Challenge Design-Build Project Delivery Addressed

The project involved excavation for a 40-foot-below-grade structure; borings revealed problematical rock underlying the site. This required significant support of excavation design, which caused significant schedule impacts. The design-build team worked with the owner and used the efficiencies of design-build to re-evaluate the schedule, optimize sequencing, add resource, stack trades and work additional shifts and hours to deliver the project early. Additionally, the team ameliorated the issue of grit in the existing facility to eliminate its effects on the downstream treatment equipment.

Summary

To solve a chronic grit-removal issue at the City of Atlanta’s largest wastewater treatment plant, the 240-million-gallons-per-day RM Clayton Water Reclamation Center, this project performed upgrades to the headworks facility while replacing the existing coarse screening and grit removal systems and installing new influent flow-monitoring equipment. Completed on time despite a delayed start date, the work included a new 12-cell multi-tray grit removal structure and dewatering building; upgrades to process equipment, 26 electric sluice gates, electrical systems and integration with existing digital control system. The work also called for excavation and drill-and-shoot of 35-foot sloped and 40-foot vertical areas within the facility.

Design-Build Team

Client/Owner: City of Atlanta Department of Watershed Management
Design-Builder: Western Summit/Anatek Construction Joint Venture
Project Manager, General Contractor: Western Summit Constructors, Inc. (WSCI)
Architect: The Architecture Group
Engineer: Brown and Caldwell
Specialty Contractor: Anatek, Inc.
Specialty Consultant: Long Engineering
Key Subcontractor: Excel Electric Technologies
Duration of Construction: 24 months
Project Cost: $ 53,504,506