Skip to main content

Construction and Startup of Treatment Wetlands on a Sloping Site

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

When the Clayton County Water Authority (CCWA) expanded its Shoal Creek Wastewater Reclamation Facility (WRF), the effluent disposal capacity was insufficient at the existing Shoal Creek Land Application System (LAS) site to accommodate the increased capacity. Due to their interest in continuing to use natural treatment systems, CH2M HILL and CCWA worked together to design engineered wetlands that would provide the additional effluent disposal capacity required by the expansion in a configuration that would work with the existing topography. The treatment wetlands will enhance the water quality of the effluent by adding a polishing step (tertiary process) to the end of the mechanical treatment process found at the Shoal Creek WRF. The use of engineered wetlands has evolved from a research concept to an accepted and effective water treatment technology by decreasing biochemical oxygen demand (BOD) concentrations, total suspended solids (TSS), nutrients, metals, pathogens, and trace organics.

Effluent is pumped from the upgraded Shoal Creek WRF through a 1.7-mile long 24-inch transmission pipeline that enters a distribution structure where flow is distributed to 22 terraced cells through three separate flow paths. With site elevations ranging from 885 to 770 feet, and site slopes ranging from 2 to 25 percent, the site topography was a challenge. The wetland cell configuration uses the site's natural sloping topography to allow gravity flow of water from cell to cell down to a pump station where the treated water is conveyed approximately 3.2 miles to the Shoal Creek Reservoir. The treated water passes through an aeration structure before traveling into the reservoir. Since the approximately 55 acres of constructed wetland cells also captures precipitation, the pump station was sized to pump up to 11.3 mgd, which will handle a 100-year, 24-hour stormwater event. The additional captured precipitation will help maintain water levels at the reservoir. Flow from the Shoal Creek Reservoir empties into the J.W. Smith Reservoir where an intake is located for a CCWA potable water production plant. Construction was finished in June 2003. Planting began in the first “northern” completed flow path in May 2003.

The newly named Inman Road Treatment Wetland Site includes approximately 360 acres and is located south of the Shoal Creek LAS, adjacent to the Flint River on the west. This site is heavily forested with mixed pines and hardwoods in upland hilly areas, and bears hardwood bottomland forest species in the floodplain of the Flint River. The topography found onsite made it impossible to construct large, continuous wetland cells as seen in many parts of the country. Therefore, a terraced multi-cell configuration was designed and constructed at the site, which required excavation of approximately 550,000 cubic yards of earth material to construct the wetland cells. Based on the magnitude of earthwork required, challenges associated with surveying, construction phasing, and earth-moving operations were encountered during the construction process.

The total project cost was approximately 6,000,000, which included the construction of the wetlands, transmission pipelines, pump station, and outfall structure. The cost of the wetland construction only was approximately 4,000,000.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Publication date: 2003-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more