Future-Ready Transformation: Building a Fresh Start for the James E. Quarles Water Treatment Plant
This award-winning design for Georgia’s second largest drinking water supplier breathes new life into a critical facility while keeping the neighbors happy.
At a Glance:
Hazen performed a detailed Facility Assessment for Cobb County-Marietta Water Authority’s (CCMWA’s) treatment facilities that evaluated options and identified the need to replace “Plant 1” at the James E. Quarles Water Treatment Plant, originally built in the 1950s.
The project involved demolishing the 70-year-old plant and constructing a new state-of-the-art facility, all while ensuring the plant operations were not interrupted throughout construction.
The Plant 1 Replacement was designed to improve redundancy, reliability, and flexibility for future expansion.
The plant was designed to save energy and reduce maintenance costs, improve safety and accessibility, and complement its residential surroundings with attractive finishes and landscaping.
David L. Haas, PE is one of Hazen and Sawyer’s most accomplished senior project managers with extensive experience in optimizing water treatment facilities. Over his career, he has performed and led complex master planning projects and numerous projects related to drinking water supply, distribution, and multi-stage treatment.
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Top Photo: Plant operators are particularly proud of the $72 million new facility’s attractive redesign, from light-filled interiors to the brick-clad exterior. (Photo courtesy of: Archer Western Construction)
In 1954, the Quarles Water Treatment Plant began supplying water to a community that was mostly rural. (Photo courtesy of CCMWA)
70 Years of Transformation
When this plant was built in 1954, it was surrounded by farms and fields, and its main customer was the Bell Aircraft factory. As the surrounding area transformed from rural to suburban, the demand for clean drinking water grew along with the population. Over the years, the James E. Quarles plant, as it came to be named, has been expanded through multiple construction projects to meet that demand, along with stricter regulations.
By 2015, the original Plant 1 was nearing the end of its useful life. In collaboration with CCMWA, Hazen performed a facility assessment to chart a course for the next 70 to 100 years.
CCMWA made the decision to tear down the old plant and rebuild a new plant in roughly the same footprint. The challenges facing designers were site optimization, maintenance of plant operations, and construction management in an area that was now tightly restricted by suburban residential development.
Located in north metro Atlanta, the Quarles plant withdraws and treats water from the Chattahoochee River and supplies purified drinking water to ten wholesale customers. The overall plant is permitted to produce 87 million gallons per day. (Photos courtesy of CCMWA)
Designed for the Future
The Quarles Plant 1 Replacement serves as a foundation for reliable capacity well into the future. Based on a downward trend in per capita consumption, the initial capacity of the new plant was designed to be 33 mgd (down from the old Plant 1 capacity of 44 mgd) with provisions included in the design for expansion up to 66 mgd.
The new facility features a static rapid mixer, three hydraulic flocculation basins, three high-rate sedimentation basins equipped with inclined plate settlers and hoseless sludge collectors, eight dual media filters with air scour backwash, and a high-service pump station with three 20 mgd horizontal split case pumps equipped with variable frequency drives. This new technology ensures the plant's reliability for years to come.
One of the project's biggest challenges was maintenance of operations while demolishing the old plant and constructing its replacement. Working closely with CCMWA, Hazen developed detailed construction sequencing plans so that a portion of the old plant could remain in service while the new facilities were constructed. During construction, this involved working collaboratively with Archer Western Construction as they carefully sectioned the project site and safeguarded existing facilities.
Natural light fills the new filter pipe gallery, where stainless steel piping eliminates the need for repainting, reducing long-term maintenance costs. (Photo courtesy of Archer Western)
In Harmony with the Neighborhood
The James E. Quarles Water Treatment Plant is a major regional water producer that overlooks the backyards of dozens of single-family homes. With these neighbors in mind, CCMWA was willing to invest in aesthetic and architectural elements not typically seen in public infrastructure.
Brick-walled sedimentation basins, standing seam metal roofs, and dark bronze accents were selected for durability and attractiveness. The site landscape creates a campus feel that workers and visitors to the facility appreciate.
Inside the plant itself, terrazzo flooring and abundant natural light brightens labs, offices, and galleries. Mounted control panels keep floors and surfaces free of clutter. Stainless steel pipes not only add to the clean, modern aesthetic, but they will also never need to be repainted, saving on maintenance costs over time. For now, the filter building wall is filled with large windows on one end; eventually this is where the gallery will be expanded to accommodate a future expansion to the facility.
Hydraulic flocculation basins and sedimentation basins equipped with inclined plate settlers use gravity and no rotating mechanical equipment, saving maintenance and energy costs over the life of the plant. The high service pump station (HSPS) was located sub grade, in the location of the old Plant 1 clearwell, to mitigate cavitation issues that were occurring with the old facility. (Photos courtesy of Archer Western)
The Quarles Plant 1 Replacement was completed in summer 2021 with minimal disruption to the community or operations. But that doesn’t mean it didn’t get any attention. In 2022, it was named the Best Water/Environmental Project by ENR Southeast, an award that recognizes projects that stand out for challenges faced and how those were overcome, for innovative ideas, and outstanding work quality.
The design of the Quarles Plant 1 Replacement included features for improved redundancy, reliability, and flexibility, addressing previous hydraulic limitations while incorporating processes that will help CCMWA meet water quality goals and future regulatory requirements. In other words, Hazen helped prepare CCMWA to meet the demands of the 21st century while still working within the site restrictions of the 1950s.
