Nashville’s historic Omohundro Water Treatment Plant has continuously supplied drinking water to the city since 1929. The original planning study for the plant indicated a need for increased treatment capacity to facilitate higher quality water output and improve efficiency. Under contract with Nashville Metro Water Services (MWS), Gresham Smith provided full-service planning, design and construction-phase services for the necessary improvements and retrofits to the plant, which were executed with minimal disruption to daily water production.


Nashville Metro Water Services


Nashville, Tennessee

Project Type



increase in treatment capacity


reduction in O&M costs


rated capacity

A Three-Phase Approach

A Three-Phase Approach

From settling tanks, flash mixers and flocculators to rectangular clarifiers and dual media filters, Omohundro’s processes are typical of a surface water treatment plant. To effectively tackle the comprehensive project, we separated the upgrades into three distinct phases:

  • Phase I – an upgrade to improve overall finished water quality.
  • Phase II – included improvements to increase the rated capacity of the treatment plant from 50 mgd to 90 mgd.
  • Phase III – converted the facility from a manual mode of operation to a fully automated treatment plant. The automation reduced the annual O&M costs by approximately 15 percent while increasing the treatment capacity by 40 percent.

A Master Plan for the Future

A Master Plan for the Future

Gresham Smith’s scope of work at Omohundro also includes a master plan of the future improvements for the facility’s new raw-water pumping facility, along with a new switchgear design (including precautions to safeguard the plant’s electrical system at a 500-year flood, 2-foot flood elevation), and state-of-the-art upgrades to the plant’s chemical feed system to enhance efficiency and chemical-feed accuracy.