12-8-2003

Sean Ramach
FIELDS Research Associate
Region 5 Superfund Division
United States Environmental Protection Agency

Sections A-D
Section E-G

Note: This report was created by analyzing work and field notes prepared by Jeff Myers, FIELDS Research Associate, conversations with Chuck Roth, FIELDS Team, and analysis work by Sean Ramach.

The sediment profile for Conard's Branch--Richland Creek has concluded that there are approximately 12,718 cubic yards of sediment in the portions of Conard's Branch/Richland Creek sampled between Nov 3-7, 2003 (see table 1). The volume of sediment was determined by utilizing 403 sediment pokes and the sediment depths obtained for each poke. The upper reaches of Conard's Branch were sampled, but no poke data was available from those locations for analysis. The GPS locations and associated data were entered into a GIS for analysis.

The data was overlain on aerial photographs of the region (Whitehall SE, SW) to aid in assessment of location and topographic analysis. The data was sectioned geographically to match the fish sampling sections on the upper reaches of Richland Creek and Conard's Branch as described by Tom Alcamo from the previous collections. The data was divided into a total of 7 sections labeled as A through G in the attached figures.

A polygon buffer was created to delineate the creek boundaries given the lack of a stream boundary layer. The following method was utilized to create the boundary. Each section was analyzed for relevant poke data. In most sections, three pokes were taken at each transect allowing for a rough estimate of creek width for that section. A line feature was created to connect the middle points in each transect and the point determined to be in the middle of the creek when less than three pokes had been taken. A buffer was then created from this line with a width equivalent to the average width from the transect data. Finally, at each transect containing three pokes, the buffer polygon was manipulated to match the width as delineated by the transect pokes.

Grids were created from the poke data with the buffer polygons as boundaries. The FIELDS Tools were then used to analyze the grids to determine the best interpolation method between IDW and NN with varying powers and neighbors. Table 1 shows the results of the analysis with the best IDW compared to the NN for each section with error and volume estimates for each method. The grid cells were interpolated to 1m squared to facilitate the calculation of volume estimates. The final grids are shown in the attached figures for each section of the creek.