Size 6 Claricone #11 and #12 Treatment Plant Expansion Project

Having a forward vision is important for water treatment plants in order to provide the most basic of necessities (potable water) to their customers. Johnston County Department of Utilities is such a plant. Located outside of Smithfield, NC the water treatment plant provides lime softening and chemical treatment of the county’s potable water. The plant was conceived with a mind to future growth of the community and laid out in such a way that “modular” expansion would be possible as growth and water demand dictated over time.

Johnston County was in need of another expansion to their water treatment plant. Welded steel upward helical flow solids contact clarifiers #11 and #12 were added to the existing system of which all ten previous clarifiers were provided to this repeat client. These vessels provide optimum performance with little maintenance or mechanical equipment.

The unique shape of these Claricone vessels provides rapid mixing, flocculation and clarification in one tank. The field erection of the tanks took place without interruption of the plant’s treatment activities and required working in an exceptionally confined area while coordinating with regular deliveries of chemical integral to the plant’s operation.

The scope of work included foundation design, detailing and installation of the slurry concentrator, process piping, a circumferential trough with steel drop box for each clarifier and all structural-steel bridges with aluminum grating and handrails interconnected to the existing walkways.

These clarifiers provided an additional 6.3 million gallons of drinking water a day to the community. Painted in North Carolina Tarheel Blue, they are likely to be a community legacy albeit a little less known than the basketball team!