Tetra Tech EM Inc. (Tetra Tech) has prepared the enclosed field oversight summary to document its remedial investigation oversight activities at the above-referenced site on July I I and 12, 2001. Viacom, Inc., the responsible party for the site, conducted the remedial investigation activities, which involved a groundwater pumping test at on-site monitoring welled. Appendix A of the field oversight summary contains a photographic log of Tetra Tech's field activities, Appendix B contains a copy of Tetra Tech's oversight field notes, and Appendix C contains a figure displaying depth-to-water measurements recorded at monitoring well-4) and surrounding wells during the pumping test.

If you have any questions about the enclosed summary, please call me at (847) 818-7189.

Sincerely,

Raj Rajaram
Site Manager

Tetra Tech Oversight Personnel: Jason Massey

Reporting Period: July 11 and 12, 2001

INTRODUCTION

As requested by the U.S. Environmental Protection Agency (EPA), Tetra Tech EM Inc. (Tetra Tech) is conducting oversight of remedial investigation activities involving groundwater conduits in karst topography at the Lemon Lane Landfill site in Bloomington, Indiana. Tetra Tech is performing this work for EPA under Contract No. 68-W6-0037, Work Assignment No. 041-RSBD-0529. Viacom, Inc. (Viacom), is the responsible party for the site. PSARA Technologies, Inc. (PSARA), is Viacom's consultant.

This report summarizes Tetra Tech's oversight observations at the Lemon Lane Landfill site on July 11 and 12, 2001. This report also discusses issues and developments and future activities at the site. Appendix A contains a photographic log of Tetra Tech's field activities, Appendix B contains a copy of Tetra Tech's oversight field notes detailing the field activities, and Appendix C contains a figure displaying depth-to-water measurements recorded at on-site monitoring well(MW)-4i and surrounding wells during a pumping test conducted on July 12, 2001.

OVERSIGHT OBSERVATIONS

Tetra Tech's oversight observations at the site on July 11 and 12, 2001, are summarized below.

Wednesday, July 11, 2001

Tetra Tech arrived at the site at 9:00 a.m. Viacom and PSARA were at the site preparing for a preliminary pumping test at MW-4i. Viacom measured the depth to water in MW-4i as 68.9 feet below the measuring point (bmp). At 9:40 a.m., PSARA inserted the pump in the well to begin the preliminary pumping test (see Photographs No. I and 2). The pumping test began at 9:55 a.m. and was stopped at 10:00 a.m. PSARA pumped the water to a depth of about 76 feet bmp at a rate of about 15 gallons per minute. At the conclusion of the preliminary pumping test, Viacom reported that it would conduct the full pumping test at MW-4i on the next day. Tetra Tech left the site at 10:00 a.m.

Thursday, July 12, 2001

Tetra Tech arrived at the site at 8:30 a.m. Viacom and PSARA were at the site and had prepared for the full pumping test at MW-4i (see Photograph No. 3). A mobile field trailer and a water holding tank were already set up for the test. PSARA measured the initial depth to water in MW-4i as 69.38 feet temp.

PSARA also measured the initial depths to water in the surrounding wells to be monitored during the pumping test. The depth-to-water measurements were as follows:

• MOO-15: 62.71 feet bmp
• MW-16: 64.71 feet bmp
• MW-19: 67.20 feet bmp
• MW-18: 68.26 feet bmp
• MW-4s: 71.03 feet bmp
• MW-17: 68.01 feet bmp
• MOO-6: 48.05 feet bmp

PSARA fitted these wells with pressure transducers to automatically record water levels in the wells at 5-minute intervals except for MOO-6, whose transducer was set to record at 1 5-minute intervals. Water levels in the other wells were occasionally measured manually to confirm that the transducers were responding properly.

The pumping test started at 10:45 a.m., and Viacom reported that the depth to water in MW-4i was 69.39 feet bmp before pumping began. PSARA then began recording depths to water and corresponding times at MW-4i (see Photograph No. 4) and the surrounding MWs. The water levels and times recorded were as follows:

• MW-17:68.51 feet bmp at 10:49 a.m.
• MW-4s:69.88 feet bmp at 10:52 a.m.
• MW-18:68.96 feet bmp at 10:5 5 a. m.
• MW-19:67.94 feet bmp at 10:58 a.m.
• MW- 16:65.46 feet bmp at 11:00 a.m.
• ù MW-15:63.45 feet bmp at 11:04 a.m.
• ù MOO-6:not measured at this time

Every 15 minutes, Viacom collected samples from the pump discharge for conductivity and temperature measurement and polychlorinated biphenyl (PCB) analysis. Conductivity and temperature were field-measured (see Photograph No. 5).

At 11:10 a.m., the water began clearing up as the turbidity decreased; about 600 gallons of water was in the holding tank. By 11:45 a.m., approximately 1,100 gallons of water was in the holding tank, as the pump was running at a rate of about 20 gallons per minute. There appeared to be a slight, oily sheen on the water samples that Viacom was collecting. During this period, PSARA began recording a second round of depths to water and corresponding times at the surrounding MWs. The water levels and times recorded were as follows:

• MW-17:69.03 feet bmp at 11:33 a.m.
• MW-4s:72.14 feet bmp at 11:35 a.m.
• MW-18:69.28 feet bmp at 11:37 a.m.
• MW-19:68.23 feet bmp at 11:41 a.m.
• MW-16:65.73 feet bmp at 11:44 a.m.
• MW-I5:63.20 feet bmp at 11:47 a.m.
• MOO-6:49.46 feet bmp at 12:00 p.m.

At 12:45 p.m., PSARA began recording the third and last round of depths to water and corresponding times at the surrounding MWs. The water levels and times recorded were as follows:

• MW-17:69.14 feet bmp at 12:57 p.m.
• MW-4s:72.18 feet bmp at 12:59 p.m.
• MW- 18:69.36 feet bmp at I :02 p.m.
• MOO-6:49.07 feet bmp at I :06 p.m.
• MW-I5:63.51 feet bmp at 1:14 p.m.
• MW-16: 65.36 feet bmp at 1:17 p.m.
• MW-19: 67.81 feet bmp at 1:19 p.m.

The pumping test was stopped at 1:10 p.m. Depths to water were recorded at MW- 15, MW- 16, and MW- 19 after the completion of the test; these readings may be misleading, as the wells may have recharged to some extent before PSARA finished recording the water level measurements. After recording all the final data from the pumping test, Tetra Tech left the site at 4:00 p.m.

ISSUES AND DEVELOPMENTS

Pumping test activities were based on a work plan for MW-4i that Viacom had previously submitted to EPA. The preliminary and full pumping tests were generally conducted in accordance with the work plan, although pumping rates and durations were modified in the field based on well-specific conditions.

Viacom has not yet provided EPA with preliminary PCB data for samples collected during the pumping test; therefore, no increasing or decreasing trend in PCB concentrations during the test can be identified at this time.

All water generated during the pumping tests was contained in a 2,500-gallon, polyethylene tank. Tetra Tech was told that this water will be treated on site by PSARA. If PCB concentrations in the treated water are less than 0.3 parts per billion (ppb), the water will be discharged to Sargent's Pond through the landfill perimeter drainage ditch. If PCB concentrations in the treated water are greater than 0.3 ppb, the water will be further treated in the mobile treatment system until concentrations are less than 0.3 ppb; at that point, the water will be discharged to Sargent's Pond. No water treatment or discharge was observed during the reporting period.

Tetra Tech noted all depth-to-water measurements and corresponding times for MW-4i during the pumping test. Table I presents all the data recorded for MW-4i. The figure in Appendix C displays the pumping test data for MW-4i and the surrounding wells. The depths to water increased sharply in MW-4i and to some extent in the surrounding wells at the beginning of the pumping test and decreased gradually before completion of the test.