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i LRRWMO Meeting Minutes March 17, 1994 Page 3 Appropriations of Waters Permit -Cornelius It was noted that an Appropriations of Waters Permit is being requested by Cornelius to remove .ground .water to depress the. water table and enable -capture of dissolved contaminants and to create a zone of influence to control the migration of contaminants. Terrence Brenner, consultant representing Cornelius, reviewed the location of the site proposed for the placement of a recovery well, the contaminants at the site, and the geology and hydrogeology of the location. Brenner also reported on the original test well and the Icvcl of contaminants being found. He explained their' permit is for 100 gallons per minute, which is comparable to the permit for the initial well. Treatment will be similar to the original well's 35 foot air striping tower, however this one will use a shallow tray aerator to push-clean air through the contaminated water to strip off contaminants:- Since it-will be located in a residential area, it will not be as high. The depth of the well will be 55 feet which will be at the base of the sand, and a five foot sump into the till, for a total depth of 55 to 60 feet. They anticipate a 50 million gallon per year discharge to the Rum River near the Highway 10 Bridge. Weaver asked where the drawdown will occur. Brenner stated, based on operational experience, the effect will be seen in an area 150 feet wide at the well. He reviewed the boundaries and explained they do not anticipate that it will develop a cone of depression. He added that they have monitored the pond level for teti years and will continue monitoring when pumping is started to assure there is no affect on the pond. It was noted there are no residential wells in this area. Weaver asked if they have explored the potential for contamination on the property north of the railroad tracks. Brenner explained there are no test wells on the north side of the tracks. He added that this is one of Cornelius' concerns. Ferguson commented on the location of the leading edge of the plume and questioned the direction of migration. Brenner explained they originally thought it would follow a direction towards the cemetery but based on borings, it is now thought the plume is being funneled by the till surface. He further explained that the contaminated water.has a heavier.density than water so ii sinks as it travels. Records indicate the till is regional and at least 100 feet thick so they do not think the contaminants will go any deeper. Weaver applauded Cornelius for addressing this issue and making a tremendous effort to remove the contaminated water. He did, however, express concern with the loss of 50 million gallons of water per year. Brenner explained that the dischazged water will be at drinking water standards prior to discharge into the River. He pointed out that they have to provide quality and discharge monitoring reports to the PCA as well as the amount of eftluent going out compared to permit levels.