Viacom

Field Sampling Plan for Bennett's Dump Wells 61, 6D, and 5

August 21, 2001

Background

The Bennett's Dump site had 8 monitoring wells installed in 1987. These wells were sampled in 1988 and a report and on-site monitoring well plan were issued to all government parties as: Onsite Groundwater Monitoring Plan. Bennett's Dump Bloominaton' Indiana in May 1989. Table 1 from that report summarizes the well construction details.

Just prior to the 1999 remediation of the site, wells MW-2 and MW-4 were removed. An Interim Monitoring Program was instituted and conducted during the remediation and continues to this point. As part of that Interim program, monitoring wells 61, 6D, and 3 have been sampled quarterly. Table 2 shows the sampling history for those wells. Figure 1 shows the location of the wells. Wells 61 and ED were initially installed in flush- mount casing. It was observed during and after remediation that storm event runoff would wash sediment into these wells. Viacom is proposing to modify 61 and 6D to extend the inner casing of these wells and remove any sediment accumulated in them.

Drilling of MW-5 was completed on October 15,1987 and that same day the well was packer tested. Oily film was noted on the packer testing apparatus and the test was suspended. On March 9,1988 a sample with a duplicate was taken of well 5 with a 4" submersible pump. An oil sheen and free product was noticed on the conductivity probe as the field parameters were measured. The well was purged dry (at 13.5 gal.) and the pump was decontaminated according to the standard field procedures. The sample results were 1,100,000 ppb of PCBs for the sample and 430,000 ppb of PCBs for the duplicate. Subsequently, it was discovered that wells sampled at the Winston-Thomas site with the same pump were cross-contaminated. Sampling of well 5 was discontinued, and the well was observed for water level and visible sheen. On June 8, 1988 no oil sheen or free product was observed. On September 7,1988 the surface was checked with a bailer and no sheen or product was noted. On December 7,1988 the surface was checked with a bailer and oil sheen was observed. On July 21,1993 well 5 was video-logged. No oil sheen or product was observed in the well. The video- log also showed a small (less than 1 inch) conduit just below the steel surface casing at about 16.5 feet below ground surface. Various shale partings were observed in the well but none were observed to be open. Viacom is proposing to clean out existing sediment and purge well 5 and then sample it.

Pre-sampling Procedures for Wells 61 and 6D

• Clear area around wells and maintain good working access.
• Extend the inner casings in each well and set protective casing and concrete surface pads around each well so runoff is directed away from the wells.
• Survey the new top of inner and outer casings and ground surface.
• Take depth to water and depth to bottom measurements so purge volumes and estimated sediment thickness can be calculated.
• Using a shallow well pump with polyethylene tubing and a foot valve, remove sediment from the wells. Continue pumping until either the water clears up or 3 well volumes are removed. Since these wells have been sampled regularly, it is not necessary to overpurge them. Decontaminate equipment after each use.
• Take a field turbidity measurement after each well volume.
• Containerize and dispose of purge water at Neals Landfill Spring Treatment Plant.
• Install dedicated aluminum tubing for low flow sampling at mid-screen level.
• Record and document all field procedures and modifications and distribute to parties.

Pre-sampling Procedures for Well 5

• Clear area around well and maintain good working access.
• Survey the top of inner and outer casings and ground surface.
• Take depth to water and depth to bottom measurements so purge volumes and estimated sediment thickness can be calculated.
• Using a bailer, check the surface of the water for oil sheen or free product.
• Slowly lower a bailer to the bottom of the well to check for free product accumulation.
• If free product has accumulated, using a shallow well pump with polyethylene tubing and a foot valve, remove the product from the bottom of the well. Containerize separately for proper disposal.
• Using a shallow well pump with polyethylene tubing and a foot valve, remove sediment from the wells. Continue pumping until 5 well volumes are removed.
• Take a field turbidity measurement after each well volume.
• Containerize and dispose of purge water at Neals Landfill Spring Treatment Plant.
• Install dedicated aluminum tubing for low flow sampling at 16.5' below ground surface.
• Record and document all field procedures and modifications and distribute to parties.

Samplinq Procedures

A minimum of two weeks will be allowed for the wells to settle back down after purging.

Sample the wells using the low purge methods (see attached general procedure) with the peristaltic pump and dedicated tubing.

Pump at a low rate such as .2 liters per minute and purge the well into a carboydrum.

Check the water level of the well every 3-5 minutes initially during purging. The goal is a minimum to no drawdown. Adjust pumping rate as appropriate to accomplish this goal. In any event, the pumping rate should not exceed .5 liters/minute.

Use field parameters of temperature, conductivity, and turbidity to determine when the purge is adequate and when to sample per FP 6 and 10. These field procedures call for the use of off line field instruments to check these parameters. These parameters should be recorded in the field notebook every 5 minutes after stabilizing the pump rate. The sample can be taken when conductivity is within 3% and turbidity within 10% for three consecutive readings. If turbidity only fails to meet this requirement within a reasonable time period, then the sample can be taken if the other parameter meets the requirement.

Collect two 1-liter samples from each well after field parameters have stabilized. The samples should be collected into a standard glass bottle with a Teflon lid. To preserve the sample, place the labeled and sealed bottles in a cooler with ice (samples should be cooled to about 4 degrees C while awaiting transport and during transport to the lab.

For this group of samples provided to the lab, a duplicate field sample will be taken of 6i, a field blank and an extra volume of sample for a MS/MSD pair will be taken, also for 6i.

Record all field procedures and measurements and prepare report for distribution to government parties.