Lemon Lane Karst Conduit Program update
Lemon Lane Karst Conduit Program December 3, 2000 (Original Proposal)
 The current focus for research and testing is MW-4 Area (East Side of Landfill).
Vaicom has found this area to be a potentiometric low point, and are hoping to find a main conduit to the Illinois Central Springs. Pump Tests were conducted at MW-4I on August 1, 2001 it was pumped at 17 gpm for 255 minutes. Then they measured the water levels in the well around MW-4I, and at IC Springs. They also measured PCB levels at MW-4I and IC Springs. Here is the original proposal for these tests.
Pump test results showed a drawdown in all wells drilled to the 795–800 ft. elevation range.
PCBs at MW-4I peaked at 4000 ppb 5 minutes into the test, while there was no decrease in PCB content at ICS at the time of the test.
Water flow at ICS decreased about 7 gpm at the start of the test, while PCBs at ICS decreased from 8.8 to 2.5 ppb 48 hours after the test.
Two pump tests were conducted on LF-6 but only about 9 gallons pumped were from each test, and it was concluded that it was not a good location for a pumping well.
Seismic crosshole work was completed by Viacom. They drilled at two locations, Stations 82.5 and 100
Viacom thinks these locations represent a converging location in the conduit system.
Dye Tracer Testing
Dye tracer testing began on October 31, 2001. Three non-toxic fluorescent dyes were injected in two phreatic wells (NN-700 and SP-1) and in LF-6. Natural gradient flow conditions were observed from October 31 to November 7. MW-21 was pumped from November 7 to November 9, 2001.
Dye sampling was done by Viacom and EPA at 30 wells and 4 springs around Lemon Lane.
Dye was visually or instrumentally detected in four wells in Valhalla Cemetery (OO-370, OO-300, OO-300A, NN-300, and NN-300A). Dye broke through at ICS about 20 hours after injection.
Dye was detected in only 2 of 42 samples at Quarry B, and one of those was at background levels.
Dye was detected in only 2 of 13 samples at ICS Swallow Hole, one of these was at background levels. There were also sporadic detections of dye in various wells on teh easast side of the landfill.
The data collected is still in draft format and under review, and results will be presented at the next CIC meeting.
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