Nashville Metro Water sought to retrofit and increase capacity of the existing K.R. Harrington Water Treatment Plant, and contracted with Gresham Smith to provide full-service planning, design and construction phase services.
The rated capacity of the facility was increased from 60 to 90 mgd. New operations and processes included the addition of flocculator-clarifiers, multimedia sand filters, a 5.0-mg clearwell, a 30,000-gpm high service pump and fully automated instrumentation and control systems. Modifications to processes included the addition of tube settlers to the existing clarifiers, revisions to flow patterns in the existing clearwells, a 30-mgd expansion of the raw water intake structure and the conversion of the existing operations and processes from manual to fully automated control systems.
The design effort took into consideration the phasing of construction activity in order to minimize disruptions to plant operations and maintain continuous operation of the treatment facility. The expansion project, along with the equipment and process upgrades, has greatly increased the efficiency of the facility.