INSPECTION & PREVENTIVE MAINTENANCE OF AERIAL SEWER STREAM CROSSINGS IN AN URBAN ENVIRONMENT

The Cobb County Water System (CCWS) operates and maintains over 2,500 miles of sanitary sewer with approximately 1,750 aerial sewer stream crossings of eight-inch size and above. Parts of the system are over fifty years old. Increasing urbanization (over 90% of available land has been developed), with a subsequent increase in impervious acreage(estimated at 36%), has caused increased runoff in terms of volume and velocity in area streams. These factors have served to undermine and endanger the aging aerial sewer stream crossings and to some degree expose previously buried stream crossings and parallel lines. One significant overflow in excess of one million gallons, caused by a heavy buildup of debris on twin thirty-inch lines, prompted the development of an enhanced inspection and preventive maintenance program for all CCWS aerial sewerstream crossings.