Metro Water Services


Nashville, TN


Water Engineering, Civil Engineering, MEP Engineering

Clean water is supplied to Nashville’s residents through the joint effort of two water treatment facilities: K.R. Harrington and Omohundro. When one was damaged in a flood, Gresham Smith expedited the repairs, as both plants were in need of major updates to upgrade the chemical feed systems—all without interrupting the city’s access to clean water.

gallons of water per day
citizens in Metro Nashville
less than 30 days from flood to up and running

Outdated to Up to Date

Both water treatment plants’ chemical feed systems were nearing the end of their lifecycles, and due to their age, replacement parts were in short supply. The team established goals for the project that included continuity of operations under flood conditions, energy efficiency, reliability, maintainability, operational flexibility and consistency between the plants. To make the necessary repairs, we coordinated tandem upgrades at both facilities, installing new systems with standard components.

Streamlining Seven Chemical Flows

During the design phase, the most complex part of the project was making all seven chemical feed systems similar. Despite the chemicals’ different functions and properties, this upgrade standardized pumps and instruments across both plants for seven separate lines: alum, carbon, fluoride, lime, polyphosphate, polymer and permanganate.

Consistency Makes Maintenance Easy

The installation of matching equipment at both water treatment plants eases friction for operations staff working between two locations. Reduced training needs and simplified upkeep were added benefits.

Group of men working on construction site.

Keeping the Water on During Construction  

During the flood K.R. Harrington was shutdown, leaving only Omohundro operational. Having experienced the negative impacts of the K.R. Harrington shut down, keeping the existing chemical feed systems operational while switching over to the new system was a key project goal. To maintain uninterrupted water flow, the project team had to create a detailed schedule for construction, startup and commissioning. This was only possible through solid relationships and constant communication with all stakeholders.

Running off Future Floods

To avoid a repeat hardship from forces of nature, both facilities were raised above the 500-year flood elevation plus 2 feet, as recommended by the Federal Emergency Management Agency (FEMA). The new state-of-the-art chemical feed systems at Nashville’s Omohundro and K.R. Harrington water treatment facilities not only enhance efficiency and chemical feed accuracy, but are flexible enough to meet both current and future water quality standards.

One of the most successful things was we stayed online the whole time. All of these chemicals changed over and we were never in violation—not once. We have got a design for [these plants] that will take us into the future. I can go home and go to sleep at night and not have to worry about it because I know that we’re going to be able to feed the chemicals and feed clean water to the city. Glen Doss Treatment Plant Manager, Metro Water Services