Minutes - Council - 12/11/1990 - Laserfiche WebLink

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heavy metal issue, they felt it was a mute point; however, he has not yet received the information on water quality. Therefore, he is not prepared to make a recommendation on the matter. Mr. Otter - gave a brief overview of the project which is scheduled to be operational by July, 1991, and that timetable is crucial. The system proposed is the best technology available today to treat Volatile Organic Compounds (VOCs) in the groundwater and meets all quality standards by the federal and state governments. He went on to explain that the~Oter will be 95 percent treated at the time it is being put into the City's storm sewer. The City will not be a party to the NPDES permit and will not be obligated to do any monitoring or recording because of that permit, as that has been verbally agreed to by the PCA. They have done water quality testing on the Mississippi River on several occasions and found no VOCs, but that can vary depending on the types and times of discharges into the river. Their requirements are to meet the Federal standards using the best available technology and that is what they are doing. Steve KQl]o~qe, Engineer for WMMI - reviewed some technical aspects of the project, that basically the PCA is looking at "no net effect to the river". They are doing what they have been told to do, and that Is to use the best available technology to remove VOCs to the 95 percent removal standard. Mr. Hartley also explained that the ground water has naturally occurring heavy metals that discharge into the river. If some are discharged to the river through this process, the amount would be so diluted that the MPCA is not concerned. Mr, Jankowskl - didn't know what background level could be used for heavy metals other than the drinking water standards. There are many environmental concerns; however, the MPCA is responsible for seeing that what WMMI does will be adequate and proper. Mr. Otter - explained how the air stripping system works, noting that no heavy metals wi]] be removed in the process. Also, mercury has not been a problem in the landfill, though they will continue to monltor and submit the results to the City, county, and MPCA. He then responded to a question on draw-down on the aquifers around the landfill. They have been carefully monitoring the groundwater levels, and that will be continually monitored, the anticipation being that there wi]] be about a one foot draw-down on Sunfish Lake after about 1 1/2 years. They will be able to determine the effect of the project after each month of operation. However, they anticipate there should be no wide spread draw-down or drying up of private wells In the area because the cone of depression from this operation will only be what one might expect from an agricultural well. Mw, Otter - thought It may be possible that the technology will change in five to ten years; however, they have deslgned the system CITY COUNCIL/DECEMBER 11, 1990 Page 12 of 17