Agenda - Council - 09/23/1980 - Special

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Mr. Steiner said the experts up to now are not able to tell if the methane gas is the cause of the tree loss, but maybe Mr. Gillman, U. S. Forest Service, will have some answers. Councilman Cox asked when it was going to be recognized that the landfill caused the problem of the tree loss. City Administrator Schnelle recom~aended making a council resolution for getting a report frc~ all the agencies who had input in these studies. John Pacey, President, Emcon Associates, said he worked on landfills across the United States and he has dealt with methane and he thought he understood the gas pretty well. He said every landfill produces gas at approx. 55% and 45% CO2 and there are other trace gases produced. The gas dilutes very quickly. Methane is non-toxic and is not toxic to plant life because it is not soluble in water. However, there may be a combustion aspect. This summer the system was shutdown and there appears to be some migration of gas. We reviewed the system and it was overdesigned by about 50%. He recommended putting monitoring probes by each pair of wells and in addition putting gas probes closer to the wells. ~e found zero gas combustion as the property llne. The system is fully effectiv? today and it controls about 30'. The system is going to be modified to extend to the north boundary. He suggested a backup system in case one system is down. He said they are going over the various monitoring procedures with Waste Management. Mayor Gamec asked if they would be able to hook up an alarm to the system. Mr. Pacey said that a variety of alarms could be hooked up to this system. It notifies an agency just like a burglar alarm. The question is what level of alarm is needed. Councilman Cox said he was told that the problem would be greatest when the · ground freezes over. Mr. Pacey said very little gets out laterally but some does and it gets out easier in the summer. In the winter time, if there is a crust on the surface and there is a buildup at the landfill, it will move laterally. Ms. Ritchie's estimate of three to four days is adequate. Monitoring will tell the story. The fact the system was down and maybe the lime sludge caused the mo¥ing out. Commissioner Fields asked if there is anything that could come out of the landfill that would be harmful to plant life. Mr. Pacey said CO2 does dissolve in water and it can lower the pH, but he said some plants thrive on landfill and others a~e sensitive. Commissioner Fields asked if there was any leachage that the U. of M. could look for. Mr. Pacey said the tree roots are too deep for leachage at 30'. The meeting was recessed at 9:00 P.M. The meeting was called back to order at 9:25 P.M. C/September 8, 1980 Page 5