SUBAQUEOUS INDUSTRAIL WASTE IN WESTERN WISCONSIN LAKES:
REDUCING/ REDIRECTING THE DREDGED MATERIALS FROM LANDFILLS.

By: Pat Dryer

Results

            At the LacCore facilities, University of Minnesota, the core (Figure 9) was extracted from an aluminum tube. The core has a piece of milled timber that exists at a depth of 0.75 m in the industrial organic sediment below the surface of the “lake bottom”.  The milled timber is of anthropogenic origin and therefore this horizon and all industrial organic sediments above the milled timber are of the logging era or post logging era.  A layer of tree bark that was deposited during the logging era is also visible. It is important to note that the vibra-corer was able to penetrate the industrial waste and reaching fluvial gravels. Vibra-core descriptions were consistent with GPR data (Figure 9).

Figure 9- Interpereted core sample from HML.

            With 114 GPR transects deposits were identified and interpreted (Figure 10). The bathymetric depth (depth to sediment) is illustrated by the shaded blue section.  Below the blue shaded section, continuous to semi-continuous horizontal reflection patterns are interpreted as the horizontally bedded industrial organic waste and are shaded yellow.  The area below the industrial organic sediment can be differentiated by the continuous to semi-continuous horizontal and dipping reflection patterns, interpreted as bedrock (green).  The area below the industrial organic waste but above the interpreted bedrock is a reflection free zone and is interpreted as fluvial gravels (shaded orange). 

Figure 10- Interpreted GPR transect HMLMR17 located in the northwestern western arm of HML. bathymetric depth (depth to sediment) is illustrated by the shaded blue section.  The horizontally bedded industrial organic waste is shaded yellow.  The bedrock is shaded green.  The orange shaded region is interpreted as fluvial gravels.   
After radar stragraphic analysis and ground truthing of the GPR transects ArcGIS was used to create a sediment thickness map.

           A map showing 1062 depth points (Figure 11) was interpreted from the 64 usable GPR transects and then entered into Excel and joined to the matching GPS file. The remaining GPR profiles were 1) collected in the summer and could not be used due to inaccurate GPS positions or 2) several profiles and antennae frequencies were not of high enough resolution to differentiate the industrial organic waste. 

Figure 11- GPR depth points used to create the industrial organic sediment thickness map.

            After radar stragraphic analysis and ground truthing of the GPR transects ArcGIS was used to create a sediment thickness map. A map showing 1062 depth points (Figure 11) was interpreted from the 64 usable GPR transects and then entered into Excel and joined to the matching GPS file. The remaining GPR profiles were 1) collected in the summer and could not be used due to inaccurate GPS positions or 2) several profiles and antennae frequencies were not of high enough resolution to differentiate the industrial organic waste. 

            An industrial organic waste sediment thickness map (Figure 12) was created by using a Triangulated Irregular Network (TIN) analysis. The thickest industrial organic waste layers are on the north-west portion of HML which correlates well with the documented sawmill locations.  Using the TIN derived sediment thickness map, a volume of 412,526.18 cubic meters of industrial organic waste is estimated.

Figure 12- Industrial organic sediment thickness map derived from TIN analysis.
            Another spatial interpolation tool in ArcMap (Kriging) was used to create a cartographically pleasing sediment thickness map (Figure 13).  The map shows that the majority of the lake has at least 1 meter of industrial organic waste on the lake bottom.  The Kriging map better illustrates the spatial variation with the quantity of interpolated GPR transects obtained on HML but adjustments need to be made to more accurately calculate the volume of industrial organic sediment.

Figure 13- Industrial organic sediment thickness map derived from Kriging analysis.

            Results from heavy metal concentrations of the industrial organic waste are in Table 1. There were elevated amounts of Fe present in the samples (originating from groundwater). There were also notable amounts of Cadmium, Zinc, Lead, and Copper but none of the heavy metal concentrations exceeded EPA regulations for health implications. There was large woody debris and rubbish in the industrial organic waste (Figure 14).

            The results suggest that the heavy metal concentrations are not an issue for composting the industrial organic sediment (NR 538.06. 2006).  The study in Rib Lake has found composting to be a viable option.

Figure 14- Large woody debris and rubbage removed from the extracted industrial organic sediemnt.

Table 1- Heavy metal concentrations for the industrial organic waste removed from HML.

ABSTRACT

BACKGROUND

PHYSICAL SETTING

METHODS

GPR

GPS

Vibra-Core

Composting

RESULTS

CONCLUSIONS

ACKNOWLEDGEMENTS

REFERENCES

APPENDIXES

APPENDIX A

APPENDIX B

APPENDIX C

FIGURES

FIGURE 1 FIGURE 2 FIGURE 3

FIGURE 4 FIGURE 5 FIGURE 6

FIGURE 7 FIGURE 8 FIGURE 9

FIGURE 10 FIGURE 11 FIGURE 12

FIGURE 13 FIGURE 14 TABLE 1