Agenda - Council - 10/22/1985 - Laserfiche WebLink

Home

Mr. Daniel A. Comeau Sept e~,h~.r 25, Page £1even anticipated that the Hvorslev Method of in situ measurement of horizontal permeability will be considered. The in situ permeability tests can be conducted only in the screened area of the existing groundwater monitoring wells. Recovery data collected during well development is also being evaluated. The need for an aquifer pumping test to determine additional aquifer hydrogeological characteristics will be considered as the results of the other analyses are evaluated. 31. 'Grounwater flow directions, ground and surface water interactions, verticle (sic) and horizontal head distribution and contaminant distributions" will be determined by analyzing horizontal and vertical water level data by the use of water level contour maps, water quality contour maps, analysis of aquifer characteristics, hydrogeological cross-sections, and modeling, as appropriate. The limitations and assumptions of the proposed techniques cannot be determined until adequate data become available to perform the analyses. The current on-going internal analysis of available hydrogeological data can be discussed and appropriate maps will be presented as part of the Preliminary Investigation package which will be provided to the MPCA in October. 32. The need and extent of possible future phases of monitoring work cannot be determined at this time because important water quality data for the second sampling event has not been received at the time of this writing. A discussion of other considerations is provided in Response No. 30. The term "possible additional exploratory techniques," as understood during negotiation of the Consent Order, could include groundwater monitoring wells as well as other undefined techniques which may become appropriate as the availability of additional data may dictate. MPCA will be advised as specific 'possible additional exploratory techniques" are considered. It is the intention of WMMI that MPCA staff will be notified of on-going field activities by 1) informal discussions, 2) sharing and discussing preliminary work products that would be submitted to MPCA, and 3) by formal submittals such as for proposed additional monitoring activities. Paragraph 4 on page 14 of the Work Plan Addendum does not indicate that SP or resistivity logs will be conducted inside hollow stem augers. These tests can, and have been, performed in mud rotary holes and in the mud-filled open hole beyond the bottom of a hollow stem auger as drilled by a tri-cone bit. Water Level Measurements 33. Page 16. Compilation of water level data and preparation of potentiometric maps is part of an internal, on-going analytical process. Preliminary information will be shared with the MPCA as part of the Preliminary Information package to be submitted in October.