Sustainable Design > Project Case Study

Send by emailPrint page

Water Storage Analysis, Master Plan, Hydraulic Model and Tank Construction

Photovoltaic solar panels power equipment at the tank site.

The photovoltaic solar panels at the tank sites are used to power the PLC, radio telemetry equipment, tank level transmitter, and a chlorine residual analyzer. The system is DC based, but includes a converter to produce AC power for the chlorine analyzer when it is used during the summer. The battery capacity at each site provides about 10 days of electrical storage. The AC solar powered equipment required significantly more array area and battery capacity than the standard DC systems.

The Bath Water District (BWD) retained Wright-Pierce to study alternatives to improve storage in the Bath water system. The study included screening multiple sites within the service area to evaluate the proper storage volume to meet fire flows and peak-hour demands. The study also focused on retaining water quality in the distribution system by managing and reducing water age. The water storage for the current system is provided by two facilities: the North End standpipe and the Witch Spring Hill tank. The North End standpipe was in very poor condition and needed major structural repair.

The study included recalibration of the District's existing hydraulic distribution system model to assess location options for new storage tanks. The options included high-elevation sites at Potter Hill and Witch Spring Hill, or retention of the North End site for a new storage tank.

Based on the study and hydraulic modeling results, Wright-Pierce recommended the construction of a 1,200,000 gallon pre-stressed concrete storage tank on Potter Hill. A thorough fire flow analysis determined that the new location would not compromise fire flows in most of the distribution system. A vertical “Tideflex” mixing system was designed and installed.

The photovoltaic solar panels at the tank sites are used to power the PLC, radio telemetry equipment, tank level transmitter, and a chlorine residual analyzer. The system is DC based, but includes a converter to produce AC power for the chlorine analyzer when it is used during the summer. The battery capacity at each site provides about 10 days of electrical storage. The AC solar powered equipment required significantly more array area and battery capacity than the standard DC systems.

Back To > Sustainable Design and Energy Management Services

Challenges

  • The present North End storage tank is old and in need of replacement.
  • The District uses chloramination for disinfection. Reducing water age in the storage system will improve water quality.
  • Storage locations must retain fire flows within the distribution system.
  • Tank water age

Solutions

  • Hydraulic modeling demonstrated that a new tank would meet the District’s goals for storage and fire flows.
  • A smaller  active storage volume was recommended to reduce water age in the system.
  • Design and installation of a “Tideflex” Mixing System.
  • Photovoltaic solar panels at the tank site is used to power the PLC, radio telemetry equipment, tank level transmitter, and a chlorine residual analyzer.