This is a pre-solicitation notice, not a request for proposals or invitation for bids; a solicitation is expected to be advertised in late November. The work is environmental remediation under an Optimized Remediation Contract at Air Force Plant 44, AZ; Davis-Monthan Air Force Base, AZ; and Nellis Air Force Base, NV. The project has an estimated value of $20,000,000 and an estimated duration of 3,650 calendar days (10 years). Activities include investigation, design, construction of remedial systems, operation and maintenance, optimization, and achievement of performance objectives at 17 Installation Restoration Program sites and 10 Military Munitions Response Program sites.