Water Distribution

The distribution system serves approximately 26,000 metered customers with 550 miles of water lines form 2 to 24 inches in diameter.  The system is supplied by three different water sources, three different treatment plants, and utilizes 12 booster stations.  There are 20 storage tanks located ranging in size from 50,000 to 2,000,000 gallons, with a total storage volume just slightly short of 10,000,000 gallons.

Like many other water systems in the semi mountainous area of Tennessee, the Hallsdale-Powell system presents challenges in design and operation.  Numerous ridges and valley split the system.  There is an 800 foot difference between the high and low elevations in the service area, representing 346 pounds-per-square inch (psi) difference in water pressure.  As a result, distribution operators are challenged maintaining appropriate levels of pressure in 10 distinctly separated regions throughout the service area.

A hydraulic study conducted by consulting engineers, Consolidated Technologies, Inc in 1999, revealed that the District was experiencing unacceptable quantities of system line loss caused by aging infrastructure.  It was estimated that roughly 32% of treated drinking water was leaking out of the pressurized system during distribution to the customer.  Large amount of small-diameter galvanized pipe in the system was isolated as contributing greatly to the losses.  Therefore, the District Leaders have allocated many dollars from the capital improvement plan to focus on reducing system line loss.  Prioritizing these projects can be challenging, with the construction and calibration of a transmissions system hydraulic model engineers can more accurately identity problematic pipe.          

Hallsdale-Powell opted to purchase the MWH water model.  Its broad capabilities range from analysis and design to management functions such as fire flow assessment, pump scheduling, water quality improvement, emergency planning, unidirectional flushing, leakage reduction, security enhancement, infrastructure defense, real-time control and record-keeping.  Upon completion of the transmission system model, HPUD management anticipates that this tool will equip the District with invaluable power to comply with drinking water quality regulations, understand and control taste and odor problems, develop cost-effective energy solutions, improve system reliability and integrity, optimize capital improvement and rehabilitation programs, enhance community relations, prioritize sound security upgrade measures, and realize maximum engineering productivity and system performance.