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HomeMy WebLinkAboutItem 05.bnolittiitwitottivittlil*ttr: ❖ Washing Away Winter Blues LAKEVILLE OPERATIONS & MAINTENANCE Christopher Petree, Director February 2011 Okay, it might not be that easy, this is still March and the very real possibility of additional snow and cold temperatures remain in the forecast. The Streets Division, however, did deal with the clean up of a recent ink spill in Airlake Industrial Park. A large container of blue ink being transported through the industrial park sprung a leak and left several roads in the industrial park with a blue coating. Recent snowfall and daytime thaws made this a very colorful event as cars and trucks drove through the area. Fortunately, the ink was water - soluble and not hazardous to the environment. Streets Division staff opened storm catch basins that were covered by snow to promote better drainage, got together the three City water tankers, and flushed the streets with water. The runoff went into storm retention ponds where the diluted ink will dissipate with the snowmelt and spring rains. This removed the majority of the blue ink from the road surface. Staff followed up with salt to make sure that the road surface did not re- freeze and become slippery. The trucking company that was responsible for the ink container will reimburse the City for its clean up efforts. • Pothole Repairs The short, but welcome, thaw in mid - February gave Streets Division staff a break from snowplowing and the opportunity to get a start on pothole repairs around the City. Potholes are caused by moisture that seeps through cracks in the asphalt surface. Once underneath the roadway, the moisture freezes and thaws, expanding and contracting, and creates a void under that section of the asphalt. Vehicles passing over that spot cause the roadway to flex and eventually to break down completely resulting in a pothole. To repair the pothole, street maintenance staff cleans out any loose material, ice, and water and fills the hole with a specific asphalt mixture for winter use. They then tamp the asphalt into the hole to make sure it adheres to the edges of the hole properly. Residents call in many of the potholes needing repair and City maintenance staff find others as they move between jobs. By whatever method they are found, the important thing is that they are repaired as quickly as possible, as weather permits, for the safety of motorists and preservation of the road surface. Crews will be out repairing potholes throughout the spring, summer, and fall. • Clearing Frozen Storm Sewer Lines Little is more disheartening or damaging as a storm sewer system overwhelmed by storm water runoff. In the winter, after a thaw, the storm system tends to fill with water from the melting snow and then freeze when the cold temps return. At the next thaw, the new snowmelt has nowhere to go and overflows the catch basins and culverts making large areas of ice on driveways and roads. Streets and Utilities Division maintenance staff work together to cut through the blockage using 2 high- pressure water. The Utilities Division sets up the Vactor to use the high - pressure hose and sewer - cleaning nozzle, called the jetter, and the Streets Division brings in a water tanker to assure a large supply of water. The jetter is placed in the manhole or culvert and water is pumped through the nozzle at 2000 psi, using about 80 gallons per minute; water from the front of the while water from the rear of the nozzle holds it in place. Once equipment is in position and the process started, it's just a mater of time. The use of cold water through the jetter affects the efficiency of the operation and the length of the blockage dictates the amount of time clearing the line might take. The jetter typically moves through a blockage at a rate of 10 to 15 feet per hour. Clearing a storm water line can take many hours and many thousands of gallons of water. nozzle cuts into the ice 3