Water Chemistry of Ephemeral Streams
Four individual, but related, studies are currently being conducted to determine the effects of clearcut and seed tree reproduction cutting methods on stream chemistry, sedimentation, and bedload movement by monitoring herbicide and nutrient movement in stemflow, overland flow, streamflow, and zonal subsurface flow. Sediment movement is being quantified for stormflow water samples. Comparative rates of movement are also being studied for imazapyr, hexazinone, and triclopyr. Analytical chemistry methods have been developed to permit detection of triciopyr at 0.5 micrograms par liter (parts per billion, ppb). Freezer storage studies are underway to demonstrate the suitability of frozen storage of water samples for herbicide analysis. Studies conducted on the epoxy paint, used throughout to protect wood and concrete surfaces during study installation, show a coeluting coextractable compound that interferes with triclopyr analysis. This compound does not appear after a 2-week curing period for the epoxy paint. Curing was complete long before triclopyr was applied to the site. Therefore, the coeluting coextractable compound will not confound any of the triclopyr analyses.