ANALYTICAL MEASUREMENTS OF ASH, SOILS, AND SEDIMENTS AFTER THE CERRO GRANDE FIRE: PRELIMINARY EVALUATIONS

New Mexico Environment Department staff collected soil, sediment, and ash samples from areas around Los Alamos to Pecos, New Mexico after the Cerro Grande and Viveash forest fires. The samples were analyzed for varying suites of radionuclides, trace metals, nutrients, and organics. The analytical results were grouped into populations that represent pre- and post-fire soils and sediments, forest floor ash, ash-laden sediments from the Cerro Grande fire, the Viveash fire, and on the banks of the Rio Grande. These measurements were compared statistically and to reference values derived from pre-fire samples.

Preliminary assessments of these comparisons suggest; (1) soils potentially impacted by smoke from the Cerro Grande fire in northern New Mexico are not different than background reference conditions, (2) forest floor ash measurements demonstrate increased concentrations of radionuclides, most trace elements, and nutrients than reference conditions, (3) ash laden sediments originating from Cerro Grande ash contain greater concentrations of these parameters than Viveash sediments, (4) Cerro Grande ash laden sediments contain lower concentrations of these parameters than the parent ash materials, and (5) ash laden sediments on the Rio Grande banks contain concentrations less than those measured in stream channel sediments within the Pajarito Plateau.

These evaluations of the ash, soil, and sediment data are preliminary. Further evaluations will be made as U.S. Environmental Protection Agency, Los Alamos National Laboratory, and additional New Mexico Environment Department analytical data become available.