SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Overhead/Lodi Door Company -2- 3 October 1990 ,The other alternative suggested was to run WET's on the samples from quadrants E and J, using the de-ionized (DI) water extraction solution, and analyze for nickel . This should more closely estimate the potential for leaching nickel from the impoundment, providing their backfill material is clean and the pH is neutral to alkaline. Mr. Schweizer stated that they have not yet located the fill material . Sample results will also have to be submitted for the fill material , to ensure it is free of contamination. It was agreed that the fill material will be sampled and analyzed for pH and metals. If the results of the DI-WET are acceptable, the Board will be satisfied that the concentrations of nickel remaining in the impoundment do not pose a significant threat to ground water quality. Mr. Schweizer stated that the labs still have the samples from 16 May 1990. It was agreed that DI-WET's will be run for composite samples from quadrants E and J and for one other quadrant, as a check. The extract will be analyzed for nickel only. Ms. Hogg said she would check with DHS's lab and run the DI-WETS on the split samples she collected, if they had been retained. We also discussed the need to confirm that other wastes have been removed from the surface impoundment, other than the indicator parameters nickel and zinc. Nickel and zinc were the hazardous constituents in the original pond sludges. Therefore, we have been using them as indicator parameters. Concentrations of chromium and lead were also elevated in the original pond waste, although not at hazardous concentrations. Mr. Vaughn stated that the only other constituent that needs to be tested for is chromium, since chromium was in the original waste and there is significant concentrations of chromium in the ground water. We need to confirm that the soils remaining in the impoundment do not contain levels of chromium that would be of concern. It was agreed that the same samples that will be analyzed using the DI-WET (E, J, and one other) will also be run for total chromium. (On 5 September 1990, I collected samples from quadrants E and J of the impoundment on 5 September 1990. The samples were analyzed for both total and chromium VI. Brian Pletcher from RSI collected split samples for duplicate analysis. ) Once the sample results are received and approved by DHS and the Board, the impoundment can be backfilled as proposed in the closure plan. DHS will then write a letter certifying that the impoundment is closed and the contamination that remains in the impoundment is insignificant and poses no threat to human health or water quality. The sample results should provide that assurance. Ms. Hogg stated that after the impoundment is backfilled, DHS would consider the impoundment closed and the 0/LDC will no longer be considered a disposal facility. That will mean no more DHS disposal facility fees. The ground water investigation will continue under the Board's direction. GROUND WATER MONITORING SYSTEM We also discussed the adequacy of the current ground water monitoring system at the facility. I had prepared a memorandum discussing the subject and distributed it at the meeting. One of the Board's concerns is that chromium has generally remained above the drinking water standard of 0.05 mg/l in monitoring well MW-1 and periodically in MW-2. While it appears that nickel in the ground water has dissipated, chromium has not. Since the ground water has been impacted by chromium and it does not seem to be dissipating after almost five years of monitoring, a more aggressive approach is needed. The memorandum explained that we need to know the size, shape, and velocity of the plume and more refined S,T, and K values for the shallow water bearing zone.