Design-Build Team Members
Johnston Construction Company, as an integrated design-build General Contractor, provided engineering
design for the installation of a 0.27 MGD wastewater pretreatment facility. Subsequently, a
change order was initiated to complete the construction and commissioning services bringing the total design-build
fixed price contract to $2,482,000.
The Siemens AIMS Wastewater Pretreatment Facility serves the wastewater treatment needs generated by Northrop Grumman’s new printed circuit board manufacturing line. The Siemens equipment provides a microfiltration wastewater treatment process followed by a reverse osmosis (RO) system that allows up to 80% of the treated wastewater to be recycled back into the NGC manufacturing process.
Installation of the Siemens equipment includes a dual 12,000 gallon equalization tank with transfer pumps; chemical mixing and reaction tanks for wastewater pretreatment; chemical mixing and reaction tanks for cyanide destruction; a Memtek® membrane microfiltration system for clarification and solids removal; sludge thickening and material handling system; filter press system for solids dewatering; an equalization tank with chemical mixing and pumping for RO pretreatment; the RO system followed by ultraviolet disinfection for treated water recycling; neutralization system for non-metal bearing solutions; integrated PLC controls with displays, alarms, communications, and data collection; and, and various tanks, pumps, chemical handling equipment, and accessories for a complete and operational system.
Johnston Construction Company supplied a 2HP and a 5 HP, 460V Stancor Pump Company chemical-handling duplex sump pump with control panel and float switches. Another requirement was a 40 HP, 460V water-cooled, oil-free Curtis Toledo belt-drive rotary-screw duplex air compressor system with Ultra-Air desiccant air dryer, 200 gallon vertical air receiver, and control panel to supply a minimum of 127 scfm compressed air at 100 psig.
The project was started in December 2007 and completed in October 2008.