentrations among the highest in the nation. Mercury concentrations have also been measured in snowpack at a few sites in the San Juan Mountains by the USGS and moderate concentrations similar to the Colorado Front Range have been recorded.

Due to national concerns over mercury pollution, environmental and public health agencies are being asked to investigate mercury pollution and associated pollution reduction activities. To address these concerns and issues in Colorado, in 2000 the Colorado Department of Public Health and Environment (CDPHE) began investigating aggressive and holistic options for reducing mercury pollution. This cross media program, the “Mercury-Free Colorado Campaign,” is designed to reduce the emissions of and impacts from mercury pollution. From this vision, CDPHE developed and implemented six primary areas of focus including: a nationally-recognized automotive switch removal initiative, a crematoria/Best Management Practices program, a dental amalgam effort, a consumer outreach endeavor for thermometers and thermostats, a problem haracterization exercise to identify the issues, and an education and outreach campaign to increase the public’s understanding of this issue.

This mostly policy focused presentation will provide attendees with information regarding efforts the State of Colorado and our partners have taken to better characterize mercury impacts and steps to minimize the emissions of and impacts from mercury. Such efforts include local interest in expanding mercury deposition monitoring (wet and dry) and developing a comprehensive mercury source apportionment study to investigate the impact of local and regional coal combustion sources on atmospheric mercury deposition. In addition, environmental metrics to gauge and direct the success of the mercury program will be shared.