Sewer System

The City of Defiance’s sewer system was started in the late 1800’s. The initial sewers were combined sewers carrying both wastewater and surface runoff during wet weather periods. In the early 1950’s, there were 32 combined sewers discharging directly to the Maumee River, Auglaize River, and Preston Run ravine. In 1956, the City constructed a system of sewage regulators, intercepting sewers, pumping stations, and a Water Pollution Control Facility (WPCF). Regulators were installed on each of the 32 combined sewers, which diverted dry weather wastewater flow, and some wet weather surface runoff flow to the intercepting sewers. The intercepting sewers and pumping stations then transport the wastewater to the WPCF, which provided settling or primary treatment with provisions for chemical addition and chlorination of the effluent.

Currently, the city’s sewer system consists of both combined and sanitary sewer lines ranging from 6-inches to 54-inches in size. Combined sewers are designed to carry both domestic sewage and rainwater or surface runoff. Sanitary sewer lines are designed to convey strictly domestic sewage and industrial discharges. This system consists of over 93 miles of combined and sanitary sewers; more than 6 miles of sewer force mains ranging in size from 4-inches to 20-inches; over 2,600 manholes; 44 combined sewer overflows, (CSO’s), of which 32 are mechanical devices called storm water regulators; 4 river crossings; and 14 air release valve devices.

Water Pollution Control employees provide daily emergency and preventive maintenance to the maze of underground pipes, numerous manhole structures, regulator and overflow devices, river siphons, and a network of 19 pump stations located both inside and outside the city. A comprehensive computerized work order system is used to schedule preventive and corrective maintenance tasks. Much of the sewer line maintenance is accomplished by utilizing the City’s combination high pressure sewer jet / vacuum truck.

Other maintenance concerns include the routine inspection of restaurant grease traps; car wash grit traps; flushing of inverted siphons; inspection and maintenance of overflow tidegate / tideflex valves; inspection and cleaning of sewer system interconnects; river siphon inspection and cleanings; cleaning of the sewer system by sections; misc. sewer line and manhole repairs; root removal; dye testing; responding to property owners sewer problems, and tracing of sewer lines.

Maintenance
On a daily basis Water Pollution Control employees provide emergency and preventive maintenance on the 90 miles of city combined and sanitary sewers. Here the Collection & Maintenance Supervisor and the Division’s two Equipment Operators prepare to perform sewer line maintenance using the Division’s modern Vac-Truck.