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

By: Pat Dryer

GPR

            To investigate, map, and identify industrial organic waste in Half Moon Lake first ground penetrating radar (GPR) was used to collect profiles of the industrial organic waste. GPR was used for preliminary reconnaissance to determine what frequencies were to be utilized. Transects were run throughout the lake to determine the best frequency and set up of GPR equipment.
            GPR operates by transmitting electromagnetic (EM) pulses into the subsurface and measuring the return time (Appendix A). When the transmitting antennae (1) sends electromagnetic (EM) waves into the ground the waves reflect from layers in the subsurface (e.g. subaqueous deposits) and are picked up by the receiving antennae (2).  The digital information travels to the computer (3) via fiber-optic cables (4) (Figure 3). For this project a pulseEKKO 100 GPR system with 100 MHz antennae was used to collect data (Figure 3).  In order to efficiently collect data over ice, the GPR antennae were pulled on a sled at a constant rate while an odometer triggered traces to be collected every 0.2 m.  In optimum conditions, using this setup one hundred meters of data could be collected in approximately 15 minutes.

Figure 3- GPR operates by transmitting electromagnetic (EM) pulses into the subsurface and measuring the return time. When the transmitting antennae (1) sends electromagnetic (EM) waves into the ground the waves reflect from layers in the subsurface (e.g. subaqueous deposits) and are picked up by the receiving antennae (2). The digital information travels to the computer (3) via fiber-optic cables (4).

            A GPR coverage map (Figure 4) displays the spatial distribution of GPR transects on HML.  The map shows a total of 114 GPR transects (excluding GPR antennae testing during summer 2005) that were collected and subsequently georeferenced with a Trimble ProXR GPS. 

Figure 4- GPR coverage map of HML. GPR transects were georefereneced using a Trimble PRO XR GPS.

           The GPR profile (Figure 5) provides an example of a GPR transects.  Continuous to semi-continuous horizontal reflection patterns were noted as well as continuous to semi-continuous horizontal and dipping reflection patterns.  Also present is a reflection free zone.

Figure 5-Raw GPR data from transect HMLMR17 located in the northwestern western arm of 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